c++ - 使用streambuf作为缓冲区来 boost asio读写

Question

我正在使用此代码阅读

  socket_.async_read_some(boost::asio::buffer(data_, max_length),
        boost::bind(&session::handle_read, this,
        boost::asio::placeholders::error,
        boost::asio::placeholders::bytes_transferred));

这就是写作

boost::asio::async_write(socket_,
    boost::asio::buffer(data_, bytes_transferred),
    boost::bind(&session::handle_write, this,
    boost::asio::placeholders::error));

其中socket_是socket，max_length是枚举，值为1024，data_是char数组，长度为max_length。

但我想用 streambuf 替换 char 数组缓冲区。我试过了

  boost::asio::streambuf streamBuffer;
  socket_.async_read_some(boost::asio::buffer(streamBuffer),
        boost::bind(&session::handle_read, this,
        boost::asio::placeholders::error,
        boost::asio::placeholders::bytes_transferred));

但不起作用。我该怎么做？

Answer 1

您需要获得 mutable_buffers_type从 streambuf 中用作 async_read_some 的第一个参数。

  boost::asio::streambuf streamBuffer;
  boost::asio::streambuf::mutable_buffers_type mutableBuffer =
      streamBuffer.prepare(max_length);
  socket_.async_read_some(boost::asio::buffer(mutableBuffer),
        boost::bind(&session::handle_read, this,
        boost::asio::placeholders::error,
        boost::asio::placeholders::bytes_transferred));

参见 asio 文档 here和 here了解更多信息。