使用websocketpp进行websocket通信
Notaregular 人气:1websocketpp介绍
websocketpp是一个只有头文件的支持websocket协议的C++开源库,支持websocket客户端和服务器功能,网络传输模块基于boost::asio
提供 server 功能的 websocketpp::server 和提供 client 功能的 websocketpp:client 都继承自基类 websocketpp::endpoint , endpoint提供了一些通用的功能函数:
void set_access_channels(log::level channels);//设置日志级别
void clear_access_channels(log::level channels)//屏蔽某个级别的日志
void set_open_handler(open_handler h);//设置打开连接时的回调函数
void set_close_handler(close_handler h);//设置关闭连接时的回调函数
void set_fail_handler(fail_handler h);//设置连接失败时的回调函数
void set_message_handler(message_handler h);//设置收到消息时的回调函数
服务器代码
#include <websocketpp/config/asio_no_tls.hpp>
#include <websocketpp/server.hpp>
#include <functional>
typedef websocketpp::server<websocketpp::config::asio> server;
class utility_server {
public:
utility_server() {
// 设置log
m_endpoint.set_error_channels(websocketpp::log::elevel::all);
m_endpoint.set_access_channels(websocketpp::log::alevel::all ^ websocketpp::log::alevel::frame_payload);
// 初始化Asio
m_endpoint.init_asio();
// 设置消息回调为echo_handler
m_endpoint.set_message_handler(std::bind(
&utility_server::echo_handler, this,
std::placeholders::_1, std::placeholders::_2
));
}
void echo_handler(websocketpp::connection_hdl hdl, server::message_ptr msg) {
// 发送消息
m_endpoint.send(hdl, msg->get_payload(), msg->get_opcode());
}
void run() {
// 监听端口 9002
m_endpoint.listen(9002);
m_endpoint.start_accept();
// 开始Asio事件循环
m_endpoint.run();
}
private:
server m_endpoint;
};
int main() {
utility_server s;
s.run();
return 0;
}
运行后执行到 s.run() 当前线程会进入Asio的消息循环,可以调用s.top()退出
客户端代码
#include <websocketpp/config/asio_no_tls_client.hpp>
#include <websocketpp/client.hpp>
#include <iostream>
typedef websocketpp::client<websocketpp::config::asio_client> client;
using websocketpp::lib::placeholders::_1;
using websocketpp::lib::placeholders::_2;
using websocketpp::lib::bind;
typedef websocketpp::config::asio_client::message_type::ptr message_ptr;
void on_open(client *c, websocketpp::connection_hdl hdl)
{
std::string msg = "hello";
c->send(hdl, msg, websocketpp::frame::opcode::text);
c->get_alog().write(websocketpp::log::alevel::app, "Tx: " + msg);
}
void on_message(client *c, websocketpp::connection_hdl hdl, message_ptr msg)
{
std::cout << "on_message called with hdl: " << hdl.lock().get()
<< " and message: " << msg->get_payload()
<< std::endl;
websocketpp::lib::error_code ec;
//c->send(hdl,msg->get_payload(),msg->get_opcode(),ec);
if(ec)
{
std::cout << "Echo failed because " << ec.message() << std::endl;
}
}
//定时器回调函数
void Timeout(client *c, websocketpp::connection_hdl &hdl, boost::asio::deadline_timer *pt, const boost::system::error_code &ec)
{
if(ec)
{
std::cout << "timer is cancel " << std::endl;
return;
}
static int count = 0;
c->send(hdl, "hello", websocketpp::frame::opcode::text);
count++;
if(count > 5)//定时器触发五次后关闭连接
{
c->close(hdl, websocketpp::close::status::normal, "");
return;
}
pt->expires_at(pt->expires_at() + boost::posix_time::seconds(5));
pt->async_wait(bind(Timeout, c, hdl, pt, ::_1));
}
int main(int argc, char *argv[])
{
client c;
