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/* Copyright (c) 2018-2022 Marcelo Zimbres Silva (mzimbres@gmail.com)
*
* Distributed under the Boost Software License, Version 1.0. (See
* accompanying file LICENSE.txt)
*/
#include <boost/redis/connection.hpp>
#include <boost/asio/co_spawn.hpp>
#include <boost/asio/consign.hpp>
#include <boost/asio/detached.hpp>
#include <boost/asio/posix/stream_descriptor.hpp>
#include <boost/asio/read_until.hpp>
#include <boost/asio/redirect_error.hpp>
#include <boost/asio/signal_set.hpp>
#include <iostream>
#include <unistd.h>
#if defined(BOOST_ASIO_HAS_CO_AWAIT)
#if defined(BOOST_ASIO_HAS_POSIX_STREAM_DESCRIPTOR)
namespace asio = boost::asio;
using asio::posix::stream_descriptor;
using asio::signal_set;
using boost::asio::async_read_until;
using boost::asio::awaitable;
using boost::asio::co_spawn;
using boost::asio::consign;
using boost::asio::detached;
using boost::asio::dynamic_buffer;
using boost::asio::redirect_error;
using boost::asio::use_awaitable;
using boost::redis::config;
using boost::redis::connection;
using boost::redis::generic_response;
using boost::redis::ignore;
using boost::redis::request;
using boost::system::error_code;
using namespace std::chrono_literals;
// Chat over Redis pubsub. To test, run this program from multiple
// terminals and type messages to stdin.
auto receiver(std::shared_ptr<connection> conn) -> awaitable<void>
{
request req;
req.push("SUBSCRIBE", "channel");
generic_response resp;
conn->set_receive_response(resp);
while (conn->will_reconnect()) {
// Subscribe to channels.
co_await conn->async_exec(req, ignore);
// Loop reading Redis push messages.
for (error_code ec;;) {
co_await conn->async_receive(redirect_error(use_awaitable, ec));
if (ec)
break; // Connection lost, break so we can reconnect to channels.
std::cout << resp.value().at(1).value << " " << resp.value().at(2).value << " "
<< resp.value().at(3).value << std::endl;
resp.value().clear();
}
}
}
// Publishes stdin messages to a Redis channel.
auto publisher(std::shared_ptr<stream_descriptor> in, std::shared_ptr<connection> conn)
-> awaitable<void>
{
for (std::string msg;;) {
auto n = co_await async_read_until(*in, dynamic_buffer(msg, 1024), "\n");
request req;
req.push("PUBLISH", "channel", msg);
co_await conn->async_exec(req, ignore);
msg.erase(0, n);
}
}
// Called from the main function (see main.cpp)
auto co_main(config cfg) -> awaitable<void>
{
auto ex = co_await asio::this_coro::executor;
auto conn = std::make_shared<connection>(ex);
auto stream = std::make_shared<stream_descriptor>(ex, ::dup(STDIN_FILENO));
co_spawn(ex, receiver(conn), detached);
co_spawn(ex, publisher(stream, conn), detached);
conn->async_run(cfg, consign(detached, conn));
signal_set sig_set{ex, SIGINT, SIGTERM};
co_await sig_set.async_wait();
conn->cancel();
stream->cancel();
}
#else // defined(BOOST_ASIO_HAS_POSIX_STREAM_DESCRIPTOR)
auto co_main(config const&) -> awaitable<void>
{
std::cout << "Requires support for posix streams." << std::endl;
co_return;
}
#endif // defined(BOOST_ASIO_HAS_POSIX_STREAM_DESCRIPTOR)
#endif // defined(BOOST_ASIO_HAS_CO_AWAIT)
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