Cleanup for displaying old versions
[lhc/web/wiklou.git] / includes / MessageCache.php
old mode 100755 (executable)
new mode 100644 (file)
index 8d868ec..9bd3321
@@ -1,7 +1,7 @@
 <?php
 /**
- *
- * @package MediaWiki
+ * @file
+ * @ingroup Cache
  */
 
 /**
 define( 'MSG_LOAD_TIMEOUT', 60);
 define( 'MSG_LOCK_TIMEOUT', 10);
 define( 'MSG_WAIT_TIMEOUT', 10);
+define( 'MSG_CACHE_VERSION', 1 );
 
 /**
  * Message cache
- * Performs various useful MediaWiki namespace-related functions
- *
- * @package MediaWiki
+ * Performs various MediaWiki namespace-related functions
+ * @ingroup Cache
  */
-class MessageCache
-{
+class MessageCache {
        var $mCache, $mUseCache, $mDisable, $mExpiry;
        var $mMemcKey, $mKeys, $mParserOptions, $mParser;
-       var $mExtensionMessages;
+       var $mExtensionMessages = array();
        var $mInitialised = false;
+       var $mDeferred = true;
+       var $mAllMessagesLoaded;
 
-       function initialise( &$memCached, $useDB, $expiry, $memcPrefix) {
-               $fname = 'MessageCache::initialise';
-               wfProfileIn( $fname );
+       function __construct( &$memCached, $useDB, $expiry, $memcPrefix) {
+               wfProfileIn( __METHOD__ );
 
                $this->mUseCache = !is_null( $memCached );
                $this->mMemc = &$memCached;
@@ -36,16 +36,136 @@ class MessageCache
                $this->mMemcKey = $memcPrefix.':messages';
                $this->mKeys = false; # initialised on demand
                $this->mInitialised = true;
+               $this->mParser = null;
 
-               wfProfileIn( $fname.'-parseropt' );
-               $this->mParserOptions = ParserOptions::newFromUser( $u=NULL );
-               wfProfileOut( $fname.'-parseropt' );
-               wfProfileIn( $fname.'-parser' );
-               $this->mParser = new Parser;
-               wfProfileOut( $fname.'-parser' );
+               # When we first get asked for a message,
+               # then we'll fill up the cache. If we
+               # can return a cache hit, this saves
+               # some extra milliseconds
+               $this->mDeferred = true;
 
