COMET基于HTTP长连接的推送-PHP源码-php.cn

Home

php教程

PHP源码

COMET基于HTTP长连接的推送

PHP中文网

May 25, 2016 pm 05:05 PM

COMET基于HTTP长连接的推送
比如web IM 消息比轮询即时。减轻服务器压力。减少TCP三次握手的次数

1. [文件] comnet.php

<?php

/*
Simple COMET script tested to work with IE6, IE8, IE9, Chrome 5, Chrome 10, Firefox 3.6.16, Firefox 4, Safari 5, Opera 11
*/

header("Cache-Control: no-cache, must-revalidate");
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");

//Turn of Apache output compression
// Necessary if you have gzip setup in your httpd.conf (e.g. LoadModule deflate_module modules/mod_deflate.so)
apache_setenv(&#39;no-gzip&#39;, 1);
ini_set(&#39;zlib.output_compression&#39;, 0);

//Disable all PHP output buffering
ini_set(&#39;output_buffering&#39;, &#39;Off&#39;);
ini_set(&#39;implicit_flush&#39;, 1);
ob_implicit_flush(1);

for ($i = 0, $level = ob_get_level(); $i < $level; $i++) { ob_end_flush(); } //Flush all levels of the buffer to start

error_reporting(E_ALL);

?><html>
<head>
  <title>Comet php backend</title>
</head>
<body>
<script type="text/javascript">
	var dumpText = window.parent.dumpText;
</script>
<?php

$startTime = time();
$maxLoopTime = 100;

while(time()-$startTime < $maxLoopTime) {

	echo &#39;<script type="text/javascript">&#39;;
	echo "dumpText(".time().&#39;);&#39;.str_repeat(&#39; &#39;,500); //500 characters of padding
	echo "</script>\r\n";

	flush();

  	$randSleep = mt_rand(100000, 2000000); //sleep between 100 ms and 2 seconds
	usleep($randSleep);
}

?>
<script type="text/javascript">dumpText("Output Finished");location.reload();</script>
</body>
</html>

2. [文件] in.php

<html>
<head>
	<title>Comet demo</title>
	<style type="text/css">
    	.hiddenIframe {
    		position:absolute;
    		top:0px;
    		left:0px;
    		display:block;
    		z-index:-999;
    		visibility:hidden;
		}
	</style>
</head>
<body>
<p id="content">The server time will be shown here</p>
<script type="text/javascript">

	var content = document.getElementById(&#39;content&#39;);
	var dumpText = function(text){
		content.innerHTML = content.innerHTML + &#39;<BR>&#39;+ text;
	}
</script>
<iframe src="comnet.php"></iframe>
</body>
</html>

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn