beast/example/websocket/server/chat-multi/shared_state.cpp
2019-02-21 11:09:02 -08:00

60 lines
1.6 KiB
C++

//
// 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/vinniefalco/CppCon2018
//
#include "shared_state.hpp"
#include "websocket_session.hpp"
shared_state::
shared_state(std::string doc_root)
: doc_root_(std::move(doc_root))
{
}
void
shared_state::
join(websocket_session* session)
{
std::lock_guard<std::mutex> lock(mutex_);
sessions_.insert(session);
}
void
shared_state::
leave(websocket_session* session)
{
std::lock_guard<std::mutex> lock(mutex_);
sessions_.erase(session);
}
// Broadcast a message to all websocket client sessions
void
shared_state::
send(std::string message)
{
// Put the message in a shared pointer so we can re-use it for each client
auto const ss = boost::make_shared<std::string const>(std::move(message));
// Make a local list of all the weak pointers representing
// the sessions, so we can do the actual sending without
// holding the mutex:
std::vector<boost::weak_ptr<websocket_session>> v;
{
std::lock_guard<std::mutex> lock(mutex_);
v.reserve(sessions_.size());
for(auto p : sessions_)
v.emplace_back(p->weak_from_this());
}
// For each session in our local list, try to acquire a strong
// pointer. If successful, then send the message on that session.
for(auto const& wp : v)
if(auto sp = wp.lock())
sp->send(ss);
}