+<?php
+
+/**
+ * Standard output handler for use with ob_start
+ */
+function wfOutputHandler( $s ) {
+ global $wgDisableOutputCompression;
+ $s = wfMangleFlashPolicy( $s );
+ if ( !ini_get( 'zlib.output_compression' ) ) {
+ if ( $wgDisableOutputCompression || !defined( 'MW_NO_OUTPUT_COMPRESSION' ) ) {
+ $s = wfGzipHandler( $s );
+ }
+ if ( !ini_get( 'output_handler' ) ) {
+ wfDoContentLength( strlen( $s ) );
+ }
+ }
+ return $s;
+}
+
+/**
+ * Handler that compresses data with gzip if allowed by the Accept header.
+ * Unlike ob_gzhandler, it works for HEAD requests too.
+ */
+function wfGzipHandler( $s ) {
+ if ( $s !== '' && function_exists( 'gzencode' ) && !headers_sent() ) {
+ $tokens = preg_split( '/[,; ]/', $_SERVER['HTTP_ACCEPT_ENCODING'] );
+ if ( in_array( 'gzip', $tokens ) ) {
+ header( 'Content-Encoding: gzip' );
+ $s = gzencode( $s, 3 );
+
+ # Set vary header if it hasn't been set already
+ $headers = headers_list();
+ $foundVary = false;
+ foreach ( $headers as $header ) {
+ if ( substr( $header, 0, 5 ) == 'Vary:' ) {
+ $foundVary == true;
+ break;
+ }
+ }
+ if ( !$foundVary ) {
+ header( 'Vary: Accept-Encoding' );
+ }
+ }
+ }
+ return $s;
+}
+
+/**
+ * Mangle flash policy tags which open up the site to XSS attacks.
+ */
+function wfMangleFlashPolicy( $s ) {
+ return preg_replace( '/\<\s*cross-domain-policy\s*\>/i', '<NOT-cross-domain-policy>', $s );
+}
+
+/**
+ * Add a Content-Length header if possible. This makes it cooperate with squid better.
+ */
+function wfDoContentLength( $length ) {
+ if ( !headers_sent() && $_SERVER['SERVER_PROTOCOL'] == 'HTTP/1.0' ) {
+ header( "Content-Length: $length" );
+ }
+}
+
+?>