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标题: Mojo系统 [打印本页]

作者: Qter 时间: 2024-10-31 16:55
标题: Mojo系统
Mojo系统在不同平台上使用不同的底层通信技术，我来详细解析：

1. Windows平台:
```cpp
// 基于 Windows Named Pipes
class NamedPipeChannel {
private:
HANDLE pipe_handle_;

public:
bool Connect(const std::wstring& pipe_name) {
      pipe_handle_ = CreateFileW(
         pipe_name.c_str(),
         GENERIC_READ | GENERIC_WRITE,
         0,             // 不共享
         nullptr,       // 默认安全属性
         OPEN_EXISTING,  // 打开已存在的管道
         FILE_FLAG_OVERLAPPED,  // 异步I/O
         nullptr
      );
      return pipe_handle_ != INVALID_HANDLE_VALUE;
}

bool Write(const void* data, size_t size) {
      DWORD bytes_written;
      return WriteFile(
         pipe_handle_,
         data,
         size,
         &bytes_written,
         nullptr
      );
}
};
```

2. Unix/Linux平台:
```cpp
// 基于 Unix Domain Sockets
class UnixDomainSocket {
private:
int socket_fd_;

public:
bool Connect(const std::string& socket_path) {
      socket_fd_ = socket(AF_UNIX, SOCK_STREAM, 0);
      struct sockaddr_un addr;
      addr.sun_family = AF_UNIX;
      strncpy(addr.sun_path, socket_path.c_str(), sizeof(addr.sun_path));

      return connect(socket_fd_,
                  (struct sockaddr*)&addr,
                  sizeof(addr)) == 0;
}

ssize_t Write(const void* data, size_t size) {
      return write(socket_fd_, data, size);
}
};
```

3. 共享内存实现:
```cpp
// Windows 实现
class SharedMemoryWindows {
private:
HANDLE mapping_handle_;
void* base_address_;

public:
bool Create(size_t size) {
      mapping_handle_ = CreateFileMapping(
         INVALID_HANDLE_VALUE,
         nullptr,
         PAGE_READWRITE,
         0,
         size,
         nullptr
      );

      base_address_ = MapViewOfFile(
         mapping_handle_,
         FILE_MAP_ALL_ACCESS,
         0, 0, size
      );

      return base_address_ != nullptr;
}
};

// Linux 实现
class SharedMemoryLinux {
private:
int shm_fd_;
void* base_address_;

public:
bool Create(size_t size) {
      shm_fd_ = shm_open(
         "/mojo_shm",
         O_CREAT | O_RDWR,
         S_IRUSR | S_IWUSR
      );

      ftruncate(shm_fd_, size);

      base_address_ = mmap(
         nullptr,
         size,
         PROT_READ | PROT_WRITE,
         MAP_SHARED,
         shm_fd_,
         0
      );

      return base_address_ != MAP_FAILED;
}
};
```

4. 传输层优化:
```cpp
class TransportLayer {
private:
// 缓冲区管理
class Buffer {
      std::vector<char> data_;
      size_t read_pos_;
      size_t write_pos_;
};

// 异步IO完成端口(Windows)或epoll(Linux)
class IOMultiplexer {
      #ifdef _WIN32
         HANDLE iocp_handle_;
      #else
         int epoll_fd_;
      #endif
};

public:
// 零拷贝传输
bool SendWithZeroCopy(const void* data, size_t size);

// 批量传输
bool SendBatch(const std::vector<Message>& messages);
};
```

5. 套接字选项优化:
```cpp
class SocketOptimizer {
public:
static void OptimizeSocket(int socket_fd) {
      // 设置发送缓冲区
      int send_buffer_size = 256 * 1024;  // 256KB
      setsockopt(socket_fd,
               SOL_SOCKET,
               SO_SNDBUF,
               &send_buffer_size,
               sizeof(send_buffer_size));

      // 启用 TCP_NODELAY
      int flag = 1;
      setsockopt(socket_fd,
               IPPROTO_TCP,
               TCP_NODELAY,
               &flag,
               sizeof(flag));

      // 启用保活机制
      setsockopt(socket_fd,
               SOL_SOCKET,
               SO_KEEPALIVE,
               &flag,
               sizeof(flag));
}
};
```

6. 消息帧格式:
```cpp
struct MessageFrame {
uint32_t magic;    // 魔数，用于校验
uint32_t version; // 协议版本
uint64_t message_id; // 消息ID
uint32_t payload_size; // 负载大小
uint32_t flags;    // 消息标志
uint8_t payload[]; // 变长负载
};
```

7. 错误处理与恢复:
```cpp
class ConnectionManager {
public:
void HandleDisconnect() {
      // 重连逻辑
      while (!is_connected_ && retry_count_ < max_retries_) {
         if (TryReconnect()) {
            break;
         }
         Sleep(retry_interval_ms_);
         retry_count_++;
      }
}

void HandleError(Error error) {
      switch (error) {
         case Error::CONNECTION_RESET:
            HandleDisconnect();
            break;
         case Error::BUFFER_FULL:
            FlushBuffers();
            break;
      }
}
};
```

总结一下，Mojo系统底层通信主要依赖于：

1. Windows: Named Pipes
2. Unix/Linux: Unix Domain Sockets
3. 共享内存:
- Windows: CreateFileMapping/MapViewOfFile
- Linux: shm_open/mmap

这些底层机制都经过了优化和封装，以提供:
- 高性能的数据传输
- 可靠的连接管理
- 有效的错误恢复
- 灵活的消息处理

你想深入了解哪个具体实现细节吗？

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