-               $this->load();
-               wfProfileOut( $fname );
+               wfProfileOut( __METHOD__ );
+       }
+
+       function getParserOptions() {
+               if ( !$this->mParserOptions ) {
+                       $this->mParserOptions = new ParserOptions;
+               }
+               return $this->mParserOptions;
+       }
+
+       /**
+        * Try to load the cache from a local file
+        */
+       function loadFromLocal( $hash ) {
+               global $wgLocalMessageCache, $wgLocalMessageCacheSerialized;
+
+               if ( $wgLocalMessageCache === false ) {
+                       return;
+               }
+
+               $filename = "$wgLocalMessageCache/messages-" . wfWikiID();
+
+               wfSuppressWarnings();
+               $file = fopen( $filename, 'r' );
+               wfRestoreWarnings();
+               if ( !$file ) {
+                       return;
+               }
+
+               if ( $wgLocalMessageCacheSerialized ) {
+                       // 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 = '';
+                               while ( !feof( $file ) ) {
+                                       $serialized .= fread( $file, 100000 );
+                               }
+                               $this->setCache( unserialize( $serialized ) );
+                       }
+                       fclose( $file );
+               } else {
+                       $localHash=substr(fread($file,40),8);
+                       fclose($file);
+                       if ($hash!=$localHash) {
+                               return;
+                       }
+
+                       require("$wgLocalMessageCache/messages-" . wfWikiID());
+                       $this->setCache( $this->mCache);
+               }
+       }
+
+       /**
+        * Save the cache to a local file
+        */
+       function saveToLocal( $serialized, $hash ) {
+               global $wgLocalMessageCache, $wgLocalMessageCacheSerialized;
+
+               if ( $wgLocalMessageCache === false ) {
+                       return;
+               }
+
+               $filename = "$wgLocalMessageCache/messages-" . wfWikiID();
+               $oldUmask = umask( 0 );
+               wfMkdirParents( $wgLocalMessageCache, 0777 );
+               umask( $oldUmask );
+
+               $file = fopen( $filename, 'w' );
+               if ( !$file ) {
+                       wfDebug( "Unable to open local cache file for writing\n" );
+                       return;
+               }
+
+               fwrite( $file, $hash . $serialized );
+               fclose( $file );
+               @chmod( $filename, 0666 );
+       }
+
+       function loadFromScript( $hash ) {
+               wfDeprecated( __METHOD__ );
+               $this->loadFromLocal( $hash );
+       }
+
+       function saveToScript($array, $hash) {
+               global $wgLocalMessageCache;
+               if ( $wgLocalMessageCache === false ) {
+                       return;
+               }
+
+               $filename = "$wgLocalMessageCache/messages-" . wfWikiID();
+               $oldUmask = umask( 0 );
+               wfMkdirParents( $wgLocalMessageCache, 0777 );
+               umask( $oldUmask );
+               $file = fopen( $filename.'.tmp', 'w');
+               fwrite($file,"<?php\n//$hash\n\n \$this->mCache = array(");
+
+               foreach ($array as $key => $message) {
+                       fwrite($file, "'". $this->escapeForScript($key).
+                               "' => '" . $this->escapeForScript($message).
+                               "',\n");
+               }
+               fwrite($file,");\n?>");
+               fclose($file);
+               rename($filename.'.tmp',$filename);
+       }
+
+       function escapeForScript($string) {
+               $string = str_replace( '\\', '\\\\', $string );
+               $string = str_replace( '\'', '\\\'', $string );
+               return $string;
+       }
+
+       /**
+        * Set the cache to $cache, if it is valid. Otherwise set the cache to false.
+        */
+       function setCache( $cache ) {
+               if ( isset( $cache['VERSION'] ) && $cache['VERSION'] == MSG_CACHE_VERSION ) {
+                       $this->mCache = $cache;
+               } else {
+                       $this->mCache = false;
+               }
        }
 
        /**
@@ -54,65 +174,115 @@ class MessageCache
         * Returns false for a reportable error, true otherwise
         */
        function load() {
-               global $wgAllMessagesEn;
+               global $wgLocalMessageCache, $wgLocalMessageCacheSerialized;
 
                if ( $this->mDisable ) {
-                       wfDebug( "MessageCache::load(): disabled\n" );
+                       static $shownDisabled = false;
+                       if ( !$shownDisabled ) {
+                               wfDebug( "MessageCache::load(): disabled\n" );
+                               $shownDisabled = true;
+                       }
                        return true;
                }
+               if ( !$this->mUseCache ) {
+                       $this->mDeferred = false;
+                       return true;
+               }
+
                $fname = 'MessageCache::load';
                wfProfileIn( $fname );
                $success = true;
 
-               if ( $this->mUseCache ) {
-                       wfProfileIn( $fname.'-fromcache' );
-                       $this->mCache = $this->mMemc->get( $this->mMemcKey );
-                       wfProfileOut( $fname.'-fromcache' );
+               $this->mCache = false;
 
-                       # If there's nothing in memcached, load all the messages from the database
-                       if ( !$this->mCache ) {
-                               wfDebug( "MessageCache::load(): loading all messages\n" );
-                               $this->lock();
-                               # Other threads don't need to load the messages if another thread is doing it.
-                               $success = $this->mMemc->add( $this->mMemcKey, "loading", MSG_LOAD_TIMEOUT );
-                               if ( $success ) {
-                                       wfProfileIn( $fname.'-load' );
-                                       $this->loadFromDB();
-                                       wfProfileOut( $fname.'-load' );
-                                       # Save in memcached
-                                       # Keep trying if it fails, this is kind of important
-                                       wfProfileIn( $fname.'-save' );
-                                       for ( $i=0; $i<20 && !$this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry ); $i++ ) {
-                                               usleep(mt_rand(500000,1500000));
+               # Try local cache
+               if ( $wgLocalMessageCache !== false ) {
+                       wfProfileIn( $fname.'-fromlocal' );
+                       $hash = $this->mMemc->get( "{$this->mMemcKey}-hash" );
+                       if ( $hash ) {
+                               $this->loadFromLocal( $hash );
+                               if ( $this->mCache ) {
+                                       wfDebug( "MessageCache::load(): got from local cache\n" );
+                               }
+                       }
+                       wfProfileOut( $fname.'-fromlocal' );
+               }
+
+               # Try memcached
+               if ( !$this->mCache ) {
+                       wfProfileIn( $fname.'-fromcache' );
+                       $this->setCache( $this->mMemc->get( $this->mMemcKey ) );
+                       if ( $this->mCache ) {
+                               wfDebug( "MessageCache::load(): got from global cache\n" );
+                               # 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 );
                                        }
-                                       wfProfileOut( $fname.'-save' );
-                                       if ( $i == 20 ) {
-                                               $this->mMemc->set( $this->mMemcKey, 'error', 86400 );
-                                               wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
+                                       if ($wgLocalMessageCacheSerialized) {
+                                               $this->saveToLocal( $serialized,$hash );
+                                       } else {
+                                               $this->saveToScript( $this->mCache, $hash );
                                        }
                                }
-                               $this->unlock();
                        }
+                       wfProfileOut( $fname.'-fromcache' );
+               }
+
+
+               # If there's nothing in memcached, load all the messages from the database
+               if ( !$this->mCache ) {
+                       wfDebug( "MessageCache::load(): cache is empty\n" );
+                       $this->lock();
+                       # Other threads don't need to load the messages if another thread is doing it.
+                       $success = $this->mMemc->add( $this->mMemcKey.'-status', "loading", MSG_LOAD_TIMEOUT );
+                       if ( $success ) {
+                               wfProfileIn( $fname.'-load' );
+                               wfDebug( "MessageCache::load(): loading all messages from DB\n" );
+                               $this->loadFromDB();
+                               wfProfileOut( $fname.'-load' );
+
+                               # Save in memcached
+                               # Keep trying if it fails, this is kind of important
+                               wfProfileIn( $fname.'-save' );
+                               for ($i=0; $i<20 &&
+                                                  !$this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
+                                        $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, $this->mExpiry );
+                                       if ($wgLocalMessageCacheSerialized) {
+                                               $this->saveToLocal( $serialized,$hash );
+                                       } else {
+                                               $this->saveToScript( $this->mCache, $hash );
+                                       }
+                               }
 
-                       if ( !is_array( $this->mCache ) ) {
-                               wfMsg( "MessageCache::load(): individual message mode\n" );
-                               # If it is 'loading' or 'error', switch to individual message mode, otherwise disable
-                               # Causing too much DB load, disabling -- TS
-                               $this->mDisable = true;
-                               /*
-                               if ( $this->mCache == "loading" ) {
-                                       $this->mUseCache = false;
-                               } elseif ( $this->mCache == "error" ) {
-                                       $this->mUseCache = false;
-                                       $success = false;
+                               wfProfileOut( $fname.'-save' );
+                               if ( $i == 20 ) {
+                                       $this->mMemc->set( $this->mMemcKey.'-status', 'error', 60*5 );
+                                       wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
                                } else {
-                                       $this->mDisable = true;
-                                       $success = false;
-                               }*/
-                               $this->mCache = false;
+                                       $this->mMemc->delete( $this->mMemcKey.'-status' );
+                               }
                        }
+                       $this->unlock();
+               }
+
+               if ( !is_array( $this->mCache ) ) {
+                       wfDebug( "MessageCache::load(): unable to load cache, disabled\n" );
+                       $this->mDisable = true;
+                       $this->mCache = false;
                }
                wfProfileOut( $fname );
+               $this->mDeferred = false;
                return $success;
        }
 
