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         /**
  22          * Process local cache of loaded messages that are defined in
  23          * MediaWiki namespace. First array level is a language code,
  24          * second level is message key and the values are either message
  25          * content prefixed with space, or !NONEXISTENT for negative
  26          * caching.
  27          */
  28         protected $mCache;
  29
  30         // Should  mean that database cannot be used, but check
  31         protected $mDisable;
  32
  33         /// Lifetime for cache, used by object caching
  34         protected $mExpiry;
  35
  36         /**
  37          * Message cache has it's own parser which it uses to transform
  38          * messages.
  39          */
  40         protected $mParserOptions, $mParser;
  41
  42         /// Variable for tracking which variables are already loaded
  43         protected $mLoadedLanguages = array();
  44
  45         function __construct( $memCached, $useDB, $expiry ) {
  46                 if ( !$memCached ) {
  47                         $memCached = wfGetCache( CACHE_NONE );
  48                 }
  49
  50                 $this->mMemc = $memCached;
  51                 $this->mDisable = !$useDB;
  52                 $this->mExpiry = $expiry;
  53         }
  54
  55
  56         /**
  57          * ParserOptions is lazy initialised.
  58          */
  59         function getParserOptions() {
  60                 if ( !$this->mParserOptions ) {
  61                         $this->mParserOptions = new ParserOptions;
  62                 }
  63                 return $this->mParserOptions;
  64         }
  65
  66         /**
  67          * Try to load the cache from a local file.
  68          * Actual format of the file depends on the $wgLocalMessageCacheSerialized
  69          * setting.
  70          *
  71          * @param $hash String: the hash of contents, to check validity.
  72          * @param $code Mixed: Optional language code, see documenation of load().
  73          * @return false on failure.
  74          */
  75         function loadFromLocal( $hash, $code ) {
  76                 global $wgCacheDirectory, $wgLocalMessageCacheSerialized;
  77
  78                 $filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
  79
  80                 # Check file existence
  81                 wfSuppressWarnings();
  82                 $file = fopen( $filename, 'r' );
  83                 wfRestoreWarnings();
  84                 if ( !$file ) {
  85                         return false; // No cache file
  86                 }
  87
  88                 if ( $wgLocalMessageCacheSerialized ) {
  89                         // Check to see if the file has the hash specified
  90                         $localHash = fread( $file, 32 );
  91                         if ( $hash === $localHash ) {
  92                                 // All good, get the rest of it
  93                                 $serialized = '';
  94                                 while ( !feof( $file ) ) {
  95                                         $serialized .= fread( $file, 100000 );
  96                                 }
  97                                 fclose( $file );
  98                                 return $this->setCache( unserialize( $serialized ), $code );
  99                         } else {
 100                                 fclose( $file );
 101                                 return false; // Wrong hash
 102                         }
 103                 } else {
 104                         $localHash=substr(fread($file,40),8);
 105                         fclose($file);
 106                         if ($hash!=$localHash) {
 107                                 return false; // Wrong hash
 108                         }
 109
 110                         # Require overwrites the member variable or just shadows it?
 111                         require( $filename );
 112                         return $this->setCache( $this->mCache, $code );
 113                 }
 114         }
 115
 116         /**
 117          * Save the cache to a local file.
