includes/MessageCache.php

   1 <?php
   2 /**
   3  * @file
   4  * @ingroup Cache
   5  */
   6
   7 /**
   8  *
   9  */
  10 define( 'MSG_LOAD_TIMEOUT', 60);
  11 define( 'MSG_LOCK_TIMEOUT', 10);
  12 define( 'MSG_WAIT_TIMEOUT', 10);
  13 define( 'MSG_CACHE_VERSION', 1 );
  14
  15 /**
  16  * Message cache
  17  * Performs various MediaWiki namespace-related functions
  18  * @ingroup Cache
  19  */
  20 class MessageCache {
  21         // Holds loaded messages that are defined in MediaWiki namespace.
  22         var $mCache;
  23
  24         var $mUseCache, $mDisable, $mExpiry;
  25         var $mKeys, $mParserOptions, $mParser;
  26         var $mExtensionMessages = array();
  27         var $mInitialised = false;
  28         var $mAllMessagesLoaded = array(); // Extension messages
  29
  30         // Variable for tracking which variables are loaded
  31         var $mLoadedLanguages = array();
  32
  33         function __construct( &$memCached, $useDB, $expiry, /*ignored*/ $memcPrefix ) {
  34                 $this->mUseCache = !is_null( $memCached );
  35                 $this->mMemc = &$memCached;
  36                 $this->mDisable = !$useDB;
  37                 $this->mExpiry = $expiry;
  38                 $this->mDisableTransform = false;
  39                 $this->mKeys = false; # initialised on demand
  40                 $this->mInitialised = true;
  41                 $this->mParser = null;
  42         }
  43
  44
  45         /**
  46          * ParserOptions is lazy initialised.
  47          */
  48         function getParserOptions() {
  49                 if ( !$this->mParserOptions ) {
  50                         $this->mParserOptions = new ParserOptions;
  51                 }
  52                 return $this->mParserOptions;
  53         }
  54
  55         /**
  56          * Try to load the cache from a local file.
  57          * Actual format of the file depends on the $wgLocalMessageCacheSerialized
  58          * setting.
  59          *
  60          * @param $hash String: the hash of contents, to check validity.
  61          * @param $code Mixed: Optional language code, see documenation of load().
  62          * @return false on failure.
  63          */
  64         function loadFromLocal( $hash, $code ) {
  65                 global $wgLocalMessageCache, $wgLocalMessageCacheSerialized;
  66
  67                 $filename = "$wgLocalMessageCache/messages-" . wfWikiID() . "-$code";
  68
  69                 # Check file existence
  70                 wfSuppressWarnings();
  71                 $file = fopen( $filename, 'r' );
  72                 wfRestoreWarnings();
  73                 if ( !$file ) {
  74                         return false; // No cache file
  75                 }
  76
  77                 if ( $wgLocalMessageCacheSerialized ) {
  78                         // Check to see if the file has the hash specified
  79                         $localHash = fread( $file, 32 );
  80                         if ( $hash === $localHash ) {
  81                                 // All good, get the rest of it
  82                                 $serialized = '';
  83                                 while ( !feof( $file ) ) {
  84                                         $serialized .= fread( $file, 100000 );
  85                                 }
  86                                 fclose( $file );
  87                                 return $this->setCache( unserialize( $serialized ), $code );
  88                         } else {
  89                                 fclose( $file );
  90                                 return false; // Wrong hash
  91                         }
  92                 } else {
  93                         $localHash=substr(fread($file,40),8);
  94                         fclose($file);
  95                         if ($hash!=$localHash) {
  96                                 return false; // Wrong hash
  97                         }
  98
  99                         # Require overwrites the member variable or just shadows it?
 100                         require( $filename );
 101                         return $this->setCache( $this->mCache, $code );
 102                 }
 103         }
 104
 105         /**
 106          * Save the cache to a local file.
 107          */
 108         function saveToLocal( $serialized, $hash, $code ) {
 109                 global $wgLocalMessageCache;
 110
 111                 $filename = "$wgLocalMessageCache/messages-" . wfWikiID() . "-$code";
 112                 wfMkdirParents( $wgLocalMessageCache ); // might fail
 113
 114                 wfSuppressWarnings();
 115                 $file = fopen( $filename, 'w' );
 116                 wfRestoreWarnings();
 117
 118                 if ( !$file ) {
 119                         wfDebug( "Unable to open local cache file for writing\n" );
 120                         return;
 121                 }
 122
 123                 fwrite( $file, $hash . $serialized );
 124                 fclose( $file );
 125                 @chmod( $filename, 0666 );
 126         }
 127
 128         function saveToScript( $array, $hash, $code ) {
 129                 global $wgLocalMessageCache;
 130
 131                 $filename = "$wgLocalMessageCache/messages-" . wfWikiID() . "-$code";
 132                 $tempFilename = $filename . '.tmp';
 133                 wfMkdirParents( $wgLocalMessageCache ); // might fail
 134
 135                 wfSuppressWarnings();
 136                 $file = fopen( $tempFilename, 'w');
 137                 wfRestoreWarnings();
 138
 139                 if ( !$file ) {
 140                         wfDebug( "Unable to open local cache file for writing\n" );
 141                         return;
 142                 }
 143
 144                 fwrite($file,"<?php\n//$hash\n\n \$this->mCache = array(");
 145
 146                 foreach ($array as $key => $message) {
 147                         $key = $this->escapeForScript($key);
 148                         $messages = $this->escapeForScript($message);
 149                         fwrite($file, "'$key' => '$message',\n");
 150                 }
 151
 152                 fwrite($file,");\n?>");
 153                 fclose($file);
 154                 rename($tempFilename, $filename);
 155         }
 156
 157         function escapeForScript($string) {
 158                 $string = str_replace( '\\', '\\\\', $string );
 159                 $string = str_replace( '\'', '\\\'', $string );
 160                 return $string;
 161         }
 162
 163         /**
 164          * Set the cache to $cache, if it is valid. Otherwise set the cache to false.
 165          */
 166         function setCache( $cache, $code ) {
 167                 if ( isset( $cache['VERSION'] ) && $cache['VERSION'] == MSG_CACHE_VERSION ) {
 168                         $this->mCache[$code] = $cache;
 169                         return true;
 170                 } else {
 171                         return false;
 172                 }
 173         }
 174
 175         /**
 176          * Loads messages from caches or from database in this order:
 177          * (1) local message cache (if $wgLocalMessageCache is enabled)
 178          * (2) memcached
 179          * (3) from the database.
 180          *
 181          * When succesfully loading from (2) or (3), all higher level caches are
 182          * updated for the newest version.
 183          *
 184          * Nothing is loaded if  member variable mDisabled is true, either manually
 185          * set by calling code or if message loading fails (is this possible?).
 186          *
 187          * Returns true if cache is already populated or it was succesfully populated,
 188          * or false if populating empty cache fails. Also returns true if MessageCache
 189          * is disabled.
 190          *
 191          * @param $code String: language to which load messages
 192          */
 193         function load( $code = false ) {
 194                 global $wgLocalMessageCache;
 195
 196                 if ( !$this->mUseCache ) {
 197                         return true;
 198                 }
 199
 200                 if( !is_string( $code ) ) {
 201                         # This isn't really nice, so at least make a note about it and try to
 202                         # fall back
 203                         wfDebug( __METHOD__ . " called without providing a language code\n" );
 204                         $code = 'en';
 205                 }
 206
 207                 # Don't do double loading...
 208                 if ( isset($this->mLoadedLanguages[$code]) ) return true;
 209
 210                 # 8 lines of code just to say (once) that message cache is disabled
 211                 if ( $this->mDisable ) {
 212                         static $shownDisabled = false;
 213                         if ( !$shownDisabled ) {
 214                                 wfDebug( __METHOD__ . ": disabled\n" );
 215                                 $shownDisabled = true;
 216                         }
 217                         return true;
 218                 }
 219
 220                 # Loading code starts
 221                 wfProfileIn( __METHOD__ );
 222                 $success = false; # Keep track of success
 223                 $where = array(); # Debug info, delayed to avoid spamming debug log too much
 224                 $cacheKey = wfMemcKey( 'messages', $code ); # Key in memc for messages
 225
 226
 227                 # (1) local cache
 228                 # Hash of the contents is stored in memcache, to detect if local cache goes
 229                 # out of date (due to update in other thread?)
