Validate MQTT 5 SUBSCRIBE identifiers (#2262)

Observe packet task failures to prevent unobserved overflow exceptions

Server dispatch and session enqueue operations create packet bus items without
waiting for delivery. When the pending-message queue overflows, Fail faults
the item's completion task, which can later raise UnobservedTaskException
even if the application handles the dropped-message notification.

Observe the completion task's exception inside MqttPacketBusItem.Fail. This
keeps the task faulted and preserves the original exception for existing and
future WaitAsync callers, including DeliverApplicationMessageAsync.

Add a garbage-collection regression test for failures without a waiter and
verify that requesting the task before or after failure preserves the original
overflow exception. Re-enable unobserved-exception tracking in the existing
overflow integration tests for both drop strategies.

Before the fix, the focused run failed the new unobserved-exception test and
both enqueue overflow tests. After the fix, all nine focused cases and all
489 tests in the .NET 10 Release test suite pass.

Fixes https://github.com/dotnet/MQTTnet/issues/2271

.editorconfig

@@ -21,14 +21,14 @@ dotnet_naming_rule.static_readonly_rule.symbols = static_readonly_symbols
 dotnet_naming_style.lower_camel_case_style.capitalization = camel_case
 dotnet_naming_style.lower_camel_case_style.required_prefix = _
 dotnet_naming_style.upper_camel_case_style.capitalization = pascal_case
-dotnet_naming_symbols.constants_symbols.applicable_accessibilities = public,internal,protected,protected_internal,private_protected
+dotnet_naming_symbols.constants_symbols.applicable_accessibilities = public, internal, protected, protected_internal, private_protected
 dotnet_naming_symbols.constants_symbols.applicable_kinds = field
 dotnet_naming_symbols.constants_symbols.required_modifiers = const
-dotnet_naming_symbols.public_fields_symbols.applicable_accessibilities = public,internal,protected,protected_internal,private_protected
+dotnet_naming_symbols.public_fields_symbols.applicable_accessibilities = public, internal, protected, protected_internal, private_protected
 dotnet_naming_symbols.public_fields_symbols.applicable_kinds = field
-dotnet_naming_symbols.static_readonly_symbols.applicable_accessibilities = public,internal,protected,protected_internal,private_protected
+dotnet_naming_symbols.static_readonly_symbols.applicable_accessibilities = public, internal, protected, protected_internal, private_protected
 dotnet_naming_symbols.static_readonly_symbols.applicable_kinds = field
-dotnet_naming_symbols.static_readonly_symbols.required_modifiers = static,readonly
+dotnet_naming_symbols.static_readonly_symbols.required_modifiers = static, readonly
 dotnet_style_parentheses_in_arithmetic_binary_operators = never_if_unnecessary:none
 dotnet_style_parentheses_in_other_binary_operators = never_if_unnecessary:none
 dotnet_style_parentheses_in_relational_binary_operators = never_if_unnecessary:none
@@ -40,7 +40,6 @@ dotnet_style_qualification_for_method = false:suggestion
 dotnet_style_qualification_for_property = false:suggestion
 
 # ReSharper properties
-resharper_autodetect_indent_settings = true
 resharper_default_private_modifier = implicit
 resharper_place_accessorholder_attribute_on_same_line = false
 resharper_use_indent_from_vs = false
@@ -61,7 +60,7 @@ resharper_web_config_wrong_module_highlighting = warning
 [*]
 charset = utf-8
 end_of_line = crlf
-trim_trailing_whitespace = false
+trim_trailing_whitespace = true
 insert_final_newline = false
 indent_style = space
 indent_size = 4

.github/workflows/ci.yml

@@ -3,65 +3,130 @@ name: CI
 on: [push, pull_request]
 
 env:
-  VERSION: "4.1.0.${{github.run_number}}"
+  VERSION: "5.2.0.${{github.run_number}}"
+  PACKAGE_SUFFIX: ""
 
 jobs:
   build:
 
-    runs-on: windows-2022
+    runs-on: ubuntu-latest
 
     steps:
-      - name: Setup Windows SDK
-        uses: GuillaumeFalourd/setup-windows10-sdk-action@v1
-        with:
-          sdk-version: 18362
-
       - name: Setup .NET SDK
-        uses: actions/setup-dotnet@v1.9.0
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: |
-            3.1.x
-            6.0.x
+            8.0.x
+            10.0.x
 
-      - name: Setup MSBuild
-        uses: microsoft/setup-msbuild@v1.1
+      - name: Checkout code
+        uses: actions/checkout@v4
 
-      - name: Checkout Code
-        uses: actions/checkout@v2
-
-      - name: Setup Signing Certificate
+      - name: Load strong name certificate
+        if: ${{ github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository }}
         run: |
-          $secret = '${{ secrets.SNC_BASE64 }}'
-          $decoded = [System.Convert]::FromBase64CharArray($secret, 0, $secret.Length)
-          Set-Content -Path ${{ github.workspace }}\certificate.snk -Value $decoded -AsByteStream
+          echo "$SNC_BASE64" | base64 --decode > "${{ github.workspace }}/certificate.snk"
+        shell: bash
+        env:
+          SNC_BASE64: ${{ secrets.SNC_BASE64 }}
 
-      - name: Restore nuget packages
-        run: msbuild MQTTnet.sln /t:Restore /p:Configuration="Release" /verbosity:m
+      - name: Build package (signed)
+        if: ${{ github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository }}
+        run: dotnet build MQTTnet.slnx --configuration Release /p:FileVersion=${{ env.VERSION }} /p:AssemblyVersion=${{ env.VERSION }} /p:PackageVersion=${{ env.VERSION }}${{ env.PACKAGE_SUFFIX }} /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=${{ github.workspace }}/certificate.snk
 
-      - name: Build solution
-        run: msbuild MQTTnet.sln /t:Build /p:Configuration="Release" /verbosity:m /p:FileVersion=${{ env.VERSION }} /p:AssemblyVersion=${{ env.VERSION }} /p:PackageVersion=${{ env.VERSION }} /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=${{ github.workspace }}\certificate.snk
+      - name: Build package (unsigned)
+        if: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name != github.repository }}
+        run: dotnet build MQTTnet.slnx --configuration Release /p:FileVersion=${{ env.VERSION }} /p:AssemblyVersion=${{ env.VERSION }} /p:PackageVersion=${{ env.VERSION }}${{ env.PACKAGE_SUFFIX }}
 
-      - name: Collect nuget Packages
-        uses: actions/upload-artifact@v2
+      - name: Upload nuget packages
+        uses: actions/upload-artifact@v4
         with:
-          name: nuget Packages
+          name: nugets
           path: |
-            **\*.nupkg
-            **\*.snupkg
+            ${{ github.workspace }}/Source/**/*.nupkg
+            ${{ github.workspace }}/Source/**/*.snupkg
 
-      - name: Setup VSTest
-        uses: darenm/Setup-VSTest@v1
+  test:
+    runs-on: ubuntu-latest
 
-      - name: Core Tests
-        run: vstest.console.exe Source\MQTTnet.Tests\bin\Release\net6.0\MQTTnet.Tests.dll
+    steps:
+      - name: Setup .NET SDK
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: |
+            8.0.x
+            10.0.x
 
-      - name: ASP.NET Tests
-        run: vstest.console.exe Source\MQTTnet.AspNetCore.Tests\bin\Release\netcoreapp3.1\MQTTnet.AspNetCore.Tests.dll
+      - name: Checkout code
+        uses: actions/checkout@v4
 
-      - name: Publish MyGet nugets
-        if: ${{ github.event_name == 'push' }}
-        run: dotnet nuget push **/*.nupkg -k ${{ secrets.MYGET_API_KEY }} -s https://www.myget.org/F/mqttnet/api/v3/index.json --skip-duplicate
+      - name: Execute tests
+        run: dotnet test --framework net10.0 --configuration Release --project Source/MQTTnet.Tests/MQTTnet.Tests.csproj
 
-#      - name: Publish nugets
-#        if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/master' }}
-#        run: dotnet nuget push **/*.nupkg -k ${{ secrets.NUGET_API_KEY }} -s https://api.nuget.org/v3/index.json --skip-duplicate
+  sign:
+    needs: build
+    runs-on: windows-latest # Code signing must run on a Windows agent for Authenticode signing (dll/exe)
+    if: github.repository == 'dotnet/MQTTnet' && (github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository)
+    steps:
+      - name: Download nuget packages
+        uses: actions/download-artifact@v4
+        with:
+          name: nugets
+          path: nugets
+
+      - name: Install sign CLI tool
+        run: dotnet tool install --tool-path . sign --version 0.9.1-beta.25379.1
+
+      - name: Sign nugets
+        shell: pwsh
+        run: >
+          ./sign code azure-key-vault `
+          "**/*.nupkg" `
+          --base-directory "${{ github.workspace }}\nugets" `
+          --publisher-name "MQTTnet" `
+          --description "MQTTnet" `
+          --description-url "https://github.com/dotnet/MQTTnet" `
+          --azure-key-vault-tenant-id "${{ secrets.AZURE_TENANT_ID }}" `
+          --azure-key-vault-client-id "${{ secrets.AZURE_CLIENT_ID }}" `
+          --azure-key-vault-client-secret "${{ secrets.AZURE_CLIENT_SECRET }}" `
+          --azure-key-vault-certificate "${{ secrets.KEY_VAULT_CERTIFICATE_ID }}" `
+          --azure-key-vault-url "${{ secrets.KEY_VAULT_URL }}"
+
+      - name: Upload signed nuget packages
+        uses: actions/upload-artifact@v4
+        with:
+          name: signed-nugets
+          path: |
+            ${{ github.workspace }}\nugets\**\*.nupkg
+            ${{ github.workspace }}\nugets\**\*.snupkg
+
+  publish-myget:
+    if: ${{ github.event_name == 'push' }}
+    needs: sign
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Download signed nuget packages
+        uses: actions/download-artifact@v4
+        with:
+          name: signed-nugets
+          path: nugets
+
+      - name: Publish myget.com nugets
+        run: dotnet nuget push ${{ github.workspace }}/nugets/**/*.nupkg -k ${{ secrets.MYGET_API_KEY }} -s https://www.myget.org/F/mqttnet/api/v3/index.json --skip-duplicate
+
+  publish-nuget:
+    # Tag schema is 'v5.1.0-rc' etc.
+    if: startsWith(github.ref, 'refs/tags/v')
+    needs: [sign, test]
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Download signed nuget packages
+        uses: actions/download-artifact@v4
+        with:
+          name: signed-nugets
+          path: nugets
+
+      - name: Publish nuget.org nugets
+        run: dotnet nuget push ${{ github.workspace }}/nugets/**/*.nupkg -k ${{ secrets.NUGET_API_KEY }} -s https://api.nuget.org/v3/index.json --skip-duplicate

Directory.Build.props

@@ -0,0 +1,34 @@
+<Project>
+    <PropertyGroup>
+        <TargetFrameworks>net8.0;net10.0</TargetFrameworks>
+        <Product>MQTTnet</Product>
+        <Authors>The contributors of MQTTnet</Authors>
+        <Company>The contributors of MQTTnet</Company>
+        <Copyright>Copyright (c) .NET Foundation and Contributors</Copyright>
+
+        <DelaySign>false</DelaySign>
+        <SignAssembly>false</SignAssembly>
+        <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>disable</Nullable>
+
+        <NeutralLanguage>en-US</NeutralLanguage>
+        <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+        <NoWarn>1591;NETSDK1138;NU1803;NU1901;NU1902</NoWarn>
+
+        <NuGetAuditMode>all</NuGetAuditMode>
+        <NuGetAudit>true</NuGetAudit>
+        <NuGetAuditLevel>low</NuGetAuditLevel>
+
+        <EnableNETAnalyzers>true</EnableNETAnalyzers>
+        <AnalysisLevel>latest</AnalysisLevel>
+        <AnalysisMode>recommended</AnalysisMode>
+        <AnalysisModeStyle>default</AnalysisModeStyle>
+    </PropertyGroup>
+
+    <PropertyGroup Condition="'$(GITHUB_ACTIONS)'=='true'">
+        <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
+    </PropertyGroup>
+
+</Project>

Directory.Build.targets

@@ -0,0 +1,24 @@
+<Project>
+
+    <PropertyGroup Condition="'$(GeneratePackageOnBuild)'=='true'">
+        <PackageLicenseFile>LICENSE</PackageLicenseFile>
+        <PackageIcon>nuget.png</PackageIcon>
+        <PackageProjectUrl>https://github.com/dotnet/MQTTnet</PackageProjectUrl>
+        <RepositoryUrl>https://github.com/dotnet/MQTTnet.git</RepositoryUrl>
+        <RepositoryType>git</RepositoryType>
+        <IncludeSymbols>true</IncludeSymbols>
+        <SymbolPackageFormat>snupkg</SymbolPackageFormat>
+        <PublishRepositoryUrl>true</PublishRepositoryUrl>
+        <EmbedUntrackedSources>true</EmbedUntrackedSources>
+    </PropertyGroup>
+
+    <ItemGroup Condition="'$(GeneratePackageOnBuild)'=='true'">
+        <None Include="README.md" Pack="true" PackagePath="" Condition="Exists('README.md')" />
+        <None Include="..\..\Images\nuget.png" Pack="true" PackagePath="" />
+        <None Include="..\..\LICENSE" Pack="true" PackagePath="" />
+    </ItemGroup>
+
+    <ItemGroup Condition="'$(IncludeSymbols)'=='true'">
+        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All"/>
+    </ItemGroup>
+</Project>

MQTTnet.sln

@@ -1,94 +0,0 @@
-
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.0.31919.166
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet", "Source\MQTTnet\MQTTnet.csproj", "{3587E506-55A2-4EB3-99C7-DC01E42D25D2}"
-EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{B3F60ECB-45BA-4C66-8903-8BB89CA67998}"
-	ProjectSection(SolutionItems) = preProject
-		LICENSE = LICENSE
-		README.md = README.md
-		CODE-OF-CONDUCT.md = CODE-OF-CONDUCT.md
-	EndProjectSection
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.AspNetCore", "Source\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj", "{F10C4060-F7EE-4A83-919F-FF723E72F94A}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Extensions.Rpc", "Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj", "{C444E9C8-95FA-430E-9126-274129DE16CD}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Extensions.ManagedClient", "Source\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj", "{C400533A-8EBA-4F0B-BF4D-295C3708604B}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Extensions.WebSocket4Net", "Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj", "{2BD01D53-4CA5-4142-BE8D-313876395E3E}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.Samples", "Samples\MQTTnet.Samples.csproj", "{71CF35F5-3327-4A91-AAF4-5340F6701771}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.Tests", "Source\MQTTnet.Tests\MQTTnet.Tests.csproj", "{B270F32A-9F3E-42EE-A989-813E35E29ADB}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.AspNetCore.Tests", "Source\MQTTnet.AspNetCore.Tests\MQTTnet.AspNetCore.Tests.csproj", "{A238BBBF-C75F-482D-9CC3-BB34ABA9B675}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.Benchmarks", "Source\MQTTnet.Benchmarks\MQTTnet.Benchmarks.csproj", "{2F516E76-AAC4-4219-B7D1-34CDD3CFF381}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.TestApp", "Source\MQTTnet.TestApp\MQTTnet.TestApp.csproj", "{175D5340-CC5B-4542-939D-4E7D15A0BC8D}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.AspTestApp", "Source\MQTTnet.AspTestApp\MQTTnet.AspTestApp.csproj", "{72867E4C-4E15-4E8E-8FAB-AE9253286BBC}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|Any CPU = Debug|Any CPU
-		Release|Any CPU = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{3587E506-55A2-4EB3-99C7-DC01E42D25D2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{3587E506-55A2-4EB3-99C7-DC01E42D25D2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{3587E506-55A2-4EB3-99C7-DC01E42D25D2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{3587E506-55A2-4EB3-99C7-DC01E42D25D2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{F10C4060-F7EE-4A83-919F-FF723E72F94A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{F10C4060-F7EE-4A83-919F-FF723E72F94A}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{F10C4060-F7EE-4A83-919F-FF723E72F94A}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{F10C4060-F7EE-4A83-919F-FF723E72F94A}.Release|Any CPU.Build.0 = Release|Any CPU
-		{C444E9C8-95FA-430E-9126-274129DE16CD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{C444E9C8-95FA-430E-9126-274129DE16CD}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{C444E9C8-95FA-430E-9126-274129DE16CD}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{C444E9C8-95FA-430E-9126-274129DE16CD}.Release|Any CPU.Build.0 = Release|Any CPU
-		{C400533A-8EBA-4F0B-BF4D-295C3708604B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{C400533A-8EBA-4F0B-BF4D-295C3708604B}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{C400533A-8EBA-4F0B-BF4D-295C3708604B}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{C400533A-8EBA-4F0B-BF4D-295C3708604B}.Release|Any CPU.Build.0 = Release|Any CPU
-		{2BD01D53-4CA5-4142-BE8D-313876395E3E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{2BD01D53-4CA5-4142-BE8D-313876395E3E}.Debug|Any CPU.Build.0 = Debug|Any CPU
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-		{2BD01D53-4CA5-4142-BE8D-313876395E3E}.Release|Any CPU.Build.0 = Release|Any CPU
-		{71CF35F5-3327-4A91-AAF4-5340F6701771}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{71CF35F5-3327-4A91-AAF4-5340F6701771}.Debug|Any CPU.Build.0 = Debug|Any CPU
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-		{A238BBBF-C75F-482D-9CC3-BB34ABA9B675}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{A238BBBF-C75F-482D-9CC3-BB34ABA9B675}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{A238BBBF-C75F-482D-9CC3-BB34ABA9B675}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{A238BBBF-C75F-482D-9CC3-BB34ABA9B675}.Release|Any CPU.Build.0 = Release|Any CPU
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-		{2F516E76-AAC4-4219-B7D1-34CDD3CFF381}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{2F516E76-AAC4-4219-B7D1-34CDD3CFF381}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{2F516E76-AAC4-4219-B7D1-34CDD3CFF381}.Release|Any CPU.Build.0 = Release|Any CPU
-		{175D5340-CC5B-4542-939D-4E7D15A0BC8D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{175D5340-CC5B-4542-939D-4E7D15A0BC8D}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{175D5340-CC5B-4542-939D-4E7D15A0BC8D}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{175D5340-CC5B-4542-939D-4E7D15A0BC8D}.Release|Any CPU.Build.0 = Release|Any CPU
-		{72867E4C-4E15-4E8E-8FAB-AE9253286BBC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{72867E4C-4E15-4E8E-8FAB-AE9253286BBC}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{72867E4C-4E15-4E8E-8FAB-AE9253286BBC}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{72867E4C-4E15-4E8E-8FAB-AE9253286BBC}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-	GlobalSection(NestedProjects) = preSolution
-	EndGlobalSection
-	GlobalSection(ExtensibilityGlobals) = postSolution
-		SolutionGuid = {07536672-5CBC-4BE3-ACE0-708A431A7894}
-	EndGlobalSection
-EndGlobal

MQTTnet.slnx

@@ -0,0 +1,28 @@
+<Solution>
+  <Configurations>
+    <Platform Name="Any CPU" />
+    <Platform Name="x64" />
+    <Platform Name="x86" />
+  </Configurations>
+  <Folder Name="/Solution Items/">
+    <File Path=".github/workflows/ci.yml" />
+    <File Path="CODE-OF-CONDUCT.md" />
+    <File Path="Directory.Build.props" />
+    <File Path="Directory.Build.targets" />
+    <File Path="LICENSE" />
+    <File Path="README.md" />
+    <File Path="Source/ReleaseNotes.md" />
+  </Folder>
+  <Project Path="Samples/MQTTnet.Samples.csproj" />
+  <Project Path="Source/MQTTnet.AspnetCore/MQTTnet.AspNetCore.csproj" />
+  <Project Path="Source/MQTTnet.AspTestApp/MQTTnet.AspTestApp.csproj" />
+  <Project Path="Source/MQTTnet.Benchmarks/MQTTnet.Benchmarks.csproj" />
+  <Project Path="Source/MQTTnet.Extensions.Rpc/MQTTnet.Extensions.Rpc.csproj" />
+  <Project Path="Source/MQTTnet.Extensions.Socks5/MQTTnet.Extensions.Socks5.csproj" />
+  <Project Path="Source/MQTTnet.Extensions.TopicTemplate/MQTTnet.Extensions.TopicTemplate.csproj" />
+  <Project Path="Source/MQTTnet.Server/MQTTnet.Server.csproj" />
+  <Project Path="Source/MQTTnet.TestApp/MQTTnet.TestApp.csproj" />
+  <Project Path="Source/MQTTnet.Tests.Extensions.Socks5/MQTTnet.Tests.Extensions.Socks5.csproj" />
+  <Project Path="Source/MQTTnet.Tests/MQTTnet.Tests.csproj" />
+  <Project Path="Source/MQTTnet/MQTTnet.csproj" />
+</Solution>

MQTTnet.slnx.DotSettings

@@ -1,4 +1,8 @@
 <wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertIfStatementToSwitchStatement/@EntryIndexedValue">DO_NOT_SHOW</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=InconsistentNaming/@EntryIndexedValue">SUGGESTION</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UncatchableException/@EntryIndexedValue">DO_NOT_SHOW</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UnthrowableException/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/BRACES_FOR_FOR/@EntryValue">Required</s:String>
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 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/BRACES_FOR_IFELSE/@EntryValue">Required</s:String>
@@ -210,6 +214,7 @@
         &lt;/Or&gt;
       &lt;/Entry.Match&gt;
         &lt;Entry.SortBy&gt;
+            &lt;Access Order="Public Internal Protected Private" /&gt;
             &lt;Name /&gt;
         &lt;/Entry.SortBy&gt;
     &lt;/Entry&gt;
@@ -229,16 +234,27 @@
 	<s:String x:Key="/Default/CodeStyle/FileHeader/FileHeaderText/@EntryValue">Licensed to the .NET Foundation under one or more agreements.
 The .NET Foundation licenses this file to you under the MIT license.
 See the LICENSE file in the project root for more information.</s:String>
+	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EFeature_002EServices_002ECodeCleanup_002EFileHeader_002EFileHeaderSettingsMigrate/@EntryIndexedValue">True</s:Boolean>
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 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpRenamePlacementToArrangementMigration/@EntryIndexedValue">True</s:Boolean>
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+	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002EMemberReordering_002EMigrations_002ECSharpFileLayoutPatternRemoveIsAttributeUpgrade/@EntryIndexedValue">True</s:Boolean>
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 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EMigrateThisQualifierSettings/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=catched/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=CONNACK/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=PINGREQ/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=PINGRESP/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=PUBACK/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=PUBCOMP/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=PUBREC/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=PUBREL/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=SUBACK/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Tnet/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/UserDictionary/Words/=unsub/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=unsub/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=UNSUBACK/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>

README.md

@@ -3,16 +3,18 @@
 <br/>
 </p>
 
-[![NuGet Badge](https://buildstats.info/nuget/MQTTnet)](https://www.nuget.org/packages/MQTTnet)
-[![CI](https://github.com/dotnet/MQTTnet/actions/workflows/ci.yml/badge.svg)](https://github.com/dotnet/MQTTnet/actions/workflows/ci.yml)
-[![MyGet](https://img.shields.io/myget/mqttnet/v/mqttnet?color=orange&label=MyGet-Preview)](https://www.myget.org/feed/mqttnet/package/nuget/MQTTnet)
+[![NuGet Badge](https://img.shields.io/nuget/dt/MQTTnet)](https://www.nuget.org/packages/MQTTnet)
+[![CI](https://github.com/dotnet/MQTTnet/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/dotnet/MQTTnet/actions/workflows/ci.yml)
+[![MyGet](https://img.shields.io/myget/mqttnet/v/mqttnet?color=orange&label=preview)](https://www.myget.org/feed/mqttnet/package/nuget/MQTTnet)
 ![Size](https://img.shields.io/github/repo-size/dotnet/MQTTnet.svg)
 [![Join the chat at https://gitter.im/MQTTnet/community](https://badges.gitter.im/MQTTnet/community.svg)](https://gitter.im/MQTTnet/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![License: MIT](https://img.shields.io/badge/License-MIT-green.svg)](https://raw.githubusercontent.com/dotnet/MQTTnet/master/LICENSE)
 
 # MQTTnet
 
-MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker) and supports the MQTT protocol up to version 5.
+MQTTnet is a high performance .NET library for MQTT based communication.
+It provides a MQTT client and a MQTT server (broker) and supports the MQTT protocol up to version 5.
+It is compatible with mostly any supported .NET Framework version and CPU architecture.
 
 ## Features
 
@@ -28,13 +30,15 @@ MQTTnet is a high performance .NET library for MQTT based communication. It prov
 * Unit tested (~636 tests)
 * No external dependencies
 
-\* Tested on local machine (Intel i7 8700K) with MQTTnet client and server running in the same process using the TCP channel. The app for verification is part of this repository and stored in _/Tests/MQTTnet.TestApp.NetCore_.
+\* Tested on local machine (Intel i7 8700K) with MQTTnet client and server running in the same process using the TCP
+channel. The app for verification is part of this repository and stored in _/Tests/MQTTnet.TestApp.NetCore_.
 
 ### Client
 
 * Communication via TCP (+TLS) or WS (WebSocket) supported
 * Included core _LowLevelMqttClient_ with low level functionality
-* Also included _ManagedMqttClient_ which maintains the connection and subscriptions automatically. Also application messages are queued and re-scheduled for higher QoS levels automatically.
+* Also included _ManagedMqttClient_ which maintains the connection and subscriptions automatically. Also application
+  messages are queued and re-scheduled for higher QoS levels automatically.
 * Rx support (via another project)
 * Compatible with Microsoft Azure IoT Hub
 
@@ -50,42 +54,28 @@ MQTTnet is a high performance .NET library for MQTT based communication. It prov
 * A custom message interceptor can be added which allows transforming or extending every received application message
 * Validate subscriptions and deny subscribing of certain topics depending on requesting clients
 
-## Supported frameworks
+## Getting Started
 
-| Framwork           | Version     |
-| ------------------ | ----------- |
-|.NET                | 5.0+        |
-|.NET Framework      | 4.5.2+      |
-|.NET Standard       | 1.3+        |
-|.NET Core           | 1.1+        |
-|.NET Core App       | 1.1+        |
-| Mono               | 5.2+        |
-| UWP                | 10.0.10240+ |
-| Xamarin.Android    | 7.5+        |
-| Xamarin.iOS        | 10.14+      |
-| Blazor WebAssembly | 3.2.0+      |
+MQTTnet is delivered via <b>NuGet</b> package manager. You can find the packages
+here: https://www.nuget.org/packages/MQTTnet/
 
-## References
+Use these command in the Package Manager console to install MQTTnet manually:
 
-This library is used in the following projects:
+```
+Install-Package MQTTnet
+```
 
-* Azure Functions MQTT Bindings, <https://github.com/keesschollaart81/CaseOnline.Azure.WebJobs.Extensions.Mqtt>)
-* HA4IoT (Open Source Home Automation system for .NET, <https://github.com/chkr1011/HA4IoT>)
-* MQTT Client Rx (Wrapper for Reactive Extensions, <https://github.com/1iveowl/MQTTClient.rx>)
-* MQTT Client Rx (Managed Client Wrapper for Reactive Extensions, <https://github.com/mmuecke/RxMQTTnet>)
-* MQTT Tester (MQTT client test app for [Android](https://play.google.com/store/apps/details?id=com.liveowl.mqtttester) and [iOS](https://itunes.apple.com/us/app/mqtt-tester/id1278621826?mt=8))
-* MQTTnet App (Cross platform client application for MQTT debugging, inspection etc., <https://github.com/chkr1011/MQTTnetApp>)
-* Wirehome.Core (Open Source Home Automation system for .NET Core, <https://github.com/chkr1011/Wirehome.Core>)
-* SparkplugNet (Sparkplug library for .Net, <https://github.com/SeppPenner/SparkplugNet>)
-* Silverback (Framework to build event-driven applications - support for MQTT, Kafka & RabbitMQ) <https://github.com/BEagle1984/silverback>
+Samples for using MQTTnet are part of this repository. For starters these samples are recommended:
 
-Further projects using this project can be found under https://github.com/dotnet/MQTTnet/network/dependents.
-
-If you use this library and want to see your project here please create a pull request.
+- [Connect with a broker](https://github.com/dotnet/MQTTnet/blob/master/Samples/Client/Client_Connection_Samples.cs)
+- [Subscribing to data](https://github.com/dotnet/MQTTnet/blob/master/Samples/Client/Client_Subscribe_Samples.cs)
+- [Publishing data](https://github.com/dotnet/MQTTnet/blob/master/Samples/Client/Client_Publish_Samples.cs)
+- [Host own broker](https://github.com/dotnet/MQTTnet/blob/master/Samples/Server/Server_Simple_Samples.cs)
 
 ## Code of Conduct
 
-This project has adopted the code of conduct defined by the Contributor Covenant to clarify expected behavior in our community.
+This project has adopted the code of conduct defined by the Contributor Covenant to clarify expected behavior in our
+community.
 For more information see the [.NET Foundation Code of Conduct](https://dotnetfoundation.org/code-of-conduct).
 
 ## .NET Foundation

Samples/Client/Client_Connection_Samples.cs

@@ -7,16 +7,66 @@
 // ReSharper disable InconsistentNaming
 
 using System.Security.Authentication;
-using MQTTnet.Client;
-using MQTTnet.Extensions.WebSocket4Net;
+using System.Security.Cryptography.X509Certificates;
+using System.Text;
 using MQTTnet.Formatter;
+using MQTTnet.Protocol;
 using MQTTnet.Samples.Helpers;
+using MQTTnet.Server;
+using MQTTnet.Server.EnhancedAuthentication;
 
 namespace MQTTnet.Samples.Client;
 
 public static class Client_Connection_Samples
 {
-    public static async Task Connect_Client()
+    const string mosquitto_org = @"
+-----BEGIN CERTIFICATE-----
+MIIEAzCCAuugAwIBAgIUBY1hlCGvdj4NhBXkZ/uLUZNILAwwDQYJKoZIhvcNAQEL
+BQAwgZAxCzAJBgNVBAYTAkdCMRcwFQYDVQQIDA5Vbml0ZWQgS2luZ2RvbTEOMAwG
+A1UEBwwFRGVyYnkxEjAQBgNVBAoMCU1vc3F1aXR0bzELMAkGA1UECwwCQ0ExFjAU
+BgNVBAMMDW1vc3F1aXR0by5vcmcxHzAdBgkqhkiG9w0BCQEWEHJvZ2VyQGF0Y2hv
+by5vcmcwHhcNMjAwNjA5MTEwNjM5WhcNMzAwNjA3MTEwNjM5WjCBkDELMAkGA1UE
+BhMCR0IxFzAVBgNVBAgMDlVuaXRlZCBLaW5nZG9tMQ4wDAYDVQQHDAVEZXJieTES
+MBAGA1UECgwJTW9zcXVpdHRvMQswCQYDVQQLDAJDQTEWMBQGA1UEAwwNbW9zcXVp
+dHRvLm9yZzEfMB0GCSqGSIb3DQEJARYQcm9nZXJAYXRjaG9vLm9yZzCCASIwDQYJ
+KoZIhvcNAQEBBQADggEPADCCAQoCggEBAME0HKmIzfTOwkKLT3THHe+ObdizamPg
+UZmD64Tf3zJdNeYGYn4CEXbyP6fy3tWc8S2boW6dzrH8SdFf9uo320GJA9B7U1FW
+Te3xda/Lm3JFfaHjkWw7jBwcauQZjpGINHapHRlpiCZsquAthOgxW9SgDgYlGzEA
+s06pkEFiMw+qDfLo/sxFKB6vQlFekMeCymjLCbNwPJyqyhFmPWwio/PDMruBTzPH
+3cioBnrJWKXc3OjXdLGFJOfj7pP0j/dr2LH72eSvv3PQQFl90CZPFhrCUcRHSSxo
+E6yjGOdnz7f6PveLIB574kQORwt8ePn0yidrTC1ictikED3nHYhMUOUCAwEAAaNT
+MFEwHQYDVR0OBBYEFPVV6xBUFPiGKDyo5V3+Hbh4N9YSMB8GA1UdIwQYMBaAFPVV
+6xBUFPiGKDyo5V3+Hbh4N9YSMA8GA1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQEL
+BQADggEBAGa9kS21N70ThM6/Hj9D7mbVxKLBjVWe2TPsGfbl3rEDfZ+OKRZ2j6AC
+6r7jb4TZO3dzF2p6dgbrlU71Y/4K0TdzIjRj3cQ3KSm41JvUQ0hZ/c04iGDg/xWf
++pp58nfPAYwuerruPNWmlStWAXf0UTqRtg4hQDWBuUFDJTuWuuBvEXudz74eh/wK
+sMwfu1HFvjy5Z0iMDU8PUDepjVolOCue9ashlS4EB5IECdSR2TItnAIiIwimx839
+LdUdRudafMu5T5Xma182OC0/u/xRlEm+tvKGGmfFcN0piqVl8OrSPBgIlb+1IKJE
+m/XriWr/Cq4h/JfB7NTsezVslgkBaoU=
+-----END CERTIFICATE-----
+";
+
+    public static async Task Clean_Disconnect()
+    {
+        /*
+         * This sample disconnects in a clean way. This will send a MQTT DISCONNECT packet
+         * to the server and close the connection afterward.
+         *
+         * See sample _Connect_Client_ for more details.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        // This will send the DISCONNECT packet. Calling _Dispose_ without DisconnectAsync the
+        // connection is closed in a "not clean" way. See MQTT specification for more details.
+        await mqttClient.DisconnectAsync(new MqttClientDisconnectOptionsBuilder().WithReason(MqttClientDisconnectOptionsReason.NormalDisconnection).Build());
+    }
+
+    public static async Task Connect()
     {
         /*
          * This sample creates a simple MQTT client and connects to a public broker.
@@ -25,193 +75,271 @@ public static class Client_Connection_Samples
          * The default version of MQTT is 3.1.1.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            // Use builder classes where possible in this project.
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        // Use builder classes where possible in this project.
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
 
-            // This will throw an exception if the server is not available.
-            // The result from this message returns additional data which was sent 
-            // from the server. Please refer to the MQTT protocol specification for details.
-            var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+        // This will throw an exception if the server is not available.
+        // The result from this message returns additional data which was sent
+        // from the server. Please refer to the MQTT protocol specification for details.
+        var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
-            Console.WriteLine("The MQTT client is connected.");
+        Console.WriteLine("The MQTT client is connected.");
 
-            response.DumpToConsole();
+        response.DumpToConsole();
 
-            // Send a clean disconnect to the server by calling _DisconnectAsync_. Without this the TCP connection
-            // gets dropped and the server will handle this as a non clean disconnect (see MQTT spec for details).
-            var mqttClientDisconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder().Build();
+        // Send a clean disconnect to the server by calling _DisconnectAsync_. Without this the TCP connection
+        // gets dropped and the server will handle this as a non clean disconnect (see MQTT spec for details).
+        var mqttClientDisconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder().Build();
 
-            await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
-        }
+        await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
     }
 
-    public static async Task Connect_Client_Timeout()
+    public static async Task Connect_Using_Enhanced_Authentication()
     {
         /*
-         * This sample creates a simple MQTT client and connects to an invalid broker using a timeout.
-         * 
-         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
+         * This sample uses enhanced authentication (Kerberos) when creating the connection.
          */
 
-        var mqttFactory = new MqttFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
+        /*
+         * Server part...
+         */
+
+        var mqttServerFactory = new MqttServerFactory();
+
+        var serverOptions = mqttServerFactory.CreateServerOptionsBuilder().WithDefaultEndpoint().Build();
+        var server = mqttServerFactory.CreateMqttServer(serverOptions);
+
+        server.ValidatingConnectionAsync += async args =>
         {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1").Build();
+            if (args.AuthenticationMethod == "GS2-KRB5")
+            {
+                var result = await args.ExchangeEnhancedAuthenticationAsync(new ExchangeEnhancedAuthenticationOptions(), args.CancellationToken);
 
-            try
-            {
-                using (var timeoutToken = new CancellationTokenSource(TimeSpan.FromSeconds(1)))
-                {
-                    await mqttClient.ConnectAsync(mqttClientOptions, timeoutToken.Token);
-                }
+                Console.WriteLine($"Received AUTH data from client: {Encoding.UTF8.GetString(result.AuthenticationData)}");
+
+                var authOptions = mqttServerFactory.CreateExchangeExtendedAuthenticationOptionsBuilder().WithAuthenticationData("reply context token").Build();
+
+                result = await args.ExchangeEnhancedAuthenticationAsync(authOptions, args.CancellationToken);
+
+                Console.WriteLine($"Received AUTH data from client: {Encoding.UTF8.GetString(result.AuthenticationData)}");
+
+                args.ResponseAuthenticationData = "outcome of authentication"u8.ToArray();
+
+                // Authentication DONE!
+                args.ReasonCode = MqttConnectReasonCode.Success; // Also the default!
             }
-            catch (OperationCanceledException)
+            else
             {
-                Console.WriteLine("Timeout while connecting.");
+                args.ReasonCode = MqttConnectReasonCode.BadAuthenticationMethod;
             }
-        }
+        };
+
+        await server.StartAsync();
+
+        /*
+         * Client part...
+         */
+
+        var mqttClientFactory = new MqttClientFactory();
+
+        // Use Kerberos sample from the MQTT RFC.
+        var kerberosAuthenticationHandler = new SampleClientKerberosAuthenticationHandler();
+
+        var clientOptions = mqttClientFactory.CreateClientOptionsBuilder()
+            .WithTcpServer("localhost")
+            .WithProtocolVersion(MqttProtocolVersion.V500)
+            .WithEnhancedAuthenticationHandler(kerberosAuthenticationHandler)
+            .WithEnhancedAuthentication("GS2-KRB5")
+            .Build();
+
+        var client = mqttClientFactory.CreateMqttClient();
+
+        var result = await client.ConnectAsync(clientOptions);
+
+        Console.WriteLine($"Client connect result: {result.ResultCode}");
     }
 