 118          */
 119         function saveToLocal( $serialized, $hash, $code ) {
 120                 global $wgCacheDirectory;
 121
 122                 $filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
 123                 wfMkdirParents( $wgCacheDirectory ); // might fail
 124
 125                 wfSuppressWarnings();
 126                 $file = fopen( $filename, 'w' );
 127                 wfRestoreWarnings();
 128
 129                 if ( !$file ) {
 130                         wfDebug( "Unable to open local cache file for writing\n" );
 131                         return;
 132                 }
 133
 134                 fwrite( $file, $hash . $serialized );
 135                 fclose( $file );
 136                 @chmod( $filename, 0666 );
 137         }
 138
 139         function saveToScript( $array, $hash, $code ) {
 140                 global $wgCacheDirectory;
 141
 142                 $filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
 143                 $tempFilename = $filename . '.tmp';
 144                 wfMkdirParents( $wgCacheDirectory ); // might fail
 145
 146                 wfSuppressWarnings();
 147                 $file = fopen( $tempFilename, 'w');
 148                 wfRestoreWarnings();
 149
 150                 if ( !$file ) {
 151                         wfDebug( "Unable to open local cache file for writing\n" );
 152                         return;
 153                 }
 154
 155                 fwrite($file,"<?php\n//$hash\n\n \$this->mCache = array(");
 156
 157                 foreach ($array as $key => $message) {
 158                         $key = $this->escapeForScript($key);
 159                         $messages = $this->escapeForScript($message);
 160                         fwrite($file, "'$key' => '$message',\n");
 161                 }
 162
 163                 fwrite($file,");\n?>");
 164                 fclose($file);
 165                 rename($tempFilename, $filename);
 166         }
 167
 168         function escapeForScript($string) {
 169                 $string = str_replace( '\\', '\\\\', $string );
 170                 $string = str_replace( '\'', '\\\'', $string );
 171                 return $string;
 172         }
 173
 174         /**
 175          * Set the cache to $cache, if it is valid. Otherwise set the cache to false.
 176          */
 177         function setCache( $cache, $code ) {
 178                 if ( isset( $cache['VERSION'] ) && $cache['VERSION'] == MSG_CACHE_VERSION ) {
 179                         $this->mCache[$code] = $cache;
 180                         return true;
 181                 } else {
 182                         return false;
 183                 }
 184         }
 185
 186         /**
 187          * Loads messages from caches or from database in this order:
 188          * (1) local message cache (if $wgUseLocalMessageCache is enabled)
 189          * (2) memcached
 190          * (3) from the database.
 191          *
 192          * When succesfully loading from (2) or (3), all higher level caches are
 193          * updated for the newest version.
 194          *
 195          * Nothing is loaded if member variable mDisable is true, either manually
 196          * set by calling code or if message loading fails (is this possible?).
 197          *
 198          * Returns true if cache is already populated or it was succesfully populated,
 199          * or false if populating empty cache fails. Also returns true if MessageCache
 200          * is disabled.
 201          *
 202          * @param $code String: language to which load messages
 203          */
 204         function load( $code = false ) {
 205                 global $wgUseLocalMessageCache;
 206
 207                 if( !is_string( $code ) ) {
 208                         # This isn't really nice, so at least make a note about it and try to
 209                         # fall back
 210                         wfDebug( __METHOD__ . " called without providing a language code\n" );
 211                         $code = 'en';
 212                 }
 213
 214                 # Don't do double loading...
 215                 if ( isset($this->mLoadedLanguages[$code]) ) return true;
 216
 217                 # 8 lines of code just to say (once) that message cache is disabled
 218                 if ( $this->mDisable ) {
 219                         static $shownDisabled = false;
 220                         if ( !$shownDisabled ) {
 221                                 wfDebug( __METHOD__ . ": disabled\n" );
 222                                 $shownDisabled = true;
 223                         }
 224                         return true;
 225                 }
 226
 227                 # Loading code starts
 228                 wfProfileIn( __METHOD__ );
 229                 $success = false; # Keep track of success
 230                 $where = array(); # Debug info, delayed to avoid spamming debug log too much
 231                 $cacheKey = wfMemcKey( 'messages', $code ); # Key in memc for messages
 232
 233
 234                 # (1) local cache
 235                 # Hash of the contents is stored in memcache, to detect if local cache goes
 236                 # out of date (due to update in other thread?)
 237                 if ( $wgUseLocalMessageCache ) {
 238                         wfProfileIn( __METHOD__ . '-fromlocal' );
 239
 240                         $hash = $this->mMemc->get( wfMemcKey( 'messages', $code, 'hash' ) );
 241                         if ( $hash ) {
 242                                 $success = $this->loadFromLocal( $hash, $code );
 243                                 if ( $success ) $where[] = 'got from local cache';
 244                         }
 245                         wfProfileOut( __METHOD__ . '-fromlocal' );
 246                 }
 247
 248                 # (2) memcache
 249                 # Fails if nothing in cache, or in the wrong version.