 230                 if ( $wgLocalMessageCache !== false ) {
 231                         wfProfileIn( __METHOD__ . '-fromlocal' );
 232
 233                         $hash = $this->mMemc->get( wfMemcKey( 'messages', $code, 'hash' ) );
 234                         if ( $hash ) {
 235                                 $success = $this->loadFromLocal( $hash, $code );
 236                                 if ( $success ) $where[] = 'got from local cache';
 237                         }
 238                         wfProfileOut( __METHOD__ . '-fromlocal' );
 239                 }
 240
 241                 # (2) memcache
 242                 # Fails if nothing in cache, or in the wrong version.
 243                 if ( !$success ) {
 244                         wfProfileIn( __METHOD__ . '-fromcache' );
 245                         $cache = $this->mMemc->get( $cacheKey );
 246                         $success = $this->setCache( $cache, $code );
 247                         if ( $success ) {
 248                                 $where[] = 'got from global cache';
 249                                 $this->saveToCaches( $cache, false, $code );
 250                         }
 251                         wfProfileOut( __METHOD__ . '-fromcache' );
 252                 }
 253
 254
 255                 # (3)
 256                 # Nothing in caches... so we need create one and store it in caches
 257                 if ( !$success ) {
 258                         $where[] = 'cache is empty';
 259                         $where[] = 'loading from database';
 260
 261                         $this->lock($cacheKey);
 262
 263                         # Limit the concurrency of loadFromDB to a single process
 264                         # This prevents the site from going down when the cache expires
 265                         $statusKey = wfMemcKey( 'messages', $code, 'status' );
 266                         $success = $this->mMemc->add( $statusKey, 'loading', MSG_LOAD_TIMEOUT );
 267                         if ( $success ) {
 268                                 $cache = $this->loadFromDB( $code );
 269                                 $success = $this->setCache( $cache, $code );
 270                         }
 271                         if ( $success ) {
 272                                 $success = $this->saveToCaches( $cache, true, $code );
 273                                 if ( $success ) {
 274                                         $this->mMemc->delete( $statusKey );
 275                                 } else {
 276                                         $this->mMemc->set( $statusKey, 'error', 60*5 );
 277                                         wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
 278                                 }
 279                         }
 280                         $this->unlock($cacheKey);
 281                 }
 282
 283                 if ( !$success ) {
 284                         # Bad luck... this should not happen
 285                         $where[] = 'loading FAILED - cache is disabled';
 286                         $info = implode( ', ', $where );
 287                         wfDebug( __METHOD__ . ": Loading $code... $info\n" );
 288                         $this->mDisable = true;
 289                         $this->mCache = false;
 290                 } else {
 291                         # All good, just record the success
 292                         $info = implode( ', ', $where );
 293                         wfDebug( __METHOD__ . ": Loading $code... $info\n" );
 294                         $this->mLoadedLanguages[$code] = true;
 295                 }
 296                 wfProfileOut( __METHOD__ );
 297                 return $success;
 298         }
 299
 300         /**
 301          * Loads cacheable messages from the database. Messages bigger than
 302          * $wgMaxMsgCacheEntrySize are assigned a special value, and are loaded
 303          * on-demand from the database later.
 304          *
 305          * @param $code Optional language code, see documenation of load().
 306          * @return Array: Loaded messages for storing in caches.
 307          */
 308         function loadFromDB( $code = false ) {
 309                 wfProfileIn( __METHOD__ );
 310                 global $wgMaxMsgCacheEntrySize, $wgContLanguageCode;
 311                 $dbr = wfGetDB( DB_SLAVE );
 312                 $cache = array();
 313
 314                 # Common conditions
 315                 $conds = array(
 316                         'page_is_redirect' => 0,
 317                         'page_namespace' => NS_MEDIAWIKI,
 318                 );
 319
 320                 if ( $code ) {
 321                         # Is this fast enough. Should not matter if the filtering is done in the
 322                         # database or in code.
 323                         if ( $code !== $wgContLanguageCode ) {
 324                                 # Messages for particular language
 325                                 $escapedCode = $dbr->escapeLike( $code );
 326                                 $conds[] = "page_title like '%%/$escapedCode'";
 327                         } else {
 328                                 # Effectively disallows use of '/' character in NS_MEDIAWIKI for uses
 329                                 # other than language code.
