ceph/src/boost/libs/beast/example/websocket/server/coro/websocket_server_coro.cpp

   1 //
   2 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
   3 //
   4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // Official repository: https://github.com/boostorg/beast
   8 //
   9
  10 //------------------------------------------------------------------------------
  11 //
  12 // Example: WebSocket server, coroutine
  13 //
  14 //------------------------------------------------------------------------------
  15
  16 #include <boost/beast/core.hpp>
  17 #include <boost/beast/websocket.hpp>
  18 #include <boost/asio/spawn.hpp>
  19 #include <algorithm>
  20 #include <cstdlib>
  21 #include <functional>
  22 #include <iostream>
  23 #include <memory>
  24 #include <string>
  25 #include <thread>
  26 #include <vector>
  27
  28 namespace beast = boost::beast;         // from <boost/beast.hpp>
  29 namespace http = beast::http;           // from <boost/beast/http.hpp>
  30 namespace websocket = beast::websocket; // from <boost/beast/websocket.hpp>
  31 namespace net = boost::asio;            // from <boost/asio.hpp>
  32 using tcp = boost::asio::ip::tcp;       // from <boost/asio/ip/tcp.hpp>
  33
  34 //------------------------------------------------------------------------------
  35
  36 // Report a failure
  37 void
  38 fail(beast::error_code ec, char const* what)
  39 {
  40     std::cerr << what << ": " << ec.message() << "\n";
  41 }
  42
  43 // Echoes back all received WebSocket messages
  44 void
  45 do_session(
  46     websocket::stream<beast::tcp_stream>& ws,
  47     net::yield_context yield)
  48 {
  49     beast::error_code ec;
  50
  51     // Set suggested timeout settings for the websocket
  52     ws.set_option(
  53         websocket::stream_base::timeout::suggested(
  54             beast::role_type::server));
  55
  56     // Set a decorator to change the Server of the handshake
  57     ws.set_option(websocket::stream_base::decorator(
  58         [](websocket::response_type& res)
  59         {
  60             res.set(http::field::server,
  61                 std::string(BOOST_BEAST_VERSION_STRING) +
  62                     " websocket-server-coro");
  63         }));
  64
  65     // Accept the websocket handshake
  66     ws.async_accept(yield[ec]);
  67     if(ec)
  68         return fail(ec, "accept");
  69
  70     for(;;)
  71     {
  72         // This buffer will hold the incoming message
  73         beast::flat_buffer buffer;
  74
  75         // Read a message
  76         ws.async_read(buffer, yield[ec]);
  77
  78         // This indicates that the session was closed
  79         if(ec == websocket::error::closed)
  80             break;
  81
  82         if(ec)
  83             return fail(ec, "read");
  84
  85         // Echo the message back
  86         ws.text(ws.got_text());
  87         ws.async_write(buffer.data(), yield[ec]);
  88         if(ec)
  89             return fail(ec, "write");
  90     }
  91 }
  92
  93 //------------------------------------------------------------------------------
  94
  95 // Accepts incoming connections and launches the sessions
  96 void
  97 do_listen(
  98     net::io_context& ioc,
  99     tcp::endpoint endpoint,
 100     net::yield_context yield)
 101 {
 102     beast::error_code ec;
 103
 104     // Open the acceptor
 105     tcp::acceptor acceptor(ioc);
 106     acceptor.open(endpoint.protocol(), ec);
 107     if(ec)
 108         return fail(ec, "open");
 109
 110     // Allow address reuse
 111     acceptor.set_option(net::socket_base::reuse_address(true), ec);
 112     if(ec)
 113         return fail(ec, "set_option");
 114
 115     // Bind to the server address
 116     acceptor.bind(endpoint, ec);
 117     if(ec)
 118         return fail(ec, "bind");
 119
 120     // Start listening for connections
 121     acceptor.listen(net::socket_base::max_listen_connections, ec);
 122     if(ec)
 123         return fail(ec, "listen");
 124
 125     for(;;)
 126     {
 127         tcp::socket socket(ioc);
 128         acceptor.async_accept(socket, yield[ec]);
 129         if(ec)
 130             fail(ec, "accept");
 131         else
 132             boost::asio::spawn(
 133                 acceptor.get_executor(),
 134                 std::bind(
 135                     &do_session,
 136                     websocket::stream<
 137                         beast::tcp_stream>(std::move(socket)),
 138                     std::placeholders::_1));
 139     }
 140 }
 141
 142 int main(int argc, char* argv[])
 143 {
 144     // Check command line arguments.
 145     if (argc != 4)
 146     {
 147         std::cerr <<
 148             "Usage: websocket-server-coro <address> <port> <threads>\n" <<
 149             "Example:\n" <<
 150             "    websocket-server-coro 0.0.0.0 8080 1\n";
 151         return EXIT_FAILURE;
 152     }
 153     auto const address = net::ip::make_address(argv[1]);
 154     auto const port = static_cast<unsigned short>(std::atoi(argv[2]));
 155     auto const threads = std::max<int>(1, std::atoi(argv[3]));
 156
 157     // The io_context is required for all I/O
 158     net::io_context ioc(threads);
 159
 160     // Spawn a listening port
 161     boost::asio::spawn(ioc,
 162         std::bind(
 163             &do_listen,
 164             std::ref(ioc),
 165             tcp::endpoint{address, port},
 166             std::placeholders::_1));
 167
 168     // Run the I/O service on the requested number of threads
 169     std::vector<std::thread> v;
 170     v.reserve(threads - 1);
 171     for(auto i = threads - 1; i > 0; --i)
 172         v.emplace_back(
 173         [&ioc]
 174         {
 175             ioc.run();
 176         });
 177     ioc.run();
 178
 179     return EXIT_SUCCESS;
 180 }