[feat] rewrite rtp module

src/common/copy_on_write_buffer.h

@@ -0,0 +1,46 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2025-01-22
+ * Copyright (c) 2025 by DI JUNKUN, All Rights Reserved.
+ */
+
+#ifndef _COPY_ON_WRITE_BUFFER_H_
+#define _COPY_ON_WRITE_BUFFER_H_
+
+#include <memory>
+#include <vector>
+
+class CopyOnWriteBuffer {
+ public:
+  CopyOnWriteBuffer() = default;
+  CopyOnWriteBuffer(const CopyOnWriteBuffer& other) = default;
+  CopyOnWriteBuffer(CopyOnWriteBuffer&& other) noexcept = default;
+  CopyOnWriteBuffer& operator=(const CopyOnWriteBuffer& other) = default;
+  CopyOnWriteBuffer& operator=(CopyOnWriteBuffer&& other) noexcept = default;
+
+  void SetData(const uint8_t* data, size_t size) {
+    buffer_ = std::make_shared<std::vector<uint8_t>>(data, data + size);
+  }
+
+  const uint8_t* data() const { return buffer_ ? buffer_->data() : nullptr; }
+
+  size_t size() const { return buffer_ ? buffer_->size() : 0; }
+
+  uint8_t& operator[](size_t index) {
+    EnsureUnique();
+    return (*buffer_)[index];
+  }
+
+  const uint8_t& operator[](size_t index) const { return (*buffer_)[index]; }
+
+ private:
+  void EnsureUnique() {
+    if (!buffer_.unique()) {
+      buffer_ = std::make_shared<std::vector<uint8_t>>(*buffer_);
+    }
+  }
+
+  std::shared_ptr<std::vector<uint8_t>> buffer_;
+};
+
+#endif