 330                                 $conds[] = "page_title not like '%%/%%'";
 331                         }
 332                 }
 333
 334                 # Conditions to fetch oversized pages to ignore them
 335                 $bigConds = $conds;
 336                 $bigConds[] = 'page_len > ' . intval( $wgMaxMsgCacheEntrySize );
 337
 338                 # Load titles for all oversized pages in the MediaWiki namespace
 339                 $res = $dbr->select( 'page', 'page_title', $bigConds, __METHOD__ );
 340                 while ( $row = $dbr->fetchObject( $res ) ) {
 341                         $cache[$row->page_title] = '!TOO BIG';
 342                 }
 343                 $dbr->freeResult( $res );
 344
 345                 # Conditions to load the remaining pages with their contents
 346                 $smallConds = $conds;
 347                 $smallConds[] = 'page_latest=rev_id';
 348                 $smallConds[] = 'rev_text_id=old_id';
 349                 $smallConds[] = 'page_len <= ' . intval( $wgMaxMsgCacheEntrySize );
 350
 351                 $res = $dbr->select( array( 'page', 'revision', 'text' ),
 352                         array( 'page_title', 'old_text', 'old_flags' ),
 353                         $smallConds, __METHOD__ );
 354
 355                 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
 356                         $cache[$row->page_title] = ' ' . Revision::getRevisionText( $row );
 357                 }
 358                 $dbr->freeResult( $res );
 359
 360                 $cache['VERSION'] = MSG_CACHE_VERSION;
 361                 wfProfileOut( __METHOD__ );
 362                 return $cache;
 363         }
 364
 365         /**
 366          * Updates cache as necessary when message page is changed
 367          *
 368          * @param $title String: name of the page changed.
 369          * @param $text Mixed: new contents of the page.
 370          */
 371         public function replace( $title, $text ) {
 372                 global $wgMaxMsgCacheEntrySize;
 373                 wfProfileIn( __METHOD__ );
 374
 375
 376                 list( , $code ) = $this->figureMessage( $title );
 377
 378                 $cacheKey = wfMemcKey( 'messages', $code );
 379                 $this->load($code);
 380                 $this->lock($cacheKey);
 381
 382                 if ( is_array($this->mCache[$code]) ) {
 383                         $titleKey = wfMemcKey( 'messages', 'individual', $title );
 384
 385                         if ( $text === false ) {
 386                                 # Article was deleted
 387                                 unset( $this->mCache[$code][$title] );
 388                                 $this->mMemc->delete( $titleKey );
 389
 390                         } elseif ( strlen( $text ) > $wgMaxMsgCacheEntrySize ) {
 391                                 # Check for size
 392                                 $this->mCache[$code][$title] = '!TOO BIG';
 393                                 $this->mMemc->set( $titleKey, ' ' . $text, $this->mExpiry );
 394
 395                         } else {
 396                                 $this->mCache[$code][$title] = ' ' . $text;
 397                                 $this->mMemc->delete( $titleKey );
 398                         }
 399
 400                         # Update caches
 401                         $this->saveToCaches( $this->mCache[$code], true, $code );
 402                 }
 403                 $this->unlock($cacheKey);
 404
 405                 // Also delete cached sidebar... just in case it is affected
 406                 global $parserMemc;
 407                 $sidebarKey = wfMemcKey( 'sidebar', $code );
 408                 $parserMemc->delete( $sidebarKey );
 409
 410                 wfProfileOut( __METHOD__ );
 411         }
 412
 413         /**
 414          * Shortcut to update caches.
 415          *
 416          * @param $cache Array: cached messages with a version.
 417          * @param $cacheKey String: Identifier for the cache.
 418          * @param $memc Bool: Wether to update or not memcache.
 419          * @param $code String: Language code.
 420          * @return False on somekind of error.
