using-yii-with-swoole.md

Using Yii with Swoole

Swoole is a PHP network framework distributed as a PECL extension. It allows you built-in async, multiple threads I/O modules. Developers can use sync or async, coroutine API to write the applications.

In the context of Yii, it allows running request handlers as workers. Each worker may handle multiple requests. Such an operation mode is often called event loop and allows not to re-initialize a framework for each request that improves performance significantly.

Installation

Swoole works on Linux and macOS and can be installed via pecl:

pecl install swoole

Putting up a server

Since Swoole doesn't have built-in PSR-7 support, you need a package fixing so:

composer require ilexn/swoole-convent-psr7

Create an entry script, server.php:

<?php

declare(strict_types=1);

use Psr\Http\Message\ServerRequestFactoryInterface;
use Psr\Http\Message\StreamFactoryInterface;
use Psr\Http\Message\UploadedFileFactoryInterface;
use Psr\Http\Message\UriFactoryInterface;
use Yiisoft\Di\Container;
use Yiisoft\Di\ContainerConfig;
use Yiisoft\Yii\Web\Application;
use Yiisoft\Config\Config;

ini_set('display_errors', 'stderr');

define('YII_ENV', getenv('env') ?: 'production');
require_once dirname(__DIR__) . '/vendor/autoload.php';

$config = new Config(
    dirname(__DIR__),
    '/config/packages',
    null,
    [
        'params',
        'events',
        'events-web',
        'events-console',
    ]
);

$containerConfig = ContainerConfig::create()
    ->withDefinitions($config->get('web'))
    ->withProviders($config->get('providers-web'));
$container = new Container($containerConfig);

$bootstrapList = $config->get('bootstrap-web');
foreach ($bootstrapList as $callback) {
    if (!(is_callable($callback))) {
        $type = is_object($callback) ? get_class($callback) : gettype($callback);

        throw new \RuntimeException("Bootstrap callback must be callable, $type given.");
    }
    $callback($container);
}

$application = $container->get(Application::class);

$serverRequestFactory = new \Ilex\SwoolePsr7\SwooleServerRequestConverter(
    $container->get(ServerRequestFactoryInterface::class),
    $container->get(UriFactoryInterface::class),
    $container->get(UploadedFileFactoryInterface::class),
    $container->get(StreamFactoryInterface::class)
);

$server = new Swoole\HTTP\Server('0.0.0.0', 9501);

$server->on('start', static function (Swoole\Http\Server $server) use ($application) {
    $application->start();
    echo "Swoole http server is started at http://127.0.0.1:9501\n";
});

$server->on('request', static function (Swoole\Http\Request $request, Swoole\Http\Response $response) use ($serverRequestFactory, $application, $container) {
    $psr7Response = null;
    try {
        $requestContainer = clone $container;
        $psr7Request = $serverRequestFactory->createFromSwoole($request);
        $psr7Response = $application->handle($psr7Request);
    
        $converter = new \Ilex\SwoolePsr7\SwooleResponseConverter($response);
        $converter->send($psr7Response);
    } catch (\Throwable $t) {
        // TODO: render it properly
        $response->end($t->getMessage());
    } finally {
        $application->afterEmit($psr7Response ?? null);
        $container->get(\Yiisoft\Di\StateResetter::class)->reset();
        $container = $requestContainer;    
    }
});

$server->on('shutdown', static function (Swoole\Http\Server $server) use ($application) {
    $application->shutdown();
});

$server->start();

Starting a server

To start a server, execute the following command:

php server.php

On scope

A scope is shared so at each iteration of event loop every service that depends on state should be reset.