Gzip сжатие

<?php
ob_start("ob_gzhandler", 2);
///// Configuration //////////////////
$PREFER_DEFLATE = false; // prefer deflate over gzip when both are supported
$FORCE_COMPRESSION = false; // force compression even when client does not report support
//////////////////////////////////////

function compress_output_gzip($output) {
return gzencode($output);
}

function compress_output_deflate($output) {
return gzdeflate($output, 3);
}

if(isset($_SERVER['HTTP_ACCEPT_ENCODING']))
$AE = $_SERVER['HTTP_ACCEPT_ENCODING'];
else
$AE = $_SERVER['HTTP_TE'];

$support_gzip = (strpos($AE, 'gzip') !== FALSE) || $FORCE_COMPRESSION;
$support_deflate = (strpos($AE, 'deflate') !== FALSE) || $FORCE_COMPRESSION;

if($support_gzip && $support_deflate) {
$support_deflate = $PREFER_DEFLATE;
}

if ($support_deflate) {
header("Content-Encoding: deflate");
ob_start("compress_output_deflate");
} else{
if($support_gzip){
header("Content-Encoding: gzip");
ob_start("compress_output_gzip");
} else {
ob_start();
}
}