 421          */
 422         protected function saveToCaches( $cache, $memc = true, $code = false ) {
 423                 wfProfileIn( __METHOD__ );
 424                 global $wgLocalMessageCache, $wgLocalMessageCacheSerialized;
 425
 426                 $cacheKey = wfMemcKey( 'messages', $code );
 427
 428                 $i = 0;
 429                 if ( $memc ) {
 430                         # Save in memcached
 431                         # Keep trying if it fails, this is kind of important
 432
 433                         for ($i=0; $i<20 &&
 434                                 !$this->mMemc->set( $cacheKey, $cache, $this->mExpiry );
 435                                 $i++ ) {
 436                                 usleep(mt_rand(500000,1500000));
 437                         }
 438                 }
 439
 440                 # Save to local cache
 441                 if ( $wgLocalMessageCache !== false ) {
 442                         $serialized = serialize( $cache );
 443                         $hash = md5( $serialized );
 444                         $this->mMemc->set( wfMemcKey( 'messages', $code, 'hash' ), $hash, $this->mExpiry );
 445                         if ($wgLocalMessageCacheSerialized) {
 446                                 $this->saveToLocal( $serialized, $hash, $code );
 447                         } else {
 448                                 $this->saveToScript( $cache, $hash, $code );
 449                         }
 450                 }
 451
 452                 if ( $i == 20 ) {
 453                         $success = false;
 454                 } else {
 455                         $success = true;
 456                 }
 457                 wfProfileOut( __METHOD__ );
 458                 return $success;
 459         }
 460
 461         /**
 462          * Returns success
 463          * Represents a write lock on the messages key
 464          */
 465         function lock($key) {
 466                 if ( !$this->mUseCache ) {
 467                         return true;
 468                 }
 469
 470                 $lockKey = $key . ':lock';
 471                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 472                         sleep(1);
 473                 }
 474
 475                 return $i >= MSG_WAIT_TIMEOUT;
 476         }
 477
 478         function unlock($key) {
 479                 if ( !$this->mUseCache ) {
 480                         return;
 481                 }
 482
 483                 $lockKey = $key . ':lock';
 484                 $this->mMemc->delete( $lockKey );
 485         }
 486
 487         /**
 488          * Get a message from either the content language or the user language.
 489          *
 490          * @param string $key The message cache key
 491          * @param bool $useDB Get the message from the DB, false to use only the localisation
 492          * @param string $langcode Code of the language to get the message for, if
 493          *                         it is a valid code create a language for that
 494          *                         language, if it is a string but not a valid code
 495          *                         then make a basic language object, if it is a
 496          *                         false boolean then use the current users
 497          *                         language (as a fallback for the old parameter
 498          *                         functionality), or if it is a true boolean then
 499          *                         use the wikis content language (also as a
 500          *                         fallback).
 501          * @param bool $isFullKey Specifies whether $key is a two part key "lang/msg".
 502          */
 503         function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {
 504                 global $wgContLanguageCode, $wgContLang;
 505
 506                 $lang = wfGetLangObj( $langcode );
 507                 $langcode = $lang->getCode();
 508
 509                 # If uninitialised, someone is trying to call this halfway through Setup.php
 510                 if( !$this->mInitialised ) {
 511                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 512                 }
 513
 514                 $message = false;
 515
 516                 # Normalise title-case input
 517                 $lckey = $wgContLang->lcfirst( $key );
 518                 $lckey = str_replace( ' ', '_', $lckey );
 519
 520                 # Try the MediaWiki namespace
 521                 if( !$this->mDisable && $useDB ) {
 522                         $title = $wgContLang->ucfirst( $lckey );
 523                         if(!$isFullKey && ($langcode != $wgContLanguageCode) ) {
 524                                 $title .= '/' . $langcode;
 525                         }
 526                         $message = $this->getMsgFromNamespace( $title, $langcode );
 527                 }
 528
 529                 # Try the extension array
 530                 if ( $message === false && isset( $this->mExtensionMessages[$langcode][$lckey] ) ) {
 531                         $message = $this->mExtensionMessages[$langcode][$lckey];
 532                 }
 533                 if ( $message === false && isset( $this->mExtensionMessages['en'][$lckey] ) ) {
 534                         $message = $this->mExtensionMessages['en'][$lckey];
 535                 }
 536
 537                 # Try the array in the language object
 538                 if ( $message === false ) {
 539                         $message = $lang->getMessage( $lckey );
 540                         if ( is_null( $message ) ) {
 541                                 $message = false;
 542                         }
 543                 }
 544
 545                 # Try the array of another language
 546                 $pos = strrpos( $lckey, '/' );
 547                 if( $message === false && $pos !== false) {
 548                         $mkey = substr( $lckey, 0, $pos );
 549                         $code = substr( $lckey, $pos+1 );
 550                         if ( $code ) {
 551                                 # We may get calls for things that are http-urls from sidebar
 552                                 # Let's not load nonexistent languages for those
 553                                 $validCodes = array_keys( Language::getLanguageNames() );
 554                                 if ( in_array( $code, $validCodes ) ) {
 555                                         $message = Language::getMessageFor( $mkey, $code );
 556                                         if ( is_null( $message ) ) {
 557                                                 $message = false;
 558                                         }
 559                                 }
 560                         }
 561                 }
 562
 563                 # Is this a custom message? Try the default language in the db...