-    public static async Task Connect_Client_Using_MQTTv5()
+    public static async Task Connect_Using_MQTTv5()
     {
         /*
          * This sample creates a simple MQTT client and connects to a public broker using MQTTv5.
-         * 
+         *
          * This is a modified version of the sample _Connect_Client_! See other sample for more details.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").WithProtocolVersion(MqttProtocolVersion.V500).Build();
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").WithProtocolVersion(MqttProtocolVersion.V500).Build();
 
-            // In MQTTv5 the response contains much more information.
-            var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+        // In MQTTv5 the response contains much more information.
+        var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
-            Console.WriteLine("The MQTT client is connected.");
+        Console.WriteLine("The MQTT client is connected.");
 
-            response.DumpToConsole();
-        }
+        response.DumpToConsole();
     }
 
-    public static async Task Connect_Client_Using_TLS_1_2()
+    public static async Task Connect_Using_TLS_1_2()
     {
         /*
          * This sample creates a simple MQTT client and connects to a public broker using TLS 1.2 encryption.
-         * 
+         *
          * This is a modified version of the sample _Connect_Client_! See other sample for more details.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io")
-                .WithTls(
-                    o =>
-                    {
-                        // The used public broker sometimes has invalid certificates. This sample accepts all
-                        // certificates. This should not be used in live environments.
-                        o.CertificateValidationHandler = _ => true;
-                        
-                        // The default value is determined by the OS. Set manually to force version.
-                        o.SslProtocol = SslProtocols.Tls12;
-                    })
-                .Build();
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io")
+            .WithTlsOptions(
+                o =>
+                {
+                    // The used public broker sometimes has invalid certificates. This sample accepts all
+                    // certificates. This should not be used in live environments.
+                    o.WithCertificateValidationHandler(_ => true);
 
-            using (var timeout = new CancellationTokenSource(5000))
-            {
-                await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
+                    // The default value is determined by the OS. Set manually to force version.
+                    o.WithSslProtocols(SslProtocols.Tls12);
+                })
+            .Build();
 
-                Console.WriteLine("The MQTT client is connected.");
-            }
-        }
+        using var timeout = new CancellationTokenSource(5000);
+        await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
+
+        Console.WriteLine("The MQTT client is connected.");
     }
 
-    public static async Task Connect_Client_Using_WebSockets()
-    {
-        /*
-         * This sample creates a simple MQTT client and connects to a public broker using a WebSocket connection.
-         * 
-         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
-         */
-
-        var mqttFactory = new MqttFactory();
-
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer("broker.hivemq.com:8000/mqtt").Build();
-
-            var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
-
-            Console.WriteLine("The MQTT client is connected.");
-
-            response.DumpToConsole();
-        }
-    }
-    
-    public static async Task Connect_Client_Using_WebSocket4Net()
-    {
-        /*
-         * This sample creates a simple MQTT client and connects to a public broker using a WebSocket connection.
-         * Instead of the .NET implementation of WebSockets the implementaion from WebSocket4Net is used. It provides more
-         * encryption algorithms and supports more platforms.
-         * 
-         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
-         */
-
-        var mqttFactory = new MqttFactory().UseWebSocket4Net();
-
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer("broker.hivemq.com:8000/mqtt").Build();
-
-            var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
-
-            Console.WriteLine("The MQTT client is connected.");
-
-            response.DumpToConsole();
-        }
-    }
-
-    public static async Task Connect_Client_With_TLS_Encryption()
+    public static async Task Connect_Using_TLS_Encryption()
     {
         /*
          * This sample creates a simple MQTT client and connects to a public broker with enabled TLS encryption.
-         * 
+         *
          * This is a modified version of the sample _Connect_Client_! See other sample for more details.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883)
-                .WithTls(
-                    o =>
-                    {
-                        // The used public broker sometimes has invalid certificates. This sample accepts all
-                        // certificates. This should not be used in live environments.
-                        o.CertificateValidationHandler = _ => true;
-                    })
-                .Build();
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883)
+            .WithTlsOptions(
+                o => o.WithCertificateValidationHandler(
+                    // The used public broker sometimes has invalid certificates. This sample accepts all
+                    // certificates. This should not be used in live environments.
+                    _ => true))
+            .Build();
 
-            // In MQTTv5 the response contains much more information.
-            using (var timeout = new CancellationTokenSource(5000))
-            {
-                var response = await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
-                
-                Console.WriteLine("The MQTT client is connected.");
+        // In MQTTv5 the response contains much more information.
+        using var timeout = new CancellationTokenSource(5000);
+        var response = await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
 
-                response.DumpToConsole();
-            }
-        }
+        Console.WriteLine("The MQTT client is connected.");
+
+        response.DumpToConsole();
+    }
+
+    public static async Task Connect_Using_TLS_With_CA_File()
+    {
+        var mqttFactory = new MqttClientFactory();
+
+        var caChain = new X509Certificate2Collection();
+        caChain.ImportFromPem(mosquitto_org); // from https://test.mosquitto.org/ssl/mosquitto.org.crt
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883)
+            .WithTlsOptions(new MqttClientTlsOptionsBuilder().WithTrustChain(caChain).Build())
+            .Build();
+
+        var connAck = await mqttClient.ConnectAsync(mqttClientOptions);
+        Console.WriteLine("Connected to test.moquitto.org:8883 with CaFile mosquitto.org.crt: " + connAck.ResultCode);
+    }
+
+    public static async Task Connect_Using_WebSockets()
+    {
+        /*
+         * This sample creates a simple MQTT client and connects to a public broker using a WebSocket connection.
+         *
+         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).Build();
+
+        var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        Console.WriteLine("The MQTT client is connected.");
+
+        response.DumpToConsole();
+    }
+
+    public static async Task Connect_With_Amazon_AWS()
+    {
+        /*
+         * This sample creates a simple MQTT client and connects to an Amazon Web Services broker.
+         *
+         * The broker requires special settings which are set here.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("amazon.web.services.broker")
+            // Disabling packet fragmentation is very important!
+            .WithoutPacketFragmentation()
+            .Build();
+
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        Console.WriteLine("The MQTT client is connected.");
+
+        await mqttClient.DisconnectAsync();
+    }
+
+    public static async Task Disconnect_Clean()
+    {
+        /*
+         * This sample disconnects from the server with sending a DISCONNECT packet.
+         * This way of disconnecting is treated as a clean disconnect which will not
+         * trigger sending the last will etc.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        // Calling _DisconnectAsync_ will send a DISCONNECT packet before closing the connection.
+        // Using a reason code requires MQTT version 5.0.0!
+        await mqttClient.DisconnectAsync(MqttClientDisconnectOptionsReason.ImplementationSpecificError);
+    }
+
+    public static async Task Disconnect_Non_Clean()
+    {
+        /*
+         * This sample disconnects from the server without sending a DISCONNECT packet.
+         * This way of disconnecting is treated as a non-clean disconnect which will
+         * trigger sending the last will etc.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        var mqttClient = mqttFactory.CreateMqttClient();
+
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        // Calling _Dispose_ or use of a _using_ statement will close the transport connection
+        // without sending a DISCONNECT packet to the server.
+        mqttClient.Dispose();
     }
 
     public static async Task Inspect_Certificate_Validation_Errors()
@@ -221,15 +349,15 @@ public static class Client_Connection_Samples
          * including the reason for that status.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io", 8883)
-                .WithTls(
-                    o =>
-                    {
-                        o.CertificateValidationHandler = eventArgs =>
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io", 8883)
+            .WithTlsOptions(
+                o =>
+                {
+                    o.WithCertificateValidationHandler(
+                        eventArgs =>
                         {
                             eventArgs.Certificate.Subject.DumpToConsole();
                             eventArgs.Certificate.GetExpirationDateString().DumpToConsole();
@@ -237,39 +365,34 @@ public static class Client_Connection_Samples
                             eventArgs.Chain.ChainStatus.DumpToConsole();
                             eventArgs.SslPolicyErrors.DumpToConsole();
                             return true;
-                        };
-                    })
-                .Build();
+                        });
+                })
+            .Build();
 
-            // In MQTTv5 the response contains much more information.
-            using (var timeout = new CancellationTokenSource(5000))
-            {
-                await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
-            }
-        }
+        // In MQTTv5 the response contains much more information.
+        using var timeout = new CancellationTokenSource(5000);
+        await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
     }
-    
+
     public static async Task Ping_Server()
     {
         /*
          * This sample sends a PINGREQ packet to the server and waits for a reply.
          *
-         * This is only supported in METTv5.0.0+.
+         * This is only supported in MQTTv5.0.0+.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
 
-            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
-            // This will throw an exception if the server does not reply.
-            await mqttClient.PingAsync(CancellationToken.None);
+        // This will throw an exception if the server does not reply.
+        await mqttClient.PingAsync(CancellationToken.None);
 
-            Console.WriteLine("The MQTT server replied to the ping request.");
-        }
+        Console.WriteLine("The MQTT server replied to the ping request.");
     }
 
     public static async Task Reconnect_Using_Event()
@@ -277,26 +400,24 @@ public static class Client_Connection_Samples
         /*
          * This sample shows how to reconnect when the connection was dropped.
          * This approach uses one of the events from the client.
-         * This approach has a risk of dead locks! Consider using the timer approach (see sample).
+         * This approach has a risk of deadlocks! Consider using the timer approach (see sample).
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+
+        mqttClient.DisconnectedAsync += async e =>
         {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
-
-            mqttClient.DisconnectedAsync += async e =>
+            if (e.ClientWasConnected)
             {
-                if (e.ClientWasConnected)
-                {
-                    // Use the current options as the new options.
-                    await mqttClient.ConnectAsync(mqttClient.Options);
-                }
-            };
+                // Use the current options as the new options.
+                await mqttClient.ConnectAsync(mqttClientOptions);
+            }
+        };
 
-            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
-        }
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
     }
 
     public static void Reconnect_Using_Timer()
@@ -307,42 +428,95 @@ public static class Client_Connection_Samples
          * This is the recommended way but requires more custom code!
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
 
-            _ = Task.Run(
-                async () =>
+        _ = Task.Run(
+            async () =>
+            {
+                // User proper cancellation and no while(true).
+                while (true)
                 {
-                    // User proper cancellation and no while(true).
-                    while (true)
+                    try
                     {
-                        try
+                        // This code will also do the very first connect! So no call to _ConnectAsync_ is required in the first place.
+                        if (!await mqttClient.TryPingAsync())
                         {
-                            // This code will also do the very first connect! So no call to _ConnectAsync_ is required
-                            // in the first place.
-                            if (!mqttClient.IsConnected)
-                            {
-                                await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+                            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
-                                // Subscribe to topics when session is clean etc.
-
-                                Console.WriteLine("The MQTT client is connected.");
-                            }
-                        }
-                        catch
-                        {
-                            // Handle the exception properly (logging etc.).
-                        }
-                        finally
-                        {
-                            // Check the connection state every 5 seconds and perform a reconnect if required.
-                            await Task.Delay(TimeSpan.FromSeconds(5));
+                            // Subscribe to topics when session is clean etc.
+                            Console.WriteLine("The MQTT client is connected.");
                         }
                     }
-                });
+                    catch
+                    {
+                        // Handle the exception properly (logging etc.).
+                    }
+                    finally
+                    {
+                        // Check the connection state every 5 seconds and perform a reconnect if required.
+                        await Task.Delay(TimeSpan.FromSeconds(5));
+                    }
+                }
+            });
+
+        Console.WriteLine("Press <Enter> to exit");
+        Console.ReadLine();
+    }
+
+    public static async Task Timeout()
+    {
+        /*
+         * This sample creates a simple MQTT client and connects to an invalid broker using a timeout.
+         *
+         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1").Build();
+
+        try
+        {
+            using var timeoutToken = new CancellationTokenSource(TimeSpan.FromSeconds(1));
+            await mqttClient.ConnectAsync(mqttClientOptions, timeoutToken.Token);
+        }
+        catch (OperationCanceledException)
+        {
+            Console.WriteLine("Timeout while connecting.");
+        }
+    }
+
+    sealed class SampleClientKerberosAuthenticationHandler : IMqttEnhancedAuthenticationHandler
+    {
+        public async Task HandleEnhancedAuthenticationAsync(MqttEnhancedAuthenticationEventArgs eventArgs)
+        {
+            if (eventArgs.AuthenticationMethod != "GS2-KRB5")
+            {
+                throw new InvalidOperationException("Wrong authentication method");
+            }
+
+            var sendOptions = new SendMqttEnhancedAuthenticationDataOptions
+            {
+                Data = "initial context token"u8.ToArray()
+            };
+
+            await eventArgs.SendAsync(sendOptions);
+
+            var response = await eventArgs.ReceiveAsync(CancellationToken.None);
+
+            Console.WriteLine($"Received AUTH data from server: {Encoding.UTF8.GetString(response.AuthenticationData)}");
+
+            // No further data is required, but we have to fulfil the exchange.
+            sendOptions = new SendMqttEnhancedAuthenticationDataOptions
+            {
+                Data = []
+            };
+
+            await eventArgs.SendAsync(sendOptions, CancellationToken.None);
         }
     }
 }

Samples/Client/Client_Publish_Samples.cs

@@ -6,7 +6,8 @@
 // ReSharper disable UnusedMember.Global
 // ReSharper disable InconsistentNaming
 
-using MQTTnet.Client;
+using System;
+using System.Text;
 
 namespace MQTTnet.Samples.Client;
 
@@ -23,24 +24,84 @@ public static class Client_Publish_Samples
          * or at least provides backward compatibility where possible.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("broker.hivemq.com")
-                .Build();
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder()
+            .WithTcpServer("broker.hivemq.com")
+            .Build();
 
-            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
-            var applicationMessage = new MqttApplicationMessageBuilder()
-                .WithTopic("samples/temperature/living_room")
-                .WithPayload("19.5")
-                .Build();
+        var applicationMessage = new MqttApplicationMessageBuilder()
+            .WithTopic("samples/temperature/living_room")
+            .WithPayload("19.5")
+            .Build();
 
-            await mqttClient.PublishAsync(applicationMessage, CancellationToken.None);
+        await mqttClient.PublishAsync(applicationMessage, CancellationToken.None);
 
-            Console.WriteLine("MQTT application message is published.");
-        }
+        await mqttClient.DisconnectAsync();
+
+        Console.WriteLine("MQTT application message is published.");
+    }
+
+    public static async Task Publish_Multiple_Application_Messages()
+    {
+        /*
+         * This sample pushes multiple simple application message including a topic and a payload.
+         *
+         * See sample _Publish_Application_Message_ for more details.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder()
+            .WithTcpServer("broker.hivemq.com")
+            .Build();
+
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        var applicationMessage = new MqttApplicationMessageBuilder()
+            .WithTopic("samples/temperature/living_room")
+            .WithPayload("19.5")
+            .Build();
+
+        await mqttClient.PublishAsync(applicationMessage, CancellationToken.None);
+
+        applicationMessage = new MqttApplicationMessageBuilder()
+            .WithTopic("samples/temperature/living_room")
+            .WithPayload("20.0")
+            .Build();
+
+        await mqttClient.PublishAsync(applicationMessage, CancellationToken.None);
+
+        applicationMessage = new MqttApplicationMessageBuilder()
+            .WithTopic("samples/temperature/living_room")
+            .WithPayload("21.0")
+            .Build();
+
+        await mqttClient.PublishAsync(applicationMessage, CancellationToken.None);
+
+        await mqttClient.DisconnectAsync();
+
+        Console.WriteLine("MQTT application message is published.");
+    }
+
+    public static MqttApplicationMessage Create_Message_With_Binary_User_Property()
+    {
+        /*
+         * MQTT v5 user properties are encoded as UTF-8 strings. When the UTF-8 payload is already available
+         * as a byte buffer, the builder APIs can avoid creating intermediate strings.
+         */
+
+        var encodedValue = Encoding.UTF8.GetBytes("sensor-01");
+
+        return new MqttApplicationMessageBuilder()
+            .WithTopic("samples/metadata/binary")
+            .WithUserProperty("client-id", encodedValue.AsMemory())
+            .WithUserProperty("checksum", new ArraySegment<byte>(encodedValue))
+            .WithPayload("metadata")
+            .Build();
     }
 }

Samples/Client/Client_Socks5_Samples.cs

@@ -0,0 +1,86 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+// ReSharper disable UnusedType.Global
+// ReSharper disable UnusedMember.Global
+// ReSharper disable InconsistentNaming
+
+using MQTTnet.Extensions.Socks5;
+using MQTTnet.Samples.Helpers;
+
+namespace MQTTnet.Samples.Client;
+
+public static class Client_Socks5_Samples
+{
+    public static async Task Connect_Tcp_Via_Socks5_No_Auth()
+    {
+        /*
+         * This sample connects to an MQTT broker through a SOCKS5 proxy that does not
+         * require authentication. The SOCKS5 stream provider performs the proxy handshake
+         * (RFC 1928) and returns a connected stream that the MQTT TCP channel can use as if
+         * it were a direct TCP connection.
+         *
+         * Host name resolution is performed by the proxy by default (ATYP=DOMAINNAME), which
+         * is the desired behavior when the MQTT broker hostname is only reachable from inside
+         * the network the proxy lives in.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+
+        var mqttClientOptions = new MqttClientOptionsBuilder()
+            .WithTcpServer("broker.internal.example", 1883)
+            .WithSocks5Proxy(socks => socks
+                .WithHost("proxy.example.com")
+                .WithPort(1080))
+            .Build();
+
+        using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(15));
+        var response = await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
+
+        Console.WriteLine("The MQTT client is connected through SOCKS5.");
+        response.DumpToConsole();
+
+        var disconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder().Build();
+        await mqttClient.DisconnectAsync(disconnectOptions, CancellationToken.None);
+    }
+
+    public static async Task Connect_Tcp_With_Tls_Via_Socks5_With_Credentials()
+    {
+        /*
+         * This sample connects to a TLS-protected MQTT broker through a SOCKS5 proxy that
+         * requires username/password authentication (RFC 1929).
+         *
+         * Note that the TLS handshake is layered on top of the SOCKS5 tunnel: the SNI used
+         * by SslStream is derived from the broker hostname (or the value passed to
+         * WithTargetHost), not from the proxy hostname.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+
+        var mqttClientOptions = new MqttClientOptionsBuilder()
+            .WithTcpServer("broker.internal.example", 8883)
+            .WithTlsOptions(tls => tls
+                .WithTargetHost("broker.internal.example"))
+            .WithSocks5Proxy(socks => socks
+                .WithHost("proxy.example.com")
+                .WithPort(1080)
+                .WithCredentials("alice", "s3cr3t")
+                .WithResolveDnsRemotely(true)
+                .WithHandshakeTimeout(TimeSpan.FromSeconds(10)))
+            .Build();
+
+        using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(15));
+        var response = await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
+
+        Console.WriteLine("The MQTT client is connected through SOCKS5 with TLS.");
+        response.DumpToConsole();
+
+        var disconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder().Build();
+        await mqttClient.DisconnectAsync(disconnectOptions, CancellationToken.None);
+    }
+}

Samples/Client/Client_Subscribe_Samples.cs

@@ -5,8 +5,11 @@
 // ReSharper disable UnusedType.Global
 // ReSharper disable UnusedMember.Global
 // ReSharper disable InconsistentNaming
+// ReSharper disable UnusedMember.Local
 
-using MQTTnet.Client;
+using System.Text;
+using MQTTnet.Packets;
+using MQTTnet.Protocol;
 using MQTTnet.Samples.Helpers;
 
 namespace MQTTnet.Samples.Client;
@@ -19,38 +22,100 @@ public static class Client_Subscribe_Samples
          * This sample subscribes to a topic and processes the received message.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+
+        // Setup message handling before connecting so that queued messages
+        // are also handled properly. When there is no event handler attached all
+        // received messages get lost.
+        mqttClient.ApplicationMessageReceivedAsync += e =>
         {
-            var mqttClientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("broker.hivemq.com")
-                .Build();
+            Console.WriteLine("Received application message.");
+            e.DumpToConsole();
 
-            // Setup message handling before connecting so that queued messages
-            // are also handled properly. When there is no event handler attached all
-            // received messages get lost.
-            mqttClient.ApplicationMessageReceivedAsync += e =>
-            {
-                Console.WriteLine("Received application message.");
-                e.DumpToConsole();
+            return Task.CompletedTask;
+        };
 
-                return Task.CompletedTask;
-            };
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
-            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+        var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder().WithTopicFilter("mqttnet/samples/topic/2").Build();
 
-            var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder()
-                .WithTopicFilter(f => { f.WithTopic("mqttnet/samples/topic/2"); })
-                .Build();
+        await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
 
-            await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
+        Console.WriteLine("MQTT client subscribed to topic.");
 
-            Console.WriteLine("MQTT client subscribed to topic.");
+        Console.WriteLine("Press enter to exit.");
+        Console.ReadLine();
+    }
 
-            Console.WriteLine("Press enter to exit.");
-            Console.ReadLine();
-        }
+    public static async Task Send_Responses()
+    {
+        /*
+         * This sample subscribes to a topic and sends a detailed response to the client. This requires at least QoS level 1 to work!
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        mqttClient.ApplicationMessageReceivedAsync += delegate(MqttApplicationMessageReceivedEventArgs args)
+        {
+            // Do some work with the message...
+
+            // Now respond to the broker with a reason code other than success.
+            args.ReasonCode = MqttApplicationMessageReceivedReasonCode.ImplementationSpecificError;
+            args.ResponseReasonString = "That did not work!";
+
+            // User properties require MQTT v5!
+            args.ResponseUserProperties.Add(new MqttUserProperty("My", Encoding.UTF8.GetBytes("Data")));
+
+            // Now the broker will resend the message again.
+            return Task.CompletedTask;
+        };
+
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder().WithTopicFilter("topic/test").Build();
+
+        var response = await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
+
+        Console.WriteLine("MQTT client subscribed to topic.");
+
+        // The response contains additional data sent by the server after subscribing.
+        response.DumpToConsole();
+    }
+
+    public static async Task Subscribe_Multiple_Topics()
+    {
+        /*
+         * This sample subscribes to several topics in a single request.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        // Create the subscribe options including several topics with different options.
+        // It is also possible to all of these topics using a dedicated call of _SubscribeAsync_ per topic.
+        var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder()
+            .WithTopicFilter(t => t.WithTopic("topic/1").WithAtLeastOnceQoS())
+            .WithTopicFilter(t => t.WithTopic("topic/2").WithAtMostOnceQoS())
+            .WithTopicFilter(t => t.WithTopic("topic/3").WithNoLocal())
+            .WithTopicFilter(t => t.WithRetainHandling(MqttRetainHandling.SendAtSubscribe))
+            .Build();
+
+        var response = await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
+
+        Console.WriteLine("MQTT client subscribed to topics.");
+
+        // The response contains additional data sent by the server after subscribing.
+        response.DumpToConsole();
     }
 
     public static async Task Subscribe_Topic()
@@ -59,26 +124,80 @@ public static class Client_Subscribe_Samples
          * This sample subscribes to a topic.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttFactory = new MqttClientFactory();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        var topicFilter = mqttFactory.CreateTopicFilterBuilder().WithTopic("mqttnet/samples/topic/2").WithAtLeastOnceQoS();
+
+        var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder().WithTopicFilter(topicFilter).Build();
+
+        var response = await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
+
+        Console.WriteLine("MQTT client subscribed to topic.");
+
+        // The response contains additional data sent by the server after subscribing.
+        response.DumpToConsole();
+    }
+
+    static void ConcurrentProcessingDisableAutoAcknowledge(IMqttClient mqttClient, CancellationToken shutdownToken)
+    {
+        /*
+         * This sample shows how to achieve concurrent processing and not have message AutoAcknowledged
+         * This to have a proper QoS1 (at-least-once) experience for what at least MQTT specification can provide
+         */
+        mqttClient.ApplicationMessageReceivedAsync += ea =>
         {
-            var mqttClientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("broker.hivemq.com")
-                .Build();
+            ea.AutoAcknowledge = false;
 
-            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+            async Task ProcessAsync()
+            {
+                // DO YOUR WORK HERE!
+                await Task.Delay(1000, shutdownToken);
+                await ea.AcknowledgeAsync(shutdownToken);
+                // WARNING: If process failures are not transient the message will be retried on every restart of the client
+                //          A failed message will not be dispatched again to the client as MQTT does not have a NACK packet to let
+                //          the broker know processing failed
+                //
+                // Optionally: Use a framework like Polly to create a retry policy: https://github.com/App-vNext/Polly#retry
+            }
 
-            var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder()
-                .WithTopicFilter(f => { f.WithTopic("mqttnet/samples/topic/1"); })
-                .Build();
+            _ = Task.Run(ProcessAsync, shutdownToken);
 
-            var response = await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
+            return Task.CompletedTask;
+        };
+    }
 
-            Console.WriteLine("MQTT client subscribed to topic.");
+    static void ConcurrentProcessingWithLimit(IMqttClient mqttClient, CancellationToken shutdownToken)
+    {
+        /*
+         * This sample shows how to achieve concurrent processing, with:
+         * - a maximum concurrency limit based on Environment.ProcessorCount
+         */
 
-            // The response contains additional data sent by the server after subscribing.
-            response.DumpToConsole();
-        }
+        var concurrent = new SemaphoreSlim(Environment.ProcessorCount);
+
+        mqttClient.ApplicationMessageReceivedAsync += async ea =>
+        {
+            await concurrent.WaitAsync(shutdownToken).ConfigureAwait(false);
+
+            async Task ProcessAsync()
+            {
+                try
+                {
+                    // DO YOUR WORK HERE!
+                    await Task.Delay(1000, shutdownToken);
+                }
+                finally
+                {
+                    concurrent.Release();
+                }
+            }
+
+            _ = Task.Run(ProcessAsync, shutdownToken);
+        };
     }
 }

Samples/Client/Client_Subscribe_TopicTemplate_Samples.cs

@@ -0,0 +1,75 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using MQTTnet.Extensions.TopicTemplate;
+using MQTTnet.Protocol;
+using MQTTnet.Samples.Helpers;
+
+// ReSharper disable UnusedType.Global
+// ReSharper disable UnusedMember.Global
+// ReSharper disable InconsistentNaming
+// ReSharper disable UnusedMember.Local
+
+namespace MQTTnet.Samples.Client;
+
+public static class Client_Subscribe_TopicTemplate_Samples
+{
+    static readonly MqttTopicTemplate SampleTemplate = new("mqttnet/samples/topic/{id}");
+
+    public static async Task Subscribe_Multiple_Topics_With_Template()
+    {
+        /*
+         * This sample subscribes to several topics in a single request.
+         *
+         * This sample requires the nuget 'MQTTnet.Extensions.TopicTemplate'.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        // Create the subscribe options including several topics with different options.
+        // It is also possible to all of these topics using a dedicated call of _SubscribeAsync_ per topic.
+        var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder()
+            .WithTopicTemplate(SampleTemplate.WithParameter("id", "1"))
+            .WithTopicTemplate(SampleTemplate.WithParameter("id", "2"), noLocal: true)
+            .WithTopicTemplate(SampleTemplate.WithParameter("id", "3"), retainHandling: MqttRetainHandling.SendAtSubscribe)
+            .Build();
+
+        var response = await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
+
+        Console.WriteLine("MQTT client subscribed to topics.");
+
+        // The response contains additional data sent by the server after subscribing.
+        response.DumpToConsole();
+    }
+
+    public static async Task Subscribe_Topic_With_Template()
+    {
+        /*
+         * This sample subscribes to a topic.
+         *
+         * This sample requires the nuget 'MQTTnet.Extensions.TopicTemplate'.
+         */
+
+        var mqttFactory = new MqttClientFactory();
+
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
+
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder().WithTopicTemplate(SampleTemplate.WithParameter("id", "1")).Build();
+
+        var response = await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
+
+        Console.WriteLine("MQTT client subscribed to topic.");
+
+        // The response contains additional data sent by the server after subscribing.
+        response.DumpToConsole();
+    }
+}

Samples/Diagnostics/Logger_Samples.cs

@@ -6,8 +6,9 @@
 // ReSharper disable UnusedMember.Global
 // ReSharper disable InconsistentNaming
 
+using System.Globalization;
 using System.Text;
-using MQTTnet.Diagnostics;
+using MQTTnet.Diagnostics.Logger;
 
 namespace MQTTnet.Samples.Diagnostics;
 
@@ -20,23 +21,21 @@ public static class Logger_Samples
          * to other loggers like Microsoft logger or Serilog or log4net etc.
          */
 
-        var mqttFactory = new MqttFactory(new MyLogger());
+        var mqttFactory = new MqttClientFactory(new MyLogger());
 
         var mqttClientOptions = mqttFactory.CreateClientOptionsBuilder()
             .WithTcpServer("broker.hivemq.com")
             .Build();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
-            Console.WriteLine("MQTT client is connected.");
+        Console.WriteLine("MQTT client is connected.");
 
-            var mqttClientDisconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder()
-                .Build();
+        var mqttClientDisconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder()
+            .Build();
 
-            await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
-        }
+        await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
     }
 
     public static async Task Use_Event_Logger()
@@ -50,10 +49,10 @@ public static class Logger_Samples
         // The logger ID is optional but can be set do distinguish different logger instances.
         var mqttEventLogger = new MqttNetEventLogger("MyCustomLogger");
 
-        mqttEventLogger.LogMessagePublished += (sender, args) =>
+        mqttEventLogger.LogMessagePublished += (_, args) =>
         {
             var output = new StringBuilder();
-            output.AppendLine($">> [{args.LogMessage.Timestamp:O}] [{args.LogMessage.ThreadId}] [{args.LogMessage.Source}] [{args.LogMessage.Level}]: {args.LogMessage.Message}");
+            output.AppendLine(CultureInfo.InvariantCulture, $">> [{args.LogMessage.Timestamp:O}] [{args.LogMessage.ThreadId}] [{args.LogMessage.Source}] [{args.LogMessage.Level}]: {args.LogMessage.Message}");
             if (args.LogMessage.Exception != null)
             {
                 output.AppendLine(args.LogMessage.Exception.ToString());
@@ -62,23 +61,21 @@ public static class Logger_Samples
             Console.Write(output);
         };
 
-        var mqttFactory = new MqttFactory(mqttEventLogger);
+        var mqttFactory = new MqttClientFactory(mqttEventLogger);
 
         var mqttClientOptions = mqttFactory.CreateClientOptionsBuilder()
             .WithTcpServer("broker.hivemq.com")
             .Build();
 
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
-            Console.WriteLine("MQTT client is connected.");
+        Console.WriteLine("MQTT client is connected.");
 
-            var mqttClientDisconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder()
-                .Build();
+        var mqttClientDisconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder()
+            .Build();
 
-            await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
-        }
+        await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
     }
 
     sealed class MyLogger : IMqttNetLogger

Samples/Diagnostics/PackageInspection_Samples.cs

@@ -6,7 +6,7 @@
 // ReSharper disable UnusedMember.Global
 // ReSharper disable InconsistentNaming
 
-using MQTTnet.Diagnostics;
+using MQTTnet.Diagnostics.PacketInspection;
 
 namespace MQTTnet.Samples.Diagnostics;
 
@@ -17,29 +17,27 @@ public static class PackageInspection_Samples
         /*
          * This sample covers the inspection of outgoing packages from the client.
          */
-        
-        var mqttFactory = new MqttFactory();
-        
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = mqttFactory.CreateClientOptionsBuilder()
-                .WithTcpServer("broker.hivemq.com")
-                .Build();
-            
-            mqttClient.InspectPackage += OnInspectPackage;
-            
-            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
-            
-            Console.WriteLine("MQTT client is connected.");
 
-            var mqttClientDisconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder()
-                .Build();
+        var mqttFactory = new MqttClientFactory();
 
-            await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
-        }
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = mqttFactory.CreateClientOptionsBuilder()
+            .WithTcpServer("broker.hivemq.com")
+            .Build();
+
+        mqttClient.InspectPacketAsync += OnInspectPacket;
+
+        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+        Console.WriteLine("MQTT client is connected.");
+
+        var mqttClientDisconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder()
+            .Build();
+
+        await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
     }
 
-    static Task OnInspectPackage(InspectMqttPacketEventArgs eventArgs)
+    static Task OnInspectPacket(InspectMqttPacketEventArgs eventArgs)
     {
         if (eventArgs.Direction == MqttPacketFlowDirection.Inbound)
         {

Samples/Helpers/ObjectExtensions.cs

@@ -8,17 +8,19 @@ namespace MQTTnet.Samples.Helpers;
 
 internal static class ObjectExtensions
 {
+    static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        WriteIndented = true
+    };
+
     public static TObject DumpToConsole<TObject>(this TObject @object)
     {
         var output = "NULL";
         if (@object != null)
         {
-            output = JsonSerializer.Serialize(@object, new JsonSerializerOptions
-            {
-                WriteIndented = true
-            });
+            output = JsonSerializer.Serialize(@object, SerializerOptions);
         }
-        
+
         Console.WriteLine($"[{@object?.GetType().Name}]:\r\n{output}");
         return @object;
     }

Samples/MQTTnet.Samples.csproj

@@ -2,25 +2,20 @@
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>
-        <TargetFramework>net6.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <IsPackable>false</IsPackable>
-        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
-        <EnableNETAnalyzers>false</EnableNETAnalyzers>
-        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
-        <NoWarn>1591</NoWarn>
+        <NoWarn>$(NoWarn);CA1707</NoWarn>
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="Microsoft.CodeAnalysis.Compilers" Version="4.0.1" />
-        <PackageReference Include="Microsoft.Net.Compilers" Version="4.0.1" />
 
-        <ProjectReference Include="..\Source\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj" />
-        <ProjectReference Include="..\Source\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj" />
-        <ProjectReference Include="..\Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj" />
-        <ProjectReference Include="..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj" />
-        <ProjectReference Include="..\Source\MQTTnet\MQTTnet.csproj" />
+        <ProjectReference Include="..\Source\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj"/>
+        <ProjectReference Include="..\Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj"/>
+        <ProjectReference Include="..\Source\MQTTnet.Extensions.Socks5\MQTTnet.Extensions.Socks5.csproj" />
+        <ProjectReference Include="..\Source\MQTTnet.Extensions.TopicTemplate\MQTTnet.Extensions.TopicTemplate.csproj" />
+        <ProjectReference Include="..\Source\MQTTnet.Server\MQTTnet.Server.csproj"/>
+        <ProjectReference Include="..\Source\MQTTnet\MQTTnet.csproj"/>
     </ItemGroup>
 
 </Project>

Samples/ManagedClient/Managed_Client_Simple_Samples.cs

@@ -1,52 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-// ReSharper disable UnusedType.Global
-// ReSharper disable UnusedMember.Global
-// ReSharper disable InconsistentNaming
-
-using MQTTnet.Client;
-using MQTTnet.Extensions.ManagedClient;
-
-namespace MQTTnet.Samples.ManagedClient;
-
-public sealed class Managed_Client_Simple_Samples
-{
-    public static async Task Connect_Client()
-    {
-        /*
-         * This sample creates a simple managed MQTT client and connects to a public broker.
-         *
-         * The managed client extends the existing _MqttClient_. It adds the following features.
-         * - Reconnecting when connection is lost.
-         * - Storing pending messages in an internal queue so that an enqueue is possible while the client remains not connected.
-         */
-        
-        var mqttFactory = new MqttFactory();
-
-        using (var managedMqttClient = mqttFactory.CreateManagedMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("broker.hivemq.com")
-                .Build();
-
-            var managedMqttClientOptions = new ManagedMqttClientOptionsBuilder()
-                .WithClientOptions(mqttClientOptions)
-                .Build();
-
-            await managedMqttClient.StartAsync(managedMqttClientOptions);
-
-            // The application message is not sent. It is stored in an internal queue and
-            // will be sent when the client is connected.
-            await managedMqttClient.EnqueueAsync("Topic", "Payload");
-
-            Console.WriteLine("The managed MQTT client is connected.");
-            
-            // Wait until the queue is fully processed.
-            SpinWait.SpinUntil(() => managedMqttClient.PendingApplicationMessagesCount == 0, 10000);
-            
-            Console.WriteLine($"Pending messages = {managedMqttClient.PendingApplicationMessagesCount}");
-        }
-    }
-}

Samples/Program.cs

@@ -2,9 +2,16 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Globalization;
 using System.Reflection;
 
-Console.WriteLine("Welcome to MQTTnet samples!");
+Console.BackgroundColor = ConsoleColor.White;
+Console.BackgroundColor = ConsoleColor.Red;
+Console.Title = "Samples - MQTTnet";
+Console.WriteLine("----------------------------------------------");
+Console.WriteLine("-         Welcome to MQTTnet samples!        -");
+Console.WriteLine("----------------------------------------------");
+Console.ResetColor();
 Console.WriteLine();
 
 var sampleClasses = Assembly.GetExecutingAssembly().GetExportedTypes().OrderBy(c => c.Name).ToList();
@@ -16,9 +23,13 @@ foreach (var sampleClass in sampleClasses)
     index++;
 }
 
+Console.WriteLine();
+Console.ForegroundColor = ConsoleColor.Green;
 Console.Write("Please choose sample class (press Enter to continue): ");
+Console.ResetColor();
+
 var input = Console.ReadLine();
-var selectedIndex = int.Parse(input ?? "0");
+var selectedIndex = int.Parse(input ?? "0", CultureInfo.InvariantCulture);
 var selectedSampleClass = sampleClasses[selectedIndex];
 var sampleMethods = selectedSampleClass.GetMethods(BindingFlags.Static | BindingFlags.Public).OrderBy(m => m.Name).ToList();
 
@@ -29,19 +40,26 @@ foreach (var sampleMethod in sampleMethods)
     index++;
 }
 
+Console.WriteLine();
+Console.ForegroundColor = ConsoleColor.Green;
 Console.Write("Please choose sample (press Enter to continue): ");
+Console.ResetColor();
+
 input = Console.ReadLine();
-selectedIndex = int.Parse(input ?? "0");
+selectedIndex = int.Parse(input ?? "0", CultureInfo.InvariantCulture);
 var selectedSampleMethod = sampleMethods[selectedIndex];
 
+Console.WriteLine();
+Console.ForegroundColor = ConsoleColor.White;
 Console.WriteLine("Executing sample...");
+Console.ResetColor();
 Console.WriteLine();
 
 try
 {
     if (selectedSampleMethod.Invoke(null, null) is Task task)
     {
-        await task;    
+        await task;
     }
 }
 catch (Exception exception)

Samples/RpcClient/RpcClient_Samples.cs

@@ -6,7 +6,6 @@
 // ReSharper disable UnusedMember.Global
 // ReSharper disable InconsistentNaming
 
-using MQTTnet.Client;
 using MQTTnet.Extensions.Rpc;
 using MQTTnet.Protocol;
 
@@ -19,38 +18,36 @@ public static class RpcClient_Samples
      * This is done via defining a pattern which uses the topic to correlate the request and the response.
      * From client usage it is possible to define a timeout.
      */
-    
+
     public static async Task Send_Request()
     {
-        var mqttFactory = new MqttFactory();
-        
+        var mqttFactory = new MqttClientFactory();
+
         // The RPC client is an addon for the existing client. So we need a regular client
         // which is wrapped later.
-        
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("broker.hivemq.com")
-                .Build();
 
-            await mqttClient.ConnectAsync(mqttClientOptions);
-            
-            using (var mqttRpcClient = mqttFactory.CreateMqttRpcClient(mqttClient))
-            {
-                // Access to a fully featured application message is not supported for RPC calls!
-                // The method will throw an exception when the response was not received in time.
-                await mqttRpcClient.ExecuteAsync(TimeSpan.FromSeconds(2), "ping", "", MqttQualityOfServiceLevel.AtMostOnce);
-            }
-            
-            Console.WriteLine("The RPC call was successful.");
+        using var mqttClient = mqttFactory.CreateMqttClient();
+        var mqttClientOptions = new MqttClientOptionsBuilder()
+            .WithTcpServer("broker.hivemq.com")
+            .Build();
+
+        await mqttClient.ConnectAsync(mqttClientOptions);
+
+        using (var mqttRpcClient = mqttFactory.CreateMqttRpcClient(mqttClient))
+        {
+            // Access to a fully featured application message is not supported for RPC calls!
+            // The method will throw an exception when the response was not received in time.
+            await mqttRpcClient.ExecuteAsync(TimeSpan.FromSeconds(2), "ping", "", MqttQualityOfServiceLevel.AtMostOnce);
         }
+
+        Console.WriteLine("The RPC call was successful.");
     }
-    
+
     /*
      * The device must respond to the request using the correct topic. The following C code shows how a
      * smart device like an ESP8266 must respond to the above sample.
      *
-        // If using the MQTT client PubSubClient it must be ensured 
+        // If using the MQTT client PubSubClient it must be ensured
         // that the request topic for each method is subscribed like the following.
         mqttClient.subscribe("MQTTnet.RPC/+/ping");
         mqttClient.subscribe("MQTTnet.RPC/+/do_something");

Samples/Server/Server_ASP_NET_Samples.cs

@@ -8,6 +8,7 @@
 // ReSharper disable EmptyConstructor
 // ReSharper disable MemberCanBeMadeStatic.Local
 
+using System.Diagnostics.CodeAnalysis;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.DependencyInjection;
@@ -17,7 +18,7 @@ using MQTTnet.Server;
 
 namespace MQTTnet.Samples.Server;
 
-public static class Server_Asp_Net_Samples
+public static class Server_ASP_NET_Samples
 {
     public static Task Start_Server_With_WebSockets_Support()
     {
@@ -51,15 +52,15 @@ public static class Server_Asp_Net_Samples
         {
             // Inject other services via constructor.
         }
-        
-        public Task OnClientConnected(ClientConnectedEventArgs eventArgs)
+
+        public static Task OnClientConnected(ClientConnectedEventArgs eventArgs)
         {
             Console.WriteLine($"Client '{eventArgs.ClientId}' connected.");
             return Task.CompletedTask;
         }
 
 
-        public Task ValidateConnection(ValidatingConnectionEventArgs eventArgs)
+        public static Task ValidateConnection(ValidatingConnectionEventArgs eventArgs)
         {
             Console.WriteLine($"Client '{eventArgs.ClientId}' wants to connect. Accepting!");
             return Task.CompletedTask;
@@ -68,6 +69,7 @@ public static class Server_Asp_Net_Samples
 
     sealed class Startup
     {
+        [SuppressMessage("Performance", "CA1822:Mark members as static")]
         public void Configure(IApplicationBuilder app, IWebHostEnvironment environment, MqttController mqttController)
         {
             app.UseRouting();
@@ -88,11 +90,12 @@ public static class Server_Asp_Net_Samples
                      * Attach event handlers etc. if required.
                      */
 
-                    server.ValidatingConnectionAsync += mqttController.ValidateConnection;
-                    server.ClientConnectedAsync += mqttController.OnClientConnected;
+                    server.ValidatingConnectionAsync += MqttController.ValidateConnection;
+                    server.ClientConnectedAsync += MqttController.OnClientConnected;
                 });
         }
 
+        [SuppressMessage("Performance", "CA1822:Mark members as static")]
         public void ConfigureServices(IServiceCollection services)
         {
             services.AddHostedMqttServer(

Samples/Server/Server_Diagnostics_Samples.cs

@@ -0,0 +1,50 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using MQTTnet.Internal;
+using MQTTnet.Packets;
+using MQTTnet.Server;
+
+namespace MQTTnet.Samples.Server;
+
+// ReSharper disable UnusedType.Global
+// ReSharper disable UnusedMember.Global
+// ReSharper disable InconsistentNaming
+// ReSharper disable EmptyConstructor
+// ReSharper disable MemberCanBeMadeStatic.Local
+public static class Server_Diagnostics_Samples
+{
+    public static async Task Get_Notified_When_Client_Received_Message()
+    {
+        /*
+         * This sample starts a MQTT server and attaches an event which gets fired whenever
+         * a client received and acknowledged a PUBLISH packet.
+         */
+
+        var mqttServerFactory = new MqttServerFactory();
+        var mqttServerOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
+
+        using var mqttServer = mqttServerFactory.CreateMqttServer(mqttServerOptions);
+        // Attach the event handler.
+        mqttServer.ClientAcknowledgedPublishPacketAsync += e =>
+        {
+            Console.WriteLine($"Client '{e.ClientId}' acknowledged packet {e.PublishPacket.PacketIdentifier} with topic '{e.PublishPacket.Topic}'");
+
+            // It is also possible to read additional data from the client response. This requires casting the response packet.
+            var qos1AcknowledgePacket = e.AcknowledgePacket as MqttPubAckPacket;
+            Console.WriteLine($"QoS 1 reason code: {qos1AcknowledgePacket?.ReasonCode}");
+
+            var qos2AcknowledgePacket = e.AcknowledgePacket as MqttPubCompPacket;
+            Console.WriteLine($"QoS 2 reason code: {qos2AcknowledgePacket?.ReasonCode}");
+            return CompletedTask.Instance;
+        };
+
+        await mqttServer.StartAsync();
+
+        Console.WriteLine("Press Enter to exit.");
+        Console.ReadLine();
+
+        await mqttServer.StopAsync();
+    }
+}

Samples/Server/Server_Intercepting_Samples.cs

@@ -0,0 +1,74 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+// ReSharper disable UnusedType.Global
+// ReSharper disable UnusedMember.Global
+// ReSharper disable InconsistentNaming
+// ReSharper disable EmptyConstructor
+// ReSharper disable MemberCanBeMadeStatic.Local
+
+using MQTTnet.Internal;
+using MQTTnet.Protocol;
+using MQTTnet.Server;
+
+namespace MQTTnet.Samples.Server;
+
+public static class Server_Intercepting_Samples
+{
+    public static async Task Intercept_Application_Messages()
+    {
+        /*
+         * This sample starts a simple MQTT server which manipulate all processed application messages.
+         * Please see _Server_Simple_Samples_ for more details on how to start a server.
+         */
+
+        var mqttServerFactory = new MqttServerFactory();
+        var mqttServerOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
+
+        using var mqttServer = mqttServerFactory.CreateMqttServer(mqttServerOptions);
+        mqttServer.InterceptingPublishAsync += args =>
+        {
+            // Here we only change the topic of the received application message.
+            // but also changing the payload etc. is required. Changing the QoS after
+            // transmitting is not supported and makes no sense at all.
+            args.ApplicationMessage.Topic += "/manipulated";
+
+            return CompletedTask.Instance;
+        };
+
+        await mqttServer.StartAsync();
+
+        Console.WriteLine("Press Enter to exit.");
+        Console.ReadLine();
+        await mqttServer.StopAsync();
+    }
+
+    public static async Task Intercept_Subscription()
+    {
+        /*
+         * This sample starts a simple MQTT server which does not allow to subscribe to '#'
+         * Start the server and try to subscribe to '#' with a client of choice.
+         */
+
+        var mqttServerFactory = new MqttServerFactory();
+        var mqttServerOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
+
+        using var mqttServer = mqttServerFactory.CreateMqttServer(mqttServerOptions);
+        mqttServer.InterceptingSubscriptionAsync += args =>
+        {
+            if (args.TopicFilter.Topic.Equals("#", StringComparison.Ordinal))
+            {
+                args.Response.ReasonCode = MqttSubscribeReasonCode.NotAuthorized;
+            }
+
+            return CompletedTask.Instance;
+        };
+
+        await mqttServer.StartAsync();
+
+        Console.WriteLine("Press Enter to exit.");
+        Console.ReadLine();
+        await mqttServer.StopAsync();
+    }
+}

Samples/Server/Server_Retained_Messages_Samples.cs

@@ -6,7 +6,11 @@
 // ReSharper disable UnusedMember.Global
 // ReSharper disable InconsistentNaming
 
+using System.Buffers;
 using System.Text.Json;
+using MQTTnet.Packets;
+using MQTTnet.Protocol;
+using MQTTnet.Server;
 
 namespace MQTTnet.Samples.Server;
 
@@ -20,63 +24,118 @@ public static class Server_Retained_Messages_Samples
 
         var storePath = Path.Combine(Path.GetTempPath(), "RetainedMessages.json");
 
-        var mqttFactory = new MqttFactory();
+        var mqttServerFactory = new MqttServerFactory();
 
         // Due to security reasons the "default" endpoint (which is unencrypted) is not enabled by default!
-        var mqttServerOptions = mqttFactory.CreateServerOptionsBuilder().WithDefaultEndpoint().Build();
+        var mqttServerOptions = mqttServerFactory.CreateServerOptionsBuilder().WithDefaultEndpoint().Build();
 
-        using (var server = mqttFactory.CreateMqttServer(mqttServerOptions))
+        using var server = mqttServerFactory.CreateMqttServer(mqttServerOptions);
+        // Make sure that the server will load the retained messages.
+        server.LoadingRetainedMessageAsync += async eventArgs =>
         {
-            // Make sure that the server will load the retained messages.
-            server.LoadingRetainedMessageAsync += async eventArgs =>
+            try
             {
-                try
-                {
-                    eventArgs.LoadedRetainedMessages = await JsonSerializer.DeserializeAsync<List<MqttApplicationMessage>>(File.OpenRead(storePath));
-                    Console.WriteLine("Retained messages loaded.");
-                }
-                catch (FileNotFoundException)
-                {
-                    // Ignore because nothing is stored yet.
-                    Console.WriteLine("No retained messages stored yet.");
-                }
-                catch (Exception exception)
-                {
-                    Console.WriteLine(exception);
-                }
-            };
+                var models = await JsonSerializer.DeserializeAsync<List<MqttRetainedMessageModel>>(File.OpenRead(storePath)) ?? new List<MqttRetainedMessageModel>();
+                var retainedMessages = models.Select(m => m.ToApplicationMessage()).ToList();
 
-            // Make sure to persist the changed retained messages.
-            server.RetainedMessageChangedAsync += async eventArgs =>
+                eventArgs.LoadedRetainedMessages = retainedMessages;
+                Console.WriteLine("Retained messages loaded.");
+            }
+            catch (FileNotFoundException)
             {
-                try
-                {
-                    // This sample uses the property _StoredRetainedMessages_ which will contain all(!) retained messages.
-                    // The event args also contain the affected retained message (property ChangedRetainedMessage). This can be
-                    // used to write all retained messages to dedicated files etc. Then all files must be loaded and a full list
-                    // of retained messages must be provided in the loaded event.
-
-                    var buffer = JsonSerializer.SerializeToUtf8Bytes(eventArgs.StoredRetainedMessages);
-                    await File.WriteAllBytesAsync(storePath, buffer);
-                    Console.WriteLine("Retained messages saved.");
-                }
-                catch (Exception exception)
-                {
-                    Console.WriteLine(exception);
-                }
-            };
-
-            // Make sure to clear the retained messages when they are all deleted via API.
-            server.RetainedMessagesClearedAsync += _ =>
+                // Ignore because nothing is stored yet.
+                Console.WriteLine("No retained messages stored yet.");
+            }
+            catch (Exception exception)
             {
-                File.Delete(storePath);
-                return Task.CompletedTask;
+                Console.WriteLine(exception);
+            }
+        };
+
+        // Make sure to persist the changed retained messages.
+        server.RetainedMessageChangedAsync += async eventArgs =>
+        {
+            try
+            {
+                // This sample uses the property _StoredRetainedMessages_ which will contain all(!) retained messages.
+                // The event args also contain the affected retained message (property ChangedRetainedMessage). This can be
+                // used to write all retained messages to dedicated files etc. Then all files must be loaded and a full list
+                // of retained messages must be provided in the loaded event.
+
+                var models = eventArgs.StoredRetainedMessages.Select(MqttRetainedMessageModel.Create);
+
+                var buffer = JsonSerializer.SerializeToUtf8Bytes(models);
+                await File.WriteAllBytesAsync(storePath, buffer);
+                Console.WriteLine("Retained messages saved.");
+            }
+            catch (Exception exception)
+            {
+                Console.WriteLine(exception);
+            }
+        };
+
+        // Make sure to clear the retained messages when they are all deleted via API.
+        server.RetainedMessagesClearedAsync += _ =>
+        {
+            File.Delete(storePath);
+            return Task.CompletedTask;
+        };
+
+        await server.StartAsync();
+
+        Console.WriteLine("Press Enter to exit.");
+        Console.ReadLine();
+    }
+
+    sealed class MqttRetainedMessageModel
+    {
+        public string? ContentType { get; set; }
+        public byte[]? CorrelationData { get; set; }
+        public byte[]? Payload { get; set; }
+        public MqttPayloadFormatIndicator PayloadFormatIndicator { get; set; }
+        public MqttQualityOfServiceLevel QualityOfServiceLevel { get; set; }
+        public string? ResponseTopic { get; set; }
+        public string? Topic { get; set; }
+        public List<MqttUserProperty>? UserProperties { get; set; }
+
+        public static MqttRetainedMessageModel Create(MqttApplicationMessage message)
+        {
+            ArgumentNullException.ThrowIfNull(message);
+
+            return new MqttRetainedMessageModel
+            {
+                Topic = message.Topic,
+
+                // Create a copy of the buffer from the payload segment because
+                // it cannot be serialized and deserialized with the JSON serializer.
+                Payload = message.Payload.ToArray(),
+                UserProperties = message.UserProperties,
+                ResponseTopic = message.ResponseTopic,
+                CorrelationData = message.CorrelationData,
+                ContentType = message.ContentType,
+                PayloadFormatIndicator = message.PayloadFormatIndicator,
+                QualityOfServiceLevel = message.QualityOfServiceLevel
+
+                // Other properties like "Retain" are not if interest in the storage.
+                // That's why a custom model makes sense.
             };
+        }
 
-            await server.StartAsync();
-
-            Console.WriteLine("Press Enter to exit.");
-            Console.ReadLine();
+        public MqttApplicationMessage ToApplicationMessage()
+        {
+            return new MqttApplicationMessage
+            {
+                Topic = Topic,
+                PayloadSegment = new ArraySegment<byte>(Payload ?? Array.Empty<byte>()),
+                PayloadFormatIndicator = PayloadFormatIndicator,
+                ResponseTopic = ResponseTopic,
+                CorrelationData = CorrelationData,
+                ContentType = ContentType,
+                UserProperties = UserProperties,
+                QualityOfServiceLevel = QualityOfServiceLevel,
+                Dup = false,
+                Retain = true
+            };
         }
     }
 }

Samples/Server/Server_Simple_Samples.cs

@@ -6,7 +6,8 @@
 // ReSharper disable UnusedMember.Global
 // ReSharper disable InconsistentNaming
 
-using MQTTnet.Diagnostics;
+using System.Globalization;
+using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Protocol;
 using MQTTnet.Server;
 
@@ -22,17 +23,15 @@ public static class Server_Simple_Samples
          * See _Run_Minimal_Server_ for more information.
          */
 
-        using (var mqttServer = await StartMqttServer())
-        {
-            // Let the client connect.
-            await Task.Delay(TimeSpan.FromSeconds(5));
+        using var mqttServer = await StartMqttServer();
+        // Let the client connect.
+        await Task.Delay(TimeSpan.FromSeconds(5));
 
-            // Now disconnect the client (if connected).
-            var affectedClient = (await mqttServer.GetClientsAsync()).FirstOrDefault(c => c.Id == "MyClient");
-            if (affectedClient != null)
-            {
-                await affectedClient.DisconnectAsync();
-            }
+        // Now disconnect the client (if connected).
+        var affectedClient = (await mqttServer.GetClientsAsync()).FirstOrDefault(c => c.Id == "MyClient");
+        if (affectedClient != null)
+        {
+            await affectedClient.DisconnectAsync();
         }
     }
 
@@ -44,18 +43,16 @@ public static class Server_Simple_Samples
          * See _Run_Minimal_Server_ for more information.
          */
 
-        using (var mqttServer = await StartMqttServer())
-        {
-            // Create a new message using the builder as usual.
-            var message = new MqttApplicationMessageBuilder().WithTopic("HelloWorld").WithPayload("Test").Build();
+        using var mqttServer = await StartMqttServer();
+        // Create a new message using the builder as usual.
+        var message = new MqttApplicationMessageBuilder().WithTopic("HelloWorld").WithPayload("Test").Build();
 
-            // Now inject the new message at the broker.
-            await mqttServer.InjectApplicationMessage(
-                new InjectedMqttApplicationMessage(message)
-                {
-                    SenderClientId = "SenderClientId"
-                });
-        }
+        // Now inject the new message at the broker.
+        await mqttServer.InjectApplicationMessage(
+            new InjectedMqttApplicationMessage(message)
+            {
+                SenderClientId = "SenderClientId"
+            });
     }
 
     public static async Task Run_Minimal_Server()
@@ -64,7 +61,7 @@ public static class Server_Simple_Samples
          * This sample starts a simple MQTT server which will accept any TCP connection.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttServerFactory = new MqttServerFactory();
 
         // The port for the default endpoint is 1883.
         // The default endpoint is NOT encrypted!
@@ -77,16 +74,14 @@ public static class Server_Simple_Samples
         //     .WithDefaultEndpointPort(1234)
         //     .Build();
 
-        using (var mqttServer = mqttFactory.CreateMqttServer(mqttServerOptions))
-        {
-            await mqttServer.StartAsync();
+        using var mqttServer = mqttServerFactory.CreateMqttServer(mqttServerOptions);
+        await mqttServer.StartAsync();
 
-            Console.WriteLine("Press Enter to exit.");
-            Console.ReadLine();
+        Console.WriteLine("Press Enter to exit.");
+        Console.ReadLine();
 
-            // Stop and dispose the MQTT server if it is no longer needed!
-            await mqttServer.StopAsync();
-        }
+        // Stop and dispose the MQTT server if it is no longer needed!
+        await mqttServer.StopAsync();
     }
 
     public static async Task Run_Server_With_Logging()
@@ -99,20 +94,18 @@ public static class Server_Simple_Samples
          * See sample "Run_Minimal_Server" for more details.
          */
 
-        var mqttFactory = new MqttFactory(new ConsoleLogger());
+        var mqttServerFactory = new MqttServerFactory(new ConsoleLogger());
 
         var mqttServerOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
 
-        using (var mqttServer = mqttFactory.CreateMqttServer(mqttServerOptions))
-        {
-            await mqttServer.StartAsync();
+        using var mqttServer = mqttServerFactory.CreateMqttServer(mqttServerOptions);
+        await mqttServer.StartAsync();
 
-            Console.WriteLine("Press Enter to exit.");
-            Console.ReadLine();
+        Console.WriteLine("Press Enter to exit.");
+        Console.ReadLine();
 
-            // Stop and dispose the MQTT server if it is no longer needed!
-            await mqttServer.StopAsync();
-        }
+        // Stop and dispose the MQTT server if it is no longer needed!
+        await mqttServer.StopAsync();
     }
 
     public static async Task Validating_Connections()
@@ -123,55 +116,53 @@ public static class Server_Simple_Samples
          * See _Run_Minimal_Server_ for more information.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttServerFactory = new MqttServerFactory();
 
         var mqttServerOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
 
-        using (var mqttServer = mqttFactory.CreateMqttServer(mqttServerOptions))
+        using var mqttServer = mqttServerFactory.CreateMqttServer(mqttServerOptions);
+        // Setup connection validation before starting the server so that there is
+        // no change to connect without valid credentials.
+        mqttServer.ValidatingConnectionAsync += e =>
         {
-            // Setup connection validation before starting the server so that there is 
-            // no change to connect without valid credentials.
-            mqttServer.ValidatingConnectionAsync += e =>
+            if (e.ClientId != "ValidClientId")
             {
-                if (e.ClientId != "ValidClientId")
-                {
-                    e.ReasonCode = MqttConnectReasonCode.ClientIdentifierNotValid;
-                }
+                e.ReasonCode = MqttConnectReasonCode.ClientIdentifierNotValid;
+            }
 
-                if (e.UserName != "ValidUser")
-                {
-                    e.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
-                }
+            if (e.UserName != "ValidUser")
+            {
+                e.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
+            }
 
-                if (e.Password != "SecretPassword")
-                {
-                    e.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
-                }
+            if (e.Password != "SecretPassword")
+            {
+                e.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
+            }
 
-                return Task.CompletedTask;
-            };
+            return Task.CompletedTask;
+        };
 
-            await mqttServer.StartAsync();
+        await mqttServer.StartAsync();
 
-            Console.WriteLine("Press Enter to exit.");
-            Console.ReadLine();
+        Console.WriteLine("Press Enter to exit.");
+        Console.ReadLine();
 
-            await mqttServer.StopAsync();
-        }
+        await mqttServer.StopAsync();
     }
 
     static async Task<MqttServer> StartMqttServer()
     {
-        var mqttFactory = new MqttFactory();
+        var mqttServerFactory = new MqttServerFactory();
 
         // Due to security reasons the "default" endpoint (which is unencrypted) is not enabled by default!
-        var mqttServerOptions = mqttFactory.CreateServerOptionsBuilder().WithDefaultEndpoint().Build();
-        var server = mqttFactory.CreateMqttServer(mqttServerOptions);
+        var mqttServerOptions = mqttServerFactory.CreateServerOptionsBuilder().WithDefaultEndpoint().Build();
+        var server = mqttServerFactory.CreateMqttServer(mqttServerOptions);
         await server.StartAsync();
         return server;
     }
 
-    class ConsoleLogger : IMqttNetLogger
+    sealed class ConsoleLogger : IMqttNetLogger
     {
         readonly object _consoleSyncRoot = new();
 
@@ -201,7 +192,7 @@ public static class Server_Simple_Samples
 
             if (parameters?.Length > 0)
             {
-                message = string.Format(message, parameters);
+                message = string.Format(CultureInfo.InvariantCulture, message, parameters);
             }
 
             lock (_consoleSyncRoot)
@@ -216,4 +207,4 @@ public static class Server_Simple_Samples
             }
         }
     }
-}
+}

Samples/Server/Server_TLS_Samples.cs

@@ -0,0 +1,71 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+// ReSharper disable UnusedType.Global
+// ReSharper disable UnusedMember.Global
+// ReSharper disable InconsistentNaming
+
+using System.Net;
+using System.Security.Cryptography;
+using System.Security.Cryptography.X509Certificates;
+using MQTTnet.Server;
+
+namespace MQTTnet.Samples.Server;
+
+public static class Server_TLS_Samples
+{
+    public static async Task Run_Server_With_Self_Signed_Certificate()
+    {
+        /*
+         * This sample starts a simple MQTT server which will accept any TCP connection.
+         * It also has an encrypted connection using a self signed TLS certificate.
+         *
+         * See sample "Run_Minimal_Server" for more details.
+         */
+
+        var mqttServerFactory = new MqttServerFactory();
+
+        // This certificate is self signed so that
+        var certificate = CreateSelfSignedCertificate("1.3.6.1.5.5.7.3.1");
+
+        var mqttServerOptions = new MqttServerOptionsBuilder().WithEncryptionCertificate(certificate).WithEncryptedEndpoint().Build();
+
+        using var mqttServer = mqttServerFactory.CreateMqttServer(mqttServerOptions);
+        await mqttServer.StartAsync();
+
+        Console.WriteLine("Press Enter to exit.");
+        Console.ReadLine();
+
+        // Stop and dispose the MQTT server if it is no longer needed!
+        await mqttServer.StopAsync();
+    }
+
+    static X509Certificate2 CreateSelfSignedCertificate(string oid)
+    {
+        var sanBuilder = new SubjectAlternativeNameBuilder();
+        sanBuilder.AddIpAddress(IPAddress.Loopback);
+        sanBuilder.AddIpAddress(IPAddress.IPv6Loopback);
+        sanBuilder.AddDnsName("localhost");
+
+        using var rsa = RSA.Create();
+        var certRequest = new CertificateRequest("CN=localhost", rsa, HashAlgorithmName.SHA512, RSASignaturePadding.Pkcs1);
+
+        certRequest.CertificateExtensions.Add(
+            new X509KeyUsageExtension(X509KeyUsageFlags.DataEncipherment | X509KeyUsageFlags.KeyEncipherment | X509KeyUsageFlags.DigitalSignature, false));
+
+        certRequest.CertificateExtensions.Add(new X509EnhancedKeyUsageExtension(new OidCollection { new(oid) }, false));
+
+        certRequest.CertificateExtensions.Add(sanBuilder.Build());
+
+        using var certificate = certRequest.CreateSelfSigned(DateTimeOffset.Now.AddMinutes(-10), DateTimeOffset.Now.AddMinutes(10));
+#pragma warning disable SYSLIB0057
+        var pfxCertificate = new X509Certificate2(
+            certificate.Export(X509ContentType.Pfx),
+            (string)null!,
+            X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.Exportable);
+#pragma warning restore SYSLIB0057
+
+        return pfxCertificate;
+    }
+}

Source/MQTTnet.AspNetCore.Tests/MQTTnet.AspNetCore.Tests.csproj

@@ -1,35 +0,0 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-    <PropertyGroup>
-        <TargetFramework>netcoreapp3.1</TargetFramework>
-        <IsPackable>false</IsPackable>
-        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
-        <EnableNETAnalyzers>false</EnableNETAnalyzers>
-        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
-    </PropertyGroup>
-
-    <ItemGroup>
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.2.0" />
-        <PackageReference Include="MSTest.TestAdapter" Version="2.2.10" />
-        <PackageReference Include="MSTest.TestFramework" Version="2.2.10" />
-        <PackageReference Include="Microsoft.CodeAnalysis.Compilers" Version="4.0.1" />
-        <PackageReference Include="Microsoft.Net.Compilers" Version="4.0.1" />
-    </ItemGroup>
-
-    <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp3.1' ">
-        <PackageReference Include="Microsoft.AspNetCore.Hosting" Version="2.2.7" />
-        <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="2.2.0" />
-    </ItemGroup>
-
-    <ItemGroup Condition=" '$(TargetFramework)' != 'netcoreapp3.1' ">
-        <PackageReference Include="Microsoft.AspNetCore.Hosting" Version="2.1.1" />
-        <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="2.1.1" />
-    </ItemGroup>
-
-    <ItemGroup>
-        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
-        <ProjectReference Include="..\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj" />
-        <ProjectReference Include="..\MQTTnet.Tests\MQTTnet.Tests.csproj" />
-    </ItemGroup>
-
-</Project>

Source/MQTTnet.AspNetCore.Tests/Mockups/ConnectionContextMockup.cs

@@ -1,26 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.Collections.Generic;
-using System.IO.Pipelines;
-using Microsoft.AspNetCore.Connections;
-using Microsoft.AspNetCore.Http.Features;
-
-namespace MQTTnet.AspNetCore.Tests.Mockups
-{
-    public class ConnectionContextMockup : ConnectionContext
-    {
-        public override string ConnectionId { get; set; }
-
-        public override IFeatureCollection Features { get; }
-
-        public override IDictionary<object, object> Items { get; set; }
-        public override IDuplexPipe Transport { get; set; }
-
-        public ConnectionContextMockup()
-        {
-            //Transport = new DefaultConnectionContext
-        }
-    }
-}

Source/MQTTnet.AspNetCore.Tests/Mockups/ConnectionHandlerMockup.cs

@@ -1,50 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using Microsoft.AspNetCore.Connections;
-using MQTTnet.Adapter;
-using MQTTnet.Formatter;
-using MQTTnet.Server;
-using System;
-using System.Threading.Tasks;
-using MQTTnet.Diagnostics;
-
-namespace MQTTnet.AspNetCore.Tests.Mockups
-{
-    public class ConnectionHandlerMockup: IMqttServerAdapter
-    {
-        public TaskCompletionSource<MqttConnectionContext> Context { get; } = new TaskCompletionSource<MqttConnectionContext>();
-        public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
-
-        public async Task OnConnectedAsync(ConnectionContext connection)
-        {
-            try
-            {
-                var formatter = new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535));
-                var context = new MqttConnectionContext(formatter, connection);
-                Context.TrySetResult(context);
-
-                await ClientHandler(context);
-            }
-            catch (Exception ex)
-            {
-                Context.TrySetException(ex);
-            }
-        }
-
-        public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
-        {
-            return Task.CompletedTask;
-        }
-
-        public Task StopAsync()
-        {
-            return Task.CompletedTask;
-        }
-
-        public void Dispose()
-        {
-        }
-    }
-}

Source/MQTTnet.AspNetCore.Tests/Mockups/DuplexPipeMockup.cs

@@ -1,28 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.IO.Pipelines;
-
-namespace MQTTnet.AspNetCore.Tests.Mockups
-{
-    public class DuplexPipeMockup : IDuplexPipe
-    {
-        public DuplexPipeMockup()
-        {
-            var pool = new LimitedMemoryPool();
-            var pipeOptions = new PipeOptions(pool);
-            Receive = new Pipe(pipeOptions);
-            Send = new Pipe(pipeOptions);
-        }
-
-        PipeReader IDuplexPipe.Input => Receive.Reader;
-
-        PipeWriter IDuplexPipe.Output => Send.Writer;
-
-
-        public Pipe Receive { get; set; } 
-
-        public Pipe Send { get; set; }
-    }
-}

Source/MQTTnet.AspNetCore.Tests/Mockups/LimitedMemoryPool.cs

@@ -1,22 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.Buffers;
-
-namespace MQTTnet.AspNetCore.Tests.Mockups
-{
-    public class LimitedMemoryPool : MemoryPool<byte>
-    {
-        protected override void Dispose(bool disposing)
-        {
-        }
-
-        public override IMemoryOwner<byte> Rent(int minBufferSize = -1)
-        {
-            return new MemoryOwner(minBufferSize);
-        }
-
-        public override int MaxBufferSize { get; }
-    }
-}

Source/MQTTnet.AspNetCore.Tests/Mockups/MemoryOwner.cs

@@ -1,37 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Buffers;
-
-namespace MQTTnet.AspNetCore.Tests.Mockups
-{
-    public class MemoryOwner : IMemoryOwner<byte>
-    {
-        private readonly byte[] _raw;
-
-        public MemoryOwner(int size)
-        {
-            if (size <= 0)
-            {
-                size = 1024;
-            }
-
-            if (size > 4096)
-            {
-                size = 4096;
-            }
-
-            _raw = ArrayPool<byte>.Shared.Rent(size);
-            Memory = _raw;
-        }
-
-        public void Dispose()
-        {
-            ArrayPool<byte>.Shared.Return(_raw);
-        }
-
-        public Memory<byte> Memory { get; }
-    }
-}

Source/MQTTnet.AspNetCore.Tests/MqttConnectionContextTest.cs

@@ -1,136 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Connections;
-using Microsoft.AspNetCore.Hosting;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-
-using System;
-using System.Net;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Adapter;
-using MQTTnet.AspNetCore.Tests.Mockups;
-using MQTTnet.Exceptions;
-using MQTTnet.Formatter;
-using MQTTnet.Packets;
-using MQTTnet.Client;
-using MQTTnet.Protocol;
-using MQTTnet.Tests.Extensions;
-
-namespace MQTTnet.AspNetCore.Tests
-{
-    [TestClass]
-    public class MqttConnectionContextTest
-    {
-        [TestMethod]
-        public async Task TestReceivePacketAsyncThrowsWhenReaderCompleted()
-        {
-            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));
-            var pipe = new DuplexPipeMockup();
-            var connection = new DefaultConnectionContext();
-            connection.Transport = pipe;
-            var ctx = new MqttConnectionContext(serializer, connection);
-
-            pipe.Receive.Writer.Complete();
-
-            await Assert.ThrowsExceptionAsync<MqttCommunicationException>(() => ctx.ReceivePacketAsync(CancellationToken.None));
-        }
-
-        [TestMethod]
-        public async Task TestCorruptedConnectPacket()
-        {
-            var writer = new MqttBufferWriter(4096, 65535);
-            var serializer = new MqttPacketFormatterAdapter(writer);
-            var pipe = new DuplexPipeMockup();
-            var connection = new DefaultConnectionContext();
-            connection.Transport = pipe;
-            var ctx = new MqttConnectionContext(serializer, connection);
-            
-            await pipe.Receive.Writer.WriteAsync(writer.AddMqttHeader(MqttControlPacketType.Connect, new byte[0]));
-
-            await Assert.ThrowsExceptionAsync<MqttProtocolViolationException>(() => ctx.ReceivePacketAsync(CancellationToken.None));
-
-            // the first exception should complete the pipes so if someone tries to use the connection after that it should throw immidiatly
-            await Assert.ThrowsExceptionAsync<InvalidOperationException>(() =>  ctx.ReceivePacketAsync(CancellationToken.None));
-        }
-
-        // COMMENTED OUT DUE TO DEAD LOCK? OR VERY VERY SLOW PERFORMANCE ON LOCAL DEV MACHINE. TEST WAS STILL RUNNING AFTER SEVERAL MINUTES!
-        //[TestMethod]
-        //public async Task TestParallelWrites()
-        //{
-        //    var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311);
-        //    var pipe = new DuplexPipeMockup();
-        //    var connection = new DefaultConnectionContext();
-        //    connection.Transport = pipe;
-        //    var ctx = new MqttConnectionContext(serializer, connection);
-
-        //    var tasks = Enumerable.Range(1, 100).Select(_ => Task.Run(async () => 
-        //    {
-        //        for (int i = 0; i < 100; i++)
-        //        {
-        //            await ctx.SendPacketAsync(new MqttPublishPacket(), TimeSpan.Zero, CancellationToken.None).ConfigureAwait(false);
-        //        }
-        //    }));
-
-        //    await Task.WhenAll(tasks).ConfigureAwait(false);
-        //}
-        
-        [TestMethod]
-        public async Task TestLargePacket()
-        {
-            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));
-            var pipe = new DuplexPipeMockup();
-            var connection = new DefaultConnectionContext();
-            connection.Transport = pipe;
-            var ctx = new MqttConnectionContext(serializer, connection);
-
-            await ctx.SendPacketAsync(new MqttPublishPacket { Payload = new byte[20_000] }, CancellationToken.None).ConfigureAwait(false);
-
-            var readResult = await pipe.Send.Reader.ReadAsync();
-            Assert.IsTrue(readResult.Buffer.Length > 20000);
-        }
-
-        private class Startup 
-        {
-            public void Configure(IApplicationBuilder app)
-            { 
-            }
-        }
-
-        [TestMethod]
-        public async Task TestEndpoint()
-        {
-            var mockup = new ConnectionHandlerMockup();
-
-
-            using (var host = new WebHostBuilder()
-                .UseKestrel(kestrel => kestrel.ListenLocalhost(1883, listener => listener.Use((ctx, next) => mockup.OnConnectedAsync(ctx))))
-                .UseStartup<Startup>()
-                .ConfigureServices((hostContext, services) =>
-                {
-                    services.AddHostedMqttServer(o => o.WithoutDefaultEndpoint());
-                    services.AddSingleton<IMqttServerAdapter>(mockup);
-                })
-                .Build())
-                
-            using (var client = new MqttFactory().CreateMqttClient())
-            {
-                host.Start();
-                await client.ConnectAsync(new MqttClientOptionsBuilder()
-                    .WithTcpServer("localhost")
-                    .Build(), CancellationToken.None);
-
-                var ctx = await mockup.Context.Task;
-#if NETCOREAPP3_1
-                var ep = IPEndPoint.Parse(ctx.Endpoint);
-                Assert.IsNotNull(ep);
-#endif
-                Assert.IsNotNull(ctx);
-            }               
-        }
-    }
-}

Source/MQTTnet.AspNetCore.Tests/ReaderExtensionsTest.cs

@@ -1,51 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-#if NETCOREAPP3_1
-using System.Buffers;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-using MQTTnet.AspNetCore;
-using MQTTnet.Formatter;
-using MQTTnet.Packets;
-
-namespace MQTTnet.AspNetCore.Tests
-{
-    [TestClass]
-    public class ReaderExtensionsTest
-    {
-        [TestMethod]
-        public void TestTryDeserialize()
-        {
-            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));
-
-            var buffer = serializer.Encode(new MqttPublishPacket {Topic = "a", Payload = new byte[5]}).Join();
-
-            var sequence = new ReadOnlySequence<byte>(buffer.Array, buffer.Offset, buffer.Count);
-
-            var part = sequence;
-            MqttPacket packet;
-            var consumed = part.Start;
-            var observed = part.Start;
-            var result = false;
-            var read = 0;
-            
-            part = sequence.Slice(sequence.Start, 0); // empty message should fail
-            result = serializer.TryDecode(part, out packet, out consumed, out observed, out read);
-            Assert.IsFalse(result);
-
-            part = sequence.Slice(sequence.Start, 1); // partial fixed header should fail
-            result = serializer.TryDecode(part, out packet, out consumed, out observed, out read);
-            Assert.IsFalse(result);
-
-            part = sequence.Slice(sequence.Start, 4); // partial body should fail
-            result = serializer.TryDecode(part, out packet, out consumed, out observed, out read);
-            Assert.IsFalse(result);
-
-            part = sequence; // complete msg should work
-            result = serializer.TryDecode(part, out packet, out consumed, out observed, out read);
-            Assert.IsTrue(result);
-        }
-    }
-}
-#endif

