php gizp压缩传输js和css文件

<?php

    /**
	 *  完整调用示例:
	 *  1、combine.php?t=j&b=public&fs=jslib.jquery,function
	 *  
	 *  该例子调用的是网站根目录下的public/jslib/jquery.js和public/function.js

	 *  
	 *  2、combine.php?t=j&fs=jslib.jquery,function
	 *  
	 *  该例子调用的是网站根目录下的jslib/jquery.js和function.js
	 *  
	 *  3、combine.php?t=c&b=public.css&fs=common,index
	 *  
	 *  该例子调用的是网站根目录下的public/css/common.css和public/css/index.css
	 *  
	 *  4、combine.php?t=c&fs=css.common
	 *  该例子调用的是网站根目录下的css/common.css
	 *  
	 *  注:多个文件名之间用,分隔;只有一个文件名最后不要有,
	 *     用,分隔的多个文件会被压缩进一个文件，一次性传给浏览器
	 **/
	$is_bad_request=false;
	$cache = true;
	$doc_root_uri=$_SERVER['DOCUMENT_ROOT'].'/';
	$cachedir = $doc_root_uri . 'public/cache';
	//文件类型，j为js，c为css
	$type=isset($_GET['t'])?($_GET['t']=='j'||$_GET['t']=='c'?$_GET['t']:''):'';
	
	//存放js和css文件的基目录, 例如:?b=public.js 代表的是/public/js文件夹，出发点是网站根目录
	//基目录参数不是必须的，如果有基目录那么这个基目录就会附加在文件名之前
    $base =isset($_GET['b'])?($doc_root_uri.str_replace('.','/',$_GET['b'])):$doc_root_uri;
	
	//文件名列表，文件名不带后缀名.比如基目录是
	//文件名的格式是 :基目录(如果有)+文件包名+文件名
	//例如:类型是j,
	//     文件名public.js.jquery
	//     如果有基路径且为public，
	//     那么转换后的文件名就是/public/public/js/jquery.js
	//     如果没有基路径
	//     那么转换后的文件名就是/public/js/jquery.js
	//多个文件名之间用,分隔
	$fs=isset($_GET['fs'])?str_replace('.','/',$_GET['fs']):'';
	$fs=str_replace(',','.'.($type=='j'?'js,':'css,'),$fs);
	$fs=$fs.($type=='j'?'.js':'.css');
	
	
	
	if($type==''||$fs==''){$is_bad_request=true;}
	//die($base);
	///////////////http://blog.ddian.cn
	if($is_bad_request){header ("HTTP/1.0 503 Not Implemented");}
	
	
	$file_type=$type=='j'?'javascript':'css';
	
	$elements = explode(',',preg_replace('/([^?]*).*/', '\1', $fs));
	
	// Determine last modification date of the files
	$lastmodified = 0;
	while (list(,$element) = each($elements)) {
		$path =$base . '/' . $element;
	
		if (($type == 'j' && substr($path, -3) != '.js') || 
			($type == 'c' && substr($path, -4) != '.css')) {
			header ("HTTP/1.0 403 Forbidden");
			exit;	
		}
	
		if (substr($path, 0, strlen($base)) != $base || !file_exists($path)) {
			header ("HTTP/1.0 404 Not Found");
			exit;
		}
		
		$lastmodified = max($lastmodified, filemtime($path));
	}
	
	// Send Etag hash
	$hash = $lastmodified . '-' . md5($fs);
	header ("Etag: \"" . $hash . "\"");
	
	if (isset($_SERVER['HTTP_IF_NONE_MATCH']) && 
		stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) == '"' . $hash . '"') 
	{
		// Return visit and no modifications, so do not send anything
		header ("HTTP/1.0 304 Not Modified");
		header ("Content-Type: text/" . $file_type);
		header ('Content-Length: 0');
	} 
	else 
	{
		// First time visit or files were modified
		if ($cache) 
		{
			// Determine supported compression method
			$gzip = strstr($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip');
			$deflate = strstr($_SERVER['HTTP_ACCEPT_ENCODING'], 'deflate');
	
			// Determine used compression method
			$encoding = $gzip ? 'gzip' : ($deflate ? 'deflate' : 'none');
	
			// Check for buggy versions of Internet Explorer
			if (!strstr($_SERVER['HTTP_USER_AGENT'], 'Opera') && 
				preg_match('/^Mozilla\/4\.0 \(compatible; MSIE ([0-9]\.[0-9])/i', $_SERVER['HTTP_USER_AGENT'], $matches)) {
				$version = floatval($matches[1]);
				
				if ($version < 6)
					$encoding = 'none';
					
				if ($version == 6 && !strstr($_SERVER['HTTP_USER_AGENT'], 'EV1')) 
					$encoding = 'none';
			}
			
			// Try the cache first to see if the combined files were already generated
			$cachefile = 'cache-' . $hash . '.' . $file_type . ($encoding != 'none' ? '.' . $encoding : '');
			
			if (file_exists($cachedir . '/' . $cachefile)) {
				if ($fp = fopen($cachedir . '/' . $cachefile, 'rb')) {

					if ($encoding != 'none') {
						header ("Content-Encoding: " . $encoding);
					}
				
					header ("Content-Type: text/" . $file_type);
					header ("Content-Length: " . filesize($cachedir . '/' . $cachefile));
					fpassthru($fp);
					fclose($fp);
					exit;
				}
			}
		}
	
		// Get contents of the files
		$contents = '';
		reset($elements);
		while (list(,$element) = each($elements)) {
			$path = $base . '/' . $element;
			$contents .= "\n\n" . file_get_contents($path);
		}
	
		// Send Content-Type
		header ("Content-Type: text/" . $file_type);
		
		if (isset($encoding) && $encoding != 'none') 
		{
			// Send compressed contents
			$contents = gzencode($contents, 9, $gzip ? FORCE_GZIP : FORCE_DEFLATE);
			header ("Content-Encoding: " . $encoding);
			header ('Content-Length: ' . strlen($contents));
			echo $contents;
		} 
		else 
		{
			// Send regular contents
			header ('Content-Length: ' . strlen($contents));
			echo $contents;
		}

		// Store cache
		if ($cache) {
			if ($fp = fopen($cachedir . '/' . $cachefile, 'wb')) {
				fwrite($fp, $contents);
				fclose($fp);
			}
		}
	}