This document discusses using ReactPHP with Symfony to build asynchronous web applications that can handle a high volume of requests with minimal server resources. It provides code examples for bootstrapping a ReactPHP server, translating requests between ReactPHP and Symfony formats, handling responses, and creating asynchronous controller actions. Additional asynchronous libraries are also listed for connecting to databases like MySQL and message brokers like RabbitMQ.

1. ReactPHP + Symfony = PROFIT
aneb 1000req/s s minimálními nároky na server
1. sraz přátel Symfony v Praze (29.10.2015)

2. O mně
• Kouzelná Almara
• Skrz.cz
• @jakubkulhan
• jakub.kulhan@gmail.com
• github.com/jakubkulhan

3. Slovníček
• klik = najedu myší na nabídku a zmáčknu tlačítko
• imprese = podíval jsem se na nabídku
(alespoň polovina nabídky byla ve viewportu
alespoň jednu sekundu)
• CTR (click-through rate) = kliky / imprese

6. ReactPHP
(neplést s ReactJS!)
http://reactphp.org/
(https://github.com/jakubkulhan/hit-server-bench)

7. ReactPHP: req, res → λ
Symfony: req → λ → res
❓

8. req → λ → promise[res]
❗

9. github.com/jakubkulhan/
reactphp-symfony

10. Boot
$kernel = new AppKernel(
$environment = $input->getOption("environment"),
$environment !== "prod"
);
$kernel->boot();
$loop = Factory::create();
/** @var Container $container */
$container = $kernel->getContainer();
$container->set("react.loop", $loop);
$socket = new Socket($loop);
$http = new Server($socket);
$http->on("request", function (
Request $request,
Response $response
) use ($kernel, $loop) {
// ...
});
$socket->listen(
$port = $input->getOption("port"),
$host = $input->getOption("host")
);
echo "Listening to {$host}:{$port}n";
$loop->run();

11. ReactPHP → Symfony
$headers = $request->getHeaders();
$cookies = [];
if (isset($headers["Cookie"])) {
foreach ((array)$headers["Cookie"] as $cookieHeader) {
foreach (explode(";", $cookieHeader) as $cookie) {
list($name, $value) = explode("=", trim($cookie), 2);
$cookies[$name] = urldecode($value);
}
}
}
$symfonyRequest = new SymfonyRequest(
$request->getQuery(),
[], // TODO: handle post data
[],
$cookies,
[],
[
"REQUEST_URI" => $request->getPath(),
"SERVER_NAME" => explode(":", $headers["Host"])[0],
"REMOTE_ADDR" => $request->remoteAddress,
"QUERY_STRING" => http_build_query($request->getQuery()),
],
null // TODO: handle post data
);
$symfonyRequest->headers->replace($headers);
$symfonyResponse = $kernel->handle($symfonyRequest);
if ($kernel instanceof TerminableInterface) {
$kernel->terminate($symfonyRequest, $symfonyResponse);
}

12. Symfony → ReactPHP
if ($symfonyResponse instanceof PromiseInterface) {
$symfonyResponse->then(function (SymfonyResponse $symfonyResponse) use ($response) {
$this->send($response, $symfonyResponse);
}, function ($error) use ($loop, $response) {
echo "Exception: ", (string) $error, "n";
$response->writeHead(500, ["Content-Type" => "text/plain"]);
$response->end("500 Internal Server Error");
$loop->stop();
});
} elseif ($symfonyResponse instanceof SymfonyResponse) {
$this->send($response, $symfonyResponse);
} else {
echo "Unsupported response type: ", get_class($symfonyResponse), "n";
$response->writeHead(500, ["Content-Type" => "text/plain"]);
$response->end("500 Internal Server Error");
$loop->stop();
}

13. Symfony → ReactPHP (2)
private function send(Response $res, SymfonyResponse $symfonyResponse)
{
$headers = $symfonyResponse->headers->allPreserveCase();
$headers["X-Powered-By"] = "Love";
$cookies = $symfonyResponse->headers->getCookies();
if (count($cookies)) {
$headers["Set-Cookie"] = [];
foreach ($symfonyResponse->headers->getCookies() as $cookie) {
$headers["Set-Cookie"][] = (string)$cookie;
}
}
$res->writeHead($symfonyResponse->getStatusCode(), $headers);
$res->end($symfonyResponse->getContent());
}

14. Controller
/**
* @Controller
*/
class IndexController
{
/**
* @var LoopInterface
*
* @Autowired
*/
public $loop;
public function indexAction(Request $request)
{
return Response::create("Hello, world!n");
}
public function promiseAction(Request $request)
{
$secs = intval($request->attributes->get("secs"));
$deferred = new Deferred();
$this->loop->addTimer($secs, function () use ($secs, $deferred) {
$deferred->resolve(Response::create("{$secs} seconds later...n"));
});
return $deferred->promise();
}
}

15. Knihovny
• ReactPHP (např. HTTP klient, ZeroMQ)
https://github.com/reactphp
• MySQL
https://github.com/kaja47/async-mysql
https://github.com/KhristenkoYura/react-mysql
https://github.com/bixuehujin/reactphp-mysql
• Redis
https://github.com/nrk/predis-async
• RabbitMQ
https://github.com/jakubkulhan/bunny

16. Díky!
Otázky?