如何修复Boost::Asio客户端Http请求错误? 我试图精益::ASIO网络库,用于C++,但我坚持使用异步线程进行请求。
守则:如何修复Boost::Asio客户端Http请求错误? 我试图精益::ASIO网络库,用于C++,但我坚持使用异步线程进行请求。,c++,multithreading,boost,boost-asio,C++,Multithreading,Boost,Boost Asio,守则: #include "stdafx.h" #include <iostream> #include <boost/asio.hpp> #include <boost/asio/ts/buffer.hpp> #include <boost/asio/ts/internet.hpp> #include <boost/system/error_code.hpp> std::vector<char> vB
#include "stdafx.h"
#include <iostream>
#include <boost/asio.hpp>
#include <boost/asio/ts/buffer.hpp>
#include <boost/asio/ts/internet.hpp>
#include <boost/system/error_code.hpp>
std::vector<char> vBuffrer(20 * 1024);
void GrabSomeData(boost::asio::ip::tcp::socket& socket) {
socket.async_read_some(boost::asio::buffer(vBuffrer.data(), vBuffrer.size()),
[&](std::error_code ec, std::size_t length)
//boost::system::error_code ec
{
if (!ec)
{
std::cout << "\n\nRead" << length << "bytes\n\n";
for (int i = 0; i < length; i++)
std::cout << vBuffrer[i];
GrabSomeData(socket);
}
});
}
int main()
{
boost::system::error_code ec;
boost::asio::io_context context;
boost::asio::io_context::work idleWork(context);
boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::make_address("13.107.21.200",ec),80);
boost::asio::ip::tcp::socket socket(context);
std::thread thrContext = std::thread([&]() {context.run(); });
std::cout << "Starting " << std::endl;
socket.connect(endpoint,ec);
if (!ec)
{
std::cout << "Connected ! " << std::endl;
}
else {
std::cout << "Fail to connect ! " << ec.message() << std::endl;
}
if (socket.is_open()) {
GrabSomeData(socket);
std::string sRequest =
"GET /index.html HTTP/1.1\r\n"
"Host: www.example.com\r\n"
"Connection: close\r\n\r\n";
socket.write_some(boost::asio::buffer(sRequest.data(), sRequest.size()), ec);
using namespace std::chrono_literals;
std::this_thread::sleep_for(2800ms);
//std::this_thread::sleep_for(1ms);
context.stop();
if (thrContext.joinable()) thrContext.join();
}
system("pause");
return 0;
}
#包括“stdafx.h”
#包括
#包括
#包括
#包括
#包括
标准:向量vBuffrer(20*1024);
void GrabSomeData(boost::asio::ip::tcp::socket和socket){
socket.async_read_some(boost::asio::buffer(vBuffrer.data(),vBuffrer.size()),
[&](标准::错误代码ec,标准::大小\u t长度)
//boost::system::错误代码ec
{
如果(!ec)
{
std::cout与评论者一样,我无法重新编写您的消息:它只是编译
- MSVC 19,/std:c++14,Boost 1.75.0:
现在,我想看看其他问题:
write\u一些
可能不会写入所有数据-您需要确保一个组合写入操作
竞争条件:由于您正在线程上执行GrabSomeData
,因此
需要同步对tcp::socket
和缓冲区的访问
共享资源)
io_上下文
本身是线程安全的
在这种情况下,很容易避免,因为您不需要这样做
在发送请求之前,请启动异步操作:
write(socket, boost::asio::buffer(sRequest));
GrabSomeData(socket);
async\u read\u有些
与写入端有类似的问题。您需要一个组合读取操作,读取预期的输出,以便read\u直到(socket,buf,“\r\n\r\n”)
然后根据内容长度
头、连接:Close
和其他内容读取预期的内容量(想想分块编码)
您目前没有很好的方法来存储和访问响应。使用streambuf(单一组合读取)会容易得多
如果您想要真正可靠,请使用Beast接收HTTP/1.1响应(甚至可以分块),而不必担心响应何时完成(库会为您完成):
auto-GrabSomeData(tcp::socket和socket){
http::res响应;
自动buf=boost::asio::动态缓冲区(vBuffer);
http::read(套接字、buf、res);
返回res;
}
哦,不要在线程上执行此操作(无论如何,这是为什么?它实际上只是引入了未定义的行为,没有任何好处):
简化代码
#include <boost/asio.hpp>
#include <boost/beast/http.hpp>
#include <iostream>
#include <iomanip>
using boost::asio::ip::tcp;
std::vector<char> vBuffer; // TODO FIXME global variable
auto GrabSomeData(tcp::socket& socket) {
namespace http = boost::beast::http;
http::response<http::string_body> res;
auto buf = boost::asio::dynamic_buffer(vBuffer);
http::read(socket, buf, res);
return res;
}
int main() try {
boost::asio::io_context context;
std::cout << "Starting " << std::endl;
tcp::endpoint endpoint(boost::asio::ip::make_address("13.107.21.200"), 80);
tcp::socket socket(context);
socket.connect(endpoint);
std::cout << "Connected" << std::endl;
std::string const sRequest = "GET /index.html HTTP/1.1\r\n"
"Host: www.example.com\r\n"
"Connection: close\r\n"
"\r\n";
write(socket, boost::asio::buffer(sRequest));
auto response = GrabSomeData(socket);
std::cout << "Response body length: " << response.body().size() << std::endl;
std::cout << "Response headers: " << response.base() << std::endl;
std::cout << "Response body: " << std::quoted(response.body()) << std::endl;
context.run(); // run_for(10s) e.g.
