在Symfony2中流式传输响应

Question

我在doc中尝试这个例子:在Symfony2中流式传输一个响应.

/**
 * @param Request $request
 * @return Response $render
 * @Route("/streamedResponse", name="streamed_response")
 * @Template("AcmeTestBundle::streamedResponse.html.twig")
 */
public function streamedResponseAction(Request $request)
{
    $response = new StreamedResponse();
    $response->setCallback(function () {
        echo 'Hello World';
        flush();
        sleep(3);
        echo 'Hello World';
        flush();
    });

    return $response;

}

这会同时输出所有内容.我做错了什么吗？

Answer 1

我尝试添加ob_flush(),它似乎正在工作.这是我的代码:

public function streamedAction()
{
    $response = new StreamedResponse();
    $response->setCallback(function () {
        echo 'Hello World';
        ob_flush();
        flush();
        sleep(3);
        echo 'Hello World';
        ob_flush();
        flush();
    });

    return $response;
}

这将返回带有分块数据的分块传输编码头.这是结果的输出:

$ telnet localhost 80
Trying ::1...
Connected to localhost.
Escape character is '^]'.
GET /app_dev.php/streamed HTTP/1.1
Host: symfony21.localdomain

HTTP/1.1 200 OK
Date: Wed, 12 Sep 2012 05:34:12 GMT
Server: Apache/2.2.17 (Unix) DAV/2 mod_ssl/2.2.17 OpenSSL/0.9.8o
cache-control: no-cache, private
x-debug-token: 50501eda7d437
Transfer-Encoding: chunked
Content-Type: text/html; charset=UTF-8

b
Hello World
b
Hello World
0

Connection closed by foreign host.

如果你在浏览器中看到这个响应,它会在加载约3秒后显示"HelloWorldHelloWorld",因为浏览器会等到收到所有的chunked数据,因为Content-Type是text/*,但当你看到网络流时,它实际上是在做通过发送分块数据进行流式传输.