 250                 if ( !$success ) {
 251                         wfProfileIn( __METHOD__ . '-fromcache' );
 252                         $cache = $this->mMemc->get( $cacheKey );
 253                         $success = $this->setCache( $cache, $code );
 254                         if ( $success ) {
 255                                 $where[] = 'got from global cache';
 256                                 $this->saveToCaches( $cache, false, $code );
 257                         }
 258                         wfProfileOut( __METHOD__ . '-fromcache' );
 259                 }
 260
 261
 262                 # (3)
 263                 # Nothing in caches... so we need create one and store it in caches
 264                 if ( !$success ) {
 265                         $where[] = 'cache is empty';
 266                         $where[] = 'loading from database';
 267
 268                         $this->lock($cacheKey);
 269
 270                         # Limit the concurrency of loadFromDB to a single process
 271                         # This prevents the site from going down when the cache expires
 272                         $statusKey = wfMemcKey( 'messages', $code, 'status' );
 273                         $success = $this->mMemc->add( $statusKey, 'loading', MSG_LOAD_TIMEOUT );
 274                         if ( $success ) {
 275                                 $cache = $this->loadFromDB( $code );
 276                                 $success = $this->setCache( $cache, $code );
 277                         }
 278                         if ( $success ) {
 279                                 $success = $this->saveToCaches( $cache, true, $code );
 280                                 if ( $success ) {
 281                                         $this->mMemc->delete( $statusKey );
 282                                 } else {
 283                                         $this->mMemc->set( $statusKey, 'error', 60*5 );
 284                                         wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
 285                                 }
 286                         }
 287                         $this->unlock($cacheKey);
 288                 }
 289
 290                 if ( !$success ) {
 291                         # Bad luck... this should not happen
 292                         $where[] = 'loading FAILED - cache is disabled';
 293                         $info = implode( ', ', $where );
 294                         wfDebug( __METHOD__ . ": Loading $code... $info\n" );
 295                         $this->mDisable = true;
 296                         $this->mCache = false;
 297                 } else {
 298                         # All good, just record the success
 299                         $info = implode( ', ', $where );
 300                         wfDebug( __METHOD__ . ": Loading $code... $info\n" );
 301                         $this->mLoadedLanguages[$code] = true;
 302                 }
 303                 wfProfileOut( __METHOD__ );
 304                 return $success;
 305         }
 306
 307         /**
 308          * Loads cacheable messages from the database. Messages bigger than
 309          * $wgMaxMsgCacheEntrySize are assigned a special value, and are loaded
 310          * on-demand from the database later.
 311          *
 312          * @param $code Optional language code, see documenation of load().
 313          * @return Array: Loaded messages for storing in caches.
 314          */
 315         function loadFromDB( $code = false ) {
 316                 wfProfileIn( __METHOD__ );
 317                 global $wgMaxMsgCacheEntrySize, $wgContLanguageCode;
 318                 $dbr = wfGetDB( DB_SLAVE );
 319                 $cache = array();
 320
 321                 # Common conditions
 322                 $conds = array(
 323                         'page_is_redirect' => 0,
 324                         'page_namespace' => NS_MEDIAWIKI,
 325                 );
 326
 327                 if ( $code ) {
 328                         # Is this fast enough. Should not matter if the filtering is done in the
 329                         # database or in code.
 330                         if ( $code !== $wgContLanguageCode ) {
 331                                 # Messages for particular language
 332                                 $conds[] = 'page_title' . $dbr->buildLike( $dbr->anyString(), "/$code" );
 333                         } else {
 334                                 # Effectively disallows use of '/' character in NS_MEDIAWIKI for uses
 335                                 # other than language code.