 564                 if( ($message === false || $message === '-' ) &&
 565                         !$this->mDisable && $useDB &&
 566                         !$isFullKey && ($langcode != $wgContLanguageCode) ) {
 567                         $message = $this->getMsgFromNamespace( $wgContLang->ucfirst( $lckey ), $wgContLanguageCode );
 568                 }
 569
 570                 # Final fallback
 571                 if( $message === false ) {
 572                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 573                 }
 574                 return $message;
 575         }
 576
 577         /**
 578          * Get a message from the MediaWiki namespace, with caching. The key must
 579          * first be converted to two-part lang/msg form if necessary.
 580          *
 581          * @param $title String: Message cache key with initial uppercase letter.
 582          * @param $code String: code denoting the language to try.
 583          */
 584         function getMsgFromNamespace( $title, $code ) {
 585                 $type = false;
 586                 $message = false;
 587
 588                 if ( $this->mUseCache ) {
 589                         $this->load( $code );
 590                         if (isset( $this->mCache[$code][$title] ) ) {
 591                                 $entry = $this->mCache[$code][$title];
 592                                 $type = substr( $entry, 0, 1 );
 593                                 if ( $type == ' ' ) {
 594                                         return substr( $entry, 1 );
 595                                 }
 596                         }
 597                 }
 598
 599                 # Call message hooks, in case they are defined
 600                 wfRunHooks('MessagesPreLoad', array( $title, &$message ) );
 601                 if ( $message !== false ) {
 602                         return $message;
 603                 }
 604
 605                 # If there is no cache entry and no placeholder, it doesn't exist
 606                 if ( $type !== '!' ) {
 607                         return false;
 608                 }
 609
 610                 $titleKey = wfMemcKey( 'messages', 'individual', $title );
 611
 612                 # Try the individual message cache
 613                 if ( $this->mUseCache ) {
 614                         $entry = $this->mMemc->get( $titleKey );
 615                         if ( $entry ) {
 616                                 $type = substr( $entry, 0, 1 );
 617
 618                                 if ( $type === ' ' ) {
 619                                         # Ok!
