Swoole v4.6 版本新特性之 Http\Response 增强

在 4.6 版本中，对 Swoole\Http\Response 进行了一些增强：

• 添加 Http\Response::isWritable (db56827) (@matyhtf)
• 增强 Response\create() 方法，可以独立于 Server 使用 (#3998) (@matyhtf)

再来看一下上一篇文章的示例代码：

use Swoole\Server;
use Swoole\Http\Request;

$server = new Server('127.0.0.1', 9501);

$server->on('Receive', function (Server $server, $fd, $reactor_id, $data) {
    /** @var Request $request */
    $request = Request::create();
    $request->parse($data);

    $body = 'Hello, Swoole';
    $body_len = strlen($body);
    $send_data = "HTTP/1.1 200 OK\r\nServer: swoole-server\r\nContent-Type: text/html;charset=utf-8\r\nContent-Length: {$body_len}\r\nConnection: keep-alive\r\n\r\n{$body}";
    $server->send($fd, $send_data);
});

$server->start();

需要用户自行处理$send_data的数据，而此次增强以后，可以这样使用：

use Swoole\Server;
use Swoole\Http\Request;
use Swoole\Http\Response;

$server = new Server('127.0.0.1', 9501);

$server->on('Receive', function (Server $server, $fd, $reactor_id, $data) {
    /** @var Request $request */
    $request = Request::create();
    $request->parse($data);

    /** @var Response $response */
    $response = Response::create($server, $fd);
    $response->status(200);
    $response->end('Hello, Swoole');
});

$server->start();

还可以这样：

$server->on('Receive', function (Server $server, $fd, $reactor_id, $data) {
    /** @var Request $request */
    $request = Request::create();
    $request->parse($data);

    /** @var Response $response */
    $response = Response::create([$server, $request], $fd);
    $response->status(200);
    $response->end('Hello, Swoole');
});

不但异步 Server 中可以使用，而且协程 Server 中也可以使用：

use Swoole\Coroutine\Server;
use Swoole\Coroutine\Server\Connection;
use Swoole\Http\Request;
use Swoole\Http\Response;
use function Swoole\Coroutine\run;

run(function () {
    $server = new Server('0.0.0.0', 9501, false);
    $server->handle(function (Connection $conn) use ($server) {
        $request = Request::create();
        while(true) {
            $data = $conn->recv();
            if (strlen($data) != $request->parse($data) || $request->isCompleted()) {
                break;
            }
        }
        $response = Response::create([$conn->exportSocket(), $request]);
        $response->end('Hello, Swoole');
    });
    $server->start();
});

这样就可以直接使用 Http\Response 的 API 进行响应处理，而不用自行组装 HTTP 协议响应数据。

isWritable

isWritable() 用来判断 Http\Response 对象是否已结束 (end) 或已分离 (detach)，例如：

use Swoole\Http\Server;
use Swoole\Http\Request;
use Swoole\Http\Response;

$http = new Server('0.0.0.0', 9501);

$http->on('request', function (Request $req, Response $resp) {
    assert($resp->isWritable(), true);
    $resp->end('hello');
    assert($resp->isWritable(), false);
    $resp->setStatusCode(403);
});

$http->start();

如果在调用end()之后，再次调用相关 API，就会发生错误

PHP Warning:  Swoole\Http\Response::setStatusCode(): http response is unavailable (maybe it has been ended or detached)