Source/MQTTnet.AspTestApp/MQTTnet.AspTestApp.csproj

@@ -1,20 +1,16 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
     <PropertyGroup>
-        <TargetFramework>net6.0</TargetFramework>
         <Nullable>enable</Nullable>
         <ImplicitUsings>enable</ImplicitUsings>
         <IsPackable>false</IsPackable>
-        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
-        <EnableNETAnalyzers>false</EnableNETAnalyzers>
-        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
+        <NoWarn>$(NoWarn);CA1707</NoWarn>
     </PropertyGroup>
 
     <ItemGroup>
         <ProjectReference Include="..\..\Source\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj"/>
-
-        <PackageReference Include="Microsoft.CodeAnalysis.Compilers" Version="4.0.1" />
-        <PackageReference Include="Microsoft.Net.Compilers" Version="4.0.1" />
+        <ProjectReference Include="..\..\Source\MQTTnet.Server\MQTTnet.Server.csproj"/>
+        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj"/>
     </ItemGroup>
 
     <ItemGroup>

Source/MQTTnet.AspTestApp/Pages/Index.cshtml

@@ -17,7 +17,7 @@
       clientId: 'mqttnet_web_client'
     }
 
-    const client  = mqtt.connect('ws://localhost:5049/mqtt')
+    const client  = mqtt.connect('ws://localhost:5000/mqtt')
 
     client.on('connect', function () {
       console.log('Connected')

Source/MQTTnet.AspTestApp/Pages/Index.cshtml.cs

@@ -4,20 +4,22 @@
 
 using Microsoft.AspNetCore.Mvc.RazorPages;
 
-namespace MQTTnet.AspTestApp.Pages
+namespace MQTTnet.AspTestApp.Pages;
+
+public partial class IndexModel : PageModel
 {
-    public class IndexModel : PageModel
+    readonly ILogger<IndexModel> _logger;
+
+    public IndexModel(ILogger<IndexModel> logger)
     {
-        private readonly ILogger<IndexModel> _logger;
-
-        public IndexModel(ILogger<IndexModel> logger)
-        {
-            _logger = logger;
-        }
-
-        public void OnGet()
-        {
-
-        }
+        _logger = logger;
     }
+
+    public void OnGet()
+    {
+        LogOnGet();
+    }
+
+    [LoggerMessage(Level = LogLevel.Information, Message = "OnGet")]
+    private partial void LogOnGet();
 }

Source/MQTTnet.AspTestApp/Program.cs

@@ -30,10 +30,7 @@ app.UseAuthorization();
 app.MapRazorPages();
 
 // Setup MQTT stuff.
-app.UseEndpoints(endpoints =>
-{
-    endpoints.MapMqtt("/mqtt");
-});
+app.MapMqtt("/mqtt");
 
 app.UseMqttServer(server =>
 {
@@ -42,7 +39,7 @@ app.UseMqttServer(server =>
         _ = Task.Run(async () =>
         {
             var mqttApplicationMessage = new MqttApplicationMessageBuilder()
-                .WithPayload($"Test application message from MQTTnet server.")
+                .WithPayload("Test application message from MQTTnet server.")
                 .WithTopic("message")
                 .Build();
 

Source/MQTTnet.AspnetCore/ApplicationBuilderExtensions.cs

@@ -2,20 +2,21 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
 using MQTTnet.Server;
 
-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore;
+
+public static class ApplicationBuilderExtensions
 {
-    public static class ApplicationBuilderExtensions
+    [Obsolete(
+        "This class is obsolete and will be removed in a future version. The recommended alternative is to use MapMqtt inside Microsoft.AspNetCore.Builder.UseEndpoints(...).")]
+    public static IApplicationBuilder UseMqttEndpoint(this IApplicationBuilder app, string path = "/mqtt")
     {
-        [Obsolete("This class is obsolete and will be removed in a future version. The recommended alternative is to use MapMqtt inside Microsoft.AspNetCore.Builder.UseEndpoints(...).")]
-        public static IApplicationBuilder UseMqttEndpoint(this IApplicationBuilder app, string path = "/mqtt")
-        {
-            app.UseWebSockets();
-            app.Use(async (context, next) =>
+        app.UseWebSockets();
+        app.Use(
+            async (context, next) =>
             {
                 if (!context.WebSockets.IsWebSocketRequest || context.Request.Path != path)
                 {
@@ -31,22 +32,19 @@ namespace MQTTnet.AspNetCore
                 }
 
                 var adapter = app.ApplicationServices.GetRequiredService<MqttWebSocketServerAdapter>();
-                using (var webSocket = await context.WebSockets.AcceptWebSocketAsync(subProtocol).ConfigureAwait(false))
-                {
-                    await adapter.RunWebSocketConnectionAsync(webSocket, context);
-                }
+                using var webSocket = await context.WebSockets.AcceptWebSocketAsync(subProtocol).ConfigureAwait(false);
+                await adapter.RunWebSocketConnectionAsync(webSocket, context);
             });
 
-            return app;
-        }
-
-        public static IApplicationBuilder UseMqttServer(this IApplicationBuilder app, Action<MqttServer> configure)
-        {
-            var server = app.ApplicationServices.GetRequiredService<MqttServer>();
-
-            configure(server);
-
-            return app;
-        }
+        return app;
     }
-}
+
+    public static IApplicationBuilder UseMqttServer(this IApplicationBuilder app, Action<MqttServer> configure)
+    {
+        var server = app.ApplicationServices.GetRequiredService<MqttServer>();
+
+        configure(server);
+
+        return app;
+    }
+}

Source/MQTTnet.AspnetCore/AspNetMqttServerOptionsBuilder.cs

@@ -3,17 +3,15 @@
 // See the LICENSE file in the project root for more information.
 
 using MQTTnet.Server;
-using System;
 
-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore;
+
+public sealed class AspNetMqttServerOptionsBuilder : MqttServerOptionsBuilder
 {
-    public sealed class AspNetMqttServerOptionsBuilder : MqttServerOptionsBuilder
+    public AspNetMqttServerOptionsBuilder(IServiceProvider serviceProvider)
     {
-        public AspNetMqttServerOptionsBuilder(IServiceProvider serviceProvider)
-        {
-            ServiceProvider = serviceProvider ?? throw new ArgumentNullException(nameof(serviceProvider));
-        }
-
-        public IServiceProvider ServiceProvider { get; }
+        ServiceProvider = serviceProvider ?? throw new ArgumentNullException(nameof(serviceProvider));
     }
-}
+
+    public IServiceProvider ServiceProvider { get; }
+}

Source/MQTTnet.AspnetCore/BufferExtensions.cs

@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Runtime.InteropServices;
+
+namespace MQTTnet.AspNetCore;
+
+public static class BufferExtensions
+{
+    public static ArraySegment<byte> GetArray(this ReadOnlyMemory<byte> memory)
+    {
+        if (!MemoryMarshal.TryGetArray(memory, out var result))
+        {
+            throw new InvalidOperationException("Buffer backed by array was expected");
+        }
+
+        return result;
+    }
+}

Source/MQTTnet.AspnetCore/Client/MqttClientConnectionContextFactory.cs

@@ -1,38 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using MQTTnet.Adapter;
-using MQTTnet.AspNetCore.Client.Tcp;
-using MQTTnet.Formatter;
-using System;
-using System.Net;
-using MQTTnet.Client;
-using MQTTnet.Diagnostics;
-
-namespace MQTTnet.AspNetCore.Client
-{
-    public sealed class MqttClientConnectionContextFactory : IMqttClientAdapterFactory
-    {
-        public IMqttChannelAdapter CreateClientAdapter(MqttClientOptions options, MqttPacketInspector packetInspector, IMqttNetLogger logger)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            switch (options.ChannelOptions)
-            {
-                case MqttClientTcpOptions tcpOptions:
-                    {
-                        var endpoint = new DnsEndPoint(tcpOptions.Server, tcpOptions.GetPort());
-                        var tcpConnection = new TcpConnection(endpoint);
-                        
-                        var formatter = new MqttPacketFormatterAdapter(options.ProtocolVersion, new MqttBufferWriter(4096, 65535));
-                        return new MqttConnectionContext(formatter, tcpConnection);
-                    }
-                default:
-                    {
-                        throw new NotSupportedException();
-                    }
-            }
-        }
-    }
-}

Source/MQTTnet.AspnetCore/Client/Tcp/BufferExtensions.cs

@@ -1,26 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Runtime.InteropServices;
-
-namespace MQTTnet.AspNetCore.Client.Tcp
-{
-    public static class BufferExtensions
-    {
-        public static ArraySegment<byte> GetArray(this Memory<byte> memory)
-        {
-            return ((ReadOnlyMemory<byte>)memory).GetArray();
-        }
-
-        public static ArraySegment<byte> GetArray(this ReadOnlyMemory<byte> memory)
-        {
-            if (!MemoryMarshal.TryGetArray(memory, out var result))
-            {
-                throw new InvalidOperationException("Buffer backed by array was expected");
-            }
-            return result;
-        }
-    }
-}

Source/MQTTnet.AspnetCore/Client/Tcp/DuplexPipe.cs

@@ -1,45 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.IO.Pipelines;
-
-namespace MQTTnet.AspNetCore.Client.Tcp
-{
-    public class DuplexPipe : IDuplexPipe
-    {
-        public DuplexPipe(PipeReader reader, PipeWriter writer)
-        {
-            Input = reader;
-            Output = writer;
-        }
-
-        public PipeReader Input { get; }
-
-        public PipeWriter Output { get; }
-
-        public static DuplexPipePair CreateConnectionPair(PipeOptions inputOptions, PipeOptions outputOptions)
-        {
-            var input = new Pipe(inputOptions);
-            var output = new Pipe(outputOptions);
-
-            var transportToApplication = new DuplexPipe(output.Reader, input.Writer);
-            var applicationToTransport = new DuplexPipe(input.Reader, output.Writer);
-
-            return new DuplexPipePair(applicationToTransport, transportToApplication);
-        }
-
-        // This class exists to work around issues with value tuple on .NET Framework
-        public readonly struct DuplexPipePair
-        {
-            public IDuplexPipe Transport { get; }
-            public IDuplexPipe Application { get; }
-
-            public DuplexPipePair(IDuplexPipe transport, IDuplexPipe application)
-            {
-                Transport = transport;
-                Application = application;
-            }
-        }
-    }
-}

Source/MQTTnet.AspnetCore/Client/Tcp/SocketAwaitable.cs

@@ -1,74 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Diagnostics;
-using System.IO.Pipelines;
-using System.Net.Sockets;
-using System.Runtime.CompilerServices;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace MQTTnet.AspNetCore.Client.Tcp
-{
-    public class SocketAwaitable : ICriticalNotifyCompletion
-    {
-        private static readonly Action _callbackCompleted = () => { };
-
-        private readonly PipeScheduler _ioScheduler;
-
-        private Action _callback;
-        private int _bytesTransferred;
-        private SocketError _error;
-
-        public SocketAwaitable(PipeScheduler ioScheduler)
-        {
-            _ioScheduler = ioScheduler;
-        }
-
-        public bool IsCompleted => ReferenceEquals(_callback, _callbackCompleted);
-
-        public SocketAwaitable GetAwaiter() => this;
-
-        public int GetResult()
-        {
-            Debug.Assert(ReferenceEquals(_callback, _callbackCompleted));
-
-            _callback = null;
-
-            if (_error != SocketError.Success)
-            {
-                throw new SocketException((int)_error);
-            }
-
-            return _bytesTransferred;
-        }
-
-        public void OnCompleted(Action continuation)
-        {
-            if (ReferenceEquals(_callback, _callbackCompleted) ||
-                ReferenceEquals(Interlocked.CompareExchange(ref _callback, continuation, null), _callbackCompleted))
-            {
-                Task.Run(continuation);
-            }
-        }
-
-        public void UnsafeOnCompleted(Action continuation)
-        {
-            OnCompleted(continuation);
-        }
-
-        public void Complete(int bytesTransferred, SocketError socketError)
-        {
-            _error = socketError;
-            _bytesTransferred = bytesTransferred;
-            var continuation = Interlocked.Exchange(ref _callback, _callbackCompleted);
-
-            if (continuation != null)
-            {
-                _ioScheduler.Schedule(state => ((Action)state)(), continuation);
-            }
-        }
-    }
-}

Source/MQTTnet.AspnetCore/Client/Tcp/SocketReceiver.cs

@@ -1,41 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.IO.Pipelines;
-using System.Net.Sockets;
-
-namespace MQTTnet.AspNetCore.Client.Tcp
-{
-    public class SocketReceiver
-    {
-        private readonly Socket _socket;
-        private readonly SocketAsyncEventArgs _eventArgs = new SocketAsyncEventArgs();
-        private readonly SocketAwaitable _awaitable;
-
-        public SocketReceiver(Socket socket, PipeScheduler scheduler)
-        {
-            _socket = socket;
-            _awaitable = new SocketAwaitable(scheduler);
-            _eventArgs.UserToken = _awaitable;
-            _eventArgs.Completed += (_, e) => ((SocketAwaitable)e.UserToken).Complete(e.BytesTransferred, e.SocketError);
-        }
-
-        public SocketAwaitable ReceiveAsync(Memory<byte> buffer)
-        {
-#if NETCOREAPP2_1
-            _eventArgs.SetBuffer(buffer);
-#else
-            var segment = buffer.GetArray();
-            _eventArgs.SetBuffer(segment.Array, segment.Offset, segment.Count);
-#endif
-            if (!_socket.ReceiveAsync(_eventArgs))
-            {
-                _awaitable.Complete(_eventArgs.BytesTransferred, _eventArgs.SocketError);
-            }
-
-            return _awaitable;
-        }
-    }
-}

Source/MQTTnet.AspnetCore/Client/Tcp/SocketSender.cs

@@ -1,105 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Buffers;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.IO.Pipelines;
-using System.Net.Sockets;
-
-#if NETCOREAPP2_1
-using System.Runtime.InteropServices;
-#endif
-
-namespace MQTTnet.AspNetCore.Client.Tcp
-{
-    public class SocketSender
-    {
-        private readonly Socket _socket;
-        private readonly SocketAsyncEventArgs _eventArgs = new SocketAsyncEventArgs();
-        private readonly SocketAwaitable _awaitable;
-
-        private List<ArraySegment<byte>> _bufferList;
-
-        public SocketSender(Socket socket, PipeScheduler scheduler)
-        {
-            _socket = socket;
-            _awaitable = new SocketAwaitable(scheduler);
-            _eventArgs.UserToken = _awaitable;
-            _eventArgs.Completed += (_, e) => ((SocketAwaitable)e.UserToken).Complete(e.BytesTransferred, e.SocketError);
-        }
-
-        public SocketAwaitable SendAsync(in ReadOnlySequence<byte> buffers)
-        {
-            if (buffers.IsSingleSegment)
-            {
-                return SendAsync(buffers.First);
-            }
-
-#if NETCOREAPP2_1
-            if (!_eventArgs.MemoryBuffer.Equals(Memory<byte>.Empty))
-#else
-            if (_eventArgs.Buffer != null)
-#endif
-            {
-                _eventArgs.SetBuffer(null, 0, 0);
-            }
-
-            _eventArgs.BufferList = GetBufferList(buffers);
-
-            if (!_socket.SendAsync(_eventArgs))
-            {
-                _awaitable.Complete(_eventArgs.BytesTransferred, _eventArgs.SocketError);
-            }
-
-            return _awaitable;
-        }
-
-        private SocketAwaitable SendAsync(ReadOnlyMemory<byte> memory)
-        {
-            // The BufferList getter is much less expensive then the setter.
-            if (_eventArgs.BufferList != null)
-            {
-                _eventArgs.BufferList = null;
-            }
-
-#if NETCOREAPP2_1
-            _eventArgs.SetBuffer(MemoryMarshal.AsMemory(memory));
-#else
-            var segment = memory.GetArray();
-            _eventArgs.SetBuffer(segment.Array, segment.Offset, segment.Count);
-#endif
-            if (!_socket.SendAsync(_eventArgs))
-            {
-                _awaitable.Complete(_eventArgs.BytesTransferred, _eventArgs.SocketError);
-            }
-
-            return _awaitable;
-        }
-
-        private List<ArraySegment<byte>> GetBufferList(in ReadOnlySequence<byte> buffer)
-        {
-            Debug.Assert(!buffer.IsEmpty);
-            Debug.Assert(!buffer.IsSingleSegment);
-
-            if (_bufferList == null)
-            {
-                _bufferList = new List<ArraySegment<byte>>();
-            }
-            else
-            {
-                // Buffers are pooled, so it's OK to root them until the next multi-buffer write.
-                _bufferList.Clear();
-            }
-
-            foreach (var b in buffer)
-            {
-                _bufferList.Add(b.GetArray());
-            }
-
-            return _bufferList;
-        }
-    }
-}

Source/MQTTnet.AspnetCore/Client/Tcp/TcpConnection.cs

@@ -1,272 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using Microsoft.AspNetCore.Connections;
-using Microsoft.AspNetCore.Http.Features;
-using MQTTnet.Exceptions;
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.IO.Pipelines;
-using System.Net;
-using System.Net.Sockets;
-using System.Threading.Tasks;
-
-namespace MQTTnet.AspNetCore.Client.Tcp
-{
-    public class TcpConnection : ConnectionContext
-    {
-        private volatile bool _aborted;
-        private readonly EndPoint _endPoint;
-        private SocketSender _sender;
-        private SocketReceiver _receiver;
-
-        private Socket _socket;
-        private IDuplexPipe _application;
-
-        public bool IsConnected { get; private set; }
-        public override string ConnectionId { get; set; }
-        public override IFeatureCollection Features { get; }
-        public override IDictionary<object, object> Items { get; set; }
-        public override IDuplexPipe Transport { get; set; }
-
-        public TcpConnection(EndPoint endPoint)
-        {
-            _endPoint = endPoint;
-        }
-
-        public TcpConnection(Socket socket)
-        {
-            _socket = socket;
-            _endPoint = socket.RemoteEndPoint;
-
-            _sender = new SocketSender(_socket, PipeScheduler.ThreadPool);
-            _receiver = new SocketReceiver(_socket, PipeScheduler.ThreadPool);
-        }
-#if NETCOREAPP3_1 || NET5_0_OR_GREATER
-        public override ValueTask DisposeAsync()
-#else
-        public Task DisposeAsync()
-#endif
-        {
-            IsConnected = false;
-
-            Transport?.Output.Complete();
-            Transport?.Input.Complete();
-
-            _socket?.Dispose();
-
-#if NETCOREAPP3_1 || NET5_0_OR_GREATER
-
-            return base.DisposeAsync();
-        }
-#else
-
-            return Task.CompletedTask;
-        }
-#endif
-
-        public async Task StartAsync()
-        {
-            if (_socket == null)
-            {
-                _socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-                _sender = new SocketSender(_socket, PipeScheduler.ThreadPool);
-                _receiver = new SocketReceiver(_socket, PipeScheduler.ThreadPool);
-                await _socket.ConnectAsync(_endPoint);
-            }
-
-            var pair = DuplexPipe.CreateConnectionPair(PipeOptions.Default, PipeOptions.Default);
-
-            Transport = pair.Transport;
-            _application = pair.Application;
-
-            _ = ExecuteAsync();
-
-            IsConnected = true;
-        }
-
-        private async Task ExecuteAsync()
-        {
-            Exception sendError = null;
-            try
-            {
-                // Spawn send and receive logic
-                var receiveTask = DoReceive();
-                var sendTask = DoSend();
-
-                // If the sending task completes then close the receive
-                // We don't need to do this in the other direction because the kestrel
-                // will trigger the output closing once the input is complete.
-                if (await Task.WhenAny(receiveTask, sendTask) == sendTask)
-                {
-                    // Tell the reader it's being aborted
-                    _socket.Dispose();
-                }
-
-                // Now wait for both to complete
-                await receiveTask;
-                sendError = await sendTask;
-
-                // Dispose the socket(should noop if already called)
-                _socket.Dispose();
-            }
-            catch (Exception ex)
-            {
-                Console.WriteLine($"Unexpected exception in {nameof(TcpConnection)}.{nameof(StartAsync)}: " + ex);
-            }
-            finally
-            {
-                // Complete the output after disposing the socket
-                _application.Input.Complete(sendError);
-            }
-        }
-        private async Task DoReceive()
-        {
-            Exception error = null;
-
-            try
-            {
-                await ProcessReceives();
-            }
-            catch (SocketException ex) when (ex.SocketErrorCode == SocketError.ConnectionReset)
-            {
-                error = new MqttCommunicationException(ex);
-            }
-            catch (SocketException ex) when (ex.SocketErrorCode == SocketError.OperationAborted ||
-                                             ex.SocketErrorCode == SocketError.ConnectionAborted ||
-                                             ex.SocketErrorCode == SocketError.Interrupted ||
-                                             ex.SocketErrorCode == SocketError.InvalidArgument)
-            {
-                if (!_aborted)
-                {
-                    // Calling Dispose after ReceiveAsync can cause an "InvalidArgument" error on *nix.
-                    error = ConnectionAborted();
-                }
-            }
-            catch (ObjectDisposedException)
-            {
-                if (!_aborted)
-                {
-                    error = ConnectionAborted();
-                }
-            }
-            catch (IOException ex)
-            {
-                error = ex;
-            }
-            catch (Exception ex)
-            {
-                error = new IOException(ex.Message, ex);
-            }
-            finally
-            {
-                if (_aborted)
-                {
-                    error = error ?? ConnectionAborted();
-                }
-
-                _application.Output.Complete(error);
-            }
-        }
-
-        private async Task ProcessReceives()
-        {
-            while (true)
-            {
-                // Ensure we have some reasonable amount of buffer space
-                var buffer = _application.Output.GetMemory();
-
-                var bytesReceived = await _receiver.ReceiveAsync(buffer);
-
-                if (bytesReceived == 0)
-                {
-                    // FIN
-                    break;
-                }
-
-                _application.Output.Advance(bytesReceived);
-
-                var flushTask = _application.Output.FlushAsync();
-
-                if (!flushTask.IsCompleted)
-                {
-                    await flushTask;
-                }
-
-                var result = flushTask.GetAwaiter().GetResult();
-                if (result.IsCompleted)
-                {
-                    // Pipe consumer is shut down, do we stop writing
-                    break;
-                }
-            }
-        }
-
-        private Exception ConnectionAborted()
-        {
-            return new MqttCommunicationException("Connection Aborted");
-        }
-
-        private async Task<Exception> DoSend()
-        {
-            Exception error = null;
-
-            try
-            {
-                await ProcessSends();
-            }
-            catch (SocketException ex) when (ex.SocketErrorCode == SocketError.OperationAborted)
-            {
-            }
-            catch (ObjectDisposedException)
-            {
-            }
-            catch (IOException ex)
-            {
-                error = ex;
-            }
-            catch (Exception ex)
-            {
-                error = new IOException(ex.Message, ex);
-            }
-            finally
-            {
-                _aborted = true;
-                _socket.Shutdown(SocketShutdown.Both);
-            }
-
-            return error;
-        }
-
-        private async Task ProcessSends()
-        {
-            while (true)
-            {
-                // Wait for data to write from the pipe producer
-                var result = await _application.Input.ReadAsync();
-                var buffer = result.Buffer;
-
-                if (result.IsCanceled)
-                {
-                    break;
-                }
-
-                var end = buffer.End;
-                var isCompleted = result.IsCompleted;
-                if (!buffer.IsEmpty)
-                {
-                    await _sender.SendAsync(buffer);
-                }
-
-                _application.Input.AdvanceTo(end);
-
-                if (isCompleted)
-                {
-                    break;
-                }
-            }
-        }
-    }
-}

Source/MQTTnet.AspnetCore/ConnectionBuilderExtensions.cs

@@ -4,13 +4,12 @@
 
 using Microsoft.AspNetCore.Connections;
 
-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore;
+
+public static class ConnectionBuilderExtensions
 {
-    public static class ConnectionBuilderExtensions
+    public static IConnectionBuilder UseMqtt(this IConnectionBuilder builder)
     {
-        public static IConnectionBuilder UseMqtt(this IConnectionBuilder builder)
-        {
-            return builder.UseConnectionHandler<MqttConnectionHandler>();
-        }
+        return builder.UseConnectionHandler<MqttConnectionHandler>();
     }
-}
+}

Source/MQTTnet.AspnetCore/ConnectionRouteBuilderExtensions.cs

@@ -1,29 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Http.Connections;
-
-#if NETCOREAPP3_1
-using System;
-#endif
-
-namespace MQTTnet.AspNetCore
-{
-    public static class ConnectionRouteBuilderExtensions
-    {
-#if NETCOREAPP3_1
-        [Obsolete("This class is obsolete and will be removed in a future version. The recommended alternative is to use MapMqtt inside Microsoft.AspNetCore.Builder.UseEndpoints(...).")]
-#endif
-#if NETCOREAPP3_1 || NETCOREAPP2_1 || NETSTANDARD
-        public static void MapMqtt(this ConnectionsRouteBuilder connection, PathString path)
-        {
-            connection.MapConnectionHandler<MqttConnectionHandler>(path, options =>
-            {
-                options.WebSockets.SubProtocolSelector = MqttSubProtocolSelector.SelectSubProtocol;
-            });
-        }
-#endif
-    }
-}

Source/MQTTnet.AspnetCore/DuplexPipe.cs

@@ -0,0 +1,44 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.IO.Pipelines;
+
+namespace MQTTnet.AspNetCore;
+
+public class DuplexPipe : IDuplexPipe
+{
+    public DuplexPipe(PipeReader reader, PipeWriter writer)
+    {
+        Input = reader;
+        Output = writer;
+    }
+
+    public PipeReader Input { get; }
+
+    public PipeWriter Output { get; }
+
+    public static DuplexPipePair CreateConnectionPair(PipeOptions inputOptions, PipeOptions outputOptions)
+    {
+        var input = new Pipe(inputOptions);
+        var output = new Pipe(outputOptions);
+
+        var transportToApplication = new DuplexPipe(output.Reader, input.Writer);
+        var applicationToTransport = new DuplexPipe(input.Reader, output.Writer);
+
+        return new DuplexPipePair(applicationToTransport, transportToApplication);
+    }
+
+    // This class exists to work around issues with value tuple on .NET Framework
+    public readonly struct DuplexPipePair
+    {
+        public IDuplexPipe Transport { get; }
+        public IDuplexPipe Application { get; }
+
+        public DuplexPipePair(IDuplexPipe transport, IDuplexPipe application)
+        {
+            Transport = transport;
+            Application = application;
+        }
+    }
+}

Source/MQTTnet.AspnetCore/EndpointRouterExtensions.cs

@@ -2,24 +2,20 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-
-#if NETCOREAPP3_1 || NET5_0_OR_GREATER
-
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Routing;
 
-namespace MQTTnet.AspNetCore
-{
-    public static class EndpointRouterExtensions
-    {
-        public static void MapMqtt(this IEndpointRouteBuilder endpoints, string pattern) 
-        {
-            endpoints.MapConnectionHandler<MqttConnectionHandler>(pattern, options =>
-            {
-                options.WebSockets.SubProtocolSelector = MqttSubProtocolSelector.SelectSubProtocol;
-            });
-        }
-    }
-}
+namespace MQTTnet.AspNetCore;
 
-#endif
+public static class EndpointRouterExtensions
+{
+    public static void MapMqtt(this IEndpointRouteBuilder endpoints, string pattern)
+    {
+        ArgumentNullException.ThrowIfNull(endpoints);
+
+        endpoints.MapConnectionHandler<MqttConnectionHandler>(pattern, options =>
+        {
+            options.WebSockets.SubProtocolSelector = MqttSubProtocolSelector.SelectSubProtocol;
+        });
+    }
+}

Source/MQTTnet.AspnetCore/MQTTnet.AspNetCore.csproj

@@ -1,65 +1,26 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFrameworks>netstandard2.0;netcoreapp2.1;netcoreapp3.1;net5.0;net6.0</TargetFrameworks>
-
         <AssemblyName>MQTTnet.AspNetCore</AssemblyName>
         <RootNamespace>MQTTnet.AspNetCore</RootNamespace>
-        <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
-        <Company>The contributors of MQTTnet</Company>
-        <Product>MQTTnet</Product>
+        <IsAotCompatible>true</IsAotCompatible>
+
+        <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
         <Description>MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker) and supports v3.1.0, v3.1.1 and v5.0.0 of the MQTT protocol.</Description>
-        <Authors>The contributors of MQTTnet</Authors>
         <PackageId>MQTTnet.AspNetCore</PackageId>
-        <SignAssembly>false</SignAssembly>
-        <DelaySign>false</DelaySign>
-        <PublishRepositoryUrl>true</PublishRepositoryUrl>
-        <IncludeSymbols>true</IncludeSymbols>
-        <SymbolPackageFormat>snupkg</SymbolPackageFormat>
-        <Copyright>Copyright (c) .NET Foundation and Contributors</Copyright>
-        <PackageProjectUrl>https://github.com/dotnet/MQTTnet</PackageProjectUrl>
-        <RepositoryUrl>https://github.com/dotnet/MQTTnet.git</RepositoryUrl>
-        <RepositoryType>git</RepositoryType>
         <PackageTags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin Blazor</PackageTags>
-        <NeutralLanguage>en-US</NeutralLanguage>
-        <EnableNETAnalyzers>false</EnableNETAnalyzers>
-        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
-        <PackageIcon>nuget.png</PackageIcon>
-        <EmbedUntrackedSources>true</EmbedUntrackedSources>
-        <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
-        <PackageLicenseExpression>MIT</PackageLicenseExpression>
         <PackageReleaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</PackageReleaseNotes>
-        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
-        <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+
         <GenerateDocumentationFile>true</GenerateDocumentationFile>
-        <NoWarn>1591</NoWarn>
     </PropertyGroup>
 
     <ItemGroup>
-        <None Include="..\..\Images\nuget.png">
-            <Pack>True</Pack>
-            <PackagePath>\</PackagePath>
-        </None>
-    </ItemGroup>
-    
-    <ItemGroup>
-        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
-    </ItemGroup>
-
-    <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
-        <DefineConstants>RELEASE;NETSTANDARD2_0</DefineConstants>
-    </PropertyGroup>
-
-    <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1' or '$(TargetFramework)' == 'net5.0' or '$(TargetFramework)' == 'net6.0' ">
-        <FrameworkReference Include="Microsoft.AspNetCore.App" />
-    </ItemGroup>
-
-    <ItemGroup Condition="'$(TargetFramework)' != 'netcoreapp3.1' and '$(TargetFramework)' != 'net5.0' and '$(TargetFramework)' != 'net6.0' ">
-        <PackageReference Include="Microsoft.AspNetCore.Http.Connections" Version="1.1.0" />
+        <FrameworkReference Include="Microsoft.AspNetCore.App"/>
     </ItemGroup>
 
     <ItemGroup>
-        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
+        <ProjectReference Include="..\MQTTnet.Server\MQTTnet.Server.csproj"/>
+        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj"/>
     </ItemGroup>
 
 </Project>

Source/MQTTnet.AspnetCore/MqttClientConnectionContextFactory.cs

@@ -0,0 +1,32 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics.Logger;
+using MQTTnet.Formatter;
+
+namespace MQTTnet.AspNetCore;
+
+public sealed class MqttClientConnectionContextFactory : IMqttClientAdapterFactory
+{
+    public IMqttChannelAdapter CreateClientAdapter(MqttClientOptions options, MqttPacketInspector packetInspector, IMqttNetLogger logger)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+
+        switch (options.ChannelOptions)
+        {
+            case MqttClientTcpOptions tcpOptions:
+            {
+                var tcpConnection = new SocketConnection(tcpOptions.RemoteEndpoint);
+
+                var formatter = new MqttPacketFormatterAdapter(options.ProtocolVersion, new MqttBufferWriter(4096, 65535));
+                return new MqttConnectionContext(formatter, tcpConnection);
+            }
+            default:
+            {
+                throw new NotSupportedException();
+            }
+        }
+    }
+}

Source/MQTTnet.AspnetCore/MqttConnectionContext.cs

@@ -2,192 +2,256 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Buffers;
+using System.IO.Pipelines;
+using System.Net;
+using System.Security.Cryptography.X509Certificates;
 using Microsoft.AspNetCore.Connections;
 using Microsoft.AspNetCore.Http.Connections.Features;
+using Microsoft.AspNetCore.Http.Features;
 using MQTTnet.Adapter;
-using MQTTnet.AspNetCore.Client.Tcp;
 using MQTTnet.Exceptions;
 using MQTTnet.Formatter;
-using MQTTnet.Packets;
-using System;
-using System.IO.Pipelines;
-using System.Security.Cryptography.X509Certificates;
-using System.Threading;
-using System.Threading.Tasks;
 using MQTTnet.Internal;
+using MQTTnet.Packets;
 
-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore;
+
+public sealed class MqttConnectionContext : IMqttChannelAdapter
 {
-    public sealed class MqttConnectionContext : IMqttChannelAdapter
+    readonly ConnectionContext _connection;
+    readonly AsyncLock _writerLock = new();
+
+    PipeReader _input;
+    PipeWriter _output;
+
+    public MqttConnectionContext(MqttPacketFormatterAdapter packetFormatterAdapter, ConnectionContext connection)
     {
-        readonly AsyncLock _writerLock = new AsyncLock();
-        
-        PipeReader _input;
-        PipeWriter _output;
-        
-        public MqttConnectionContext(MqttPacketFormatterAdapter packetFormatterAdapter, ConnectionContext connection)
-        {
-            PacketFormatterAdapter = packetFormatterAdapter ?? throw new ArgumentNullException(nameof(packetFormatterAdapter));
-            Connection = connection ?? throw new ArgumentNullException(nameof(connection));
+        PacketFormatterAdapter = packetFormatterAdapter ?? throw new ArgumentNullException(nameof(packetFormatterAdapter));
+        _connection = connection ?? throw new ArgumentNullException(nameof(connection));
 
-            if (Connection.Transport != null)
+        if (!(_connection is SocketConnection tcp) || tcp.IsConnected)
+        {
+            _input = connection.Transport.Input;
+            _output = connection.Transport.Output;
+        }
+    }
+
+    public long BytesReceived { get; private set; }
+
+    public long BytesSent { get; private set; }
+
+    public X509Certificate2 ClientCertificate
+    {
+        get
+        {
+            // mqtt over tcp
+            var tlsFeature = _connection.Features.Get<ITlsConnectionFeature>();
+            if (tlsFeature != null)
             {
-                _input = Connection.Transport.Input;
-                _output = Connection.Transport.Output;
+                return tlsFeature.ClientCertificate;
             }
+
+            // mqtt over websocket
+            var httpFeature = _connection.Features.Get<IHttpContextFeature>();
+            return httpFeature?.HttpContext?.Connection.ClientCertificate;
+        }
+    }
+
+    public bool IsSecureConnection
+    {
+        get
+        {
+            // mqtt over tcp
+            var tlsFeature = _connection.Features.Get<ITlsConnectionFeature>();
+            if (tlsFeature != null)
+            {
+                return true;
+            }
+
+            // mqtt over websocket
+            var httpFeature = _connection.Features.Get<IHttpContextFeature>();
+            if (httpFeature?.HttpContext != null)
+            {
+                return httpFeature.HttpContext.Request.IsHttps;
+            }
+
+            return false;
+        }
+    }
+
+    public EndPoint LocalEndPoint
+    {
+        get
+        {
+            // mqtt over tcp
+            if (_connection.LocalEndPoint != null)
+            {
+                return _connection.LocalEndPoint;
+            }
+
+            // mqtt over websocket
+            var httpFeature = _connection.Features.Get<IHttpConnectionFeature>();
+            if (httpFeature?.LocalIpAddress != null)
+            {
+                return new IPEndPoint(httpFeature.LocalIpAddress, httpFeature.LocalPort);
+            }
+
+            return null;
+        }
+    }
+
+    public MqttPacketFormatterAdapter PacketFormatterAdapter { get; }
+
+    public EndPoint RemoteEndPoint
+    {
+        get
+        {
+            // mqtt over tcp
+            if (_connection.RemoteEndPoint != null)
+            {
+                return _connection.RemoteEndPoint;
+            }
+
+            // mqtt over websocket
+            var httpFeature = _connection.Features.Get<IHttpConnectionFeature>();
+            if (httpFeature?.RemoteIpAddress != null)
+            {
+                return new IPEndPoint(httpFeature.RemoteIpAddress, httpFeature.RemotePort);
+            }
+
+            return null;
+        }
+    }
+
+    public async Task ConnectAsync(CancellationToken cancellationToken)
+    {
+        if (_connection is SocketConnection tcp && !tcp.IsConnected)
+        {
+            await tcp.StartAsync().ConfigureAwait(false);
         }
 
-        public string Endpoint
+        _input = _connection.Transport.Input;
+        _output = _connection.Transport.Output;
+    }
+
+    public Task DisconnectAsync(CancellationToken cancellationToken)
+    {
+        _input?.Complete();
+        _output?.Complete();
+
+        return Task.CompletedTask;
+    }
+
+    public void Dispose()
+    {
+        _writerLock.Dispose();
+    }
+
+    public async Task<MqttPacket> ReceivePacketAsync(CancellationToken cancellationToken)
+    {
+        try
         {
-            get
+            while (!cancellationToken.IsCancellationRequested)
             {
-#if NETCOREAPP3_1
-                if (Connection?.RemoteEndPoint != null)
+                ReadResult readResult;
+                var readTask = _input.ReadAsync(cancellationToken);
+                if (readTask.IsCompleted)
                 {
-                    return Connection.RemoteEndPoint.ToString();
+                    readResult = readTask.Result;
                 }
-#endif
-                var connection = Http?.HttpContext?.Connection;
-                if (connection == null)
+                else
                 {
-                    return Connection.ConnectionId;
+                    readResult = await readTask.ConfigureAwait(false);
                 }
 