 620                                         $message = substr( $entry, 1 );
 621                                         $this->mCache[$code][$title] = $entry;
 622                                         return $message;
 623                                 } elseif ( $entry === '!NONEXISTENT' ) {
 624                                         return false;
 625                                 } else {
 626                                         # Corrupt/obsolete entry, delete it
 627                                         $this->mMemc->delete( $titleKey );
 628                                 }
 629
 630                         }
 631                 }
 632
 633                 # Try loading it from the DB
 634                 $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
 635                 if( $revision ) {
 636                         $message = $revision->getText();
 637                         if ($this->mUseCache) {
 638                                 $this->mCache[$code][$title] = ' ' . $message;
 639                                 $this->mMemc->set( $titleKey, $message, $this->mExpiry );
 640                         }
 641                 } else {
 642                         # Negative caching
 643                         # Use some special text instead of false, because false gets converted to '' somewhere
 644                         $this->mMemc->set( $titleKey, '!NONEXISTENT', $this->mExpiry );
 645                         $this->mCache[$code][$title] = false;
 646                 }
 647                 return $message;
 648         }
 649
 650         function transform( $message, $interface = false, $language = null ) {
 651                 // Avoid creating parser if nothing to transfrom
 652                 if( strpos( $message, '{{' ) === false ) {
 653                         return $message;
 654                 }
 655
 656                 global $wgParser, $wgParserConf;
 657                 if ( !$this->mParser && isset( $wgParser ) ) {
 658                         # Do some initialisation so that we don't have to do it twice
 659                         $wgParser->firstCallInit();
 660                         # Clone it and store it
 661                         $class = $wgParserConf['class'];
 662                         if ( $class == 'Parser_DiffTest' ) {
 663                                 # Uncloneable
 664                                 $this->mParser = new $class( $wgParserConf );
 665                         } else {
 666                                 $this->mParser = clone $wgParser;
 667                         }
 668                         #wfDebug( __METHOD__ . ": following contents triggered transform: $message\n" );
 669                 }
 670                 if ( $this->mParser ) {
 671                         $popts = $this->getParserOptions();
 672                         $popts->setInterfaceMessage( $interface );
 673                         $popts->setTargetLanguage( $language );
 674                         $message = $this->mParser->transformMsg( $message, $popts );
 675                 }
 676                 return $message;
 677         }
 678
 679         function disable() { $this->mDisable = true; }
 680         function enable() { $this->mDisable = false; }
 681
 682         /** @deprecated */
 683         function disableTransform(){
 684                 wfDeprecated( __METHOD__ );
 685         }
 686         function enableTransform() {
 687                 wfDeprecated( __METHOD__ );
 688         }
 689         function setTransform( $x ) {
 690                 wfDeprecated( __METHOD__ );
 691         }
 692         function getTransform() {
 693                 wfDeprecated( __METHOD__ );
 694                 return false;
 695         }
 696
 697         /**
 698          * Add a message to the cache
 699          *
 700          * @param mixed $key
 701          * @param mixed $value
 702          * @param string $lang The messages language, English by default
 703          */
 704         function addMessage( $key, $value, $lang = 'en' ) {
 705                 $this->mExtensionMessages[$lang][$key] = $value;
 706         }
 707
 708         /**
 709          * Add an associative array of message to the cache
 710          *
 711          * @param array $messages An associative array of key => values to be added
 712          * @param string $lang The messages language, English by default
 713          */
 714         function addMessages( $messages, $lang = 'en' ) {
 715                 wfProfileIn( __METHOD__ );
 716                 if ( !is_array( $messages ) ) {
 717                         throw new MWException( __METHOD__.': Invalid message array' );
 718                 }
 719                 if ( isset( $this->mExtensionMessages[$lang] ) ) {
 720                         $this->mExtensionMessages[$lang] = $messages + $this->mExtensionMessages[$lang];
 721                 } else {
 722                         $this->mExtensionMessages[$lang] = $messages;
 723                 }
 724                 wfProfileOut( __METHOD__ );
 725         }
 726
 727         /**
 728          * Add a 2-D array of messages by lang. Useful for extensions.
 729          *
 730          * @param array $messages The array to be added
 731          */
 732         function addMessagesByLang( $messages ) {
 733                 wfProfileIn( __METHOD__ );
 734                 foreach ( $messages as $key => $value ) {
 735                         $this->addMessages( $value, $key );
 736                 }
 737                 wfProfileOut( __METHOD__ );
 738         }
 739
 740         /**
 741          * Get the extension messages for a specific language. Only English, interface
 742          * and content language are guaranteed to be loaded.
 743          *
 744          * @param string $lang The messages language, English by default
 745          */
 746         function getExtensionMessagesFor( $lang = 'en' ) {
 747                 wfProfileIn( __METHOD__ );
 748                 $messages = array();
 749                 if ( isset( $this->mExtensionMessages[$lang] ) ) {
 750                         $messages = $this->mExtensionMessages[$lang];
 751                 }
 752                 if ( $lang != 'en' ) {
 753                         $messages = $messages + $this->mExtensionMessages['en'];
 754                 }
 755                 wfProfileOut( __METHOD__ );
 756                 return $messages;
 757         }
 758
 759         /**
 760          * Clear all stored messages. Mainly used after a mass rebuild.
