Swoole 理解一

Swoole

网络通信引擎

常驻进程
swoole 扩展了生命周期

基于事件的高性能异步

协程

协程 线程 进程 区别

mysql 客户端

并发1万个请求从MySQL读取海量数据仅需要0.2秒

$s = microtime(true);
Co\run(function() {
    for ($c = 100; $c--;) {
        go(function () {
            $mysql = new Swoole\Coroutine\MySQL;
            $mysql->connect([
                'host' => '127.0.0.1',
                'user' => 'root',
                'password' => 'root',
                'database' => 'test'
            ]);
            $statement = $mysql->prepare('SELECT * FROM `user`');
            for ($n = 100; $n--;) {
                $result = $statement->execute();
                assert(count($result) > 0);
            }
        });
    }
});
echo 'use ' . (microtime(true) - $s) . ' s';

混合服务器

你可以在一个事件循环上创建多个服务：TCP，HTTP，Websocket和HTTP2，并且能轻松承载上万请求。

function tcp_pack(string $data): string
{
    return pack('N', strlen($data)) . $data;
}
function tcp_unpack(string $data): string
{
    return substr($data, 4, unpack('N', substr($data, 0, 4))[1]);
}
$tcp_options = [
    'open_length_check' => true,
    'package_length_type' => 'N',
    'package_length_offset' => 0,
    'package_body_offset' => 4
];

$server = new Swoole\WebSocket\Server('127.0.0.1', 9501, SWOOLE_BASE);
$server->set(['open_http2_protocol' => true]);
// http && http2
$server->on('request', function (Swoole\Http\Request $request, Swoole\Http\Response $response) {
    $response->end('Hello ' . $request->rawcontent());
});
// websocket
$server->on('message', function (Swoole\WebSocket\Server $server, Swoole\WebSocket\Frame $frame) {
    $server->push($frame->fd, 'Hello ' . $frame->data);
});
// tcp
$tcp_server = $server->listen('127.0.0.1', 9502, SWOOLE_TCP);
$tcp_server->set($tcp_options);
$tcp_server->on('receive', function (Swoole\Server $server, int $fd, int $reactor_id, string $data) {
    $server->send($fd, tcp_pack('Hello ' . tcp_unpack($data)));
});
$server->start();

多种客户端

不管是DNS查询抑或是发送请求和接收响应，都是协程调度的，不会产生任何阻塞。

go(function () {
    // http
    $http_client = new Swoole\Coroutine\Http\Client('127.0.0.1', 9501);
    assert($http_client->post('/', 'Swoole Http'));
    var_dump($http_client->body);
    // websocket
    $http_client->upgrade('/');
    $http_client->push('Swoole Websocket');
    var_dump($http_client->recv()->data);
});
go(function () {
    // http2
    $http2_client = new Swoole\Coroutine\Http2\Client('localhost', 9501);
    $http2_client->connect();
    $http2_request = new Swoole\Http2\Request;
    $http2_request->method = 'POST';
    $http2_request->data = 'Swoole Http2';
    $http2_client->send($http2_request);
    $http2_response = $http2_client->recv();
    var_dump($http2_response->data);
});
go(function () use ($tcp_options) {
    // tcp
    $tcp_client = new Swoole\Coroutine\Client(SWOOLE_TCP);
    $tcp_client->set($tcp_options);
    $tcp_client->connect('127.0.0.1', 9502);
    $tcp_client->send(tcp_pack('Swoole Tcp'));
    var_dump(tcp_unpack($tcp_client->recv()));
});

通道

通道(Channel)是协程之间通信交换数据的唯一渠道, 而协程+通道的开发组合即为著名的CSP编程模型。
在Swoole开发中，Channel常用于连接池的实现和协程并发的调度。