} catch (boost::system::system_error const& se) {
std::cerr << "Error: " << se.code().message() << std::endl;
}
#include <boost/asio.hpp>
#include <boost/beast/http.hpp>
#include <iostream>
#include <iomanip>
using boost::asio::ip::tcp;
std::vector<char> vBuffer; // TODO FIXME global variable
auto GrabSomeData(tcp::socket& socket) {
namespace http = boost::beast::http;
http::response<http::string_body> res;
auto buf = boost::asio::dynamic_buffer(vBuffer);
http::read(socket, buf, res);
return res;
}
int main() try {
boost::asio::io_context context;
std::cout << "Starting " << std::endl;
tcp::endpoint endpoint(boost::asio::ip::make_address("13.107.21.200"), 80);
tcp::socket socket(context);
socket.connect(endpoint);
std::cout << "Connected" << std::endl;
std::string const sRequest = "GET /index.html HTTP/1.1\r\n"
"Host: www.example.com\r\n"
"Connection: close\r\n"
"\r\n";
write(socket, boost::asio::buffer(sRequest));
auto response = GrabSomeData(socket);
std::cout << "Response body length: " << response.body().size() << std::endl;
std::cout << "Response headers: " << response.base() << std::endl;
std::cout << "Response body: " << std::quoted(response.body()) << std::endl;
context.run(); // run_for(10s) e.g.
} catch (boost::system::system_error const& se) {
std::cerr << "Error: " << se.code().message() << std::endl;
}
#包括
#包括
#包括
#包括
使用boost::asio::ip::tcp;
std::vector vBuffer;//TODO FIXME全局变量
自动抓取SomeData(tcp::socket和socket){
命名空间http=boost::beast::http;
http::res响应;
自动buf=boost::asio::动态缓冲区(vBuffer);
http::read(套接字、buf、res);
返回res;
}
int main()尝试{
boost::asio::io_上下文;
std::cout感谢@sehe的回答和建议,花了这么长时间,但我已经升级到新的Windows10和VisualStudio2019,以及Boost 1_76,问题解决了
这些错误与代码完全无关!不编译“致命错误:stdafx.h:没有这样的文件或目录”你是在Linux上编译的吗?是的;请使用标准的headersIt它是Windows的标准,stdafx.h是Windows的东西。如果我从Header中删除它,它就不会在Visual Studio上编译。这并不是说我喜欢它在Windows上,但教程是这样的,而且它应该是跨平台的!仅供参考,这里编译/链接/运行良好(显然,没有stdafx.h)
#include <boost/asio.hpp>
#include <boost/beast/http.hpp>
#include <iostream>
#include <iomanip>
using boost::asio::ip::tcp;
std::vector<char> vBuffer; // TODO FIXME global variable
auto GrabSomeData(tcp::socket& socket) {
namespace http = boost::beast::http;
http::response<http::string_body> res;
auto buf = boost::asio::dynamic_buffer(vBuffer);
http::read(socket, buf, res);
return res;
}
int main() try {
boost::asio::io_context context;
std::cout << "Starting " << std::endl;
tcp::endpoint endpoint(boost::asio::ip::make_address("13.107.21.200"), 80);
tcp::socket socket(context);
socket.connect(endpoint);
std::cout << "Connected" << std::endl;
std::string const sRequest = "GET /index.html HTTP/1.1\r\n"
"Host: www.example.com\r\n"
"Connection: close\r\n"
"\r\n";
write(socket, boost::asio::buffer(sRequest));
auto response = GrabSomeData(socket);
std::cout << "Response body length: " << response.body().size() << std::endl;
std::cout << "Response headers: " << response.base() << std::endl;
std::cout << "Response body: " << std::quoted(response.body()) << std::endl;
context.run(); // run_for(10s) e.g.
} catch (boost::system::system_error const& se) {
std::cerr << "Error: " << se.code().message() << std::endl;
}
Starting
Connected
Response body length: 194
Response headers: HTTP/1.1 400 Bad Request
Transfer-Encoding: chunked
X-MSEdge-Ref: 0BstXYAAAAACeQ2y+botzQISiBe2U3iGCQ0hHRURHRTE0MDgARWRnZQ==
Date: Sun, 21 Mar 2021 22:39:02 GMT
Connection: close
Response body: "<h2>Our services aren't available right now</h2><p>We're working to restore all services as soon as possible. Please check back soon.</p>0BstXYAAAAACeQ2y+botzQISiBe2U3iGCQ0hHRURHRTE0MDgARWRnZQ=="