gzip.php改良版

<?php

//注：本文件需要在其目录下关闭Gzip压缩PHP！
$cur_dir = 'wp-content/gzip-cache/';//相对网站根目录，本文件的目录

$cache = false;//Gzip压缩开关
$cachedir = 'wp-content/gzip-cache/';//相对网站根目录，存放gz文件的目录，确保可写
$ht_dir = '';//相对网站根目录，使gzip生效的.htaccess文件存放目录

$ws_dir = dirname(__FILE__);
$ws_dir = str_replace('\\','/',$ws_dir).'/';
$ws_dir = str_replace($cur_dir,'',$ws_dir);//计算出网站根目录的绝对路径

$gzip = strstr($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip');
$deflate = strstr($_SERVER['HTTP_ACCEPT_ENCODING'], 'deflate');
$encoding = $gzip ? 'gzip' : ($deflate ? 'deflate' : 'none');
 
if(!isset($_SERVER['QUERY_STRING'])) exit();
 
$key=array_shift(explode('?', $_SERVER['QUERY_STRING']));
$key=str_replace('../','',$key);

$filename=$ws_dir.$ht_dir.$key;//要压缩的文件的绝对路径
 
$symbol='^';

$cache_filename=$ws_dir.$cachedir.str_replace('/',$symbol,$key).'.gz';//生成gz文件路径

$type="Content-type: text/html"; //默认的类型信息
 
$ext = array_pop(explode('.', $filename));//根据后缀判断文件类型信息
 switch ($ext){
  case 'css':
   $type="Content-type: text/css";
   break;
  case 'js':
   $type="Content-type: application/x-javascript";
   break;
  default:
   exit();
 }
 
if($cache){
 if(file_exists($cache_filename)){//假如存在gz文件
 
 
  $mtime = filemtime($cache_filename);
  $gmt_mtime = gmdate('D, d M Y H:i:s', $mtime) . ' GMT';
 
  if( (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) &&
        array_shift(explode(';', $_SERVER['HTTP_IF_MODIFIED_SINCE'])) ==  $gmt_mtime)
   ){
 
   // 浏览器cache中的文件修改日期是否一致，将返回304
   header ("HTTP/1.1 304 Not Modified");
   header("Expires: ");
   header("Cache-Control: ");
   header("Pragma: ");
   header($type);
   header("Tips: Cache Not Modified (Gzip)");
   header ('Content-Length: 0');
 
 
  }else{
 
   //读取gz文件输出
   $content = file_get_contents($cache_filename);
   header("Last-Modified:" . $gmt_mtime);
   header("Expires: ");
   header("Cache-Control: ");
   header("Pragma: ");
   header($type);
   header("Tips: Normal Respond (Gzip)");
   header("Content-Encoding: gzip");
   echo $content;
  }
 
 
 }else if(file_exists($filename)){//没有对应的gz文件
 
  $mtime = mktime();
  $gmt_mtime = gmdate('D, d M Y H:i:s', $mtime) . ' GMT';
 
  $content = file_get_contents($filename);//读取文件
  $content = gzencode($content, 9, $gzip ? FORCE_GZIP : FORCE_DEFLATE);//压缩文件内容
 
  header("Last-Modified:" . $gmt_mtime);
  header("Expires: ");
  header("Cache-Control: ");
  header("Pragma: ");
  header($type);
  header("Tips: Build Gzip File (Gzip)");
  header ("Content-Encoding: " . $encoding);
        header ('Content-Length: ' . strlen($content));
  echo $content;
 
  if ($fp = fopen($cache_filename, 'w')) {//写入gz文件，供下次使用
                fwrite($fp, $content);
                fclose($fp);
            }
 
 }else{
  header("HTTP/1.0 404 Not Found");
  echo "<!--404 Not Found-->";
 }
}else{ //处理不使用Gzip模式下的输出。原理基本同上
 if(file_exists($filename)){
  $mtime = filemtime($filename);
  $gmt_mtime = gmdate('D, d M Y H:i:s', $mtime) . ' GMT';
 
  if( (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) &&
  array_shift(explode(';', $_SERVER['HTTP_IF_MODIFIED_SINCE'])) ==  $gmt_mtime)
  ){
 
  header ("HTTP/1.1 304 Not Modified");
  header("Expires: ");
  header("Cache-Control: ");
  header("Pragma: ");
  header($type);
  header("Tips: Cache Not Modified");
  header ('Content-Length: 0');
 
 }else{
 
  header("Last-Modified:" . $gmt_mtime);
  header("Expires: ");
  header("Cache-Control: ");
&
nbsp; header("Pragma: ");
  header($type);
  header("Tips: Normal Respond");
  $content = readfile($filename);
  echo $content;
 
  }
 }else{
  header("HTTP/1.0 404 Not Found");
  echo "<!--404 Not Found-->";
 }
}
 
?>