 761          */
 762         function clear() {
 763                 if( $this->mUseCache ) {
 764                         $langs = Language::getLanguageNames( false );
 765                         foreach ( array_keys($langs) as $code ) {
 766                                 # Global cache
 767                                 $this->mMemc->delete( wfMemcKey( 'messages', $code ) );
 768                                 # Invalidate all local caches
 769                                 $this->mMemc->delete( wfMemcKey( 'messages', $code, 'hash' ) );
 770                         }
 771                 }
 772         }
 773
 774         function loadAllMessages( $lang = false ) {
 775                 global $wgExtensionMessagesFiles;
 776                 $key = $lang === false ? '*' : $lang;
 777                 if ( isset( $this->mAllMessagesLoaded[$key] ) ) {
 778                         return;
 779                 }
 780                 $this->mAllMessagesLoaded[$key] = true;
 781
 782                 # Some extensions will load their messages when you load their class file
 783                 wfLoadAllExtensions();
 784                 # Others will respond to this hook
 785                 wfRunHooks( 'LoadAllMessages' );
 786                 # Some register their messages in $wgExtensionMessagesFiles
 787                 foreach ( $wgExtensionMessagesFiles as $name => $file ) {
 788                         wfLoadExtensionMessages( $name, $lang );
 789                 }
 790                 # Still others will respond to neither, they are EVIL. We sometimes need to know!
 791         }
 792
 793         /**
 794          * Load messages from a given file
 795          *
 796          * @param string $filename Filename of file to load.
 797          * @param string $langcode Language to load messages for, or false for
 798      *                         default behvaiour (en, content language and user
 799      *                         language).
 800          */
 801         function loadMessagesFile( $filename, $langcode = false ) {
 802                 global $wgLang, $wgContLang;
 803                 $messages = $magicWords = false;
 804                 require( $filename );
 805
 806                 $validCodes = Language::getLanguageNames();
 807                 if( is_string( $langcode ) && array_key_exists( $langcode, $validCodes ) ) {
 808                         # Load messages for given language code.
 809                         $this->processMessagesArray( $messages, $langcode );
 810                 } elseif( is_string( $langcode ) && !array_key_exists( $langcode, $validCodes ) ) {
 811                         wfDebug( "Invalid language '$langcode' code passed to MessageCache::loadMessagesFile()" );
 812                 } else {
 813                         # Load only languages that are usually used, and merge all
 814                         # fallbacks, except English.
 815                         $langs = array_unique( array( 'en', $wgContLang->getCode(), $wgLang->getCode() ) );
 816                         foreach( $langs as $code ) {
 817                                 $this->processMessagesArray( $messages, $code );
 818                         }
 819                 }
 820
 821                 if ( $magicWords !== false ) {
 822                         global $wgContLang;
 823                         $wgContLang->addMagicWordsByLang( $magicWords );
 824                 }
 825         }
 826
 827         /**
 828          * Process an array of messages, loading it into the message cache.
 829          *
 830          * @param array $messages Messages array.
 831          * @param string $langcode Language code to process.
 832          */
 833         function processMessagesArray( $messages, $langcode ) {
 834                 $fallbackCode = $langcode;
 835                 $mergedMessages = array();
 836                 do {
 837                         if ( isset($messages[$fallbackCode]) ) {
 838                                 $mergedMessages += $messages[$fallbackCode];
 839                         }
 840                         $fallbackCode = Language::getFallbackfor( $fallbackCode );
 841                 } while( $fallbackCode && $fallbackCode !== 'en' );
 842
 843                 if ( !empty($mergedMessages) )
 844                         $this->addMessages( $mergedMessages, $langcode );
 845         }
 846
 847         public function figureMessage( $key ) {
 848                 global $wgContLanguageCode;
 849                 $pieces = explode( '/', $key );
 850                 if( count( $pieces ) < 2 )
 851                         return array( $key, $wgContLanguageCode );
 852
 853                 $lang = array_pop( $pieces );
 854                 $validCodes = Language::getLanguageNames();
 855                 if( !array_key_exists( $lang, $validCodes ) )
 856                         return array( $key, $wgContLanguageCode );
 857
 858                 $message = implode( '/', $pieces );
 859                 return array( $message, $lang );
 860         }
 861
 862 }