How to enable gzip compression in php virtual host

define('ABSPATH', dirname(__FILE__).'/');
$cache = true;//Gzip compression Switch
$cachedir = 'gzip_cache/';//The directory where gz files are stored is created before use and given writable permissions
$gzip = strstr($_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);
$filename=ABSPATH.$key;
$symbol='^';
$rel_path=str_replace(ABSPATH ,'',dirname($filename));
$namespace=str_replace('/',$symbol,$rel_path);
$cache_filename=ABSPATH.$cachedir.$namespace.$symbol.basename($filename).' .gz';//Cache path
$type="Content-type: text/html"; //MIME information
$ext = array_pop(explode('.', $filename));//Get file extension< ;/p>
switch ($ext){//Update MIME information
 case 'css':
 $type="Content-type: text/css";
 break;
 case 'js':
 $type="Content-type: text/javascript";
 break;
 default:
 exit();
}
if($cache){
 if(file_exists($cache_filename) ){//If there is a gz file

 $mtime = filemtime($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)
 ){

 // If the file has not changed, return 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{
 //Read gz file output
 $content = file_get_contents($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)){ //There is no corresponding gz file
 $mtime = mktime();
 $gmt_mtime = gmdate('D, d M Y H:i:s', $mtime) . ' GMT';

 $content = file_get_contents($filename);
 $content = gzencode($content, 9, $gzip ? FORCE_GZIP : FORCE_DEFLATE);//Compressed content

 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')) {//Write cache
 fwrite($fp, $content);
 fclose($fp);
 }
 }else{
 header("HTTP/1.0 404 Not Found");
 }
}else{ //Turn off Gzip compression
//by bbs.it-home.org
 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:" . $gmt_mtime);
 header("Expires: ");
 header("Cache-Control: ") ;
 header("Pragma: ");
 header($type);
 header("Tips: Normal Respond");
 $content = readfile($filename);
 echo $content;

 }
 }else{
 header("HTTP/1.0 404 Not Found");
 }
}
?>

Next, add the following rules in .htaccess (Apache mod_rewrite) or httpd.ini (IIS ISAPI_Rewrite):

RewriteRule (.*.css$|.*.js$) /gzip.php?$1 [L]

Finally, test it. Visit each page of the website to see if there are cache files generated in the gzip_cache folder. You can also use Baidu Webmaster Tools to see whether the css/js page is compressed.