@@ -120,64 +290,80 @@ class MessageCache
         * Loads all or main part of cacheable messages from the database
         */
        function loadFromDB() {
-               global $wgPartialMessageCache;
-               $fname = 'MessageCache::loadFromDB';
-               $dbr =& wfGetDB( DB_SLAVE );
-               $conditions = array( 'cur_is_redirect' => 0, 
-                                       'cur_namespace' => NS_MEDIAWIKI);
-               if ($wgPartialMessageCache) {
-                       if (is_array($wgPartialMessageCache)) {
-                               $conditions['cur_title']=$wgPartialMessageCache;
-                       } else {
-                               require_once("MessageCacheHints.php");
-                               $conditions['cur_title']=MessageCacheHints::get();
-                       }
-               }
-               $res = $dbr->select( 'cur',
-                       array( 'cur_title', 'cur_text' ), $conditions, $fname);
+               global $wgMaxMsgCacheEntrySize;
 
+               wfProfileIn( __METHOD__ );
+               $dbr = wfGetDB( DB_SLAVE );
                $this->mCache = array();
-               for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
-                       $this->mCache[$row->cur_title] = $row->cur_text;
-               }
 
+               # Load titles for all oversized pages in the MediaWiki namespace
+               $res = $dbr->select( 'page', 'page_title',
+                       array(
+                               'page_len > ' . intval( $wgMaxMsgCacheEntrySize ),
+                               'page_is_redirect' => 0,
+                               'page_namespace' => NS_MEDIAWIKI,
+                       ),
+                       __METHOD__ );
+               while ( $row = $dbr->fetchObject( $res ) ) {
+                       $this->mCache[$row->page_title] = '!TOO BIG';
+               }
                $dbr->freeResult( $res );
-       }
 
-       /**
-        * Not really needed anymore
-        */
-       function getKeys() {
-               global $wgAllMessagesEn, $wgContLang;
-               if ( !$this->mKeys ) {
-                       $this->mKeys = array();
-                       foreach ( $wgAllMessagesEn as $key => $value ) {
-                               array_push( $this->mKeys, $wgContLang->ucfirst( $key ) );
-                       }
-               }
-               return $this->mKeys;
-       }
+               # Load text for the remaining pages
+               $res = $dbr->select( array( 'page', 'revision', 'text' ),
+                       array( 'page_title', 'old_text', 'old_flags' ),
+                       array(
+                               'page_is_redirect' => 0,
+                               'page_namespace' => NS_MEDIAWIKI,
+                               'page_latest=rev_id',
+                               'rev_text_id=old_id',
+                               'page_len <= ' . intval( $wgMaxMsgCacheEntrySize ) ),
+                       __METHOD__ );
 
-       /**
-        * Obsolete
-        */
-       function isCacheable( $key ) {
-               return true;
-               /*
-               global $wgAllMessagesEn, $wgLang;
-               return array_key_exists( $wgLang->lcfirst( $key ), $wgAllMessagesEn ) ||
-                       array_key_exists( $key, $wgAllMessagesEn );
-               */
+               for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
+                       $this->mCache[$row->page_title] = ' ' . Revision::getRevisionText( $row );
+               }
+               $this->mCache['VERSION'] = MSG_CACHE_VERSION;
+               $dbr->freeResult( $res );
+               wfProfileOut( __METHOD__ );
        }
 
        function replace( $title, $text ) {
+               global $wgLocalMessageCache, $wgLocalMessageCacheSerialized, $parserMemc;
+               global $wgMaxMsgCacheEntrySize;
+
+               wfProfileIn( __METHOD__ );
                $this->lock();
                $this->load();
                if ( is_array( $this->mCache ) ) {
-                       $this->mCache[$title] = $text;
+                       if ( $text === false ) {
+                               # Article was deleted
+                               unset( $this->mCache[$title] );
+                               $this->mMemc->delete( "$this->mMemcKey:{$title}" );
+                       } elseif ( strlen( $text ) > $wgMaxMsgCacheEntrySize ) {
+                               $this->mCache[$title] = '!TOO BIG';
+                               $this->mMemc->set( "$this->mMemcKey:{$title}", ' '.$text, $this->mExpiry );
+                       } else {
+                               $this->mCache[$title] = ' ' . $text;
+                               $this->mMemc->delete( "$this->mMemcKey:{$title}" );
+                       }
                        $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, $this->mExpiry );
+                               if ($wgLocalMessageCacheSerialized) {
+                                       $this->saveToLocal( $serialized,$hash );
+                               } else {
+                                       $this->saveToScript( $this->mCache, $hash );
+                               }
+                       }
                }
                $this->unlock();
+               $parserMemc->delete(wfMemcKey('sidebar'));
+               wfProfileOut( __METHOD__ );
        }
 
