dougang1605 2015-02-19 13:31
浏览 74

事件源 - >服务器批量返回事件流,而不是以块的形式返回

I have a php script that import large data from csv files with validations.
For that I need to show progress to the user. I have used Event Streaming for that.
When I echo something, I want it to be transferred to client one by one instead of server sent whole output in bulk.
I had already played around with ob_start(), ob_implicit_flush() & ob_flush(), but they didn't work.
My script is working perfect on another server. Below server configurations are given:

Server configuration on which the code is not responding as desired, i.e.

OS: Linux
PHP Version 5.4.36-0+deb7u3
Server API: CGI/FastCGI 
Memory_limit: 128M
output_buffering: no value

As I have said, the code is working properly on another server which has the almost same configuration, i.e.

OS: Linux
PHP Version 5.4.37
Server API: CGI/FastCGI 
Memory_limit: 256MB
output_buffering: no value

Below is my sample code for sending event:

<?php
header("Content-Type: text/event-stream");
header("Cache-Control: no-cache");
header("Access-Control-Allow-Origin: *");

$lastEventId = floatval(isset($_SERVER["HTTP_LAST_EVENT_ID"]) ? $_SERVER["HTTP_LAST_EVENT_ID"] : 0);
if ($lastEventId == 0) {
    $lastEventId = floatval(isset($_GET["lastEventId"]) ? $_GET["lastEventId"] : 0);
}

echo ":" . str_repeat(" ", 2048) . "
"; // 2 kB padding for IE
echo "retry: 2000
";

// event-stream
$i = $lastEventId;

while ($i <= 100) {
    if($i==100){
        echo "data: stop
";
        ob_flush();
        flush();
        break;
    } else {
        echo "id: " . $i . "
";
        echo "data: " . $i . ";

";
        ob_flush();
        flush();
        sleep(1);
    }
    $i++;
}
?>

Below is my client page on which I need response:

<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8" />
    <title>EventSource example</title>
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <script src="../jquery/eventsource.js"></script>
    <script>
        var es = new EventSource("events.php");
        var listener = function(event) {
            console.log(event.data);
            var type = event.type;
            if (event.data == 'stop') {
                es.close();
            } else {
                var div = document.createElement("div");
                div.appendChild(document.createTextNode(type + ": " + (type === "message" ? event.data : es.url)));
                document.body.appendChild(div);
            }
        };
        var errlistener = function(event) {
            es.close();
        }
        es.addEventListener("open", listener);
        es.addEventListener("message", listener);
        es.addEventListener("error", errlistener);
    </script>
</head>

<body>
</body>

</html>
  • 写回答

3条回答

  • drc4925 2015-11-27 16:57
    关注

    I had a similar problem. Event streams were working as expected (returning chunks) on a server using the Apache 2.0 Handler but not on a server using FastCGI (returning it in bulk). I assumed that something in FastCGI is the culprit and so tried to resolve the problem by switching to CGI. Now the event stream works as expected.

    Whether using CGI or FastCGI the Server API shows up as CGI/FastCGI so I assume that the server it works on for you is running CGI and the server it doesn't work on for you is running FastCGI. Try changing the non-working server to CGI.

    As for why it doesn't work in FastCGI I'm not entirely sure but unless it's a necessary requirement and CGI isn't possible then the above solution should work.

    评论

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