-                return $"{connection.RemoteIpAddress}:{connection.RemotePort}";
+                var buffer = readResult.Buffer;
+
+                var consumed = buffer.Start;
+                var observed = buffer.Start;
+
+                try
+                {
+                    if (!buffer.IsEmpty)
+                    {
+                        if (PacketFormatterAdapter.TryDecode(buffer, out var packet, out consumed, out observed, out var received))
+                        {
+                            BytesReceived += received;
+                            return packet;
+                        }
+                    }
+                    else if (readResult.IsCompleted)
+                    {
+                        throw new MqttCommunicationException("Connection Aborted");
+                    }
+                }
+                finally
+                {
+                    // The buffer was sliced up to where it was consumed, so we can just advance to the start.
+                    // We mark examined as buffer.End so that if we didn't receive a full frame, we'll wait for more data
+                    // before yielding the read again.
+                    _input.AdvanceTo(consumed, observed);
+                }
             }
         }
-
-        public bool IsSecureConnection => Http?.HttpContext?.Request?.IsHttps ?? false;
-
-        public X509Certificate2 ClientCertificate => Http?.HttpContext?.Connection?.ClientCertificate;
-
-        public ConnectionContext Connection { get; }
-        
-        public MqttPacketFormatterAdapter PacketFormatterAdapter { get; }
-
-        public long BytesSent { get; set; }
-
-        public long BytesReceived { get; set; }
-
-        public bool IsReadingPacket { get; private set; }
-
-        IHttpContextFeature Http => Connection.Features.Get<IHttpContextFeature>();
-
-        public async Task ConnectAsync(CancellationToken cancellationToken)
+        catch (Exception exception)
         {
-            if (Connection is TcpConnection tcp && !tcp.IsConnected)
-            {
-                await tcp.StartAsync().ConfigureAwait(false);
-            }
+            // completing the channel makes sure that there is no more data read after a protocol error
+            _input?.Complete(exception);
+            _output?.Complete(exception);
 
-            _input = Connection.Transport.Input;
-            _output = Connection.Transport.Output;
+            throw;
         }
 
-        public Task DisconnectAsync(CancellationToken cancellationToken)
+        cancellationToken.ThrowIfCancellationRequested();
+        return null;
+    }
+
+    public void ResetStatistics()
+    {
+        BytesReceived = 0;
+        BytesSent = 0;
+    }
+
+    public async Task SendPacketAsync(MqttPacket packet, CancellationToken cancellationToken)
+    {
+        using (await _writerLock.EnterAsync(cancellationToken).ConfigureAwait(false))
         {
-            _input?.Complete();
-            _output?.Complete();
-
-            return Task.CompletedTask;
-        }
-
-        public async Task<MqttPacket> ReceivePacketAsync(CancellationToken cancellationToken)
-        {
-            var input = Connection.Transport.Input;
-
             try
             {
-                while (!cancellationToken.IsCancellationRequested)
+                var buffer = PacketFormatterAdapter.Encode(packet);
+
+                if (buffer.Payload.Length == 0)
                 {
-                    ReadResult readResult;
-                    var readTask = input.ReadAsync(cancellationToken);
-                    if (readTask.IsCompleted)
-                    {
-                        readResult = readTask.Result;
-                    }
-                    else
-                    {
-                        readResult = await readTask.ConfigureAwait(false);
-                    }
-
-                    var buffer = readResult.Buffer;
-
-                    var consumed = buffer.Start;
-                    var observed = buffer.Start;
-
-                    try
-                    {
-                        if (!buffer.IsEmpty)
-                        {
-                            if (PacketFormatterAdapter.TryDecode(buffer, out var packet, out consumed, out observed, out var received))
-                            {
-                                BytesReceived += received;
-                                return packet;
-                            }
-                            else
-                            {
-                                // we did receive something but the message is not yet complete
-                                IsReadingPacket = true;
-                            }
-                        }
-                        else if (readResult.IsCompleted)
-                        {
-                            throw new MqttCommunicationException("Connection Aborted");
-                        }
-                    }
-                    finally
-                    {
-                        // The buffer was sliced up to where it was consumed, so we can just advance to the start.
-                        // We mark examined as buffer.End so that if we didn't receive a full frame, we'll wait for more data
-                        // before yielding the read again.
-                        input.AdvanceTo(consumed, observed);
-                    }
+                    // zero copy
+                    // https://github.com/dotnet/runtime/blob/e31ddfdc4f574b26231233dc10c9a9c402f40590/src/libraries/System.IO.Pipelines/src/System/IO/Pipelines/StreamPipeWriter.cs#L279
+                    await _output.WriteAsync(buffer.Packet, cancellationToken).ConfigureAwait(false);
                 }
-            }
-            catch (Exception e)
-            {
-                // completing the channel makes sure that there is no more data read after a protocol error
-                _input?.Complete(e);
-                _output?.Complete(e);
-                throw;
+                else
+                {
+                    WritePacketBuffer(_output, buffer);
+                    await _output.FlushAsync(cancellationToken).ConfigureAwait(false);
+                }
+
+                BytesSent += buffer.Length;
             }
             finally
             {
-                IsReadingPacket = false;
-            }
-
-            cancellationToken.ThrowIfCancellationRequested();
-            return null;
-        }
-
-        public void ResetStatistics()
-        {
-            BytesReceived = 0;
-            BytesSent = 0;
-        }
-
-        public async Task SendPacketAsync(MqttPacket packet, CancellationToken cancellationToken)
-        {
-            var formatter = PacketFormatterAdapter;
-            
-            using (await _writerLock.WaitAsync(cancellationToken).ConfigureAwait(false))
-            {
-                var buffer = formatter.Encode(packet);
-                var msg = buffer.Join().AsMemory();
-                var output = _output;
-                var result = await output.WriteAsync(msg, cancellationToken).ConfigureAwait(false);
-                if (result.IsCompleted)
-                {
-                    BytesSent += msg.Length;
-                }
-
                 PacketFormatterAdapter.Cleanup();
             }
         }
-
-        public void Dispose()
-        {
-        }
     }
-}
+
+    static void WritePacketBuffer(PipeWriter output, MqttPacketBuffer buffer)
+    {
+        // copy MqttPacketBuffer's Packet and Payload to the same buffer block of PipeWriter
+        // MqttPacket will be transmitted within the bounds of a WebSocket frame after PipeWriter.FlushAsync
+
+        var span = output.GetSpan(buffer.Length);
+
+        buffer.Packet.AsSpan().CopyTo(span);
+        var offset = buffer.Packet.Count;
+        buffer.Payload.CopyTo(span.Slice(offset));
+        output.Advance(buffer.Length);
+    }
+}

Source/MQTTnet.AspnetCore/MqttConnectionHandler.cs

@@ -5,54 +5,49 @@
 using Microsoft.AspNetCore.Connections;
 using Microsoft.AspNetCore.Connections.Features;
 using MQTTnet.Adapter;
-using MQTTnet.Server;
-using System;
-using System.Threading.Tasks;
-using MQTTnet.Diagnostics;
+using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Formatter;
+using MQTTnet.Server;
 
-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore;
+
+public sealed class MqttConnectionHandler : ConnectionHandler, IMqttServerAdapter
 {
-    public sealed class MqttConnectionHandler : ConnectionHandler, IMqttServerAdapter
+    MqttServerOptions _serverOptions;
+
+    public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
+
+    public void Dispose()
     {
-        MqttServerOptions _serverOptions;
-        
-        public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
+    }
 
-        public override async Task OnConnectedAsync(ConnectionContext connection)
+    public override async Task OnConnectedAsync(ConnectionContext connection)
+    {
+        // required for websocket transport to work
+        var transferFormatFeature = connection.Features.Get<ITransferFormatFeature>();
+        if (transferFormatFeature != null)
         {
-            // required for websocket transport to work
-            var transferFormatFeature = connection.Features.Get<ITransferFormatFeature>();
-            if (transferFormatFeature != null)
-            {
-                transferFormatFeature.ActiveFormat = TransferFormat.Binary;
-            }
-            
-            var formatter = new MqttPacketFormatterAdapter(new MqttBufferWriter(_serverOptions.WriterBufferSize, _serverOptions.WriterBufferSizeMax));
-            using (var adapter = new MqttConnectionContext(formatter, connection))
-            {
-                var clientHandler = ClientHandler;
-                if (clientHandler != null)
-                {
-                    await clientHandler(adapter).ConfigureAwait(false);
-                }
-            }
+            transferFormatFeature.ActiveFormat = TransferFormat.Binary;
         }
 
-        public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
-        {
-            _serverOptions = options;
-
-            return Task.CompletedTask;
-        }
-
-        public Task StopAsync()
-        {
-            return Task.CompletedTask;
-        }
-
-        public void Dispose()
+        var formatter = new MqttPacketFormatterAdapter(new MqttBufferWriter(_serverOptions.WriterBufferSize, _serverOptions.WriterBufferSizeMax));
+        using var adapter = new MqttConnectionContext(formatter, connection);
+        var clientHandler = ClientHandler;
+        if (clientHandler != null)
         {
+            await clientHandler(adapter).ConfigureAwait(false);
         }
     }
-}
+
+    public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
+    {
+        _serverOptions = options;
+
+        return Task.CompletedTask;
+    }
+
+    public Task StopAsync()
+    {
+        return Task.CompletedTask;
+    }
+}

Source/MQTTnet.AspnetCore/MqttHostedServer.cs

@@ -2,32 +2,43 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Microsoft.Extensions.Hosting;
-using MQTTnet.Adapter;
-using MQTTnet.Diagnostics;
+using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Server;
 
-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore;
+
+public sealed class MqttHostedServer : MqttServer, IHostedService
 {
-    public sealed class MqttHostedServer : MqttServer, IHostedService
+    readonly IHostApplicationLifetime _hostApplicationLifetime;
+    readonly MqttServerFactory _mqttFactory;
+
+    public MqttHostedServer(
+        IHostApplicationLifetime hostApplicationLifetime,
+        MqttServerFactory mqttFactory,
+        MqttServerOptions options,
+        IEnumerable<IMqttServerAdapter> adapters,
+        IMqttNetLogger logger) : base(options, adapters, logger)
     {
-        public MqttHostedServer(MqttServerOptions options, IEnumerable<IMqttServerAdapter> adapters, IMqttNetLogger logger) 
-            : base(options, adapters, logger)
-        {
-        }
+        _mqttFactory = mqttFactory ?? throw new ArgumentNullException(nameof(mqttFactory));
+        _hostApplicationLifetime = hostApplicationLifetime;
+    }
 
-        public Task StartAsync(CancellationToken cancellationToken)
-        {
-            _ =  StartAsync();
-            return Task.CompletedTask;
-        }
+    public async Task StartAsync(CancellationToken cancellationToken)
+    {
+        // The yield makes sure that the hosted service is considered up and running.
+        await Task.Yield();
 
-        public Task StopAsync(CancellationToken cancellationToken)
-        {
-            return StopAsync();
-        }
+        _hostApplicationLifetime.ApplicationStarted.Register(OnStarted);
+    }
+
+    public Task StopAsync(CancellationToken cancellationToken)
+    {
+        return StopAsync(_mqttFactory.CreateMqttServerStopOptionsBuilder().Build());
+    }
+
+    void OnStarted()
+    {
+        _ = StartAsync();
     }
 }

Source/MQTTnet.AspnetCore/MqttSubProtocolSelector.cs

@@ -2,36 +2,30 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Microsoft.AspNetCore.Http;
 
-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore;
+
+public static class MqttSubProtocolSelector
 {
-    public static class MqttSubProtocolSelector
+    public static string SelectSubProtocol(HttpRequest request)
     {
-        public static string SelectSubProtocol(HttpRequest request)
+        ArgumentNullException.ThrowIfNull(request);
+
+        string subProtocol = null;
+        if (request.Headers.TryGetValue("Sec-WebSocket-Protocol", out var requestedSubProtocolValues))
         {
-            if (request == null) throw new ArgumentNullException(nameof(request));
-
-            string subProtocol = null;
-            if (request.Headers.TryGetValue("Sec-WebSocket-Protocol", out var requestedSubProtocolValues))
-            {
-                subProtocol = SelectSubProtocol(requestedSubProtocolValues);
-            }
-
-            return subProtocol;
+            subProtocol = SelectSubProtocol(requestedSubProtocolValues);
         }
-        
-        public static string SelectSubProtocol(IList<string> requestedSubProtocolValues)
-        {
-            if (requestedSubProtocolValues == null) throw new ArgumentNullException(nameof(requestedSubProtocolValues));
 
-            // Order the protocols to also match "mqtt", "mqttv-3.1", "mqttv-3.11" etc.
-            return requestedSubProtocolValues
-                .OrderByDescending(p => p.Length)
-                .FirstOrDefault(p => p.ToLower().StartsWith("mqtt"));
-        }
+        return subProtocol;
     }
-}
+
+    public static string SelectSubProtocol(IList<string> requestedSubProtocolValues)
+    {
+        ArgumentNullException.ThrowIfNull(requestedSubProtocolValues);
+
+        // Order the protocols to also match "mqtt", "mqttv-3.1", "mqttv-3.11" etc.
+        return requestedSubProtocolValues.OrderByDescending(p => p.Length).FirstOrDefault(p => p.ToLowerInvariant().StartsWith("mqtt", StringComparison.InvariantCulture));
+    }
+}

Source/MQTTnet.AspnetCore/MqttWebSocketServerAdapter.cs

@@ -2,66 +2,63 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Net;
+using System.Net.WebSockets;
 using Microsoft.AspNetCore.Http;
 using MQTTnet.Adapter;
+using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Formatter;
 using MQTTnet.Implementations;
 using MQTTnet.Server;
-using System;
-using System.Net.WebSockets;
-using System.Threading.Tasks;
-using MQTTnet.Diagnostics;
 
-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore;
+
+public sealed class MqttWebSocketServerAdapter : IMqttServerAdapter
 {
-    public sealed class MqttWebSocketServerAdapter : IMqttServerAdapter
+    IMqttNetLogger _logger = MqttNetNullLogger.Instance;
+
+    public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
+
+    public void Dispose()
     {
-        IMqttNetLogger _logger = new MqttNetNullLogger();
-        
-        public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
+    }
 
-        public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
+    public async Task RunWebSocketConnectionAsync(WebSocket webSocket, HttpContext httpContext)
+    {
+        ArgumentNullException.ThrowIfNull(webSocket);
+
+        var remoteAddress = httpContext.Connection.RemoteIpAddress;
+        var remoteEndPoint = remoteAddress == null ? null : new IPEndPoint(remoteAddress, httpContext.Connection.RemotePort);
+
+        var clientCertificate = await httpContext.Connection.GetClientCertificateAsync().ConfigureAwait(false);
+        try
         {
-            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
-            return Task.CompletedTask;
-        }
+            var isSecureConnection = clientCertificate != null;
 
-        public Task StopAsync()
-        {
-            return Task.CompletedTask;
-        }
-
-        public async Task RunWebSocketConnectionAsync(WebSocket webSocket, HttpContext httpContext)
-        {
-            if (webSocket == null) throw new ArgumentNullException(nameof(webSocket));
-
-            var endpoint = $"{httpContext.Connection.RemoteIpAddress}:{httpContext.Connection.RemotePort}";
-
-            var clientCertificate = await httpContext.Connection.GetClientCertificateAsync().ConfigureAwait(false);
-            try
+            var clientHandler = ClientHandler;
+            if (clientHandler != null)
             {
-                var isSecureConnection = clientCertificate != null;
+                var formatter = new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535));
+                var channel = new MqttWebSocketChannel(webSocket, remoteEndPoint, isSecureConnection, clientCertificate);
 
-                var clientHandler = ClientHandler;
-                if (clientHandler != null)
-                {
-                    var formatter = new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535));
-                    var channel = new MqttWebSocketChannel(webSocket, endpoint, isSecureConnection, clientCertificate);
-
-                    using (var channelAdapter = new MqttChannelAdapter(channel, formatter, null, _logger))
-                    {
-                        await clientHandler(channelAdapter).ConfigureAwait(false);
-                    }
-                }
-            }
-            finally
-            {
-                clientCertificate?.Dispose();
+                using var channelAdapter = new MqttChannelAdapter(channel, formatter, _logger);
+                await clientHandler(channelAdapter).ConfigureAwait(false);
             }
         }
-
-        public void Dispose()
+        finally
         {
+            clientCertificate?.Dispose();
         }
     }
+
+    public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
+    {
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        return Task.CompletedTask;
+    }
+
+    public Task StopAsync()
+    {
+        return Task.CompletedTask;
+    }
 }

Source/MQTTnet.AspnetCore/ReaderExtensions.cs

@@ -2,112 +2,133 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Buffers;
+using System.Runtime.InteropServices;
 using MQTTnet.Adapter;
 using MQTTnet.Exceptions;
 using MQTTnet.Formatter;
 using MQTTnet.Packets;
 
-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore;
+
+public static class ReaderExtensions
 {
-    public static class ReaderExtensions
+    public static bool TryDecode(
+        this MqttPacketFormatterAdapter formatter,
+        in ReadOnlySequence<byte> input,
+        out MqttPacket packet,
+        out SequencePosition consumed,
+        out SequencePosition observed,
+        out int bytesRead)
     {
-        public static bool TryDecode(this MqttPacketFormatterAdapter formatter, 
-            in ReadOnlySequence<byte> input, 
-            out MqttPacket packet, 
-            out SequencePosition consumed, 
-            out SequencePosition observed,
-            out int bytesRead)
+        ArgumentNullException.ThrowIfNull(formatter);
+
+        packet = null;
+        consumed = input.Start;
+        observed = input.End;
+        bytesRead = 0;
+        var copy = input;
+
+        if (copy.Length < 2)
         {
-            if (formatter == null) throw new ArgumentNullException(nameof(formatter));
-
-            packet = null;
-            consumed = input.Start;
-            observed = input.End;
-            bytesRead = 0;
-            var copy = input;
-
-            if (copy.Length < 2)
-            {
-                return false;
-            }
-
-            var fixedHeader = copy.First.Span[0];
-            if (!TryReadBodyLength(ref copy, out int headerLength, out var bodyLength))
-            {
-                return false;
-            }
-
-            if (copy.Length < bodyLength)
-            {
-                return false;
-            }
-
-            var bodySlice = copy.Slice(0, bodyLength);
-            var buffer = bodySlice.GetMemory().ToArray();
-            
-            var receivedMqttPacket = new ReceivedMqttPacket(fixedHeader, new ArraySegment<byte>(buffer, 0, buffer.Length), buffer.Length + 2);
-
-            if (formatter.ProtocolVersion == MqttProtocolVersion.Unknown)
-            {
-                formatter.DetectProtocolVersion(receivedMqttPacket);
-            }
-
-            packet = formatter.Decode(receivedMqttPacket);
-            consumed = bodySlice.End;
-            observed = bodySlice.End;
-            bytesRead = headerLength + bodyLength;
-            return true;
+            return false;
         }
 
-        static ReadOnlyMemory<byte> GetMemory(this in ReadOnlySequence<byte> input)
+        if (!TryReadBodyLength(ref copy, out var headerLength, out var bodyLength))
         {
-            if (input.IsSingleSegment)
-            {
-                return input.First;
-            }
-
-            // Should be rare
-            return input.ToArray();
+            return false;
         }
 
-        static bool TryReadBodyLength(ref ReadOnlySequence<byte> input, out int headerLength, out int bodyLength)
+        var fixedHeader = copy.First.Span[0];
+        copy = copy.Slice(headerLength);
+        if (copy.Length < bodyLength)
         {
-            // Alorithm taken from https://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt-v3.1.1-errata01-os-complete.html.
-            var multiplier = 1;
-            var value = 0;
-            byte encodedByte;
-            var index = 1;
-            headerLength = 0;
-            bodyLength = 0;
-            
-            var temp = input.Slice(0, Math.Min(5, input.Length)).GetMemory().Span;
+            return false;
+        }
 
-            do
-            {
-                if (index == temp.Length)
-                {
-                    return false;
-                }
+        var bodySlice = copy.Slice(0, bodyLength);
+        var bodySegment = GetArraySegment(ref bodySlice);
 
-                encodedByte = temp[index];
-                index++;
+        var receivedMqttPacket = new ReceivedMqttPacket(fixedHeader, bodySegment, headerLength + bodyLength);
+        if (formatter.ProtocolVersion == MqttProtocolVersion.Unknown)
+        {
+            formatter.DetectProtocolVersion(receivedMqttPacket);
+        }
 
-                value += (byte)(encodedByte & 127) * multiplier;
-                if (multiplier > 128 * 128 * 128)
-                {
-                    throw new MqttProtocolViolationException($"Remaining length is invalid (Data={string.Join(",", temp.Slice(1, index).ToArray())}).");
-                }
+        packet = formatter.Decode(receivedMqttPacket);
+        consumed = bodySlice.End;
+        observed = bodySlice.End;
+        bytesRead = headerLength + bodyLength;
+        return true;
+    }
 
-                multiplier *= 128;
-            } while ((encodedByte & 128) != 0);
+    static ArraySegment<byte> GetArraySegment(ref ReadOnlySequence<byte> input)
+    {
+        if (input.IsSingleSegment && MemoryMarshal.TryGetArray(input.First, out var segment))
+        {
+            return segment;
+        }
 
-            input = input.Slice(index);
+        // Should be rare
+        var array = input.ToArray();
+        return new ArraySegment<byte>(array);
+    }
 
-            headerLength = index;
-            bodyLength = value;
-            return true;
+
+    static void ThrowProtocolViolationException(ReadOnlySpan<byte> valueSpan, int index)
+    {
+        throw new MqttProtocolViolationException($"Remaining length is invalid (Data={string.Join(",", valueSpan.Slice(1, index).ToArray())}).");
+    }
+
+    static bool TryReadBodyLength(ref ReadOnlySequence<byte> input, out int headerLength, out int bodyLength)
+    {
+        var valueSequence = input.Slice(0, Math.Min(5, input.Length));
+        if (valueSequence.IsSingleSegment)
+        {
+            var valueSpan = valueSequence.FirstSpan;
+
+            return TryReadBodyLength(valueSpan, out headerLength, out bodyLength);
+        }
+        else
+        {
+            Span<byte> valueSpan = stackalloc byte[8];
+            valueSequence.CopyTo(valueSpan);
+            valueSpan = valueSpan.Slice(0, (int)valueSequence.Length);
+            return TryReadBodyLength(valueSpan, out headerLength, out bodyLength);
         }
     }
-}
+
+    static bool TryReadBodyLength(ReadOnlySpan<byte> span, out int headerLength, out int bodyLength)
+    {
+        // Alorithm taken from https://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt-v3.1.1-errata01-os-complete.html.
+        var multiplier = 1;
+        var value = 0;
+        byte encodedByte;
+        var index = 1;
+        headerLength = 0;
+        bodyLength = 0;
+
+        do
+        {
+            if (index == span.Length)
+            {
+                return false;
+            }
+
+            encodedByte = span[index];
+            index++;
+
+            value += (byte)(encodedByte & 127) * multiplier;
+            if (multiplier > 128 * 128 * 128)
+            {
+                ThrowProtocolViolationException(span, index);
+            }
+
+            multiplier *= 128;
+        } while ((encodedByte & 128) != 0);
+
+        headerLength = index;
+        bodyLength = value;
+        return true;
+    }
+}

Source/MQTTnet.AspnetCore/ServiceCollectionExtensions.cs

@@ -2,104 +2,107 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Hosting;
-using MQTTnet.Adapter;
-using MQTTnet.Diagnostics;
-using MQTTnet.Implementations;
+using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Server;
+using MQTTnet.Server.Internal.Adapter;
 
-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore;
+
+public static class ServiceCollectionExtensions
 {
-    public static class ServiceCollectionExtensions
+    public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, MqttServerOptions options)
     {
-        public static IServiceCollection AddMqttServer(this IServiceCollection serviceCollection, Action<MqttServerOptionsBuilder> configure = null)
-        {
-            if (serviceCollection is null)
-            {
-                throw new ArgumentNullException(nameof(serviceCollection));
-            }
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentNullException.ThrowIfNull(options);
 
-            serviceCollection.AddMqttConnectionHandler();
-            serviceCollection.AddHostedMqttServer(configure);
-            
-            return serviceCollection;
-        }
+        services.AddSingleton(options);
+        services.AddHostedMqttServer();
 
-        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, MqttServerOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
+        return services;
+    }
 
-            services.AddSingleton(options);
+    public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, Action<MqttServerOptionsBuilder> configure)
+    {
+        ArgumentNullException.ThrowIfNull(services);
 
-            services.AddHostedMqttServer();
+        var serverOptionsBuilder = new MqttServerOptionsBuilder();
 
-            return services;
-        }
+        configure?.Invoke(serverOptionsBuilder);
 
-        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, Action<MqttServerOptionsBuilder> configure = null)
-        {
-            services.AddSingleton(s =>
-            {
-                var serverOptionsBuilder = new MqttServerOptionsBuilder();
-                configure?.Invoke(serverOptionsBuilder);
-                return serverOptionsBuilder.Build();
-            });
+        var options = serverOptionsBuilder.Build();
 
-            services.AddHostedMqttServer();
+        return AddHostedMqttServer(services, options);
+    }
 
-            return services;
-        }
+    public static void AddHostedMqttServer(this IServiceCollection services)
+    {
+        // The user may have these services already registered.
+        services.TryAddSingleton<IMqttNetLogger>(MqttNetNullLogger.Instance);
+        services.TryAddSingleton(new MqttServerFactory());
 
-        public static IServiceCollection AddHostedMqttServerWithServices(this IServiceCollection services, Action<AspNetMqttServerOptionsBuilder> configure)
-        {
-            services.AddSingleton(s =>
+        services.AddSingleton<MqttHostedServer>();
+        services.AddSingleton<IHostedService>(s => s.GetService<MqttHostedServer>());
+        services.AddSingleton<MqttServer>(s => s.GetService<MqttHostedServer>());
+    }
+
+    public static IServiceCollection AddHostedMqttServerWithServices(this IServiceCollection services, Action<AspNetMqttServerOptionsBuilder> configure)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+
+        services.AddSingleton(
+            s =>
             {
                 var builder = new AspNetMqttServerOptionsBuilder(s);
                 configure(builder);
                 return builder.Build();
             });
 
-            services.AddHostedMqttServer();
+        services.AddHostedMqttServer();
 
-            return services;
-        }
-
-        static IServiceCollection AddHostedMqttServer(this IServiceCollection services)
-        {
-            var logger = new MqttNetEventLogger();
-
-            services.AddSingleton<IMqttNetLogger>(logger);
-            services.AddSingleton<MqttHostedServer>();
-            services.AddSingleton<IHostedService>(s => s.GetService<MqttHostedServer>());
-            services.AddSingleton<MqttServer>(s => s.GetService<MqttHostedServer>());
-
-            return services;
-        }
-
-        public static IServiceCollection AddMqttWebSocketServerAdapter(this IServiceCollection services)
-        {
-            services.AddSingleton<MqttWebSocketServerAdapter>();
-            services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttWebSocketServerAdapter>());
-
-            return services;
-        }
-
-        public static IServiceCollection AddMqttTcpServerAdapter(this IServiceCollection services)
-        {
-            services.AddSingleton<MqttTcpServerAdapter>();
-            services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttTcpServerAdapter>());
-
-            return services;
-        }
-
-        public static IServiceCollection AddMqttConnectionHandler(this IServiceCollection services)
-        {
-            services.AddSingleton<MqttConnectionHandler>();
-            services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttConnectionHandler>());
-
-            return services;
-        }
+        return services;
     }
-}
+
+    public static IServiceCollection AddMqttConnectionHandler(this IServiceCollection services)
+    {
+        services.AddSingleton<MqttConnectionHandler>();
+        services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttConnectionHandler>());
+
+        return services;
+    }
+
+    public static void AddMqttLogger(this IServiceCollection services, IMqttNetLogger logger)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+
+        services.AddSingleton(logger);
+    }
+
+    public static IServiceCollection AddMqttServer(this IServiceCollection serviceCollection, Action<MqttServerOptionsBuilder> configure = null)
+    {
+        ArgumentNullException.ThrowIfNull(serviceCollection);
+
+        serviceCollection.AddMqttConnectionHandler();
+        serviceCollection.AddHostedMqttServer(configure);
+
+        return serviceCollection;
+    }
+
+    public static IServiceCollection AddMqttTcpServerAdapter(this IServiceCollection services)
+    {
+        services.AddSingleton<MqttTcpServerAdapter>();
+        services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttTcpServerAdapter>());
+
+        return services;
+    }
+
+    public static IServiceCollection AddMqttWebSocketServerAdapter(this IServiceCollection services)
+    {
+        services.AddSingleton<MqttWebSocketServerAdapter>();
+        services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttWebSocketServerAdapter>());
+
+        return services;
+    }
+}

Source/MQTTnet.AspnetCore/SocketAwaitable.cs

@@ -0,0 +1,68 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics;
+using System.IO.Pipelines;
+using System.Net.Sockets;
+using System.Runtime.CompilerServices;
+
+namespace MQTTnet.AspNetCore;
+
+public class SocketAwaitable(PipeScheduler ioScheduler) : ICriticalNotifyCompletion
+{
+    static readonly Action CallbackCompleted = () =>
+    {
+    };
+
+    int _bytesTransferred;
+
+    Action _callback;
+    SocketError _error;
+
+    public bool IsCompleted => ReferenceEquals(_callback, CallbackCompleted);
+
+    public void Complete(int bytesTransferred, SocketError socketError)
+    {
+        _error = socketError;
+        _bytesTransferred = bytesTransferred;
+        var continuation = Interlocked.Exchange(ref _callback, CallbackCompleted);
+
+        if (continuation != null)
+        {
+            ioScheduler.Schedule(state => ((Action)state)(), continuation);
+        }
+    }
+
+    public SocketAwaitable GetAwaiter()
+    {
+        return this;
+    }
+
+    public int GetResult()
+    {
+        Debug.Assert(ReferenceEquals(_callback, CallbackCompleted));
+
+        _callback = null;
+
+        if (_error != SocketError.Success)
+        {
+            throw new SocketException((int)_error);
+        }
+
+        return _bytesTransferred;
+    }
+
+    public void OnCompleted(Action continuation)
+    {
+        if (ReferenceEquals(_callback, CallbackCompleted) || ReferenceEquals(Interlocked.CompareExchange(ref _callback, continuation, null), CallbackCompleted))
+        {
+            Task.Run(continuation);
+        }
+    }
+
+    public void UnsafeOnCompleted(Action continuation)
+    {
+        OnCompleted(continuation);
+    }
+}

Source/MQTTnet.AspnetCore/SocketConnection.cs

@@ -0,0 +1,263 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.IO.Pipelines;
+using System.Net;
+using System.Net.Sockets;
+using Microsoft.AspNetCore.Connections;
+using Microsoft.AspNetCore.Http.Features;
+using MQTTnet.Exceptions;
+
+namespace MQTTnet.AspNetCore;
+
+public sealed class SocketConnection : ConnectionContext
+{
+    readonly EndPoint _endPoint;
+
+    volatile bool _aborted;
+    IDuplexPipe _application;
+    SocketReceiver _receiver;
+    SocketSender _sender;
+    Socket _socket;
+
+    public SocketConnection(EndPoint endPoint)
+    {
+        _endPoint = endPoint;
+    }
+
+    public SocketConnection(Socket socket)
+    {
+        _socket = socket;
+        _endPoint = socket.RemoteEndPoint;
+
+        _sender = new SocketSender(_socket, PipeScheduler.ThreadPool);
+        _receiver = new SocketReceiver(_socket, PipeScheduler.ThreadPool);
+    }
+
+    public override string ConnectionId { get; set; }
+
+    public override IFeatureCollection Features { get; }
+
+    public bool IsConnected { get; private set; }
+
+    public override IDictionary<object, object> Items { get; set; }
+
+    public override IDuplexPipe Transport { get; set; }
+
+    public override ValueTask DisposeAsync()
+    {
+        IsConnected = false;
+
+        Transport?.Output.Complete();
+        Transport?.Input.Complete();
+
+        _socket?.Dispose();
+
+        return base.DisposeAsync();
+    }
+
+    public async Task StartAsync()
+    {
+        if (_socket == null)
+        {
+            _socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
+            _sender = new SocketSender(_socket, PipeScheduler.ThreadPool);
+            _receiver = new SocketReceiver(_socket, PipeScheduler.ThreadPool);
+            await _socket.ConnectAsync(_endPoint);
+        }
+
+        var pair = DuplexPipe.CreateConnectionPair(PipeOptions.Default, PipeOptions.Default);
+
+        Transport = pair.Transport;
+        _application = pair.Application;
+
+        _ = ExecuteAsync();
+
+        IsConnected = true;
+    }
+
+    static MqttCommunicationException ConnectionAborted()
+    {
+        return new MqttCommunicationException("Connection Aborted");
+    }
+
+    async Task DoReceive()
+    {
+        Exception error = null;
+
+        try
+        {
+            await ProcessReceives();
+        }
+        catch (SocketException ex) when (ex.SocketErrorCode == SocketError.ConnectionReset)
+        {
+            error = new MqttCommunicationException(ex);
+        }
+        catch (SocketException ex) when (ex.SocketErrorCode is SocketError.OperationAborted or SocketError.ConnectionAborted or SocketError.Interrupted or SocketError.InvalidArgument)
+        {
+            if (!_aborted)
+            {
+                // Calling Dispose after ReceiveAsync can cause an "InvalidArgument" error on *nix.
+                error = ConnectionAborted();
+            }
+        }
+        catch (ObjectDisposedException)
+        {
+            if (!_aborted)
+            {
+                error = ConnectionAborted();
+            }
+        }
+        catch (IOException ex)
+        {
+            error = ex;
+        }
+        catch (Exception ex)
+        {
+            error = new IOException(ex.Message, ex);
+        }
+        finally
+        {
+            if (_aborted)
+            {
+                error ??= ConnectionAborted();
+            }
+
+            await _application.Output.CompleteAsync(error);
+        }
+    }
+
+    async Task<Exception> DoSend()
+    {
+        Exception error = null;
+
+        try
+        {
+            await ProcessSends();
+        }
+        catch (SocketException ex) when (ex.SocketErrorCode == SocketError.OperationAborted)
+        {
+        }
+        catch (ObjectDisposedException)
+        {
+        }
+        catch (IOException ex)
+        {
+            error = ex;
+        }
+        catch (Exception ex)
+        {
+            error = new IOException(ex.Message, ex);
+        }
+        finally
+        {
+            _aborted = true;
+            _socket.Shutdown(SocketShutdown.Both);
+        }
+
+        return error;
+    }
+
+    async Task ExecuteAsync()
+    {
+        Exception sendError = null;
+        try
+        {
+            // Spawn send and receive logic
+            var receiveTask = DoReceive();
+            var sendTask = DoSend();
+
+            // If the sending task completes then close the receive
+            // We don't need to do this in the other direction because the kestrel
+            // will trigger the output closing once the input is complete.
+            if (await Task.WhenAny(receiveTask, sendTask).ConfigureAwait(false) == sendTask)
+            {
+                // Tell the reader it's being aborted
+                _socket.Dispose();
+            }
+
+            // Now wait for both to complete
+            await receiveTask;
+            sendError = await sendTask;
+
+            // Dispose the socket(should noop if already called)
+            _socket.Dispose();
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Unexpected exception in {nameof(SocketConnection)}.{nameof(StartAsync)}: " + ex);
+        }
+        finally
+        {
+            // Complete the output after disposing the socket
+            await _application.Input.CompleteAsync(sendError).ConfigureAwait(false);
+        }
+    }
+
+    async Task ProcessReceives()
+    {
+        while (true)
+        {
+            // Ensure we have some reasonable amount of buffer space
+            var buffer = _application.Output.GetMemory();
+
+            var bytesReceived = await _receiver.ReceiveAsync(buffer);
+
+            if (bytesReceived == 0)
+            {
+                // FIN
+                break;
+            }
+
+            _application.Output.Advance(bytesReceived);
+
+            var flushTask = _application.Output.FlushAsync();
+
+            FlushResult result;
+            if (!flushTask.IsCompleted)
+            {
+                result = await flushTask;
+            }
+            else
+            {
+                result = flushTask.GetAwaiter().GetResult();
+            }
+
+            if (result.IsCompleted)
+            {
+                // Pipe consumer is shut down, do we stop writing
+                break;
+            }
+        }
+    }
+
+    async Task ProcessSends()
+    {
+        while (true)
+        {
+            // Wait for data to write from the pipe producer
+            var result = await _application.Input.ReadAsync();
+            var buffer = result.Buffer;
+
+            if (result.IsCanceled)
+            {
+                break;
+            }
+
+            var end = buffer.End;
+            var isCompleted = result.IsCompleted;
+            if (!buffer.IsEmpty)
+            {
+                await _sender.SendAsync(buffer);
+            }
+
+            _application.Input.AdvanceTo(end);
+
+            if (isCompleted)
+            {
+                break;
+            }
+        }
+    }
+}

Source/MQTTnet.AspnetCore/SocketReceiver.cs

@@ -0,0 +1,40 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.IO.Pipelines;
+using System.Net.Sockets;
+
+namespace MQTTnet.AspNetCore;
+
+public sealed class SocketReceiver : IDisposable
+{
+    readonly SocketAwaitable _awaitable;
+    readonly SocketAsyncEventArgs _eventArgs = new();
+    readonly Socket _socket;
+
+    public SocketReceiver(Socket socket, PipeScheduler scheduler)
+    {
+        _socket = socket;
+        _awaitable = new SocketAwaitable(scheduler);
+        _eventArgs.UserToken = _awaitable;
+        _eventArgs.Completed += (_, e) => ((SocketAwaitable)e.UserToken).Complete(e.BytesTransferred, e.SocketError);
+    }
+
+    public SocketAwaitable ReceiveAsync(Memory<byte> buffer)
+    {
+        _eventArgs.SetBuffer(buffer);
+
+        if (!_socket.ReceiveAsync(_eventArgs))
+        {
+            _awaitable.Complete(_eventArgs.BytesTransferred, _eventArgs.SocketError);
+        }
+
+        return _awaitable;
+    }
+
+    public void Dispose()
+    {
+        _eventArgs.Dispose();
+    }
+}