        /**
@@ -206,92 +392,205 @@ class MessageCache
                $this->mMemc->delete( $lockKey );
        }
 
-       function get( $key, $useDB, $forcontent=true ) {
-               global $wgContLanguageCode;
-               if( $forcontent ) {
-                       global $wgContLang;
+       /**
+        * Get a message from either the content language or the user language.
+        *
+        * @param string $key The message cache key
+        * @param bool $useDB Get the message from the DB, false to use only the localisation
+        * @param string $langcode Code of the language to get the message for, if
+        *                         it is a valid code create a language for that
+        *                         language, if it is a string but not a valid code
+        *                         then make a basic language object, if it is a
+        *                         false boolean then use the current users
+        *                         language (as a fallback for the old parameter
+        *                         functionality), or if it is a true boolean then
+        *                         use the wikis content language (also as a
+        *                         fallback).
+        * @param bool $isFullKey Specifies whether $key is a two part key "lang/msg".
+        */
+       function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {
+               global $wgContLanguageCode, $wgContLang, $wgLang;
+
+               # Identify which language to get or create a language object for.
+               if( $langcode === $wgContLang->getCode() || $langcode === true ) {
+                       # $langcode is the language code of the wikis content language object.
+                       # or it is a boolean and value is true
                        $lang =& $wgContLang;
-                       $langcode = $wgContLanguageCode;
-               } else {
-                       global $wgLang, $wgLanguageCode;
+               } elseif( $langcode === $wgLang->getCode() || $langcode === false ) {
+                       # $langcode is the language code of user language object.
+                       # or it was a boolean and value is false
                        $lang =& $wgLang;
-                       $langcode = $wgLanguageCode;
+               } else {
+                       $validCodes = array_keys( Language::getLanguageNames() );
+                       if( in_array( $langcode, $validCodes ) ) {
+                               # $langcode corresponds to a valid language.
+                               $lang = Language::factory( $langcode );
+                       } else {
+                               # $langcode is a string, but not a valid language code; use content language.
+                               $lang =& $wgContLang;
+                               wfDebug( 'Invalid language code passed to MessageCache::get, falling back to content language.' );
+                       }
                }
+
+               $langcode = $lang->getCode();
+
                # If uninitialised, someone is trying to call this halfway through Setup.php
                if( !$this->mInitialised ) {
-                       return "&lt;$key&gt;";
+                       return '&lt;' . htmlspecialchars($key) . '&gt;';
+               }
+               # If cache initialization was deferred, start it now.
+               if( $this->mDeferred && !$this->mDisable && $useDB ) {
+                       $this->load();
                }
 
                $message = false;
+
+               # Normalise title-case input
+               $lckey = $wgContLang->lcfirst( $key );
+               $lckey = str_replace( ' ', '_', $lckey );
+
+               # Try the MediaWiki namespace
                if( !$this->mDisable && $useDB ) {
-                       $title = $lang->ucfirst( $key );
-                       if( $langcode != $wgContLanguageCode ) {
+                       $title = $wgContLang->ucfirst( $lckey );
+                       if(!$isFullKey && ($langcode != $wgContLanguageCode) ) {
                                $title .= '/' . $langcode;
                        }
+                       $message = $this->getMsgFromNamespace( $title );
+               }
+               # Try the extension array
+               if( $message === false && isset( $this->mExtensionMessages[$langcode][$lckey] ) ) {
+                       $message = $this->mExtensionMessages[$langcode][$lckey];
+               }
+               if ( $message === false && isset( $this->mExtensionMessages['en'][$lckey] ) ) {
+                       $message = $this->mExtensionMessages['en'][$lckey];
+               }
 
