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。