Source/MQTTnet.AspnetCore/SocketSender.cs

@@ -0,0 +1,96 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Buffers;
+using System.Diagnostics;
+using System.IO.Pipelines;
+using System.Net.Sockets;
+using System.Runtime.InteropServices;
+
+namespace MQTTnet.AspNetCore;
+
+public sealed class SocketSender : IDisposable
+{
+    readonly SocketAwaitable _awaitable;
+    readonly SocketAsyncEventArgs _eventArgs = new();
+    readonly Socket _socket;
+
+    List<ArraySegment<byte>> _bufferList;
+
+    public SocketSender(Socket socket, PipeScheduler scheduler)
+    {
+        _socket = socket;
+        _awaitable = new SocketAwaitable(scheduler);
+        _eventArgs.UserToken = _awaitable;
+        _eventArgs.Completed += (_, e) => ((SocketAwaitable)e.UserToken).Complete(e.BytesTransferred, e.SocketError);
+    }
+
+    public void Dispose()
+    {
+        _eventArgs.Dispose();
+    }
+
+    public SocketAwaitable SendAsync(in ReadOnlySequence<byte> buffers)
+    {
+        if (buffers.IsSingleSegment)
+        {
+            return SendAsync(buffers.First);
+        }
+
+        if (!_eventArgs.MemoryBuffer.Equals(Memory<byte>.Empty))
+        {
+            _eventArgs.SetBuffer(null, 0, 0);
+        }
+
+        _eventArgs.BufferList = GetBufferList(buffers);
+
+        if (!_socket.SendAsync(_eventArgs))
+        {
+            _awaitable.Complete(_eventArgs.BytesTransferred, _eventArgs.SocketError);
+        }
+
+        return _awaitable;
+    }
+
+    List<ArraySegment<byte>> GetBufferList(in ReadOnlySequence<byte> buffer)
+    {
+        Debug.Assert(!buffer.IsEmpty);
+        Debug.Assert(!buffer.IsSingleSegment);
+
+        if (_bufferList == null)
+        {
+            _bufferList = new List<ArraySegment<byte>>();
+        }
+        else
+        {
+            // Buffers are pooled, so it's OK to root them until the next multi-buffer write.
+            _bufferList.Clear();
+        }
+
+        foreach (var b in buffer)
+        {
+            _bufferList.Add(b.GetArray());
+        }
+
+        return _bufferList;
+    }
+
+    SocketAwaitable SendAsync(ReadOnlyMemory<byte> memory)
+    {
+        // The BufferList getter is much less expensive then the setter.
+        if (_eventArgs.BufferList != null)
+        {
+            _eventArgs.BufferList = null;
+        }
+
+        _eventArgs.SetBuffer(MemoryMarshal.AsMemory(memory));
+
+        if (!_socket.SendAsync(_eventArgs))
+        {
+            _awaitable.Complete(_eventArgs.BytesTransferred, _eventArgs.SocketError);
+        }
+
+        return _awaitable;
+    }
+}

Source/MQTTnet.Benchmarks/AssemblyInfo.cs

@@ -0,0 +1 @@
+[assembly: DoNotParallelize]

Source/MQTTnet.Benchmarks/AsyncLockBenchmark.cs

@@ -0,0 +1,60 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Internal;
+
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[MemoryDiagnoser]
+public class AsyncLockBenchmark : BaseBenchmark
+{
+    [Benchmark]
+    public async Task Synchronize_100_Tasks()
+    {
+        const int tasksCount = 100;
+
+        var tasks = new Task[tasksCount];
+        var asyncLock = new AsyncLock();
+        var globalI = 0;
+
+        for (var i = 0; i < tasksCount; i++)
+        {
+            tasks[i] = Task.Run(
+                async () =>
+                {
+                    using (await asyncLock.EnterAsync().ConfigureAwait(false))
+                    {
+                        var localI = globalI;
+                        await Task.Delay(5).ConfigureAwait(false); // Increase the chance for wrong data.
+                        localI++;
+                        globalI = localI;
+                    }
+                });
+        }
+
+        await Task.WhenAll(tasks).ConfigureAwait(false);
+
+        if (globalI != tasksCount)
+        {
+            throw new InvalidOperationException($"Code is broken ({globalI})!");
+        }
+    }
+
+    [Benchmark]
+    public async Task Wait_100_000_Times()
+    {
+        var asyncLock = new AsyncLock();
+
+        using var cancellationToken = new CancellationTokenSource();
+        for (var i = 0; i < 100000; i++)
+        {
+            using (await asyncLock.EnterAsync(cancellationToken.Token).ConfigureAwait(false))
+            {
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/BaseBenchmark.cs

@@ -1,6 +1,9 @@
-namespace MQTTnet.Benchmarks
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace MQTTnet.Benchmarks;
+
+public abstract class BaseBenchmark
 {
-    public abstract class BaseBenchmark
-    {
-    }
 }

Source/MQTTnet.Benchmarks/ChannelAdapterBenchmark.cs

@@ -4,88 +4,89 @@
 
 using BenchmarkDotNet.Attributes;
 using MQTTnet.Adapter;
-using MQTTnet.Internal;
-using MQTTnet.Packets;
-using System;
-using System.IO;
-using System.Threading;
-using MQTTnet.Diagnostics;
+using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Formatter;
+using MQTTnet.Packets;
 using MQTTnet.Tests.Mockups;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[MemoryDiagnoser]
+public sealed class ChannelAdapterBenchmark : BaseBenchmark, IDisposable
 {
-    [MemoryDiagnoser]
-    public sealed class ChannelAdapterBenchmark
+    MqttChannelAdapter _channelAdapter;
+    int _iterations;
+    MqttPublishPacket _packet;
+    MemoryStream _stream;
+
+    [Benchmark]
+    public void Receive_10000_Messages()
     {
-        MqttChannelAdapter _channelAdapter;
-        int _iterations;
-        MemoryStream _stream;
-        MqttPublishPacket _packet;
+        _stream.Position = 0;
 
-        [GlobalSetup]
-        public void Setup()
+        for (var i = 0; i < 10000; i++)
         {
-            _packet = new MqttPublishPacket
-            {
-                Topic = "A"
-            };
-
-            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));
-            
-            var serializedPacket = Join(serializer.Encode(_packet).Join());
-
-            _iterations = 10000;
-
-            _stream = new MemoryStream(_iterations * serializedPacket.Length);
-
-            for (var i = 0; i < _iterations; i++)
-            {
-                _stream.Write(serializedPacket, 0, serializedPacket.Length);
-            }
-
-            _stream.Position = 0;
-
-            var channel = new MemoryMqttChannel(_stream);
-            
-            _channelAdapter = new MqttChannelAdapter(channel, serializer, null, new MqttNetEventLogger());
+            _channelAdapter.ReceivePacketAsync(CancellationToken.None).GetAwaiter().GetResult();
         }
 
-        [Benchmark]
-        public void Receive_10000_Messages()
-        {
-            _stream.Position = 0;
-
-            for (var i = 0; i < 10000; i++)
-            {
-                _channelAdapter.ReceivePacketAsync(CancellationToken.None).GetAwaiter().GetResult();
-            }
-
-            _stream.Position = 0;
-        }
-
-        [Benchmark]
-        public void Send_10000_Messages()
-        {
-            _stream.Position = 0;
-
-            for (var i = 0; i < 10000; i++)
-            {
-                _channelAdapter.SendPacketAsync(_packet, CancellationToken.None).GetAwaiter().GetResult();
-            }
-
-            _stream.Position = 0;
-        }
-
-        static byte[] Join(params ArraySegment<byte>[] chunks)
-        {
-            var buffer = new MemoryStream();
-            foreach (var chunk in chunks)
-            {
-                buffer.Write(chunk.Array, chunk.Offset, chunk.Count);
-            }
-
-            return buffer.ToArray();
-        }
+        _stream.Position = 0;
     }
-}
+
+    [Benchmark]
+    public void Send_10000_Messages()
+    {
+        _stream.Position = 0;
+
+        for (var i = 0; i < 10000; i++)
+        {
+            _channelAdapter.SendPacketAsync(_packet, CancellationToken.None).GetAwaiter().GetResult();
+        }
+
+        _stream.Position = 0;
+    }
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        _packet = new MqttPublishPacket
+        {
+            Topic = "A"
+        };
+
+        var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));
+
+        var serializedPacket = Join(serializer.Encode(_packet).Join());
+
+        _iterations = 10000;
+
+        _stream = new MemoryStream(_iterations * serializedPacket.Length);
+
+        for (var i = 0; i < _iterations; i++)
+        {
+            _stream.Write(serializedPacket, 0, serializedPacket.Length);
+        }
+
+        _stream.Position = 0;
+
+        var channel = new MemoryMqttChannel(_stream);
+
+        _channelAdapter = new MqttChannelAdapter(channel, serializer, new MqttNetEventLogger());
+    }
+
+    static byte[] Join(params ArraySegment<byte>[] chunks)
+    {
+        var buffer = new MemoryStream();
+        foreach (var chunk in chunks)
+        {
+            buffer.Write(chunk.Array, chunk.Offset, chunk.Count);
+        }
+
+        return buffer.ToArray();
+    }
+
+    public void Dispose()
+    {
+        _channelAdapter?.Dispose();
+        _stream?.Dispose();
+    }
+}

Source/MQTTnet.Benchmarks/Configurations/AllowNonOptimized.cs

@@ -1,22 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using BenchmarkDotNet.Jobs;
-using BenchmarkDotNet.Validators;
-
-namespace MQTTnet.Benchmarks.Configurations
-{
-    /// <summary>
-    /// this options may be used to run benchmarks in debugmode and attach a performance profiler
-    /// https://benchmarkdotnet.org/Configs/Configs.htm
-    /// </summary>
-    public class AllowNonOptimized : BaseConfig
-    {
-        public AllowNonOptimized()
-        {
-            AddValidator(JitOptimizationsValidator.DontFailOnError); // ALLOW NON-OPTIMIZED DLLS
-            AddJob(Job.InProcess);
-        }
-    }
-}

Source/MQTTnet.Benchmarks/Configurations/BaseConfig.cs

@@ -1,19 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using BenchmarkDotNet.Configs;
-using System.Linq;
-
-namespace MQTTnet.Benchmarks.Configurations
-{
-    public class BaseConfig : ManualConfig
-    {
-        public BaseConfig()
-        {
-            AddLogger(DefaultConfig.Instance.GetLoggers().ToArray()); // manual config has no loggers by default
-            AddExporter(DefaultConfig.Instance.GetExporters().ToArray()); // manual config has no exporters by default
-            AddColumnProvider(DefaultConfig.Instance.GetColumnProviders().ToArray()); // manual config has no columns by default
-        }
-    }
-}

Source/MQTTnet.Benchmarks/Configurations/RuntimeCompareConfig.cs

@@ -1,19 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using BenchmarkDotNet.Environments;
-using BenchmarkDotNet.Jobs;
-using BenchmarkDotNet.Toolchains.CsProj;
-
-namespace MQTTnet.Benchmarks.Configurations
-{
-    public class RuntimeCompareConfig : BaseConfig
-    {
-        public RuntimeCompareConfig()
-        {
-            AddJob(Job.Default.WithRuntime(ClrRuntime.Net48));
-            AddJob(Job.Default.WithRuntime(CoreRuntime.Core50).WithToolchain(CsProjCoreToolchain.NetCoreApp50));
-        }
-    }
-}

Source/MQTTnet.Benchmarks/LoggerBenchmark.cs

@@ -2,90 +2,90 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Diagnostics;
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Jobs;
-using MQTTnet.Diagnostics;
+using MQTTnet.Diagnostics.Logger;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[RPlotExporter]
+[MemoryDiagnoser]
+public class LoggerBenchmark : BaseBenchmark
 {
-    [SimpleJob(RuntimeMoniker.Net60)]
-    [RPlotExporter]
-    [MemoryDiagnoser]
-    public class LoggerBenchmark
+    MqttNetNullLogger _nullLogger;
+    MqttNetSourceLogger _sourceNullLogger;
+
+    MqttNetEventLogger _eventLogger;
+    MqttNetSourceLogger _sourceEventLogger;
+
+    MqttNetEventLogger _eventLoggerNoListener;
+    MqttNetSourceLogger _sourceEventLoggerNoListener;
+
+    bool _useHandler;
+
+    [GlobalSetup]
+    public void Setup()
     {
-        MqttNetNullLogger _nullLogger;
-        MqttNetSourceLogger _sourceNullLogger;
-        
-        MqttNetEventLogger _eventLogger;
-        MqttNetSourceLogger _sourceEventLogger;
-        
-        MqttNetEventLogger _eventLoggerNoListener;
-        MqttNetSourceLogger _sourceEventLoggerNoListener;
-        
-        bool _useHandler;
+        _nullLogger = new MqttNetNullLogger();
+        _sourceNullLogger = _nullLogger.WithSource("Source");
 
-        [GlobalSetup]
-        public void Setup()
-        {
-            _nullLogger = new MqttNetNullLogger();
-            _sourceNullLogger = _nullLogger.WithSource("Source");
-            
-            _eventLogger = new MqttNetEventLogger();
-            _eventLogger.LogMessagePublished += OnLogMessagePublished;
-            _sourceEventLogger = _eventLogger.WithSource("Source");
-            
-            _eventLoggerNoListener = new MqttNetEventLogger();
-            _sourceEventLoggerNoListener = _eventLoggerNoListener.WithSource("Source");
-        }
+        _eventLogger = new MqttNetEventLogger();
+        _eventLogger.LogMessagePublished += OnLogMessagePublished;
+        _sourceEventLogger = _eventLogger.WithSource("Source");
 
-        void OnLogMessagePublished(object sender, MqttNetLogMessagePublishedEventArgs eventArgs)
-        {
-            if (_useHandler)
-            {
-                eventArgs.LogMessage.ToString();
-            }
-        }
+        _eventLoggerNoListener = new MqttNetEventLogger();
+        _sourceEventLoggerNoListener = _eventLoggerNoListener.WithSource("Source");
+    }
 
-        [Benchmark]
-        public void Log_10000_Messages_No_Listener()
+    void OnLogMessagePublished(object sender, MqttNetLogMessagePublishedEventArgs eventArgs)
+    {
+        if (_useHandler)
         {
-            _useHandler = false;
-            
-            for (var i = 0; i < 10000; i++)
-            {
-                _sourceEventLoggerNoListener.Verbose("test log message {0}", "parameter");
-            }
-        }
-
-        [Benchmark]
-        public void Log_10000_Messages_With_To_String()
-        {
-            _useHandler = true;
-            
-            for (var i = 0; i < 10000; i++)
-            {
-                _sourceEventLogger.Verbose("test log message {0}", "parameter");
-            }
-        }
-        
-        [Benchmark]
-        public void Log_10000_Messages_Without_To_String()
-        {
-            _useHandler = false;
-            
-            for (var i = 0; i < 10000; i++)
-            {
-                _sourceEventLogger.Verbose("test log message {0}", "parameter");
-            }
-        }
-        
-        [Benchmark]
-        public void Log_10000_Messages_With_NullLogger()
-        {
-            for (var i = 0; i < 10000; i++)
-            {
-                _sourceNullLogger.Verbose("test log message {0}", "parameter");
-            }
+            Debug.WriteLine(eventArgs.LogMessage.ToString());
         }
     }
-}
+
+    [Benchmark]
+    public void Log_10000_Messages_No_Listener()
+    {
+        _useHandler = false;
+
+        for (var i = 0; i < 10000; i++)
+        {
+            _sourceEventLoggerNoListener.Verbose("test log message {0}", "parameter");
+        }
+    }
+
+    [Benchmark]
+    public void Log_10000_Messages_With_To_String()
+    {
+        _useHandler = true;
+
+        for (var i = 0; i < 10000; i++)
+        {
+            _sourceEventLogger.Verbose("test log message {0}", "parameter");
+        }
+    }
+
+    [Benchmark]
+    public void Log_10000_Messages_Without_To_String()
+    {
+        _useHandler = false;
+
+        for (var i = 0; i < 10000; i++)
+        {
+            _sourceEventLogger.Verbose("test log message {0}", "parameter");
+        }
+    }
+
+    [Benchmark]
+    public void Log_10000_Messages_With_NullLogger()
+    {
+        for (var i = 0; i < 10000; i++)
+        {
+            _sourceNullLogger.Verbose("test log message {0}", "parameter");
+        }
+    }
+}

Source/MQTTnet.Benchmarks/MQTTnet.Benchmarks.csproj

@@ -1,39 +1,22 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>
         <DebugType>Full</DebugType>
-        <TargetFrameworks>net5.0;net6.0</TargetFrameworks>
-        <LangVersion>7.2</LangVersion>
         <IsPackable>false</IsPackable>
-        <EnableNETAnalyzers>false</EnableNETAnalyzers>
-        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
-        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
+        <NoWarn>$(NoWarn);CS8892;CA1707;CA1051;CA1822</NoWarn>
+        <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="BenchmarkDotNet" Version="0.13.1" />
-        <PackageReference Include="Microsoft.AspNetCore" Version="2.2.0" />
-    </ItemGroup>
-
-    <ItemGroup Condition="'$(TargetFramework)' != 'net5.0'">
-        <PackageReference Include="System.IO.Pipelines" Version="4.7.2" />
-    </ItemGroup>
-
-    <ItemGroup Condition="'$(TargetFramework)' == 'net5.0'">
-        <PackageReference Include="System.IO.Pipelines" Version="5.0.0" />
-    </ItemGroup>
-
-    <ItemGroup Condition="'$(TargetFramework)' == 'net6.0'">
-        <PackageReference Include="System.IO.Pipelines" Version="5.0.0" />
+        <PackageReference Include="BenchmarkDotNet" Version="0.15.4" />
     </ItemGroup>
 
     <ItemGroup>
-        <ProjectReference Include="..\..\Source\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj" />
-
-        <PackageReference Include="Microsoft.CodeAnalysis.Compilers" Version="4.0.1" />
-        <PackageReference Include="Microsoft.Net.Compilers" Version="4.0.1" />
-        <ProjectReference Include="..\MQTTnet.Tests\MQTTnet.Tests.csproj" />
+        <ProjectReference Include="..\..\Source\MQTTnet.Server\MQTTnet.Server.csproj"/>
+        <ProjectReference Include="..\..\Source\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj"/>
+        <ProjectReference Include="..\MQTTnet.Tests\MQTTnet.Tests.csproj"/>
+        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj"/>
     </ItemGroup>
 
 </Project>

Source/MQTTnet.Benchmarks/MemoryCopyBenchmark.cs

@@ -0,0 +1,39 @@
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+
+
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[RPlotExporter, RankColumn]
+[MemoryDiagnoser]
+public class MemoryCopyBenchmark
+{
+    const int MaxLength = 1024 * 8;
+
+    byte[] _source;
+    byte[] _target;
+
+    [Params(64 - 1, 128 - 1, 256 - 1, 512 - 1, 1024 - 1, 2048 - 1, 5096 - 1)]
+    public int Length { get; set; }
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        _source = new byte[MaxLength];
+        _target = new byte[MaxLength];
+    }
+
+    [Benchmark(Baseline = true)]
+    public void Array_Copy()
+    {
+        Array.Copy(_source, 0, _target, 0, Length);
+    }
+
+    [Benchmark]
+    public void Memory_Copy()
+    {
+        Internal.MqttMemoryHelper.Copy(_source, 0, _target, 0, Length);
+    }
+
+}

Source/MQTTnet.Benchmarks/MessageDeliveryBenchmark.cs

@@ -1,234 +1,196 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
 using BenchmarkDotNet.Attributes;
-using BenchmarkDotNet.Jobs;
-using MQTTnet.Client;
+using MQTTnet.Packets;
 using MQTTnet.Server;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 
+namespace MQTTnet.Benchmarks;
 
-namespace MQTTnet.Benchmarks
+[MemoryDiagnoser]
+public sealed class MessageDeliveryBenchmark : BaseBenchmark, IDisposable
 {
-    /// <summary>
-    /// Create a number of topics, publish, subscribe, and wait for response
-    /// </summary>
-    [MemoryDiagnoser]
-    public class MessageDeliveryBenchmark
+    List<string> _allSubscribedTopics; // Keep track of the subset of topics that are subscribed
+    CancellationTokenSource _cancellationTokenSource;
+
+    object _lockMsgCount;
+    int _messagesExpectedCount;
+    int _messagesReceivedCount;
+    Dictionary<string, IMqttClient> _mqttPublisherClientsByPublisherName;
+    MqttServer _mqttServer;
+    List<IMqttClient> _mqttSubscriberClients;
+
+    [Params(1000, 10000)] public int _numPublishers;
+
+    [Params(5, 10, 20, 50)] public int _numSubscribedTopicsPerSubscriber;
+
+    [Params(10)] public int _numSubscribers;
+
+    [Params(1, 5)] public int _numTopicsPerPublisher;
+    Dictionary<string, string> _publisherByTopic;
+    Dictionary<string, List<string>> _topicsByPublisher;
+
+    [GlobalCleanup]
+    public void Cleanup()
     {
-        List<MqttApplicationMessage> _topicPublishMessages;
-
-        [Params(1, 5)]
-        public int NumTopicsPerPublisher;
-
-        [Params(1000, 10000)]
-        public int NumPublishers;
-
-        [Params(10)]
-        public int NumSubscribers;
-
-        [Params(5, 10, 20, 50)]
-        public int NumSubscribedTopicsPerSubscriber;
-
-        object _lockMsgCount;
-        int _messagesReceivedCount;
-        int _messagesExpectedCount;
-        CancellationTokenSource _cancellationTokenSource;
-
-        MqttServer _mqttServer;
-        List<IMqttClient> _mqttSubscriberClients;
-        Dictionary<string, IMqttClient> _mqttPublisherClientsByPublisherName;
-
-        Dictionary<string, List<string>> _topicsByPublisher;
-        Dictionary<string, string> _publisherByTopic;        
-        List<string> _allSubscribedTopics; // Keep track of the subset of topics that are subscribed
-
-
-        [GlobalSetup]
-        public void Setup()
+        foreach (var mp in _mqttPublisherClientsByPublisherName)
         {
-            _lockMsgCount = new object();
-
-            Dictionary<string, List<string>> singleWildcardTopicsByPublisher;
-            Dictionary<string, List<string>> multiWildcardTopicsByPublisher;
-
-            TopicGenerator.Generate(NumPublishers, NumTopicsPerPublisher, out _topicsByPublisher, out singleWildcardTopicsByPublisher, out multiWildcardTopicsByPublisher);
-
-            var topics = _topicsByPublisher.First().Value;
-            _topicPublishMessages = new List<MqttApplicationMessage>();
-            // Prepare messages, same for each publisher
-            foreach (var topic in topics)
-            {
-                var message = new MqttApplicationMessageBuilder()
-                    .WithTopic(topic)
-                    .WithPayload(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 })
-                    .Build();
-                _topicPublishMessages.Add(message);
-            }
-
-            // Create server
-            var factory = new MqttFactory();
-            var serverOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
-            _mqttServer = factory.CreateMqttServer(serverOptions);
-            _mqttServer.StartAsync().GetAwaiter().GetResult();
-
-            // Create publisher clients
-            _mqttPublisherClientsByPublisherName = new Dictionary<string, IMqttClient>();
-            foreach (var pt in _topicsByPublisher)
-            {
-                var publisherName = pt.Key;
-                var mqttClient = factory.CreateMqttClient();
-                var publisherOptions = new MqttClientOptionsBuilder()
-                    .WithTcpServer("localhost")
-                    .WithClientId(publisherName)
-                    .WithKeepAlivePeriod(TimeSpan.FromSeconds(30))
-                    .Build();
-                mqttClient.ConnectAsync(publisherOptions).GetAwaiter().GetResult();
-                _mqttPublisherClientsByPublisherName.Add(publisherName, mqttClient);
-            }
-
-            // Create subscriber clients
-            _mqttSubscriberClients = new List<IMqttClient>();
-            for (var i = 0; i < NumSubscribers; i++)
-            {
-                var mqttSubscriberClient = factory.CreateMqttClient();
-                _mqttSubscriberClients.Add(mqttSubscriberClient);
-
-                var subscriberOptions = new MqttClientOptionsBuilder()
-                       .WithTcpServer("localhost")
-                       .WithClientId("subscriber" + i)
-                       .Build();
-                mqttSubscriberClient.ApplicationMessageReceivedAsync += r =>
-                {
-                    // count messages and signal cancellation when expected message count is reached
-                    lock (_lockMsgCount)
-                    {
-                        ++_messagesReceivedCount;
-                        if (_messagesReceivedCount == _messagesExpectedCount)
-                        {
-                            _cancellationTokenSource.Cancel();
-                        }
-                    }
-                    return Task.CompletedTask;
-                };
-                mqttSubscriberClient.ConnectAsync(subscriberOptions).GetAwaiter().GetResult();
-            }
-
-
-            List<string> allTopics = new List<string>();
-            _publisherByTopic = new Dictionary<string, string>();
-            foreach (var t in _topicsByPublisher)
-            {
-                foreach (var topic in t.Value)
-                {
-                    _publisherByTopic.Add(topic, t.Key);
-                    allTopics.Add(topic);
-                }
-            }
-
-            // Subscribe to NumSubscribedTopics topics spread across all topics
-            _allSubscribedTopics = new List<string>();
-
-            var totalNumTopics = NumPublishers * NumTopicsPerPublisher;
-            int topicIndexStep = totalNumTopics / (NumSubscribedTopicsPerSubscriber * NumSubscribers);
-            if (topicIndexStep * NumSubscribedTopicsPerSubscriber * NumSubscribers != totalNumTopics)
-            {
-                throw new System.Exception(
-                    String.Format("The total number of topics must be divisible by the number of subscribed topics across all subscribers. Total number of topics: {0}, topic step: {1}", 
-                    totalNumTopics, topicIndexStep
-                    ));
-            }
-
-            var topicIndex = 0;
-            foreach (var mqttSubscriber in _mqttSubscriberClients)
-            {
-                for (var i = 0; i < NumSubscribedTopicsPerSubscriber; ++i, topicIndex += topicIndexStep)
-                {
-                    var topic = allTopics[topicIndex];
-                    _allSubscribedTopics.Add(topic);
-                    var subOptions = new Client.MqttClientSubscribeOptionsBuilder().WithTopicFilter(
-                        new Packets.MqttTopicFilter() { Topic = topic })
-                        .Build();
-                    mqttSubscriber.SubscribeAsync(subOptions).GetAwaiter().GetResult();
-                }
-            }
-
-            Task.Delay(1000).GetAwaiter().GetResult();
+            var mqttPublisherClient = mp.Value;
+            mqttPublisherClient.DisconnectAsync().GetAwaiter().GetResult();
+            mqttPublisherClient.Dispose();
         }
 
-        /// <summary>
-        /// Publish messages and wait for messages sent to subscribers
-        /// </summary>
-        [Benchmark]
-        public void DeliverMessages()
+        _mqttPublisherClientsByPublisherName.Clear();
+
+        foreach (var mqttSubscriber in _mqttSubscriberClients)
         {
-            // There should be one message received per publish for each subscribed topic
-            _messagesExpectedCount = NumSubscribedTopicsPerSubscriber * NumSubscribers;
-
-            // Loop for a while and exchange messages
-
-            _messagesReceivedCount = 0;
-
-            _cancellationTokenSource = new CancellationTokenSource();
-
-            // same payload for all messages
-            var payload = new byte[] { 1, 2, 3, 4 };
-
-            var tasks = new List<Task>();
-
-            // publish a message for each subscribed topic
-            foreach (var topic in _allSubscribedTopics)
-            {
-                var message = new MqttApplicationMessageBuilder()
-                    .WithTopic(topic)
-                    .WithPayload(payload)
-                    .Build();
-                // pick the correct publisher
-                var publisherName = _publisherByTopic[topic];
-                var publisherClient = _mqttPublisherClientsByPublisherName[publisherName];
-                _ = publisherClient.PublishAsync(message);
-            }
-      
-            // Wait one message per publish to be received by subscriber (in the subscriber's application message handler)
-            try
-            {
-                Task.Delay(30000, _cancellationTokenSource.Token).GetAwaiter().GetResult();
-            }
-            catch
-            {
-
-            }
-
-            _cancellationTokenSource.Dispose();
-
-            if (_messagesReceivedCount < _messagesExpectedCount)
-            {
-                throw new Exception(string.Format("Messages Received Count mismatch, expected {0}, received {1}", _messagesExpectedCount, _messagesReceivedCount));
-            }
+            mqttSubscriber.DisconnectAsync().GetAwaiter().GetResult();
+            mqttSubscriber.Dispose();
         }
 
-        [GlobalCleanup]
-        public void Cleanup()
+        _mqttSubscriberClients.Clear();
+
+        _mqttServer.StopAsync().GetAwaiter().GetResult();
+        _mqttServer.Dispose();
+        _mqttServer = null;
+    }
+
+    [Benchmark]
+    public void DeliverMessages()
+    {
+        // There should be one message received per publish for each subscribed topic
+        _messagesExpectedCount = _numSubscribedTopicsPerSubscriber * _numSubscribers;
+
+        // Loop for a while and exchange messages
+
+        _messagesReceivedCount = 0;
+
+        _cancellationTokenSource = new CancellationTokenSource();
+
+        // same payload for all messages
+        var payload = new byte[] { 1, 2, 3, 4 };
+
+        // publish a message for each subscribed topic
+        foreach (var topic in _allSubscribedTopics)
         {
-            foreach (var mp in _mqttPublisherClientsByPublisherName)
-            {
-                var mqttPublisherClient = mp.Value;
-                mqttPublisherClient.DisconnectAsync().GetAwaiter().GetResult();
-                mqttPublisherClient.Dispose();
-            }
-            _mqttPublisherClientsByPublisherName.Clear();
+            var message = new MqttApplicationMessageBuilder().WithTopic(topic).WithPayload(payload).Build();
+            // pick the correct publisher
+            var publisherName = _publisherByTopic[topic];
+            var publisherClient = _mqttPublisherClientsByPublisherName[publisherName];
+            _ = publisherClient.PublishAsync(message);
+        }
 
-            foreach (var mqttSubscriber in _mqttSubscriberClients)
-            {
-                mqttSubscriber.DisconnectAsync().GetAwaiter().GetResult();
-                mqttSubscriber.Dispose();
-            }
-            _mqttSubscriberClients.Clear();
+        // Wait one message per publish to be received by subscriber (in the subscriber's application message handler)
+        try
+        {
+            Task.Delay(30000, _cancellationTokenSource.Token).GetAwaiter().GetResult();
+        }
+        catch
+        {
+            // Ignore all errors.
+        }
 
-            _mqttServer.StopAsync().GetAwaiter().GetResult();
-            _mqttServer.Dispose();
-            _mqttServer = null;
+        _cancellationTokenSource.Dispose();
+
+        if (_messagesReceivedCount < _messagesExpectedCount)
+        {
+            throw new InvalidOperationException($"Messages Received Count mismatch, expected {_messagesExpectedCount}, received {_messagesReceivedCount}");
         }
     }
-}
+
+    public void Dispose()
+    {
+        _cancellationTokenSource?.Dispose();
+        _mqttServer?.Dispose();
+    }
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        _lockMsgCount = new object();
+
+        TopicGenerator.Generate(_numPublishers, _numTopicsPerPublisher, out _topicsByPublisher, out _, out _);
+
+        // Create server
+        var serverFactory = new MqttServerFactory();
+        var clientFactory = new MqttClientFactory();
+        var serverOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
+        _mqttServer = serverFactory.CreateMqttServer(serverOptions);
+        _mqttServer.StartAsync().GetAwaiter().GetResult();
+
+        // Create publisher clients
+        _mqttPublisherClientsByPublisherName = [];
+        foreach (var pt in _topicsByPublisher)
+        {
+            var publisherName = pt.Key;
+            var mqttClient = clientFactory.CreateMqttClient();
+            var publisherOptions = new MqttClientOptionsBuilder().WithTcpServer("localhost").WithClientId(publisherName).WithKeepAlivePeriod(TimeSpan.FromSeconds(30)).Build();
+            mqttClient.ConnectAsync(publisherOptions).GetAwaiter().GetResult();
+            _mqttPublisherClientsByPublisherName.Add(publisherName, mqttClient);
+        }
+
+        // Create subscriber clients
+        _mqttSubscriberClients = new List<IMqttClient>();
+        for (var i = 0; i < _numSubscribers; i++)
+        {
+            var mqttSubscriberClient = clientFactory.CreateMqttClient();
+            _mqttSubscriberClients.Add(mqttSubscriberClient);
+
+            var subscriberOptions = new MqttClientOptionsBuilder().WithTcpServer("localhost").WithClientId("subscriber" + i).Build();
+            mqttSubscriberClient.ApplicationMessageReceivedAsync += _ =>
+            {
+                // count messages and signal cancellation when expected message count is reached
+                lock (_lockMsgCount)
+                {
+                    ++_messagesReceivedCount;
+                    if (_messagesReceivedCount == _messagesExpectedCount)
+                    {
+                        _cancellationTokenSource.Cancel();
+                    }
+                }
+
+                return Task.CompletedTask;
+            };
+
+            mqttSubscriberClient.ConnectAsync(subscriberOptions).GetAwaiter().GetResult();
+        }
+
+
+        var allTopics = new List<string>();
+        _publisherByTopic = [];
+        foreach (var t in _topicsByPublisher)
+        {
+            foreach (var topic in t.Value)
+            {
+                _publisherByTopic.Add(topic, t.Key);
+                allTopics.Add(topic);
+            }
+        }
+
+        // Subscribe to NumSubscribedTopics topics spread across all topics
+        _allSubscribedTopics = new List<string>();
+
+        var totalNumTopics = _numPublishers * _numTopicsPerPublisher;
+        var topicIndexStep = totalNumTopics / (_numSubscribedTopicsPerSubscriber * _numSubscribers);
+        if (topicIndexStep * _numSubscribedTopicsPerSubscriber * _numSubscribers != totalNumTopics)
+        {
+            throw new InvalidOperationException(
+                $"The total number of topics must be divisible by the number of subscribed topics across all subscribers. Total number of topics: {totalNumTopics}, topic step: {topicIndexStep}");
+        }
+
+        var topicIndex = 0;
+        foreach (var mqttSubscriber in _mqttSubscriberClients)
+        {
+            for (var i = 0; i < _numSubscribedTopicsPerSubscriber; ++i, topicIndex += topicIndexStep)
+            {
+                var topic = allTopics[topicIndex];
+                _allSubscribedTopics.Add(topic);
+                var subOptions = new MqttClientSubscribeOptionsBuilder().WithTopicFilter(new MqttTopicFilter { Topic = topic }).Build();
+                mqttSubscriber.SubscribeAsync(subOptions).GetAwaiter().GetResult();
+            }
+        }
+
+        Task.Delay(1000).GetAwaiter().GetResult();
+    }
+}

Source/MQTTnet.Benchmarks/MessageProcessingBenchmark.cs

@@ -4,48 +4,45 @@
 
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Jobs;
-using MQTTnet.Client;
 using MQTTnet.Server;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[RPlotExporter]
+[RankColumn]
+[MemoryDiagnoser]
+public class MessageProcessingBenchmark : BaseBenchmark
 {
-    [SimpleJob(RuntimeMoniker.Net60)]
-    [RPlotExporter, RankColumn]
-    [MemoryDiagnoser]
-    public class MessageProcessingBenchmark
+    MqttApplicationMessage _message;
+    IMqttClient _mqttClient;
+    MqttServer _mqttServer;
+
+    [Benchmark]
+    public void Send_10000_Messages()
     {
-        MqttServer _mqttServer;
-        IMqttClient _mqttClient;
-        MqttApplicationMessage _message;
-
-        [GlobalSetup]
-        public void Setup()
+        for (var i = 0; i < 10000; i++)
         {
-            var serverOptions = new MqttServerOptionsBuilder().Build();
-            
-            var factory = new MqttFactory();
-            _mqttServer = factory.CreateMqttServer(serverOptions);
-            _mqttClient = factory.CreateMqttClient();
-
-            _mqttServer.StartAsync().GetAwaiter().GetResult();
-
-            var clientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("localhost").Build();
-
-            _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
-
-            _message = new MqttApplicationMessageBuilder()
-                .WithTopic("A")
-                .Build();
-        }
-
-        [Benchmark]
-        public void Send_10000_Messages()
-        {
-            for (var i = 0; i < 10000; i++)
-            {
-                _mqttClient.PublishAsync(_message).GetAwaiter().GetResult();
-            }
+            _mqttClient.PublishAsync(_message).GetAwaiter().GetResult();
         }
     }
-}
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        var serverOptions = new MqttServerOptionsBuilder().Build();
+
+        var serverFactory = new MqttServerFactory();
+        _mqttServer = serverFactory.CreateMqttServer(serverOptions);
+        var clientFactory = new MqttClientFactory();
+        _mqttClient = clientFactory.CreateMqttClient();
+
+        _mqttServer.StartAsync().GetAwaiter().GetResult();
+
+        var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("localhost").Build();
+
+        _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
+
+        _message = new MqttApplicationMessageBuilder().WithTopic("A").Build();
+    }
+}