-                       # Try the cache
-                       if( $this->mUseCache && is_array( $this->mCache ) && array_key_exists( $title, $this->mCache ) ) {
-                               $message = $this->mCache[$title];
+               # Try the array in the language object
+               if( $message === false ) {
+                       #wfDebug( "Trying language object for message $key\n" );
+                       wfSuppressWarnings();
+                       $message = $lang->getMessage( $lckey );
+                       wfRestoreWarnings();
+                       if ( is_null( $message ) ) {
+                               $message = false;
                        }
+               }
 
-                       if ( !$message && $this->mUseCache ) {
-                               $message = $this->mMemc->get( $this->mMemcKey . ':' . $title );
-                               if( $message ) {
-                                       $this->mCache[$title] = $message;
+               # Try the array of another language
+               $pos = strrpos( $lckey, '/' );
+               if( $message === false && $pos !== false) {
+                       $mkey = substr( $lckey, 0, $pos );
+                       $code = substr( $lckey, $pos+1 );
+                       if ( $code ) {
+                               $validCodes = array_keys( Language::getLanguageNames() );
+                               if ( in_array( $code, $validCodes ) ) {
+                                       $message = Language::getMessageFor( $mkey, $code );
+                                       if ( is_null( $message ) ) {
+                                               $message = false;
+                                       }
+                               } else {
+                                       wfDebug( __METHOD__ . ": Invalid code $code for $mkey/$code, not trying messages array\n" );
                                }
                        }
+               }
 
-                       # If it wasn't in the cache, load each message from the DB individually
-                       if ( !$message ) {
-                               $dbr =& wfGetDB( DB_SLAVE );
-                               $result = $dbr->selectRow( 'cur', array('cur_text'),
-                                 array( 'cur_namespace' => NS_MEDIAWIKI, 'cur_title' => $title ),
-                                 'MessageCache::get' );
-                               if ( $result ) {
-                                       $message = $result->cur_text;
-                                       if( $this->mUseCache ) {
-                                               $this->mCache[$title] = $message;
-                                               /* individual messages may be often 
-                                                  recached until proper purge code exists 
-                                               */
-                                               $this->mMemc->set( $this->mMemcKey . ':' . $title, $message, 300 );
-                                       }
-                               }
+               # Is this a custom message? Try the default language in the db...
+               if( ($message === false || $message === '-' ) &&
+                       !$this->mDisable && $useDB &&
+                       !$isFullKey && ($langcode != $wgContLanguageCode) ) {
+                       $message = $this->getMsgFromNamespace( $wgContLang->ucfirst( $lckey ) );
+               }
+
+               # Final fallback
+               if( $message === false ) {
+                       return '&lt;' . htmlspecialchars($key) . '&gt;';
+               }
+               return $message;
+       }
+
+       /**
+        * Get a message from the MediaWiki namespace, with caching. The key must
+        * first be converted to two-part lang/msg form if necessary.
+        *
+        * @param string $title Message cache key with initial uppercase letter
+        */
+       function getMsgFromNamespace( $title ) {
+               $message = false;
+               $type = false;
+
+               # Try the cache
+               if( $this->mUseCache && isset( $this->mCache[$title] ) ) {
+                       $entry = $this->mCache[$title];
+                       $type = substr( $entry, 0, 1 );
+                       if ( $type == ' ' ) {
+                               return substr( $entry, 1 );
                        }
                }
-               # Try the extension array
-               if( !$message ) {
-                       $message = @$this->mExtensionMessages[$key];
+
+               # Call message hooks, in case they are defined
+               wfRunHooks('MessagesPreLoad', array( $title, &$message ) );
+               if ( $message !== false ) {
+                       return $message;
                }
 
-               # Try the array in the language object
-               if( !$message ) {
-                       wfSuppressWarnings();
-                       $message = $lang->getMessage( $key );
-                       wfRestoreWarnings();
+               # If there is no cache entry and no placeholder, it doesn't exist
+               if ( $type != '!' && $message === false ) {
+                       return false;
                }
 
