php使用gzip压缩传输js和css文件的方法

本文实例讲述了php使用gzip压缩传输js和css文件的方法。分享给大家供大家参考。具体如下：

<?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);

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);

}

}

}

希望本文所述对大家的php程序设计有所帮助。