Source/MQTTnet.Benchmarks/MessageProcessingMqttConnectionContextBenchmark.cs

@@ -4,72 +4,69 @@
 
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Jobs;
-using MQTTnet.Client;
 using Microsoft.AspNetCore;
 using Microsoft.AspNetCore.Hosting;
-using MQTTnet.AspNetCore.Client;
 using MQTTnet.AspNetCore;
-using MQTTnet.Diagnostics;
+using MQTTnet.Diagnostics.Logger;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[MemoryDiagnoser]
+public class MessageProcessingMqttConnectionContextBenchmark : BaseBenchmark
 {
-    [SimpleJob(RuntimeMoniker.Net60)]
-    [MemoryDiagnoser]
-    public class MessageProcessingMqttConnectionContextBenchmark
+    IWebHost _host;
+    IMqttClient _mqttClient;
+    MqttApplicationMessage _message;
+
+    [GlobalSetup]
+    public void Setup()
     {
-        IWebHost _host;
-        IMqttClient _mqttClient;
-        MqttApplicationMessage _message;
+        _host = WebHost.CreateDefaultBuilder()
+            .UseKestrel(o => o.ListenAnyIP(1883, l => l.UseMqtt()))
+            .ConfigureServices(services => {
+                services
+                    .AddHostedMqttServer(mqttServerOptions => mqttServerOptions.WithoutDefaultEndpoint())
+                    .AddMqttConnectionHandler();
+            })
+            .Configure(app => {
+                app.UseMqttServer(_ => {
 
-        [GlobalSetup]
-        public void Setup()
+                });
+            })
+            .Build();
+
+        var factory = new MqttClientFactory();
+        _mqttClient = factory.CreateMqttClient(new MqttNetEventLogger(), new MqttClientConnectionContextFactory());
+
+        _host.StartAsync().GetAwaiter().GetResult();
+
+        var clientOptions = new MqttClientOptionsBuilder()
+            .WithTcpServer("localhost").Build();
+
+        _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
+
+        _message = new MqttApplicationMessageBuilder()
+            .WithTopic("A")
+            .Build();
+    }
+
+    [GlobalCleanup]
+    public void Cleanup()
+    {
+        _mqttClient.DisconnectAsync().GetAwaiter().GetResult();
+        _mqttClient.Dispose();
+
+        _host.StopAsync().GetAwaiter().GetResult();
+        _host.Dispose();
+    }
+
+    [Benchmark]
+    public void Send_10000_Messages()
+    {
+        for (var i = 0; i < 10000; i++)
         {
-            _host = WebHost.CreateDefaultBuilder()
-                   .UseKestrel(o => o.ListenAnyIP(1883, l => l.UseMqtt()))
-                   .ConfigureServices(services => {
-                        services
-                            .AddHostedMqttServer(mqttServerOptions => mqttServerOptions.WithoutDefaultEndpoint())
-                            .AddMqttConnectionHandler();
-                   })
-                   .Configure(app => {
-                       app.UseMqttServer(s => {
-
-                       });
-                   })
-                   .Build();
-
-            var factory = new MqttFactory();
-            _mqttClient = factory.CreateMqttClient(new MqttNetEventLogger(), new MqttClientConnectionContextFactory());
-
-            _host.StartAsync().GetAwaiter().GetResult();
-
-            var clientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("localhost").Build();
-
-            _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
-
-            _message = new MqttApplicationMessageBuilder()
-                .WithTopic("A")
-                .Build();
-        }
-
-        [GlobalCleanup]
-        public void Cleanup()
-        {
-            _mqttClient.DisconnectAsync().GetAwaiter().GetResult();
-            _mqttClient.Dispose();
-
-            _host.StopAsync().GetAwaiter().GetResult();
-            _host.Dispose();
-        }
-
-        [Benchmark]
-        public void Send_10000_Messages()
-        {
-            for (var i = 0; i < 10000; i++)
-            {
-                _mqttClient.PublishAsync(_message).GetAwaiter().GetResult();
-            }
+            _mqttClient.PublishAsync(_message).GetAwaiter().GetResult();
         }
     }
-}
+}

Source/MQTTnet.Benchmarks/MqttBufferReaderBenchmark.cs

@@ -0,0 +1,41 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Text;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Formatter;
+
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[MemoryDiagnoser]
+public class MqttBufferReaderBenchmark
+{
+    byte[] _buffer;
+    int _bufferLength;
+
+    [GlobalSetup]
+    public void GlobalSetup()
+    {
+        var writer = new MqttBufferWriter(1024, 1024);
+        writer.WriteString("hgfjkdfkjlghfdjghdfljkdfhgdlkjfshgsldkfjghsdflkjghdsflkjhrstiuoghlkfjbhnfbutghjoiöjhklötnbhtroliöuhbjntluiobkjzbhtdrlskbhtruhjkfthgbkftgjhgfiklhotriuöhbjtrsioöbtrsötrhträhtrühjtriüoätrhjtsrölbktrbnhtrulöbionhströloubinströoliubhnsöotrunbtöroisntröointröioujhgötiohjgötorshjnbgtöorihbnjtröoihbjntröobntröoibntrjhötrohjbtröoihntröoibnrtoiöbtrjnboöitrhjtnriohötrhjtöroihjtroöihjtroösibntsroönbotöirsbntöoihjntröoihntroöbtrboöitrnhoöitrhjntröoishbnjtröosbhtröbntriohjtröoijtöoitbjöotibjnhöotirhbjntroöibhnjrtoöibnhtroöibnhtörsbnhtöoirbnhtöroibntoörhjnbträöbtrbträbtrbtirbätrsibohjntrsöiobthnjiohjsrtoib");
+
+        _buffer = writer.GetBuffer();
+        _bufferLength = writer.Length;
+    }
+
+    [Benchmark]
+    public void Use_Span()
+    {
+        var span = _buffer.AsSpan(0, _bufferLength);
+        Encoding.UTF8.GetString(span);
+    }
+
+    [Benchmark]
+    public void Use_Encoding()
+    {
+        Encoding.UTF8.GetString(_buffer, 0, _bufferLength);
+    }
+}

Source/MQTTnet.Benchmarks/MqttPacketReaderWriterBenchmark.cs

@@ -1,93 +1,94 @@
-using System;
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Jobs;
-using MQTTnet.AspNetCore;
 using MQTTnet.Formatter;
 using MQTTnet.Tests.Mockups;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[MemoryDiagnoser]
+public class MqttPacketReaderWriterBenchmark : BaseBenchmark
 {
-    [SimpleJob(RuntimeMoniker.Net60)]
-    [MemoryDiagnoser]
-    public class MqttPacketReaderWriterBenchmark
+    readonly byte[] _demoPayload = new byte[1024];
+
+    byte[] _readPayload;
+
+    [GlobalCleanup]
+    public void GlobalCleanup()
     {
-        readonly byte[] _demoPayload = new byte[1024];
-        
-        byte[] _readPayload;
+    }
 
-        [GlobalCleanup]
-        public void GlobalCleanup()
+    [GlobalSetup]
+    public void GlobalSetup()
+    {
+        TestEnvironment.EnableLogger = false;
+
+        var writer = new MqttBufferWriter(4096, 65535);
+        writer.WriteString("A relative short string.");
+        writer.WriteBinary(_demoPayload);
+        writer.WriteByte(0x01);
+        writer.WriteByte(0x02);
+        writer.WriteVariableByteInteger(5647382);
+        writer.WriteString("A relative short string.");
+        writer.WriteVariableByteInteger(8574489);
+        writer.WriteBinary(_demoPayload);
+        writer.WriteByte(2);
+        writer.WriteByte(0x02);
+        writer.WriteString("fjgffiogfhgfhoihgoireghreghreguhreguireoghreouighreouighreughreguiorehreuiohruiorehreuioghreug");
+        writer.WriteBinary(_demoPayload);
+
+        _readPayload = new ArraySegment<byte>(writer.GetBuffer(), 0, writer.Length).ToArray();
+    }
+
+    [Benchmark]
+    public void Read_100_000_Messages()
+    {
+        var reader = new MqttBufferReader();
+        reader.SetBuffer(_readPayload, 0, _readPayload.Length);
+
+        for (var i = 0; i < 100000; i++)
         {
+            reader.Seek(0);
+
+            reader.ReadString();
+            reader.ReadBinaryData();
+            reader.ReadByte();
+            reader.ReadByte();
+            reader.ReadVariableByteInteger();
+            reader.ReadString();
+            reader.ReadVariableByteInteger();
+            reader.ReadBinaryData();
+            reader.ReadByte();
+            reader.ReadByte();
+            reader.ReadString();
+            reader.ReadBinaryData();
         }
+    }
 
-        [GlobalSetup]
-        public void GlobalSetup()
+    [Benchmark]
+    public void Write_100_000_Messages()
+    {
+        var writer = new MqttBufferWriter(4096, 65535);
+
+        for (var i = 0; i < 100000; i++)
         {
-            TestEnvironment.EnableLogger = false;
-            
-            var writer = new MqttBufferWriter(4096, 65535);
             writer.WriteString("A relative short string.");
-            writer.WriteBinaryData(_demoPayload);
             writer.WriteByte(0x01);
             writer.WriteByte(0x02);
             writer.WriteVariableByteInteger(5647382);
             writer.WriteString("A relative short string.");
-            writer.WriteVariableByteInteger(8574489);
-            writer.WriteBinaryData(_demoPayload);
+            writer.WriteVariableByteInteger(8574589);
+            writer.WriteBinary(_demoPayload);
             writer.WriteByte(2);
             writer.WriteByte(0x02);
             writer.WriteString("fjgffiogfhgfhoihgoireghreghreguhreguireoghreouighreouighreughreguiorehreuiohruiorehreuioghreug");
-            writer.WriteBinaryData(_demoPayload);
+            writer.WriteBinary(_demoPayload);
 
-            _readPayload = new ArraySegment<byte>(writer.GetBuffer(), 0, writer.Length).ToArray();
-        }
-
-        [Benchmark]
-        public void Read_100_000_Messages()
-        {
-            var reader = new MqttBufferReader();
-            reader.SetBuffer(_readPayload, 0, _readPayload.Length);
-
-            for (var i = 0; i < 100000; i++)
-            {
-                reader.Seek(0);
-
-                reader.ReadString();
-                reader.ReadBinaryData();
-                reader.ReadByte();
-                reader.ReadByte();
-                reader.ReadVariableByteInteger();
-                reader.ReadString();
-                reader.ReadVariableByteInteger();
-                reader.ReadBinaryData();
-                reader.ReadByte();
-                reader.ReadByte();
-                reader.ReadString();
-                reader.ReadBinaryData();
-            }
-        }
-        
-        [Benchmark]
-        public void Write_100_000_Messages()
-        {
-            var writer = new MqttBufferWriter(4096, 65535);
-
-            for (var i = 0; i < 100000; i++)
-            {
-                writer.WriteString("A relative short string.");
-                writer.WriteByte(0x01);
-                writer.WriteByte(0x02);
-                writer.WriteVariableByteInteger(5647382);
-                writer.WriteString("A relative short string.");
-                writer.WriteVariableByteInteger(8574589);
-                writer.WriteBinaryData(_demoPayload);
-                writer.WriteByte(2);
-                writer.WriteByte(0x02);
-                writer.WriteString("fjgffiogfhgfhoihgoireghreghreguhreguireoghreouighreouighreughreguiorehreuiohruiorehreuioghreug");
-                writer.WriteBinaryData(_demoPayload);
-
-                writer.Reset(0);
-            }
+            writer.Reset(0);
         }
     }
 }

Source/MQTTnet.Benchmarks/MqttTcpChannelBenchmark.cs

@@ -2,87 +2,91 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Buffers;
+using System.Reflection;
 using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
 using MQTTnet.Channel;
+using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Implementations;
 using MQTTnet.Server;
-using System.Threading;
-using System.Threading.Tasks;
-using BenchmarkDotNet.Jobs;
-using MQTTnet.Client;
-using MQTTnet.Diagnostics;
+using MQTTnet.Server.Internal.Adapter;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[MemoryDiagnoser]
+public sealed class MqttTcpChannelBenchmark : BaseBenchmark, IDisposable
 {
-    [SimpleJob(RuntimeMoniker.Net60)]
-    [MemoryDiagnoser]
-    public sealed class MqttTcpChannelBenchmark
+    MqttTcpChannel _clientChannel;
+    MqttServer _mqttServer;
+    IMqttChannel _serverChannel;
+
+    [Benchmark]
+    public async Task Send_10000_Chunks()
     {
-        MqttServer _mqttServer;
-        IMqttChannel _serverChannel;
-        IMqttChannel _clientChannel;
+        var size = 5;
+        var iterations = 10000;
 
-        [GlobalSetup]
-        public void Setup()
+        await Task.WhenAll(WriteAsync(iterations, size), ReadAsync(iterations, size));
+    }
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        var serverFactory = new MqttServerFactory();
+        var tcpServer = new MqttTcpServerAdapter();
+        tcpServer.ClientHandler += args =>
         {
-            var factory = new MqttFactory();
-            var tcpServer = new MqttTcpServerAdapter();
-            tcpServer.ClientHandler += args =>
-            {
-                _serverChannel =
-                    (IMqttChannel)args.GetType().GetField("_channel",
-                            System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)
-                        .GetValue(args);
+            _serverChannel = (IMqttChannel)args.GetType().GetField("_channel", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(args);
 
-                return Task.CompletedTask;
-            };
+            return Task.CompletedTask;
+        };
 
-            var serverOptions = new MqttServerOptionsBuilder().Build();
-            _mqttServer = factory.CreateMqttServer(serverOptions, new[] { tcpServer }, new MqttNetEventLogger());
+        var serverOptions = new MqttServerOptionsBuilder().Build();
+        _mqttServer = serverFactory.CreateMqttServer(serverOptions, new[] { tcpServer }, new MqttNetEventLogger());
 
-            
-            _mqttServer.StartAsync().GetAwaiter().GetResult();
 
-            var clientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("localhost").Build();
+        _mqttServer.StartAsync().GetAwaiter().GetResult();
 
-            var tcpOptions = (MqttClientTcpOptions)clientOptions.ChannelOptions;
-            _clientChannel = new MqttTcpChannel(new MqttClientOptions { ChannelOptions = tcpOptions });
+        var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("localhost").Build();
 
-            _clientChannel.ConnectAsync(CancellationToken.None).GetAwaiter().GetResult();
-        }
+        var tcpOptions = (MqttClientTcpOptions)clientOptions.ChannelOptions;
+        _clientChannel = new MqttTcpChannel(new MqttClientOptions { ChannelOptions = tcpOptions });
 
-        [Benchmark]
-        public async Task Send_10000_Chunks()
+        _clientChannel.ConnectAsync(CancellationToken.None).GetAwaiter().GetResult();
+    }
+
+    async Task ReadAsync(int iterations, int size)
+    {
+        await Task.Yield();
+
+        var expected = iterations * size;
+        long read = 0;
+
+        while (read < expected)
         {
-            var size = 5;
-            var iterations = 10000;
-
-            await Task.WhenAll(WriteAsync(iterations, size), ReadAsync(iterations, size));
-        }
-
-        async Task ReadAsync(int iterations, int size)
-        {
-            await Task.Yield();
-
-            var expected = iterations * size;
-            long read = 0;
-
-            while (read < expected)
-            {
-                var readresult = await _clientChannel.ReadAsync(new byte[size], 0, size, CancellationToken.None).ConfigureAwait(false);
-                read += readresult;
-            }
-        }
-
-        async Task WriteAsync(int iterations, int size)
-        {
-            await Task.Yield();
-
-            for (var i = 0; i < iterations; i++)
-            {
-                await _serverChannel.WriteAsync(new byte[size], 0, size, CancellationToken.None).ConfigureAwait(false);
-            }
+            var readResult = await _clientChannel.ReadAsync(new byte[size], 0, size, CancellationToken.None).ConfigureAwait(false);
+            read += readResult;
         }
     }
+
+    async Task WriteAsync(int iterations, int size)
+    {
+        await Task.Yield();
+
+        var buffer = new ReadOnlySequence<byte>(new byte[size]);
+
+        for (var i = 0; i < iterations; i++)
+        {
+            await _serverChannel.WriteAsync(buffer, true, CancellationToken.None).ConfigureAwait(false);
+        }
+    }
+
+    public void Dispose()
+    {
+        _clientChannel?.Dispose();
+        _mqttServer?.Dispose();
+        _serverChannel?.Dispose();
+    }
 }

Source/MQTTnet.Benchmarks/Program.cs

@@ -2,82 +2,135 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using BenchmarkDotNet.Running;
-using MQTTnet.Benchmarks.Configurations;
-using MQTTnet.Diagnostics;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+public static class Program
 {
-    public static class Program
+    static int _selectedBenchmarkIndex;
+    static List<Type> _benchmarks;
+
+    public static void Main(string[] arguments)
     {
-        public static void Main(string[] args)
+        _benchmarks = CollectBenchmarks();
+        HandleArguments(arguments);
+
+        while (true)
         {
-            Console.WriteLine($"MQTTnet - Benchmarks ({TargetFrameworkProvider.TargetFramework})");
-            Console.WriteLine("--------------------------------------------------------");
-            Console.WriteLine("1 = MessageProcessingBenchmark");
-            Console.WriteLine("2 = SerializerBenchmark");
-            Console.WriteLine("3 = LoggerBenchmark");
-            Console.WriteLine("4 = TopicFilterComparerBenchmark");
-            Console.WriteLine("5 = ChannelAdapterBenchmark");
-            Console.WriteLine("6 = MqttTcpChannelBenchmark");
-            Console.WriteLine("7 = TcpPipesBenchmark");
-            Console.WriteLine("8 = MessageProcessingMqttConnectionContextBenchmark");
-            Console.WriteLine("9 = ServerProcessingBenchmark");
-            Console.WriteLine("a = MqttPacketReaderWriterBenchmark");
-            Console.WriteLine("b = RoundtripBenchmark");
-            Console.WriteLine("c = SubscribeBenchmark");
-            Console.WriteLine("d = UnsubscribeBenchmark");
-            Console.WriteLine("e = MessageDeliveryBenchmark");
+            RenderMenu();
 
-            var pressedKey = Console.ReadKey(true);
-            switch (pressedKey.KeyChar)
+            var key = Console.ReadKey(true);
+
+            if (key.Key == ConsoleKey.DownArrow)
             {
-                case '1':
-                    BenchmarkRunner.Run<MessageProcessingBenchmark>();
-                    break;
-                case '2':
-                    BenchmarkRunner.Run<SerializerBenchmark>();
-                    break;
-                case '3':
-                    BenchmarkRunner.Run<LoggerBenchmark>();
-                    break;
-                case '4':
-                    BenchmarkRunner.Run<TopicFilterComparerBenchmark>();
-                    break;
-                case '5':
-                    BenchmarkRunner.Run<ChannelAdapterBenchmark>();
-                    break;
-                case '6':
-                    BenchmarkRunner.Run<MqttTcpChannelBenchmark>();
-                    break;
-                case '7':
-                    BenchmarkRunner.Run<TcpPipesBenchmark>();
-                    break;
-                case '8':
-                    BenchmarkRunner.Run<MessageProcessingMqttConnectionContextBenchmark>(new RuntimeCompareConfig());
-                    break;
-                case '9':
-                    BenchmarkRunner.Run<ServerProcessingBenchmark>();
-                    break;
-                case 'a':
-                    BenchmarkRunner.Run(typeof(MqttPacketReaderWriterBenchmark));
-                    break;
-                case 'b':
-                    BenchmarkRunner.Run<RoundtripProcessingBenchmark>();
-                    break;
-                case 'c':
-                    BenchmarkRunner.Run<SubscribeBenchmark>();
-                    break;
-                case 'd':
-                    BenchmarkRunner.Run<UnsubscribeBenchmark>();
-                    break;
-                case 'e':
-                    BenchmarkRunner.Run<MessageDeliveryBenchmark>();
-                    break;
+                _selectedBenchmarkIndex++;
+                if (_selectedBenchmarkIndex > _benchmarks.Count - 1)
+                {
+                    _selectedBenchmarkIndex = 0;
+                }
             }
+            else if (key.Key == ConsoleKey.UpArrow)
+            {
+                _selectedBenchmarkIndex--;
+                if (_selectedBenchmarkIndex < 0)
+                {
+                    _selectedBenchmarkIndex = _benchmarks.Count - 1;
+                }
+            }
+            else if (key.Key == ConsoleKey.Escape)
+            {
+                Environment.Exit(0);
+            }
+            else if (key.Key == ConsoleKey.Enter)
+            {
+                break;
+            }
+        }
 
-            Console.ReadLine();
+        BenchmarkRunner.Run(_benchmarks[_selectedBenchmarkIndex]);
+
+        Console.ForegroundColor = ConsoleColor.Yellow;
+        Console.WriteLine("Press any key to exit");
+        Console.ReadLine();
+    }
+
+    static List<Type> CollectBenchmarks()
+    {
+        var benchmarks = new List<Type>();
+
+        var types = typeof(Program).Assembly.GetExportedTypes();
+        foreach (var type in types)
+        {
+            if (typeof(BaseBenchmark).IsAssignableFrom(type))
+            {
+                if (type != typeof(BaseBenchmark))
+                {
+                    benchmarks.Add(type);
+                }
+            }
+        }
+
+        return benchmarks.OrderBy(b => b.Name).ToList();
+    }
+
+    static void HandleArguments(string[] arguments)
+    {
+        if (arguments.Length == 0)
+        {
+            return;
+        }
+
+        // Allow for preselection to avoid developer frustration.
+
+        if (int.TryParse(arguments[0], out var benchmarkIndex))
+        {
+            _selectedBenchmarkIndex = benchmarkIndex;
+            return;
+        }
+
+        _selectedBenchmarkIndex = _benchmarks.FindIndex(b => b.Name.Equals(arguments[0], StringComparison.Ordinal));
+
+        if (_selectedBenchmarkIndex < 0)
+        {
+            _selectedBenchmarkIndex = 0;
+        }
+
+        if (_selectedBenchmarkIndex > _benchmarks.Count - 1)
+        {
+            _selectedBenchmarkIndex = _benchmarks.Count - 1;
         }
     }
-}
+
+    static void RenderMenu()
+    {
+        Console.Clear();
+
+        Console.WriteLine($"MQTTnet - Benchmarks");
+        Console.WriteLine("-----------------------------------------------");
+        Console.ForegroundColor = ConsoleColor.Yellow;
+        Console.WriteLine("Press arrow keys for benchmark selection");
+        Console.WriteLine("Press Enter for benchmark execution");
+        Console.WriteLine("Press Esc for exit");
+        Console.ForegroundColor = ConsoleColor.White;
+        Console.WriteLine();
+
+        for (var index = 0; index < _benchmarks.Count; index++)
+        {
+            var benchmark = _benchmarks[index];
+
+            if (_selectedBenchmarkIndex == index)
+            {
+                Console.Write("-> ");
+            }
+            else
+            {
+                Console.Write("   ");
+            }
+
+            Console.WriteLine(benchmark.Name);
+        }
+
+        Console.WriteLine();
+    }
+}

Source/MQTTnet.Benchmarks/ReaderExtensionsBenchmark.cs

@@ -0,0 +1,97 @@
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.AspNetCore;
+using MQTTnet.Exceptions;
+using MQTTnet.Formatter;
+using System.Buffers;
+using System.IO.Pipelines;
+
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[RPlotExporter, RankColumn]
+[MemoryDiagnoser]
+public sealed class ReaderExtensionsBenchmark : IDisposable, IAsyncDisposable
+{
+    MqttPacketFormatterAdapter _mqttPacketFormatter;
+    MemoryStream _stream;
+
+    [GlobalSetup]
+    public void GlobalSetup()
+    {
+        _mqttPacketFormatter = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));
+        var mqttMessage = new MqttApplicationMessageBuilder()
+            .WithTopic("topic")
+            .WithPayload(new byte[10 * 1024])
+            .Build();
+
+        var packet = MqttPublishPacketFactory.Create(mqttMessage);
+
+        var buffer = _mqttPacketFormatter.Encode(packet);
+        _stream = new MemoryStream();
+        _stream.Write(buffer.Packet);
+        _stream.Write(buffer.Payload.ToArray());
+        _mqttPacketFormatter.Cleanup();
+    }
+
+    [Benchmark]
+    public async Task After()
+    {
+        _stream.Position = 0;
+        var input = PipeReader.Create(_stream);
+
+        while (true)
+        {
+            ReadResult readResult;
+            var readTask = input.ReadAsync();
+            if (readTask.IsCompleted)
+            {
+                readResult = readTask.Result;
+            }
+            else
+            {
+                readResult = await readTask.ConfigureAwait(false);
+            }
+
+            var buffer = readResult.Buffer;
+
+            var consumed = buffer.Start;
+            var observed = buffer.Start;
+
+            try
+            {
+                if (!buffer.IsEmpty)
+                {
+                    if (_mqttPacketFormatter.TryDecode(buffer, out _, out consumed, out observed, out _))
+                    {
+                        break;
+                    }
+                }
+                else if (readResult.IsCompleted)
+                {
+                    throw new MqttCommunicationException("Connection Aborted");
+                }
+            }
+            finally
+            {
+                // The buffer was sliced up to where it was consumed, so we can just advance to the start.
+                // We mark examined as buffer.End so that if we didn't receive a full frame, we'll wait for more data
+                // before yielding the read again.
+                input.AdvanceTo(consumed, observed);
+            }
+        }
+    }
+
+    public void Dispose()
+    {
+        _stream?.Dispose();
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_stream != null)
+        {
+            await _stream.DisposeAsync();
+        }
+    }
+}

Source/MQTTnet.Benchmarks/RoundtripProcessingBenchmark.cs

@@ -1,30 +1,28 @@
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Jobs;
 using MQTTnet.Tests.Mockups;
-using MQTTnet.Tests.Server;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[RPlotExporter, RankColumn]
+[MemoryDiagnoser]
+public class RoundtripProcessingBenchmark : BaseBenchmark
 {
-    [SimpleJob(RuntimeMoniker.Net60)]
-    [RPlotExporter, RankColumn]
-    [MemoryDiagnoser]
-    public class RoundtripProcessingBenchmark
+    [GlobalSetup]
+    public void GlobalSetup()
     {
-        [GlobalSetup]
-        public void GlobalSetup()
-        {
-            TestEnvironment.EnableLogger = false;
-        }
-        
-        [GlobalCleanup]
-        public void GlobalCleanup()
-        {
-        }
-        
-        [Benchmark]
-        public void Handle_100_000_Messages_In_Receiving_Client()
-        {
-            new Load_Tests().Handle_100_000_Messages_In_Receiving_Client().GetAwaiter().GetResult();
-        }
+        TestEnvironment.EnableLogger = false;
+    }
+
+    [GlobalCleanup]
+    public void GlobalCleanup()
+    {
+    }
+
+    [Benchmark]
+    public void Handle_100_000_Messages_In_Receiving_Client()
+    {
+        //new Load_Tests().Handle_100_000_Messages_In_Receiving_Client().GetAwaiter().GetResult();
     }
 }

Source/MQTTnet.Benchmarks/SendPacketAsyncBenchmark.cs

@@ -0,0 +1,78 @@
+using System.Buffers;
+using System.IO.Pipelines;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Formatter;
+
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[RPlotExporter]
+[RankColumn]
+[MemoryDiagnoser]
+public sealed class SendPacketAsyncBenchmark : BaseBenchmark, IDisposable, IAsyncDisposable
+{
+    MqttPacketBuffer _buffer;
+    MemoryStream _stream;
+
+    [Benchmark]
+    public async ValueTask After()
+    {
+        _stream.Position = 0;
+        var output = PipeWriter.Create(_stream);
+
+        if (_buffer.Payload.Length == 0)
+        {
+            await output.WriteAsync(_buffer.Packet).ConfigureAwait(false);
+        }
+        else
+        {
+            WritePacketBuffer(output, _buffer);
+            await output.FlushAsync().ConfigureAwait(false);
+        }
+    }
+
+    [Benchmark(Baseline = true)]
+    public async ValueTask Before()
+    {
+        _stream.Position = 0;
+        var output = PipeWriter.Create(_stream);
+
+        WritePacketBuffer(output, _buffer);
+        await output.FlushAsync();
+    }
+
+    public void Dispose()
+    {
+        _stream?.Dispose();
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_stream != null)
+        {
+            await _stream.DisposeAsync();
+        }
+    }
+
+    [GlobalSetup]
+    public void GlobalSetup()
+    {
+        _stream = new MemoryStream(1024);
+        var packet = new ArraySegment<byte>(new byte[10]);
+        _buffer = new MqttPacketBuffer(packet);
+    }
+
+    static void WritePacketBuffer(PipeWriter output, MqttPacketBuffer buffer)
+    {
+        // copy MqttPacketBuffer's Packet and Payload to the same buffer block of PipeWriter
+        // MqttPacket will be transmitted within the bounds of a WebSocket frame after PipeWriter.FlushAsync
+
+        var span = output.GetSpan(buffer.Length);
+
+        buffer.Packet.AsSpan().CopyTo(span);
+        buffer.Payload.CopyTo(span[buffer.Packet.Count..]);
+
+        output.Advance(buffer.Length);
+    }
+}

Source/MQTTnet.Benchmarks/SerializerBenchmark.cs

@@ -4,114 +4,114 @@
 
 using BenchmarkDotNet.Attributes;
 using MQTTnet.Packets;
-using System;
 using System.Security.Cryptography.X509Certificates;
-using System.Threading;
-using System.Threading.Tasks;
 using MQTTnet.Adapter;
 using MQTTnet.Channel;
 using MQTTnet.Formatter;
 using MQTTnet.Formatter.V3;
 using BenchmarkDotNet.Jobs;
-using MQTTnet.Diagnostics;
+using MQTTnet.Diagnostics.Logger;
+using System.Buffers;
+using System.Net;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[RPlotExporter]
+[MemoryDiagnoser]
+public class SerializerBenchmark : BaseBenchmark
 {
-    [SimpleJob(RuntimeMoniker.Net60)]
-    [RPlotExporter]
-    [MemoryDiagnoser]
-    public class SerializerBenchmark : BaseBenchmark
+    MqttPacket _packet;
+    ArraySegment<byte> _serializedPacket;
+    MqttV3PacketFormatter _serializer;
+    MqttBufferWriter _bufferWriter;
+
+    [GlobalSetup]
+    public void GlobalSetup()
     {
-        MqttPacket _packet;
-        ArraySegment<byte> _serializedPacket;
-        IMqttPacketFormatter _serializer;
-        MqttBufferWriter _bufferWriter;
-
-        [GlobalSetup]
-        public void GlobalSetup()
+        _packet = new MqttPublishPacket
         {
-            _packet = new MqttPublishPacket
-            {
-                Topic = "A"
-            };
+            Topic = "A"
+        };
 
-            _bufferWriter = new MqttBufferWriter(4096, 65535);
-            _serializer = new MqttV3PacketFormatter(_bufferWriter, MqttProtocolVersion.V311);
-            _serializedPacket = _serializer.Encode(_packet).Join();
-        }
+        _bufferWriter = new MqttBufferWriter(4096, 65535);
+        _serializer = new MqttV3PacketFormatter(_bufferWriter, MqttProtocolVersion.V311);
+        _serializedPacket = _serializer.Encode(_packet).Join();
+    }
 
-        [Benchmark]
-        public void Serialize_10000_Messages()
+    [Benchmark]
+    public void Serialize10000Messages()
+    {
+        for (var i = 0; i < 10000; i++)
         {
-            for (var i = 0; i < 10000; i++)
-            {
-                _serializer.Encode(_packet);
-                _bufferWriter.Cleanup();
-            }
-        }
-
-        [Benchmark]
-        public void Deserialize_10000_Messages()
-        {
-            var channel = new BenchmarkMqttChannel(_serializedPacket);
-            var reader = new MqttChannelAdapter(channel, new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535)), null, new MqttNetEventLogger());
-
-            for (var i = 0; i < 10000; i++)
-            {
-                channel.Reset();
-
-                var header = reader.ReceivePacketAsync(CancellationToken.None).GetAwaiter().GetResult();
-            }
-        }
-
-        class BenchmarkMqttChannel : IMqttChannel
-        {
-            readonly ArraySegment<byte> _buffer;
-            int _position;
-
-            public BenchmarkMqttChannel(ArraySegment<byte> buffer)
-            {
-                _buffer = buffer;
-                _position = _buffer.Offset;
-            }
-
-            public string Endpoint { get; } = string.Empty;
-
-            public bool IsSecureConnection { get; } = false;
-
-            public X509Certificate2 ClientCertificate { get; }
-
-            public void Reset()
-            {
-                _position = _buffer.Offset;
-            }
-
-            public Task ConnectAsync(CancellationToken cancellationToken)
-            {
-                throw new NotSupportedException();
-            }
-
-            public Task DisconnectAsync(CancellationToken cancellationToken)
-            {
-                throw new NotSupportedException();
-            }
-
-            public Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-            {
-                Array.Copy(_buffer.Array, _position, buffer, offset, count);
-                _position += count;
-
-                return Task.FromResult(count);
-            }
-
-            public Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-            {
-                throw new NotSupportedException();
-            }
-
-            public void Dispose()
-            {
-            }
+            _serializer.Encode(_packet);
+            _bufferWriter.Cleanup();
         }
     }
-}
+
+    [Benchmark]
+    public void Deserialize10000Messages()
+    {
+        var channel = new BenchmarkMqttChannel(_serializedPacket);
+        var reader = new MqttChannelAdapter(channel, new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535)), new MqttNetEventLogger());
+
+        for (var i = 0; i < 10000; i++)
+        {
+            channel.Reset();
+
+            reader.ReceivePacketAsync(CancellationToken.None).GetAwaiter().GetResult();
+        }
+    }
+
+    sealed class BenchmarkMqttChannel : IMqttChannel
+    {
+        readonly ArraySegment<byte> _buffer;
+        int _position;
+
+        public BenchmarkMqttChannel(ArraySegment<byte> buffer)
+        {
+            _buffer = buffer;
+            _position = _buffer.Offset;
+        }
+
+        public EndPoint RemoteEndPoint { get; set; }
+
+        public EndPoint LocalEndPoint { get; set; }
+
+        public bool IsSecureConnection { get; }
+
+        public X509Certificate2 ClientCertificate { get; set; }
+
+        public void Reset()
+        {
+            _position = _buffer.Offset;
+        }
+
+        public Task ConnectAsync(CancellationToken cancellationToken)
+        {
+            throw new NotSupportedException();
+        }
+
+        public Task DisconnectAsync(CancellationToken cancellationToken)
+        {
+            throw new NotSupportedException();
+        }
+
+        public Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            Array.Copy(_buffer!.Array!, _position, buffer, offset, count);
+            _position += count;
+
+            return Task.FromResult(count);
+        }
+
+        public Task WriteAsync(ReadOnlySequence<byte> buffer, bool isEndOfPacket, CancellationToken cancellationToken)
+        {
+            throw new NotSupportedException();
+        }
+
+        public void Dispose()
+        {
+        }
+    }
+}

Source/MQTTnet.Benchmarks/ServerProcessingBenchmark.cs

@@ -1,36 +1,38 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Jobs;
 using MQTTnet.Tests.Mockups;
-using MQTTnet.Tests.Server;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[RPlotExporter, RankColumn]
+[MemoryDiagnoser]
+public class ServerProcessingBenchmark : BaseBenchmark
 {
-    [SimpleJob(RuntimeMoniker.Net60)]
-    [RPlotExporter, RankColumn]
-    [MemoryDiagnoser]
-    public class ServerProcessingBenchmark
+    [GlobalSetup]
+    public void GlobalSetup()
     {
-        [GlobalSetup]
-        public void GlobalSetup()
-        {
-            TestEnvironment.EnableLogger = false;
-        }
-        
-        [GlobalCleanup]
-        public void GlobalCleanup()
-        {
-        }
-        
-        [Benchmark]
-        public void Handle_100_000_Messages_In_Server_MqttClient()
-        {
-            new Load_Tests().Handle_100_000_Messages_In_Server().GetAwaiter().GetResult();
-        }
-        
-        //[Benchmark]
-        public void Handle_100_000_Messages_In_Server_LowLevelMqttClient()
-        {
-            new Load_Tests().Handle_100_000_Messages_In_Low_Level_Client().GetAwaiter().GetResult();
-        }
+        TestEnvironment.EnableLogger = false;
+    }
+
+    [GlobalCleanup]
+    public void GlobalCleanup()
+    {
+    }
+
+    [Benchmark]
+    public void Handle_100_000_Messages_In_Server_MqttClient()
+    {
+        //new Load_Tests().Handle_100_000_Messages_In_Server().GetAwaiter().GetResult();
+    }
+
+    [Benchmark]
+    public void Handle_100_000_Messages_In_Server_LowLevelMqttClient()
+    {
+        //new Load_Tests().Handle_100_000_Messages_In_Low_Level_Client().GetAwaiter().GetResult();
     }
 }

Source/MQTTnet.Benchmarks/SubscribeBenchmark.cs

@@ -1,62 +1,58 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
 using BenchmarkDotNet.Attributes;
-using BenchmarkDotNet.Jobs;
-using MQTTnet.Client;
 using MQTTnet.Server;
-using System.Collections.Generic;
-using System.Linq;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[MemoryDiagnoser]
+public class SubscribeBenchmark : BaseBenchmark
 {
-    [MemoryDiagnoser]
-    public class SubscribeBenchmark
+    const int NumPublishers = 1;
+    const int NumTopicsPerPublisher = 10000;
+    IMqttClient _mqttClient;
+    MqttServer _mqttServer;
+
+    List<string> _topics;
+
+    [GlobalCleanup]
+    public void Cleanup()
     {
-        MqttServer _mqttServer;
-        IMqttClient _mqttClient;
+        _mqttClient.DisconnectAsync().GetAwaiter().GetResult();
+        _mqttServer.StopAsync().GetAwaiter().GetResult();
+        _mqttServer.Dispose();
+    }
 
-        const int NumPublishers = 1;
-        const int NumTopicsPerPublisher = 10000;
+    [GlobalSetup]
+    public void Setup()
+    {
+        TopicGenerator.Generate(NumPublishers, NumTopicsPerPublisher, out var topicsByPublisher, out _, out _);
+        _topics = topicsByPublisher.Values.First();
 
-        List<string> _topics;
+        var serverOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
 