-               # Try the English array
-               if( !$message && $langcode != 'en' ) {
-                       wfSuppressWarnings();
-                       $message = Language::getMessage( $key );
-                       wfRestoreWarnings();
+               $memcKey = $this->mMemcKey . ':' . $title;
+
+               # Try the individual message cache
+               if ( $this->mUseCache ) {
+                       $entry = $this->mMemc->get( $memcKey );
+                       if ( $entry ) {
+                               $type = substr( $entry, 0, 1 );
+
+                               if ( $type == ' ' ) {
+                                       $message = substr( $entry, 1 );
+                                       $this->mCache[$title] = $entry;
+                                       return $message;
+                               } elseif ( $entry == '!NONEXISTENT' ) {
+                                       return false;
+                               } else {
+                                       # Corrupt/obsolete entry, delete it
+                                       $this->mMemc->delete( $memcKey );
+                               }
+
+                       }
                }
 
-               # Final fallback
-               if( !$message ) {
-                       $message = "&lt;$key&gt;";
+               # Try loading it from the DB
+               $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
+               if( $revision ) {
+                       $message = $revision->getText();
+                       if ($this->mUseCache) {
+                               $this->mCache[$title] = ' ' . $message;
+                               $this->mMemc->set( $memcKey, $message, $this->mExpiry );
+                       }
+               } else {
+                       # Negative caching
+                       # Use some special text instead of false, because false gets converted to '' somewhere
+                       $this->mMemc->set( $memcKey, '!NONEXISTENT', $this->mExpiry );
+                       $this->mCache[$title] = false;
                }
 
-               # Replace brace tags
-               $message = $this->transform( $message );
                return $message;
        }
 
-       function transform( $message ) {
-               if( !$this->mDisableTransform ) {
+       function transform( $message, $interface = false ) {
+               global $wgParser;
+               if ( !$this->mParser && isset( $wgParser ) ) {
+                       # Do some initialisation so that we don't have to do it twice
+                       $wgParser->firstCallInit();
+                       # Clone it and store it
+                       $this->mParser = clone $wgParser;
+               }
+               if ( $this->mParser ) {
                        if( strpos( $message, '{{' ) !== false ) {
-                               $message = $this->mParser->transformMsg( $message, $this->mParserOptions );
+                               $popts = $this->getParserOptions();
+                               $popts->setInterfaceMessage( $interface );
+                               $message = $this->mParser->transformMsg( $message, $popts );
                        }
                }
                return $message;
@@ -299,26 +598,167 @@ class MessageCache
 
        function disable() { $this->mDisable = true; }
        function enable() { $this->mDisable = false; }
-       function disableTransform() { $this->mDisableTransform = true; }
-       function enableTransform() { $this->mDisableTransform = false; }
 
-       function addMessage( $key, $value ) {
-               $this->mExtensionMessages[$key] = $value;
+       /** @deprecated */
+       function disableTransform(){
+               wfDeprecated( __METHOD__ );
+       }
+       function enableTransform() {
+               wfDeprecated( __METHOD__ );
+       }
+       function setTransform( $x ) {
+               wfDeprecated( __METHOD__ );
+       }
+       function getTransform() {
+               wfDeprecated( __METHOD__ );
+               return false;
+       }
+
+       /**
+        * Add a message to the cache
+        *
+        * @param mixed $key
+        * @param mixed $value
+        * @param string $lang The messages language, English by default
+        */
+       function addMessage( $key, $value, $lang = 'en' ) {
+               $this->mExtensionMessages[$lang][$key] = $value;
        }
 
-       function addMessages( $messages ) {
+       /**
+        * Add an associative array of message to the cache
+        *
+        * @param array $messages An associative array of key => values to be added
+        * @param string $lang The messages language, English by default
+        */
+       function addMessages( $messages, $lang = 'en' ) {
+               wfProfileIn( __METHOD__ );
+               if ( !is_array( $messages ) ) {
+                       throw new MWException( __METHOD__.': Invalid message array' );
+               }
+               if ( isset( $this->mExtensionMessages[$lang] ) ) {
+                       $this->mExtensionMessages[$lang] = $messages + $this->mExtensionMessages[$lang];
+               } else {
+                       $this->mExtensionMessages[$lang] = $messages;
+               }
+               wfProfileOut( __METHOD__ );
+       }
+
+       /**
+        * Add a 2-D array of messages by lang. Useful for extensions.
+        *
+        * @param array $messages The array to be added
+        */
+       function addMessagesByLang( $messages ) {
+               wfProfileIn( __METHOD__ );
                foreach ( $messages as $key => $value ) {
-                       $this->mExtensionMessages[$key] = $value;
+                       $this->addMessages( $value, $key );
                }
+               wfProfileOut( __METHOD__ );
+       }
+
+       /**
+        * Get the extension messages for a specific language. Only English, interface
+        * and content language are guaranteed to be loaded.
+        *
+        * @param string $lang The messages language, English by default
+        */
+       function getExtensionMessagesFor( $lang = 'en' ) {
+               wfProfileIn( __METHOD__ );
+               $messages = array();
+               if ( isset( $this->mExtensionMessages[$lang] ) ) {
+                       $messages = $this->mExtensionMessages[$lang];
+               }
+               if ( $lang != 'en' ) {
+                       $messages = $messages + $this->mExtensionMessages['en'];
+               }
+               wfProfileOut( __METHOD__ );
+               return $messages;
        }
 
