Added local message cache feature ($wgLocalMessageCache), to reduce bandwidth require...

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index a5e1582..8dc3a02 100644 (file)
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -212,7 +212,8 @@ fully support the editing toolbar, but was found to be too confusing.
 * Require POST for action=purge, to stop bots from purging the cache
 * (bug 3817) Use localized date formats in preferences; 'no preference' option
   localizable as 'datedefault' message. Tweaked lots of languages files...
-
+* Added local message cache feature ($wgLocalMessageCache), to reduce bandwidth
+  requirements to the memcached server.
 
 === Caveats ===
 

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index a95925b..a671dd2 100644 (file)
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -533,6 +533,10 @@ $wgMemCachedDebug   = false; # Will be set to false in Setup.php, if the server
 $wgMemCachedServers = array( '127.0.0.1:11000' );
 $wgMemCachedDebug   = false;
 
+/**
+ * Directory for local copy of message cache, for use in addition to memcached
+ */
+$wgLocalMessageCache = false;
 
 
 # Language settings

diff --git a/includes/MessageCache.php b/includes/MessageCache.php
index 1987fe9..a02bd62 100755 (executable)
--- a/includes/MessageCache.php
+++ b/includes/MessageCache.php
@@ -30,6 +30,7 @@ class MessageCache
        var $mDeferred = true;
 
        function initialise( &$memCached, $useDB, $expiry, $memcPrefix) {
+               global $wgLocalMessageCache;
                $fname = 'MessageCache::initialise';
                wfProfileIn( $fname );
 
@@ -58,13 +59,65 @@ class MessageCache
                wfProfileOut( $fname );
        }
 
+       /** 
+        * Try to load the cache from a local file
+        */
+       function loadFromLocal( $hash ) {
+               global $wgLocalMessageCache, $wgDBname;
+
+               $this->mCache = false;
+               if ( $wgLocalMessageCache === false ) {
+                       return;
+               }
+               
+               $filename = "$wgLocalMessageCache/messages-$wgDBname";
+
+               $file = fopen( $filename, 'r' );
+               if ( !$file ) {
+                       return;
+               }
+
+               // Check to see if the file has the hash specified
+               $localHash = fread( $file, 32 );
+               if ( $hash == $localHash ) {
+                       // All good, get the rest of it
+                       $serialized = fread( $file, 1000000 );
+                       $this->mCache = unserialize( $serialized );
+               }
+               fclose( $file );
+       }
+
+       /**
+        * Save the cache to a local file
+        */
+       function saveToLocal( $serialized, $hash ) {
+               global $wgLocalMessageCache, $wgDBname;
+
+               if ( $wgLocalMessageCache === false ) {
+                       return;
+               }
+               
+               $filename = "$wgLocalMessageCache/messages-$wgDBname";
+               wfMkdirParents( $wgLocalMessageCache, 0777 );
+
+               $file = fopen( $filename, 'w' );
+               if ( !$file ) {
+                       wfDebug( "Unable to open local cache file for writing\n" );
+                       return;
+               }
+
+               fwrite( $file, $hash . $serialized );
+               fclose( $file );
+       }
+
+
        /**
         * Loads messages either from memcached or the database, if not disabled
         * On error, quietly switches to a fallback mode
         * Returns false for a reportable error, true otherwise
         */
        function load() {
-               global $wgAllMessagesEn;
+               global $wgAllMessagesEn, $wgLocalMessageCache;
 
                if ( $this->mDisable ) {
                        static $shownDisabled = false;
@@ -79,9 +132,33 @@ class MessageCache
                $success = true;
 
                if ( $this->mUseCache ) {
-                       wfProfileIn( $fname.'-fromcache' );
-                       $this->mCache = $this->mMemc->get( $this->mMemcKey );
-                       wfProfileOut( $fname.'-fromcache' );
+                       $this->mCache = false;
+
+                       # Try local cache
+                       wfProfileIn( $fname.'-fromlocal' );
+                       $hash = $this->mMemc->get( "{$this->mMemcKey}-hash" );
+                       if ( $hash ) {
+                               $this->loadFromLocal( $hash );
+                       }
+                       wfProfileOut( $fname.'-fromlocal' );
+
+                       # Try memcached
+                       if ( !$this->mCache ) {
+                               wfProfileIn( $fname.'-fromcache' );
+                               $this->mCache = $this->mMemc->get( $this->mMemcKey );
+
+                               # Save to local cache
+                               if ( $wgLocalMessageCache !== false ) { 
+                                       $serialized = serialize( $this->mCache );
+                                       if ( !$hash ) {
+                                               $hash = md5( $serialized );
+                                               $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
+                                       }
+                                       $this->saveToLocal( $serialized, $hash );
+                               }
+                               wfProfileOut( $fname.'-fromcache' );
+                       }
+
 
                        # If there's nothing in memcached, load all the messages from the database
                        if ( !$this->mCache ) {
@@ -93,6 +170,7 @@ class MessageCache
                                        wfProfileIn( $fname.'-load' );
                                        $this->loadFromDB();
                                        wfProfileOut( $fname.'-load' );
+
                                        # Save in memcached
                                        # Keep trying if it fails, this is kind of important
                                        wfProfileIn( $fname.'-save' );
@@ -101,6 +179,15 @@ class MessageCache
                                             $i++ ) {
                                                usleep(mt_rand(500000,1500000));
                                        }
+
+                                       # Save to local cache
+                                       if ( $wgLocalMessageCache !== false ) { 
+                                               $serialized = serialize( $this->mCache );
+                                               $hash = md5( $serialized );
+                                               $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
+                                               $this->saveToLocal( $serialized, $hash );
+                                       }
+
                                        wfProfileOut( $fname.'-save' );
                                        if ( $i == 20 ) {
                                                $this->mMemc->set( $this->mMemcKey.'-status', 'error', 60*5 );
@@ -199,11 +286,23 @@ class MessageCache
        }
 
        function replace( $title, $text ) {
+               global $wgLocalMessageCache;
+
                $this->lock();
                $this->load();
                if ( is_array( $this->mCache ) ) {
                        $this->mCache[$title] = $text;
                        $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
+                       
+                       # Save to local cache
+                       if ( $wgLocalMessageCache !== false ) { 
+                               $serialized = serialize( $this->mCache );
+                               $hash = md5( $serialized );
+                               $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
+                               $this->saveToLocal( $serialized, $hash );
+                       }
+
+
                }
                $this->unlock();
        }