-        [GlobalSetup]
-        public void Setup()
+        var serverFactory = new MqttServerFactory();
+        _mqttServer = serverFactory.CreateMqttServer(serverOptions);
+        var clientFactory = new MqttClientFactory();
+        _mqttClient = clientFactory.CreateMqttClient();
+
+        _mqttServer.StartAsync().GetAwaiter().GetResult();
+
+        var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("localhost").Build();
+
+        _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
+    }
+
+    [Benchmark]
+    public void Subscribe_10000_Topics()
+    {
+        foreach (var topic in _topics)
         {
-            TopicGenerator.Generate(NumPublishers, NumTopicsPerPublisher, out var topicsByPublisher, out var singleWildcardTopicsByPublisher, out var multiWildcardTopicsByPublisher);
-            _topics = topicsByPublisher.Values.First();
+            var subscribeOptions = new MqttClientSubscribeOptionsBuilder().WithTopicFilter(topic).Build();
 
-            var serverOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
-
-            var factory = new MqttFactory();
-            _mqttServer = factory.CreateMqttServer(serverOptions);
-            _mqttClient = factory.CreateMqttClient();
-
-            _mqttServer.StartAsync().GetAwaiter().GetResult();
-
-            var clientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("localhost").Build();
-
-            _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
-        }
-
-        [GlobalCleanup]
-        public void Cleanup()
-        {
-            _mqttClient.DisconnectAsync().GetAwaiter().GetResult();
-            _mqttServer.StopAsync().GetAwaiter().GetResult();
-            _mqttServer.Dispose();
-        }
-
-        [Benchmark]
-        public void Subscribe_10000_Topics()
-        {
-            foreach (var topic in _topics)
-            {
-                var subscribeOptions = new MqttClientSubscribeOptionsBuilder()
-                       .WithTopicFilter(topic, Protocol.MqttQualityOfServiceLevel.AtMostOnce)
-                       .Build();
-                
-                _mqttClient.SubscribeAsync(subscribeOptions).GetAwaiter().GetResult();
-            }
+            _mqttClient.SubscribeAsync(subscribeOptions).GetAwaiter().GetResult();
         }
     }
-}
+}

Source/MQTTnet.Benchmarks/TcpPipesBenchmark.cs

@@ -5,76 +5,73 @@
 using System.IO.Pipelines;
 using System.Net;
 using System.Net.Sockets;
-using System.Threading;
-using System.Threading.Tasks;
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Jobs;
-using MQTTnet.AspNetCore.Client.Tcp;
+using MQTTnet.AspNetCore;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[MemoryDiagnoser]
+public class TcpPipesBenchmark : BaseBenchmark
 {
-    [SimpleJob(RuntimeMoniker.Net60)]
-    [MemoryDiagnoser]
-    public class TcpPipesBenchmark
+    IDuplexPipe _client;
+    IDuplexPipe _server;
+
+    [GlobalSetup]
+    public void Setup()
     {
-        IDuplexPipe _client;
-        IDuplexPipe _server;
+        var server = new TcpListener(IPAddress.Any, 1883);
 
-        [GlobalSetup]
-        public void Setup()
+        server.Start(1);
+
+        var task = Task.Run(() => server.AcceptSocket());
+
+        var clientConnection = new SocketConnection(new IPEndPoint(IPAddress.Loopback, 1883));
+
+        clientConnection.StartAsync().GetAwaiter().GetResult();
+        _client = clientConnection.Transport;
+
+        var serverConnection = new SocketConnection(task.GetAwaiter().GetResult());
+        serverConnection.StartAsync().GetAwaiter().GetResult();
+        _server = serverConnection.Transport;
+    }
+
+
+    [Benchmark]
+    public async Task Send_10000_Chunks_Pipe()
+    {
+        var size = 5;
+        var iterations = 10000;
+
+        await Task.WhenAll(WriteAsync(iterations, size), ReadAsync(iterations, size));
+    }
+
+    async Task ReadAsync(int iterations, int size)
+    {
+        await Task.Yield();
+
+        var expected = iterations * size;
+        long read = 0;
+        var input = _client.Input;
+
+        while (read < expected)
         {
-            var server = new TcpListener(IPAddress.Any, 1883);
-
-            server.Start(1);
-
-            var task = Task.Run(() => server.AcceptSocket());
-
-            var clientConnection = new TcpConnection(new IPEndPoint(IPAddress.Loopback, 1883));
-
-            clientConnection.StartAsync().GetAwaiter().GetResult();
-            _client = clientConnection.Transport;
-
-            var serverConnection = new TcpConnection(task.GetAwaiter().GetResult());
-            serverConnection.StartAsync().GetAwaiter().GetResult();
-            _server = serverConnection.Transport;
-        }
-
-
-        [Benchmark]
-        public async Task Send_10000_Chunks_Pipe()
-        {
-            var size = 5;
-            var iterations = 10000;
-
-            await Task.WhenAll(WriteAsync(iterations, size), ReadAsync(iterations, size));
-        }
-
-        async Task ReadAsync(int iterations, int size)
-        {
-            await Task.Yield();
-
-            var expected = iterations * size;
-            long read = 0;
-            var input = _client.Input;
-
-            while (read < expected)
-            {
-                var readresult = await input.ReadAsync(CancellationToken.None).ConfigureAwait(false);
-                input.AdvanceTo(readresult.Buffer.End);
-                read += readresult.Buffer.Length;
-            }
-        }
-
-        async Task WriteAsync(int iterations, int size)
-        {
-            await Task.Yield();
-
-            var output = _server.Output;
-
-            for (var i = 0; i < iterations; i++)
-            {
-                await output.WriteAsync(new byte[size], CancellationToken.None).ConfigureAwait(false);
-            }
+            var readresult = await input.ReadAsync(CancellationToken.None).ConfigureAwait(false);
+            input.AdvanceTo(readresult.Buffer.End);
+            read += readresult.Buffer.Length;
         }
     }
-}
+
+    async Task WriteAsync(int iterations, int size)
+    {
+        await Task.Yield();
+
+        var output = _server.Output;
+
+        for (var i = 0; i < iterations; i++)
+        {
+            await output.WriteAsync(new byte[size], CancellationToken.None).ConfigureAwait(false);
+        }
+    }
+}

Source/MQTTnet.Benchmarks/TopicFilterComparerBenchmark.cs

@@ -2,276 +2,32 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Jobs;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net60)]
+[RPlotExporter]
+[MemoryDiagnoser]
+public class TopicFilterComparerBenchmark : BaseBenchmark
 {
-    [SimpleJob(RuntimeMoniker.Net60)]
-    [RPlotExporter]
-    [MemoryDiagnoser]
-    public class TopicFilterComparerBenchmark
+    readonly string _longTopic =
+        "AAAAAAAAAAAAAssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssshhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkAAAAAAAAAAAAAAABBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC";
+
+    [Benchmark]
+    public void MqttTopicFilterComparer_10000_LoopMethod()
     {
-        static readonly char[] TopicLevelSeparator = { '/' };
-
-        readonly string _longTopic =
-            "AAAAAAAAAAAAAssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssshhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkAAAAAAAAAAAAAAABBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC";
-
-        [Benchmark]
-        public void MqttTopicFilterComparer_10000_LoopMethod()
+        for (var i = 0; i < 100000; i++)
         {
-            for (var i = 0; i < 100000; i++)
-            {
-                MqttTopicFilterComparer.Compare("sport/tennis/player1", "sport/#");
-                MqttTopicFilterComparer.Compare("sport/tennis/player1/ranking", "sport/#/ranking");
-                MqttTopicFilterComparer.Compare("sport/tennis/player1/score/wimbledon", "sport/+/player1/#");
-                MqttTopicFilterComparer.Compare("sport/tennis/player1", "sport/tennis/+");
-                MqttTopicFilterComparer.Compare("/finance", "+/+");
-                MqttTopicFilterComparer.Compare("/finance", "/+");
-                MqttTopicFilterComparer.Compare("/finance", "+");
-                MqttTopicFilterComparer.Compare(_longTopic, _longTopic);
-            }
-        }
-
-        [Benchmark]
-        public void MqttTopicFilterComparer_10000_LoopMethod_Without_Pointer()
-        {
-            for (var i = 0; i < 100000; i++)
-            {
-                MqttTopicFilterComparerWithoutPointer.Compare("sport/tennis/player1", "sport/#");
-                MqttTopicFilterComparerWithoutPointer.Compare("sport/tennis/player1/ranking", "sport/#/ranking");
-                MqttTopicFilterComparerWithoutPointer.Compare("sport/tennis/player1/score/wimbledon", "sport/+/player1/#");
-                MqttTopicFilterComparerWithoutPointer.Compare("sport/tennis/player1", "sport/tennis/+");
-                MqttTopicFilterComparerWithoutPointer.Compare("/finance", "+/+");
-                MqttTopicFilterComparerWithoutPointer.Compare("/finance", "/+");
-                MqttTopicFilterComparerWithoutPointer.Compare("/finance", "+");
-                MqttTopicFilterComparerWithoutPointer.Compare(_longTopic, _longTopic);
-            }
-        }
-
-        [Benchmark]
-        public void MqttTopicFilterComparer_10000_StringSplitMethod()
-        {
-            for (var i = 0; i < 100000; i++)
-            {
-                LegacyMethodByStringSplit("sport/tennis/player1", "sport/#");
-                LegacyMethodByStringSplit("sport/tennis/player1/ranking", "sport/#/ranking");
-                LegacyMethodByStringSplit("sport/tennis/player1/score/wimbledon", "sport/+/player1/#");
-                LegacyMethodByStringSplit("sport/tennis/player1", "sport/tennis/+");
-                LegacyMethodByStringSplit("/finance", "+/+");
-                LegacyMethodByStringSplit("/finance", "/+");
-                LegacyMethodByStringSplit("/finance", "+");
-                MqttTopicFilterComparer.Compare(_longTopic, _longTopic);
-            }
-        }
-
-        [GlobalSetup]
-        public void Setup()
-        {
-        }
-
-        static bool LegacyMethodByStringSplit(string topic, string filter)
-        {
-            if (topic == null)
-            {
-                throw new ArgumentNullException(nameof(topic));
-            }
-
-            if (filter == null)
-            {
-                throw new ArgumentNullException(nameof(filter));
-            }
-
-            if (string.Equals(topic, filter, StringComparison.Ordinal))
-            {
-                return true;
-            }
-
-            var fragmentsTopic = topic.Split(TopicLevelSeparator, StringSplitOptions.None);
-            var fragmentsFilter = filter.Split(TopicLevelSeparator, StringSplitOptions.None);
-
-            // # > In either case it MUST be the last character specified in the Topic Filter [MQTT-4.7.1-2].
-            for (var i = 0; i < fragmentsFilter.Length; i++)
-            {
-                if (fragmentsFilter[i] == "+")
-                {
-                    continue;
-                }
-
-                if (fragmentsFilter[i] == "#")
-                {
-                    return true;
-                }
-
-                if (i >= fragmentsTopic.Length)
-                {
-                    return false;
-                }
-
-                if (!string.Equals(fragmentsFilter[i], fragmentsTopic[i], StringComparison.Ordinal))
-                {
-                    return false;
-                }
-            }
-
-            return fragmentsTopic.Length == fragmentsFilter.Length;
-        }
-
-        public static class MqttTopicFilterComparerWithoutPointer
-        {
-            public const char LevelSeparator = '/';
-            public const char MultiLevelWildcard = '#';
-            public const char SingleLevelWildcard = '+';
-            public const char ReservedTopicPrefix = '$';
-
-            public static MqttTopicFilterCompareResult Compare(string topic, string filter)
-            {
-                if (string.IsNullOrEmpty(topic))
-                {
-                    return MqttTopicFilterCompareResult.TopicInvalid;
-                }
-
-                if (string.IsNullOrEmpty(filter))
-                {
-                    return MqttTopicFilterCompareResult.FilterInvalid;
-                }
-
-                var filterOffset = 0;
-                var filterLength = filter.Length;
-
-                var topicOffset = 0;
-                var topicLength = topic.Length;
-
-                var topicPointer = topic;
-                var filterPointer = filter;
-
-                var isMultiLevelFilter = filterPointer[filterLength - 1] == MultiLevelWildcard;
-                var isReservedTopic = topicPointer[0] == ReservedTopicPrefix;
-
-                if (isReservedTopic && filterLength == 1 && isMultiLevelFilter)
-                {
-                    // It is not allowed to receive i.e. '$foo/bar' with filter '#'.
-                    return MqttTopicFilterCompareResult.NoMatch;
-                }
-
-                if (isReservedTopic && filterPointer[0] == SingleLevelWildcard)
-                {
-                    // It is not allowed to receive i.e. '$SYS/monitor/Clients' with filter '+/monitor/Clients'.
-                    return MqttTopicFilterCompareResult.NoMatch;
-                }
-
-                if (filterLength == 1 && isMultiLevelFilter)
-                {
-                    // Filter '#' matches basically everything.
-                    return MqttTopicFilterCompareResult.IsMatch;
-                }
-
-                // Go through the filter char by char.
-                while (filterOffset < filterLength && topicOffset < topicLength)
-                {
-                    // Check if the current char is a multi level wildcard. The char is only allowed
-                    // at the very las position.
-                    if (filterPointer[filterOffset] == MultiLevelWildcard && filterOffset != filterLength - 1)
-                    {
-                        return MqttTopicFilterCompareResult.FilterInvalid;
-                    }
-
-                    if (filterPointer[filterOffset] == topicPointer[topicOffset])
-                    {
-                        if (topicOffset == topicLength - 1)
-                        {
-                            // Check for e.g. "foo" matching "foo/#"
-                            if (filterOffset == filterLength - 3 && filterPointer[filterOffset + 1] == LevelSeparator && isMultiLevelFilter)
-                            {
-                                return MqttTopicFilterCompareResult.IsMatch;
-                            }
-
-                            // Check for e.g. "foo/" matching "foo/#"
-                            if (filterOffset == filterLength - 2 && filterPointer[filterOffset] == LevelSeparator && isMultiLevelFilter)
-                            {
-                                return MqttTopicFilterCompareResult.IsMatch;
-                            }
-                        }
-
-                        filterOffset++;
-                        topicOffset++;
-
-                        // Check if the end was reached and i.e. "foo/bar" matches "foo/bar"
-                        if (filterOffset == filterLength && topicOffset == topicLength)
-                        {
-                            return MqttTopicFilterCompareResult.IsMatch;
-                        }
-
-                        var endOfTopic = topicOffset == topicLength;
-
-                        if (endOfTopic && filterOffset == filterLength - 1 && filterPointer[filterOffset] == SingleLevelWildcard)
-                        {
-                            if (filterOffset > 0 && filterPointer[filterOffset - 1] != LevelSeparator)
-                            {
-                                return MqttTopicFilterCompareResult.FilterInvalid;
-                            }
-
-                            return MqttTopicFilterCompareResult.IsMatch;
-                        }
-                    }
-                    else
-                    {
-                        if (filterPointer[filterOffset] == SingleLevelWildcard)
-                        {
-                            // Check for invalid "+foo" or "a/+foo" subscription
-                            if (filterOffset > 0 && filterPointer[filterOffset - 1] != LevelSeparator)
-                            {
-                                return MqttTopicFilterCompareResult.FilterInvalid;
-                            }
-
-                            // Check for bad "foo+" or "foo+/a" subscription
-                            if (filterOffset < filterLength - 1 && filterPointer[filterOffset + 1] != LevelSeparator)
-                            {
-                                return MqttTopicFilterCompareResult.FilterInvalid;
-                            }
-
-                            filterOffset++;
-                            while (topicOffset < topicLength && topicPointer[topicOffset] != LevelSeparator)
-                            {
-                                topicOffset++;
-                            }
-
-                            if (topicOffset == topicLength && filterOffset == filterLength)
-                            {
-                                return MqttTopicFilterCompareResult.IsMatch;
-                            }
-                        }
-                        else if (filterPointer[filterOffset] == MultiLevelWildcard)
-                        {
-                            if (filterOffset > 0 && filterPointer[filterOffset - 1] != LevelSeparator)
-                            {
-                                return MqttTopicFilterCompareResult.FilterInvalid;
-                            }
-
-                            if (filterOffset + 1 != filterLength)
-                            {
-                                return MqttTopicFilterCompareResult.FilterInvalid;
-                            }
-
-                            return MqttTopicFilterCompareResult.IsMatch;
-                        }
-                        else
-                        {
-                            // Check for e.g. "foo/bar" matching "foo/+/#".
-                            if (filterOffset > 0 && filterOffset + 2 == filterLength && topicOffset == topicLength && filterPointer[filterOffset - 1] == SingleLevelWildcard &&
-                                filterPointer[filterOffset] == LevelSeparator && isMultiLevelFilter)
-                            {
-                                return MqttTopicFilterCompareResult.IsMatch;
-                            }
-
-                            return MqttTopicFilterCompareResult.NoMatch;
-                        }
-                    }
-                }
-
-                return MqttTopicFilterCompareResult.NoMatch;
-            }
+            MqttTopicFilterComparer.Compare("sport/tennis/player1", "sport/#");
+            MqttTopicFilterComparer.Compare("sport/tennis/player1/ranking", "sport/#/ranking");
+            MqttTopicFilterComparer.Compare("sport/tennis/player1/score/wimbledon", "sport/+/player1/#");
+            MqttTopicFilterComparer.Compare("sport/tennis/player1", "sport/tennis/+");
+            MqttTopicFilterComparer.Compare("/finance", "+/+");
+            MqttTopicFilterComparer.Compare("/finance", "/+");
+            MqttTopicFilterComparer.Compare("/finance", "+");
+            MqttTopicFilterComparer.Compare(_longTopic, _longTopic);
         }
     }
 }

Source/MQTTnet.Benchmarks/TopicGenerator.cs

@@ -1,81 +1,80 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
+namespace MQTTnet.Benchmarks;
 
-namespace MQTTnet.Benchmarks
+public class TopicGenerator
 {
-    public class TopicGenerator
+    public static void Generate(
+        int numPublishers,
+        int numTopicsPerPublisher,
+        out Dictionary<string, List<string>> topicsByPublisher,
+        out Dictionary<string, List<string>> singleWildcardTopicsByPublisher,
+        out Dictionary<string, List<string>> multiWildcardTopicsByPublisher)
     {
-        public static void Generate(
-           int numPublishers, int numTopicsPerPublisher,
-           out Dictionary<string, List<string>> topicsByPublisher,
-           out Dictionary<string, List<string>> singleWildcardTopicsByPublisher,
-           out Dictionary<string, List<string>> multiWildcardTopicsByPublisher
-           )
+        topicsByPublisher = new Dictionary<string, List<string>>();
+        singleWildcardTopicsByPublisher = new Dictionary<string, List<string>>();
+        multiWildcardTopicsByPublisher = new Dictionary<string, List<string>>();
+
+        // Find some reasonable distribution across three topic levels
+        var topicsPerLevel = (int)Math.Pow(numTopicsPerPublisher, 1.0 / 3.0);
+        if (topicsPerLevel <= 0)
         {
-            topicsByPublisher = new Dictionary<string, List<string>>();
-            singleWildcardTopicsByPublisher = new Dictionary<string, List<string>>();
-            multiWildcardTopicsByPublisher = new Dictionary<string, List<string>>();
+            topicsPerLevel = 1;
+        }
 
-            // Find some reasonable distribution across three topic levels
-            var topicsPerLevel = (int)Math.Pow(numTopicsPerPublisher, (1.0 / 3.0));
-            if (topicsPerLevel <= 0)
+        var numLevel1Topics = topicsPerLevel;
+        var numLevel2Topics = topicsPerLevel;
+
+        var maxNumLevel3Topics = 1 + (int)((double)numTopicsPerPublisher / numLevel1Topics / numLevel2Topics);
+        if (maxNumLevel3Topics <= 0)
+        {
+            maxNumLevel3Topics = 1;
+        }
+
+        for (var p = 0; p < numPublishers; ++p)
+        {
+            var publisherTopicCount = 0;
+            var publisherName = "pub" + p;
+            for (var l1 = 0; l1 < numLevel1Topics; ++l1)
             {
-                topicsPerLevel = 1;
-            }
-
-            int numLevel1Topics = topicsPerLevel;
-            int numLevel2Topics = topicsPerLevel;
-
-            var maxNumLevel3Topics = 1 + (int)((double)numTopicsPerPublisher / numLevel1Topics / numLevel2Topics);
-            if (maxNumLevel3Topics <= 0)
-            {
-                maxNumLevel3Topics = 1;
-            }
-
-            for (var p = 0; p < numPublishers; ++p)
-            {
-                int publisherTopicCount = 0;
-                var publisherName = "pub" + p;
-                for (var l1 = 0; l1 < numLevel1Topics; ++l1)
+                for (var l2 = 0; l2 < numLevel2Topics; ++l2)
                 {
-                    for (var l2 = 0; l2 < numLevel2Topics; ++l2)
+                    for (var l3 = 0; l3 < maxNumLevel3Topics; ++l3)
                     {
-                        for (var l3 = 0; l3 < maxNumLevel3Topics; ++l3)
+                        if (publisherTopicCount >= numTopicsPerPublisher)
                         {
-                            if (publisherTopicCount >= numTopicsPerPublisher)
-                                break;
-
-                            var topic = string.Format("{0}/building{1}/level{2}/sensor{3}", publisherName, l1 + 1, l2 + 1, l3 + 1);
-                            AddPublisherTopic(publisherName, topic, topicsByPublisher);
-
-                            if (l2 == 0)
-                            {
-                                var singleWildcardTopic = string.Format("{0}/building{1}/+/sensor{2}", publisherName, l1 + 1, l3 + 1);
-                                AddPublisherTopic(publisherName, singleWildcardTopic, singleWildcardTopicsByPublisher);
-                            }
-                            if ((l1 == 0) && (l3 == 0))
-                            {
-                                var multiWildcardTopic = string.Format("{0}/+/level{1}/+", publisherName, l2 + 1);
-                                AddPublisherTopic(publisherName, multiWildcardTopic, multiWildcardTopicsByPublisher);
-                            }
-
-                            ++publisherTopicCount;
+                            break;
                         }
+
+                        var topic = $"{publisherName}/building{l1 + 1}/level{l2 + 1}/sensor{l3 + 1}";
+                        AddPublisherTopic(publisherName, topic, topicsByPublisher);
+
+                        if (l2 == 0)
+                        {
+                            var singleWildcardTopic = $"{publisherName}/building{l1 + 1}/+/sensor{l3 + 1}";
+                            AddPublisherTopic(publisherName, singleWildcardTopic, singleWildcardTopicsByPublisher);
+                        }
+
+                        if (l1 == 0 && l3 == 0)
+                        {
+                            var multiWildcardTopic = $"{publisherName}/+/level{l2 + 1}/+";
+                            AddPublisherTopic(publisherName, multiWildcardTopic, multiWildcardTopicsByPublisher);
+                        }
+
+                        ++publisherTopicCount;
                     }
                 }
             }
         }
-
-        static void AddPublisherTopic(string publisherName, string topic, Dictionary<string, List<string>> topicsByPublisher)
-        {
-            List<string> topicList;
-            if (!topicsByPublisher.TryGetValue(publisherName, out topicList))
-            {
-                topicList = new List<string>();
-                topicsByPublisher.Add(publisherName, topicList);
-            }
-            topicList.Add(topic);
-        }
     }
-}
+
+    static void AddPublisherTopic(string publisherName, string topic, Dictionary<string, List<string>> topicsByPublisher)
+    {
+        List<string> topicList;
+        if (!topicsByPublisher.TryGetValue(publisherName, out topicList))
+        {
+            topicList = new List<string>();
+            topicsByPublisher.Add(publisherName, topicList);
+        }
+
+        topicList.Add(topic);
+    }
+}

Source/MQTTnet.Benchmarks/UnsubscribeBenchmark.cs

@@ -1,60 +1,55 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
 using BenchmarkDotNet.Attributes;
-using MQTTnet.Client;
 using MQTTnet.Server;
-using System.Collections.Generic;
-using System.Linq;
 
-namespace MQTTnet.Benchmarks
+namespace MQTTnet.Benchmarks;
+
+[MemoryDiagnoser]
+public class UnsubscribeBenchmark : BaseBenchmark
 {
-    [MemoryDiagnoser]
-    public class UnsubscribeBenchmark
+    const int NumPublishers = 1;
+    const int NumTopicsPerPublisher = 10000;
+
+    IMqttClient _mqttClient;
+    MqttServer _mqttServer;
+    List<string> _topics;
+
+    [GlobalSetup]
+    public void Setup()
     {
-        MqttServer _mqttServer;
-        IMqttClient _mqttClient;
+        TopicGenerator.Generate(NumPublishers, NumTopicsPerPublisher, out var topicsByPublisher, out _, out _);
+        _topics = topicsByPublisher.Values.First();
 
-        const int NumPublishers = 1;
-        const int NumTopicsPerPublisher = 10000;
+        var serverOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
 
-        List<string> _topics;
+        var serverFactory = new MqttServerFactory();
+        _mqttServer = serverFactory.CreateMqttServer(serverOptions);
+        var clientFactory = new MqttClientFactory();
+        _mqttClient = clientFactory.CreateMqttClient();
 
-        [GlobalSetup]
-        public void Setup()
+        _mqttServer.StartAsync().GetAwaiter().GetResult();
+
+        var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("localhost").Build();
+
+        _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
+
+        foreach (var topic in _topics)
         {
-            TopicGenerator.Generate(NumPublishers, NumTopicsPerPublisher, out var topicsByPublisher, out var singleWildcardTopicsByPublisher, out var multiWildcardTopicsByPublisher);
-            _topics = topicsByPublisher.Values.First();
-
-            var serverOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
-
-            var factory = new MqttFactory();
-            _mqttServer = factory.CreateMqttServer(serverOptions);
-            _mqttClient = factory.CreateMqttClient();
-
-            _mqttServer.StartAsync().GetAwaiter().GetResult();
-
-            var clientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("localhost").Build();
-
-            _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
-
-            foreach (var topic in _topics)
-            {
-                var subscribeOptions = new MqttClientSubscribeOptionsBuilder()
-                       .WithTopicFilter(topic)
-                       .Build();
-                _mqttClient.SubscribeAsync(subscribeOptions).GetAwaiter().GetResult();
-            }
-        }
-
-        [Benchmark]
-        public void Unsubscribe_10000_Topics()
-        {
-            foreach (var topic in _topics)
-            {
-                var unsubscribeOptions = new MqttClientUnsubscribeOptionsBuilder()
-                       .WithTopicFilter(topic)
-                       .Build();
-                _mqttClient.UnsubscribeAsync(unsubscribeOptions).GetAwaiter().GetResult();
-            }
+            var subscribeOptions = new MqttClientSubscribeOptionsBuilder().WithTopicFilter(topic).Build();
+            _mqttClient.SubscribeAsync(subscribeOptions).GetAwaiter().GetResult();
         }
     }
-}
+
+    [Benchmark]
+    public void Unsubscribe_10000_Topics()
+    {
+        foreach (var topic in _topics)
+        {
+            var unsubscribeOptions = new MqttClientUnsubscribeOptionsBuilder().WithTopicFilter(topic).Build();
+            _mqttClient.UnsubscribeAsync(unsubscribeOptions).GetAwaiter().GetResult();
+        }
+    }
+}

Source/MQTTnet.Benchmarks/packages.config

@@ -1,54 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<packages>
-  <package id="BenchmarkDotNet" version="0.10.14" targetFramework="net462" />
-  <package id="BenchmarkDotNet.Core" version="0.10.14" targetFramework="net462" />
-  <package id="BenchmarkDotNet.Toolchains.Roslyn" version="0.10.14" targetFramework="net462" />
-  <package id="Microsoft.CodeAnalysis.Analyzers" version="1.1.0" targetFramework="net462" />
-  <package id="Microsoft.CodeAnalysis.Common" version="2.6.1" targetFramework="net462" />
-  <package id="Microsoft.CodeAnalysis.CSharp" version="2.6.1" targetFramework="net462" />
-  <package id="Microsoft.DotNet.InternalAbstractions" version="1.0.0" targetFramework="net462" />
-  <package id="Microsoft.DotNet.PlatformAbstractions" version="1.1.1" targetFramework="net462" />
-  <package id="Microsoft.Win32.Registry" version="4.3.0" targetFramework="net462" />
-  <package id="System.AppContext" version="4.3.0" targetFramework="net462" />
-  <package id="System.Collections" version="4.3.0" targetFramework="net462" />
-  <package id="System.Collections.Concurrent" version="4.3.0" targetFramework="net462" />
-  <package id="System.Collections.Immutable" version="1.3.1" targetFramework="net462" />
-  <package id="System.Console" version="4.3.0" targetFramework="net462" />
-  <package id="System.Diagnostics.Debug" version="4.3.0" targetFramework="net462" />
-  <package id="System.Diagnostics.FileVersionInfo" version="4.3.0" targetFramework="net462" />
-  <package id="System.Diagnostics.StackTrace" version="4.3.0" targetFramework="net462" />
-  <package id="System.Diagnostics.Tools" version="4.3.0" targetFramework="net462" />
-  <package id="System.Dynamic.Runtime" version="4.3.0" targetFramework="net462" />
-  <package id="System.Globalization" version="4.3.0" targetFramework="net462" />
-  <package id="System.IO.Compression" version="4.3.0" targetFramework="net462" />
-  <package id="System.IO.FileSystem" version="4.3.0" targetFramework="net462" />
-  <package id="System.IO.FileSystem.Primitives" version="4.3.0" targetFramework="net462" />
-  <package id="System.Linq" version="4.3.0" targetFramework="net462" />
-  <package id="System.Linq.Expressions" version="4.3.0" targetFramework="net462" />
-  <package id="System.Reflection" version="4.3.0" targetFramework="net462" />
-  <package id="System.Reflection.Metadata" version="1.4.2" targetFramework="net462" />
-  <package id="System.Resources.ResourceManager" version="4.3.0" targetFramework="net462" />
-  <package id="System.Runtime" version="4.3.0" targetFramework="net462" />
-  <package id="System.Runtime.Extensions" version="4.3.0" targetFramework="net462" />
-  <package id="System.Runtime.InteropServices" version="4.3.0" targetFramework="net462" />
-  <package id="System.Runtime.Numerics" version="4.3.0" targetFramework="net462" />
-  <package id="System.Security.Cryptography.Algorithms" version="4.3.0" targetFramework="net462" />
-  <package id="System.Security.Cryptography.Encoding" version="4.3.0" targetFramework="net462" />
-  <package id="System.Security.Cryptography.Primitives" version="4.3.0" targetFramework="net462" />
-  <package id="System.Security.Cryptography.X509Certificates" version="4.3.0" targetFramework="net462" />
-  <package id="System.Text.Encoding" version="4.3.0" targetFramework="net462" />
-  <package id="System.Text.Encoding.CodePages" version="4.3.0" targetFramework="net462" />
-  <package id="System.Text.Encoding.Extensions" version="4.3.0" targetFramework="net462" />
-  <package id="System.Threading" version="4.3.0" targetFramework="net462" />
-  <package id="System.Threading.Tasks" version="4.3.0" targetFramework="net462" />
-  <package id="System.Threading.Tasks.Extensions" version="4.3.0" targetFramework="net462" />
-  <package id="System.Threading.Tasks.Parallel" version="4.3.0" targetFramework="net462" />
-  <package id="System.Threading.Thread" version="4.3.0" targetFramework="net462" />
-  <package id="System.ValueTuple" version="4.3.0" targetFramework="net462" />
-  <package id="System.Xml.ReaderWriter" version="4.3.0" targetFramework="net462" />
-  <package id="System.Xml.XDocument" version="4.3.0" targetFramework="net462" />
-  <package id="System.Xml.XmlDocument" version="4.3.0" targetFramework="net462" />
-  <package id="System.Xml.XmlSerializer" version="4.3.0" targetFramework="net462" />
-  <package id="System.Xml.XPath" version="4.3.0" targetFramework="net462" />
-  <package id="System.Xml.XPath.XDocument" version="4.3.0" targetFramework="net462" />
-</packages>

Source/MQTTnet.Extensions.ManagedClient/ApplicationMessageProcessedEventArgs.cs

@@ -1,24 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public sealed class ApplicationMessageProcessedEventArgs : EventArgs
-    {
-        public ApplicationMessageProcessedEventArgs(ManagedMqttApplicationMessage applicationMessage, Exception exception)
-        {
-            ApplicationMessage = applicationMessage ?? throw new ArgumentNullException(nameof(applicationMessage));
-            Exception = exception;
-        }
-
-        public ManagedMqttApplicationMessage ApplicationMessage { get; }
-        
-        /// <summary>
-        /// Then this is _null_ the message was processed successfully without any error.
-        /// </summary>
-        public Exception Exception { get; }
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/ApplicationMessageSkippedEventArgs.cs

@@ -1,18 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public sealed class ApplicationMessageSkippedEventArgs : EventArgs
-    {
-        public ApplicationMessageSkippedEventArgs(ManagedMqttApplicationMessage applicationMessage)
-        {
-            ApplicationMessage = applicationMessage ?? throw new ArgumentNullException(nameof(applicationMessage));
-        }
-
-        public ManagedMqttApplicationMessage ApplicationMessage { get; }
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/ConnectingFailedEventArgs.cs

@@ -1,21 +0,0 @@
-using System;
-using MQTTnet.Client;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public sealed class ConnectingFailedEventArgs : EventArgs
-    {
-        public ConnectingFailedEventArgs(MqttClientConnectResult connectResult, Exception exception)
-        {
-            ConnectResult = connectResult;
-            Exception = exception;
-        }
-
-        /// <summary>
-        /// This is null when the connection was failing and the server was not reachable.
-        /// </summary>
-        public MqttClientConnectResult ConnectResult { get; }
-
-        public Exception Exception { get; }
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/IManagedMqttClient.cs

@@ -1,52 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Client;
-using MQTTnet.Packets;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public interface IManagedMqttClient : IDisposable
-    {
-        event Func<ApplicationMessageProcessedEventArgs, Task> ApplicationMessageProcessedAsync;
-        
-        event Func<MqttApplicationMessageReceivedEventArgs, Task> ApplicationMessageReceivedAsync;
-        
-        event Func<ApplicationMessageSkippedEventArgs, Task> ApplicationMessageSkippedAsync;
-        
-        event Func<MqttClientConnectedEventArgs, Task> ConnectedAsync;
-        
-        event Func<ConnectingFailedEventArgs, Task> ConnectingFailedAsync;
-        
-        event Func<EventArgs, Task> ConnectionStateChangedAsync;
-        
-        event Func<MqttClientDisconnectedEventArgs, Task> DisconnectedAsync;
-        
-        event Func<ManagedProcessFailedEventArgs, Task> SynchronizingSubscriptionsFailedAsync;
-        
-        IMqttClient InternalClient { get; }
-        
-        bool IsConnected { get; }
-        
-        bool IsStarted { get; }
-        
-        ManagedMqttClientOptions Options { get; }
-        
-        int PendingApplicationMessagesCount { get; }
-        
-        Task EnqueueAsync(MqttApplicationMessage applicationMessage);
-        
-        Task EnqueueAsync(ManagedMqttApplicationMessage applicationMessage);
-        
-        Task PingAsync(CancellationToken cancellationToken = default);
-        
-        Task StartAsync(ManagedMqttClientOptions options);
-        
-        Task StopAsync();
-        
-        Task SubscribeAsync(ICollection<MqttTopicFilter> topicFilters);
-        
-        Task UnsubscribeAsync(ICollection<string> topics);
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/IManagedMqttClientStorage.cs

@@ -1,16 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.Collections.Generic;
-using System.Threading.Tasks;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public interface IManagedMqttClientStorage
-    {
-        Task SaveQueuedMessagesAsync(IList<ManagedMqttApplicationMessage> messages);
-
-        Task<IList<ManagedMqttApplicationMessage>> LoadQueuedMessagesAsync();
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/MQTTnet.Extensions.ManagedClient.csproj

@@ -1,67 +0,0 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-    <PropertyGroup>
-        <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1;netcoreapp3.1;net5.0;net6.0</TargetFrameworks>
-        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
-        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
-        
-        <AssemblyName>MQTTnet.Extensions.ManagedClient</AssemblyName>
-        <RootNamespace>MQTTnet.Extensions.ManagedClient</RootNamespace>
-        <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
-        <Company>The contributors of MQTTnet</Company>
-        <Product>MQTTnet</Product>
-        <Description>This is an extension library which provides a managed MQTT client with additional features using MQTTnet.</Description>
-        <Authors>The contributors of MQTTnet</Authors>
-        <PackageId>MQTTnet.Extensions.ManagedClient</PackageId>
-        <SignAssembly>false</SignAssembly>
-        <DelaySign>false</DelaySign>
-        <PublishRepositoryUrl>true</PublishRepositoryUrl>
-        <IncludeSymbols>true</IncludeSymbols>
-        <SymbolPackageFormat>snupkg</SymbolPackageFormat>
-        <Copyright>Copyright (c) .NET Foundation and Contributors</Copyright>
-        <PackageProjectUrl>https://github.com/dotnet/MQTTnet</PackageProjectUrl>
-        <RepositoryUrl>https://github.com/dotnet/MQTTnet.git</RepositoryUrl>
-        <RepositoryType>git</RepositoryType>
-        <PackageTags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin Blazor</PackageTags>
-        <NeutralLanguage>en-US</NeutralLanguage>
-        <EnableNETAnalyzers>false</EnableNETAnalyzers>
-        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
-        <PackageIcon>nuget.png</PackageIcon>
-        <EmbedUntrackedSources>true</EmbedUntrackedSources>
-        <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
-        <PackageLicenseExpression>MIT</PackageLicenseExpression>
-        <PackageReleaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</PackageReleaseNotes>
-        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
-        <GenerateDocumentationFile>true</GenerateDocumentationFile>
-        <NoWarn>1591</NoWarn>
-    </PropertyGroup>
-
-    <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
-        <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
-        <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
-        <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
-        <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
-        <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
-        <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
-        <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
-        <DefineConstants>$(DefineConstants);WINDOWS_UWP</DefineConstants>
-        <DefaultLanguage>en</DefaultLanguage>
-        <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
-    </PropertyGroup>
-
-    <ItemGroup>
-        <None Include="..\..\Images\nuget.png">
-            <Pack>True</Pack>
-            <PackagePath>\</PackagePath>
-        </None>
-    </ItemGroup>
-    
-    <ItemGroup>
-        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
-    </ItemGroup>
-
-    <ItemGroup>
-        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
-    </ItemGroup>
-
-</Project>