libs/beast/example/websocket/server/coro/websocket_server_coro.cpp
//
// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/boostorg/beast
//
//------------------------------------------------------------------------------
//
// Example: WebSocket server, coroutine
//
//------------------------------------------------------------------------------
#include <boost/beast/core.hpp>
#include <boost/beast/websocket.hpp>
#include <boost/asio/spawn.hpp>
#include <algorithm>
#include <cstdlib>
#include <functional>
#include <iostream>
#include <memory>
#include <string>
#include <thread>
#include <vector>
namespace beast = boost::beast; // from <boost/beast.hpp>
namespace http = beast::http; // from <boost/beast/http.hpp>
namespace websocket = beast::websocket; // from <boost/beast/websocket.hpp>
namespace net = boost::asio; // from <boost/asio.hpp>
using tcp = boost::asio::ip::tcp; // from <boost/asio/ip/tcp.hpp>
//------------------------------------------------------------------------------
// Report a failure
void
fail(beast::error_code ec, char const* what)
{
std::cerr << what << ": " << ec.message() << "\n";
}
// Echoes back all received WebSocket messages
void
do_session(
websocket::stream<beast::tcp_stream>& ws,
net::yield_context yield)
{
beast::error_code ec;
// Set suggested timeout settings for the websocket
ws.set_option(
websocket::stream_base::timeout::suggested(
beast::role_type::server));
// Set a decorator to change the Server of the handshake
ws.set_option(websocket::stream_base::decorator(
[](websocket::response_type& res)
{
res.set(http::field::server,
std::string(BOOST_BEAST_VERSION_STRING) +
" websocket-server-coro");
}));
// Accept the websocket handshake
ws.async_accept(yield[ec]);
if(ec)
return fail(ec, "accept");
for(;;)
{
// This buffer will hold the incoming message
beast::flat_buffer buffer;
// Read a message
ws.async_read(buffer, yield[ec]);
// This indicates that the session was closed
if(ec == websocket::error::closed)
break;
if(ec)
return fail(ec, "read");
// Echo the message back
ws.text(ws.got_text());
ws.async_write(buffer.data(), yield[ec]);
if(ec)
return fail(ec, "write");
}
}
//------------------------------------------------------------------------------
// Accepts incoming connections and launches the sessions
void
do_listen(
net::io_context& ioc,
tcp::endpoint endpoint,
net::yield_context yield)
{
beast::error_code ec;
// Open the acceptor
tcp::acceptor acceptor(ioc);
acceptor.open(endpoint.protocol(), ec);
if(ec)
return fail(ec, "open");
// Allow address reuse
acceptor.set_option(net::socket_base::reuse_address(true), ec);
if(ec)
return fail(ec, "set_option");
// Bind to the server address
acceptor.bind(endpoint, ec);
if(ec)
return fail(ec, "bind");
// Start listening for connections
acceptor.listen(net::socket_base::max_listen_connections, ec);
if(ec)
return fail(ec, "listen");
for(;;)
{
tcp::socket socket(ioc);
acceptor.async_accept(socket, yield[ec]);
if(ec)
fail(ec, "accept");
else
boost::asio::spawn(
acceptor.get_executor(),
std::bind(
&do_session,
websocket::stream<
beast::tcp_stream>(std::move(socket)),
std::placeholders::_1));
}
}
int main(int argc, char* argv[])
{
// Check command line arguments.
if (argc != 4)
{
std::cerr <<
"Usage: websocket-server-coro <address> <port> <threads>\n" <<
"Example:\n" <<
" websocket-server-coro 0.0.0.0 8080 1\n";
return EXIT_FAILURE;
}
auto const address = net::ip::make_address(argv[1]);
auto const port = static_cast<unsigned short>(std::atoi(argv[2]));
auto const threads = std::max<int>(1, std::atoi(argv[3]));
// The io_context is required for all I/O
net::io_context ioc(threads);
// Spawn a listening port
boost::asio::spawn(ioc,
std::bind(
&do_listen,
std::ref(ioc),
tcp::endpoint{address, port},
std::placeholders::_1));
// Run the I/O service on the requested number of threads
std::vector<std::thread> v;
v.reserve(threads - 1);
for(auto i = threads - 1; i > 0; --i)
v.emplace_back(
[&ioc]
{
ioc.run();
});
ioc.run();
return EXIT_SUCCESS;
}