如何重用http::beast::flat_buffer和http::response？

Question

我在我的项目中使用 boost::beast。以下代码是示例代码的修改版本。我尝试在下面的代码中重复使用 flat_buffer 和 http::response，但结果是错误的。在第二个查询中，响应主体是两个查询结果的连接。我怎么解决这个问题？

#include <iostream>
#include <string>

#include <boost/beast/core.hpp>
#include <boost/beast/http.hpp>
#include <boost/beast/version.hpp>
#include <boost/asio/connect.hpp>
#include <boost/asio/ip/tcp.hpp>

int main(int argc, char** argv) {
  using tcp = boost::asio::ip::tcp;       // from <boost/asio/ip/tcp.hpp>
  namespace http = boost::beast::http;    // from <boost/beast/http.hpp>
  auto const host = "www.example.com";
  auto const port = "80";
  auto const target = "/";
  int version = 11;

  boost::asio::io_context ioc;
  tcp::resolver resolver{ioc};
  tcp::socket socket{ioc};

  auto const results = resolver.resolve(host, port);

  // Make the connection on the IP address we get from a lookup
  boost::asio::connect(socket, results.begin(), results.end());

  // Set up an HTTP GET request message
  http::request<http::string_body> req{http::verb::get, target, version};
  req.set(http::field::host, host);
  req.set(http::field::user_agent, BOOST_BEAST_VERSION_STRING);

  // This buffer is used for reading and must be persisted
  boost::beast::flat_buffer buffer;
  // Declare a container to hold the response
  http::response<http::dynamic_body> res;

  for (int n = 0; n < 2; n++) {
    http::write(socket, req);
    http::read(socket, buffer, res);
    // Write the message to standard out
    std::cout << res << std::endl;
    std::cout << "+++++++++++++++++\n";
  }

  // Gracefully close the socket
  boost::system::error_code ec;
  socket.shutdown(tcp::socket::shutdown_both, ec);
  return EXIT_SUCCESS;
}

Answer 1

http::read是加法。如果您希望在调用 read 之前清空缓冲区，则需要手动执行此操作。

一种方式是这样的：

buffer.consume(buffer.size());

如果您可以访问 slack，野兽团队总是很乐意为您提供帮助：

http://slack.cpp.al

频道#beast

如何重用http::beast::flat_buffer和http::response？

How to reuse http::beast::flat_buffer and http::response?

c++

boost-asio

boost-beast