Experimental optional compression support for page cache

diff --git a/includes/Article.php b/includes/Article.php
index 4e81c27..52f77f7 100644 (file)
--- a/includes/Article.php
+++ b/includes/Article.php
@@ -1537,12 +1537,25 @@ name=\"wpSummary\" maxlength=200 size=60><br>
        }
 
        function loadFromFileCache() {
+               global $wgUseGzip;
                wfDebug(" loadFromFileCache()\n");
-               readfile($this->fileCacheName());
+               $filename=$this->fileCacheName();
+               $filenamegz = "{$filename}.gz";
+               if( $wgUseGzip
+                       && wfClientAcceptsGzip()
+                       && file_exists( $filenamegz)
+                       && ( filemtime( $filenamegz ) >= filemtime( $filename ) ) ) {
+                       wfDebug("  sending gzip\n");
+                       header( "Content-Encoding: gzip" );
+                       header( "Vary: Accept-Encoding" );
+                       $filename = $filenamegz;
+               }
+               readfile( $filename );
        }
        
        function saveToFileCache( $text ) {
-
+               global $wgUseGzip, $wgCompressByDefault;
+               
         wfDebug(" saveToFileCache()\n");
                $filename=$this->fileCacheName();
                $mydir2=substr($filename,0,strrpos($filename,"/")); # subdirectory level 2
@@ -1551,10 +1564,38 @@ name=\"wpSummary\" maxlength=200 size=60><br>
                if(!file_exists($mydir2)) { mkdir($mydir2,0777); }                      
                $f = fopen( $filename, "w" );
                if($f) {
+                       $now = wfTimestampNow();
                        fwrite( $f, str_replace( "</html>",
-                               "<!-- Cached " . wfTimestampNow() . " -->\n</html>",
+                               "<!-- Cached $now -->\n</html>",
                                $text ) );
                        fclose( $f );
+                       if( $wgUseGzip and $wgCompressByDefault ) {
+                               $start = microtime();
+                               wfDebug("  saving gzip\n");
+                               $gzout = gzencode( str_replace( "</html>",
+                                               "<!-- Cached/compressed $now -->\n</html>",
+                                               $text ) );
+                               if( $gzout === false ) {
+                                       wfDebug("  failed to gzip compress, sending plaintext\n");
+                                       return $text;
+                               }
+                               if( $f = fopen( "{$filename}.gz", "w" ) ) {
+                                       fwrite( $f, $gzout );
+                                       fclose( $f );
+                                       $end = microtime();
+                                       
+                                       list($usec1, $sec1) = explode(" ",$start);
+                                       list($usec2, $sec2) = explode(" ",$end);
+                                       $interval = ((float)$usec2 + (float)$sec2) -
+                                                               ((float)$usec1 + (float)$sec1);
+                                       wfDebug("  saved gzip in $interval\n");
+                               } else {
+                                       wfDebug("  failed to write gzip, still sending\n" );
+                               }
+                               header( "Content-Encoding: gzip" );
+                               header( "Vary: Accept-Encoding" );
+                               return $gzout;
+                       }
                }
                return $text;
        }

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 56724b2..d3128ab 100644 (file)
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -75,6 +75,12 @@ $wgMiserMode = false; # Disable database-intensive features
 $wgUseTeX = false;
 $wgProfiling = false; # Enable for more detailed by-function times in debug log
 
+# We can serve pages compressed in order to save bandwidth,
+# but this will increase CPU usage.
+# Requires zlib support enabled in PHP.
+$wgUseGzip = false;
+$wgCompressByDefault = true;
+
 # Which namespaces should support subpages?
 # See Language.php for a list of namespaces.
 #

diff --git a/includes/GlobalFunctions.php b/includes/GlobalFunctions.php
index e2244c6..05d4ea5 100644 (file)
--- a/includes/GlobalFunctions.php
+++ b/includes/GlobalFunctions.php
@@ -499,4 +499,20 @@ function wfNumLink( $offset, $limit, $link, $query = "" )
        return $s;
 }
 
+function wfClientAcceptsGzip() {
+       global $wgUseGzip;
+       if( $wgUseGzip ) {
+               # FIXME: we may want to blacklist some broken browsers
+               if( preg_match(
+                       '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
+                       $_SERVER["HTTP_ACCEPT_ENCODING"],
+                       $m ) ) {
+                       if( ( $m[1] == "q" ) && ( $m[2] == 0 ) ) return false;
+                       wfDebug( " accepts gzip\n" );
+                       return true;
+               }
+       }
+       return false;
+}
+
 ?>