std::string uri = "ws://xx.xx.xx.xx:xxx";
c.set_access_channels(websocketpp::log::alevel::all);
c.clear_access_channels(websocketpp::log::alevel::frame_payload);
c.clear_access_channels(websocketpp::log::alevel::frame_header);
// 初始化 ASIO
c.init_asio();
// 注册消息回调
c.set_message_handler(bind(&on_message, &c, ::_1, ::_2));
c.set_open_handler(bind(&on_open, &c, _1));
websocketpp::lib::error_code ec;
client::connection_ptr con = c.get_connection(uri, ec);
con->add_subprotocol("janus-protocol");
if(ec)
{
std::cout << "could not create connection because: " << ec.message() << std::endl;
return 0;
}
auto hdl = con->get_handle();
c.connect(con);
boost::asio::deadline_timer t(c.get_io_service(), boost::posix_time::seconds(5)); //设置一个5s超时的定时器
t.async_wait(bind(&Timeout, &c, hdl, &t, ::_1));
std::thread th([&c] { c.run(); });
//休眠13s后取消定时器并关闭连接
sleep(13);
t.cancel();
c.close(hdl, websocketpp::close::status::normal, "");
th.join();
}
我们可以利用 Asio 的一些其它组件,如定时器等;初始化定时器传入 c.get_io_service() 在一个io循环中处理定时事件和其它事件
当客户端调用 close 关闭连接时,则自动退出c.run()开启的循环
重复关闭和打开连接
#include <websocketpp/config/asio_no_tls_client.hpp>
#include <websocketpp/client.hpp>
#include <iostream>
typedef websocketpp::client<websocketpp::config::asio_client> client;
using websocketpp::lib::placeholders::_1;
using websocketpp::lib::placeholders::_2;
typedef websocketpp::config::asio_client::message_type::ptr message_ptr;
class connection
{
public:
void on_open(websocketpp::connection_hdl hdl)
{
std::string msg = "hello";
c.send(hdl, msg, websocketpp::frame::opcode::text);
c.get_alog().write(websocketpp::log::alevel::app, "Tx: " + msg);
}
void on_message(websocketpp::connection_hdl hdl, message_ptr msg)
{
std::cout << "on_message called with hdl: " << hdl.lock().get()
<< " and message: " << msg->get_payload()
<< std::endl;
websocketpp::lib::error_code ec;
if(ec)
{
std::cout << "Echo failed because " << ec.message() << std::endl;
}
}
int init()
{
uri = "ws://xx.xx.xx.xx:xx";
c.set_access_channels(websocketpp::log::alevel::all);
c.clear_access_channels(websocketpp::log::alevel::frame_payload);
c.clear_access_channels(websocketpp::log::alevel::frame_header);
c.init_asio();
c.set_message_handler(websocketpp::lib::bind(&connection::on_message, this,::_1, ::_2));
c.set_open_handler(websocketpp::lib::bind(&connection::on_open, this, _1));
c.start_perpetual();
thread_=websocketpp::lib::make_shared<websocketpp::lib::thread>(&client::run,&c);
}
void connect()
{
websocketpp::lib::error_code ec;
client::connection_ptr con = c.get_connection(uri, ec);
if(ec)
{
std::cout << "could not create connection because: " << ec.message() << std::endl;
return ;
}
hdl_ = con->get_handle();
c.connect(con);
}
void close()
{
c.close(hdl_, websocketpp::close::status::normal, "");
}
void terminate()
{
c.stop_perpetual();
thread_->join();
}
private:
client c;
websocketpp::lib::shared_ptr<websocketpp::lib::thread> thread_;
websocketpp::connection_hdl hdl_;
std::string uri;
};
需要重复打开关闭连接时,只调用一次init_asio()函数,然后调用start_perpetual()将endpoint设置为永久的,不会在连接断开时自动退出。需要结束循环,调用stop_perpetual()
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