        /**
         * Clear all stored messages. Mainly used after a mass rebuild.
         */
        function clear() {
+               global $wgLocalMessageCache;
                if( $this->mUseCache ) {
+                       # Global cache
                        $this->mMemc->delete( $this->mMemcKey );
+                       # Invalidate all local caches
+                       $this->mMemc->delete( "{$this->mMemcKey}-hash" );
+               }
+       }
+
+       function loadAllMessages() {
+               global $wgExtensionMessagesFiles;
+               if ( $this->mAllMessagesLoaded ) {
+                       return;
+               }
+               $this->mAllMessagesLoaded = true;
+
+               # Some extensions will load their messages when you load their class file
+               wfLoadAllExtensions();
+               # Others will respond to this hook
+               wfRunHooks( 'LoadAllMessages' );
+               # Some register their messages in $wgExtensionMessagesFiles
+               foreach ( $wgExtensionMessagesFiles as $name => $file ) {
+                       wfLoadExtensionMessages( $name );
+               }
+               # Still others will respond to neither, they are EVIL. We sometimes need to know!
+       }
+
+       /**
+        * Load messages from a given file
+        * 
+        * @param string $filename Filename of file to load.
+        * @param string $langcode Language to load messages for, or false for 
+     *                         default behvaiour (en, content language and user
+     *                         language).
+        */
+       function loadMessagesFile( $filename, $langcode = false ) {
+               global $wgLang, $wgContLang;
+               $messages = $magicWords = false;
+               require( $filename );
+
+               $validCodes = Language::getLanguageNames();
+               if( is_string( $langcode ) && array_key_exists( $langcode, $validCodes ) ) {
+                       # Load messages for given language code.
+                       $this->processMessagesArray( $messages, $langcode );
+               } elseif( is_string( $langcode ) && !array_key_exists( $langcode, $validCodes ) ) {
+                       wfDebug( "Invalid language '$langcode' code passed to MessageCache::loadMessagesFile()" );
+               } else {
+                       # Load only languages that are usually used, and merge all
+                       # fallbacks, except English.
+                       $langs = array_unique( array( 'en', $wgContLang->getCode(), $wgLang->getCode() ) );
+                       foreach( $langs as $code ) {
+                               $this->processMessagesArray( $messages, $code );
+                       }
+               }
+
+               if ( $magicWords !== false ) {
+                       global $wgContLang;
+                       $wgContLang->addMagicWordsByLang( $magicWords );
                }
        }
+
+       /**
+        * Process an array of messages, loading it into the message cache.
+        *
+        * @param array $messages Messages array.
+        * @param string $langcode Language code to process.
+        */
+       function processMessagesArray( $messages, $langcode ) {
+               $fallbackCode = $langcode;
+               $mergedMessages = array();
+               do {
+                       if ( isset($messages[$fallbackCode]) ) {
+                               $mergedMessages += $messages[$fallbackCode];
+                       }
+                       $fallbackCode = Language::getFallbackfor( $fallbackCode );
+               } while( $fallbackCode && $fallbackCode !== 'en' );
+               
+               if ( !empty($mergedMessages) )
+                       $this->addMessages( $mergedMessages, $langcode );
+       }
+
 }
-?>