连接池最简示例

在以下示例中，我们并发了一千个redis请求，通常的情况下，这已经超过了Redis最大的连接数，将会抛出连接异常， 但基于Channel实现的连接池可以完美地调度请求，开发者就无需担心连接过载。

class RedisPool
{
    /**@var \Swoole\Coroutine\Channel */
    protected $pool;
    /**
     * RedisPool constructor.
     * @param int $size max connections
     */
    public function __construct(int $size = 100)
    {
        $this->pool = new \Swoole\Coroutine\Channel($size);
        for ($i = 0; $i < $size; $i++) {
            $redis = new \Swoole\Coroutine\Redis();
            $res = $redis->connect('127.0.0.1', 6379);
            if ($res == false) {
                throw new \RuntimeException("failed to connect redis server.");
            } else {
                $this->put($redis);
            }
        }
    }
    public function get(): \Swoole\Coroutine\Redis
    {
        return $this->pool->pop();
    }
    public function put(\Swoole\Coroutine\Redis $redis)
    {
        $this->pool->push($redis);
    }
    public function close(): void
    {
        $this->pool->close();
        $this->pool = null;
    }
}
go(function () {
    $pool = new RedisPool();
    // max concurrency num is more than max connections
    // but it's no problem, channel will help you with scheduling
    for ($c = 0; $c < 1000; $c++) {
        go(function () use ($pool, $c) {
            for ($n = 0; $n < 100; $n++) {
                $redis = $pool->get();
                assert($redis->set("awesome-{$c}-{$n}", 'swoole'));
                assert($redis->get("awesome-{$c}-{$n}") === 'swoole');
                assert($redis->delete("awesome-{$c}-{$n}"));
                $pool->put($redis);
            }
        });
    }
});

生产和消费

Swoole的部分客户端实现了defer机制来进行并发，但你依然可以用协程和通道的组合来灵活地实现它。

go(function () {
    // User: I need you to bring me some information back.
    // Channel: OK! I will be responsible for scheduling.
    $channel = new Swoole\Coroutine\Channel;
    go(function () use ($channel) {
        // Coroutine A: Ok! I will show you the github addr info
        $addr_info = Co::getaddrinfo('github.com');
        $channel->push(['A', json_encode($addr_info, JSON_PRETTY_PRINT)]);
    });
    go(function () use ($channel) {
        // Coroutine B: Ok! I will show you what your code look like
        $mirror = Co::readFile(__FILE__);
        $channel->push(['B', $mirror]);
    });
    go(function () use ($channel) {
        // Coroutine C: Ok! I will show you the date
        $channel->push(['C', date(DATE_W3C)]);
    });
    for ($i = 3; $i--;) {
        list($id, $data) = $channel->pop();
        echo "From {$id}:\n {$data}\n";
    }
    // User: Amazing, I got every information at earliest time!
});

定时器

$id = Swoole\Timer::tick(100, function () {
    echo "⚙ Do something...\n";
});
Swoole\Timer::after(500, function () use ($id) {
    Swoole\Timer::clear($id);
    echo "⏰ Done\n";
});
Swoole\Timer::after(1000, function () use ($id) {
    if (!Swoole\Timer::exists($id)) {
        echo "✅ All right!\n";
    }
});

使用协程方法

go(function () {
    $i = 0;
    while (true) {
        Co::sleep(0.1);
        echo "📝 Do something...\n";
        if (++$i === 5) {
            echo "🛎 Done\n";
            break;
        }
    }
    echo "🎉 All right!\n";
});

强大的运行时钩子

在最新版本的Swoole中，我们添加了一项新功能，使PHP原生的同步网络库一键化成为协程库。
只需在脚本顶部调用Swoole\Runtime::enableCoroutine()方法并使用php-redis，并发1万个请求从Redis读取数据仅需0.1秒！

Swoole\Runtime::enableCoroutine();
$s = microtime(true);
Co\run(function() {
    for ($c = 100; $c--;) {
        go(function () {
            ($redis = new Redis)->connect('127.0.0.1', 6379);
            for ($n = 100; $n--;) {
                assert($redis->get('awesome') === 'swoole');
            }
        });
    }
});
echo 'use ' . (microtime(true) - $s) . ' s';

调用它之后，Swoole内核将替换ZendVM中的Stream函数指针，如果使用基于php_stream的扩展，则所有套接字操作都可以在运行时动态转换为协程调度的异步IO。

参考资料:
swoole微课程
twosee.cn
github