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Files
redis/examples/subscriber.cpp
Marcelo Zimbres df68fb0235 Changes:
- Ports from boost::container::pmr to std::pmr.
- Fixes clang-tidy issues.
- Adds resp3::request unit-tests.
2022-10-31 22:17:58 +01:00

104 lines
3.0 KiB
C++

/* 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 <string>
#include <vector>
#include <iostream>
#include <tuple>
#include <boost/asio.hpp>
#if defined(BOOST_ASIO_HAS_CO_AWAIT)
#include <boost/asio/experimental/awaitable_operators.hpp>
#include <aedis.hpp>
#include "print.hpp"
// Include this in no more than one .cpp file.
#include <aedis/src.hpp>
namespace net = boost::asio;
using namespace net::experimental::awaitable_operators;
using aedis::adapt;
using aedis::resp3::request;
using aedis::resp3::node;
using aedis::endpoint;
using tcp_socket = net::use_awaitable_t<>::as_default_on_t<net::ip::tcp::socket>;
using stimer = net::use_awaitable_t<>::as_default_on_t<net::steady_timer>;
using connection = aedis::connection<tcp_socket>;
/* This example will subscribe and read pushes indefinitely.
*
* To test send messages with redis-cli
*
* $ redis-cli -3
* 127.0.0.1:6379> PUBLISH channel some-message
* (integer) 3
* 127.0.0.1:6379>
*
* To test reconnection try, for example, to close all clients currently
* connected to the Redis instance
*
* $ redis-cli
* > CLIENT kill TYPE pubsub
*/
// Receives pushes.
net::awaitable<void> push_receiver(std::shared_ptr<connection> conn)
{
for (std::vector<node<std::string>> resp;;) {
co_await conn->async_receive(adapt(resp));
print_push(resp);
resp.clear();
}
}
// See
// - https://redis.io/docs/manual/sentinel.
// - https://redis.io/docs/reference/sentinel-clients.
net::awaitable<void> reconnect(std::shared_ptr<connection> conn)
{
request req;
req.get_config().cancel_if_not_connected = false;
req.get_config().cancel_on_connection_lost = true;
req.push("SUBSCRIBE", "channel");
stimer timer{co_await net::this_coro::executor};
endpoint ep{"127.0.0.1", "6379"};
for (;;) {
boost::system::error_code ec1, ec2;
co_await (
conn->async_run(ep, {}, net::redirect_error(net::use_awaitable, ec1)) &&
conn->async_exec(req, adapt(), net::redirect_error(net::use_awaitable, ec2))
);
std::clog << "async_run: " << ec1.message() << "\n"
<< "async_exec: " << ec2.message() << std::endl;
conn->reset_stream();
timer.expires_after(std::chrono::seconds{1});
co_await timer.async_wait();
}
}
auto main() -> int
{
try {
net::io_context ioc;
auto conn = std::make_shared<connection>(ioc);
net::co_spawn(ioc, push_receiver(conn), net::detached);
net::co_spawn(ioc, reconnect(conn), net::detached);
net::signal_set signals(ioc, SIGINT, SIGTERM);
signals.async_wait([&](auto, auto){ ioc.stop(); });
ioc.run();
} catch (std::exception const& e) {
std::cerr << "Error: " << e.what() << std::endl;
}
}
#else // defined(BOOST_ASIO_HAS_CO_AWAIT)
auto main() -> int {std::cout << "Requires coroutine support." << std::endl; return 0;}
#endif // defined(BOOST_ASIO_HAS_CO_AWAIT)