Extend MQTTnet.Server application.

Source/MQTTnet.Server/Scripting/DataSharing/DataSharingService.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using Microsoft.Extensions.Logging;
+
+namespace MQTTnet.Server.Scripting.DataSharing
+{
+    public class DataSharingService
+    {
+        private readonly Dictionary<string, object> _storage = new Dictionary<string, object>();
+        private readonly PythonScriptHostService _pythonScriptHostService;
+        private readonly ILogger<DataSharingService> _logger;
+
+        public DataSharingService(PythonScriptHostService pythonScriptHostService, ILogger<DataSharingService> logger)
+        {
+            _pythonScriptHostService = pythonScriptHostService ?? throw new ArgumentNullException(nameof(pythonScriptHostService));
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }
+
+        public void Configure()
+        {
+            _pythonScriptHostService.RegisterProxyObject("write_shared_data", new Action<string, object>(Write));
+            _pythonScriptHostService.RegisterProxyObject("read_shared_data", new Func<string, object, object>(Read));
+        }
+
+        public void Write(string key, object value)
+        {
+            lock (_storage)
+            {
+                _storage[key] = value;
+                _logger.LogInformation($"Shared data with key '{key}' updated.");
+            }
+        }
+
+        public object Read(string key, object defaultValue)
+        {
+            lock (_storage)
+            {
+                if (!_storage.TryGetValue(key, out var value))
+                {
+                    return defaultValue;
+                }
+
+                return value;
+            }
+        }
+    }
+}