 336                                 $conds[] = 'page_title NOT' . $dbr->buildLike( $dbr->anyString(), '/', $dbr->anyString() );
 337                         }
 338                 }
 339
 340                 # Conditions to fetch oversized pages to ignore them
 341                 $bigConds = $conds;
 342                 $bigConds[] = 'page_len > ' . intval( $wgMaxMsgCacheEntrySize );
 343
 344                 # Load titles for all oversized pages in the MediaWiki namespace
 345                 $res = $dbr->select( 'page', 'page_title', $bigConds, __METHOD__ . "($code)-big" );
 346                 foreach ( $res as $row ) {
 347                         $cache[$row->page_title] = '!TOO BIG';
 348                 }
 349
 350                 # Conditions to load the remaining pages with their contents
 351                 $smallConds = $conds;
 352                 $smallConds[] = 'page_latest=rev_id';
 353                 $smallConds[] = 'rev_text_id=old_id';
 354                 $smallConds[] = 'page_len <= ' . intval( $wgMaxMsgCacheEntrySize );
 355
 356                 $res = $dbr->select( array( 'page', 'revision', 'text' ),
 357                         array( 'page_title', 'old_text', 'old_flags' ),
 358                         $smallConds, __METHOD__ . "($code)-small" );
 359
 360                 foreach ( $res as $row ) {
 361                         $cache[$row->page_title] = ' ' . Revision::getRevisionText( $row );
 362                 }
 363
 364                 $cache['VERSION'] = MSG_CACHE_VERSION;
 365                 wfProfileOut( __METHOD__ );
 366                 return $cache;
 367         }
 368
 369         /**
 370          * Updates cache as necessary when message page is changed
 371          *
 372          * @param $title String: name of the page changed.
 373          * @param $text Mixed: new contents of the page.
 374          */
 375         public function replace( $title, $text ) {
 376                 global $wgMaxMsgCacheEntrySize;
 377                 wfProfileIn( __METHOD__ );
 378
 379                 if ( $this->mDisable ) {
 380                         return;
 381                 }
 382
 383                 list( , $code ) = $this->figureMessage( $title );
 384
 385                 $cacheKey = wfMemcKey( 'messages', $code );
 386                 $this->load( $code );
 387                 $this->lock( $cacheKey );
 388
 389                 $titleKey = wfMemcKey( 'messages', 'individual', $title );
 390
 391                 if ( $text === false ) {
 392                         # Article was deleted
 393                         $this->mCache[$code][$title] = '!NONEXISTENT';
 394                         $this->mMemc->delete( $titleKey );
 395
 396                 } elseif ( strlen( $text ) > $wgMaxMsgCacheEntrySize ) {
 397                         # Check for size
 398                         $this->mCache[$code][$title] = '!TOO BIG';
 399                         $this->mMemc->set( $titleKey, ' ' . $text, $this->mExpiry );
 400
 401                 } else {
 402                         $this->mCache[$code][$title] = ' ' . $text;
 403                         $this->mMemc->delete( $titleKey );
 404                 }
 405
 406                 # Update caches
 407                 $this->saveToCaches( $this->mCache[$code], true, $code );
 408                 $this->unlock( $cacheKey );
 409
 410                 // Also delete cached sidebar... just in case it is affected
 411                 $codes = array( $code );
 412                 if ( $code === 'en'  ) {
 413                         // Delete all sidebars, like for example on action=purge on the
 414                         // sidebar messages
 415                         $codes = array_keys( Language::getLanguageNames() );
 416                 }
 417
 418                 global $parserMemc;
 419                 foreach ( $codes as $code ) {
 420                         $sidebarKey = wfMemcKey( 'sidebar', $code );
 421                         $parserMemc->delete( $sidebarKey );
 422                 }
 423
 424                 wfRunHooks( "MessageCacheReplace", array( $title, $text ) );
 425
 426                 wfProfileOut( __METHOD__ );
 427         }
 428
 429         /**
 430          * Shortcut to update caches.
 431          *
 432          * @param $cache Array: cached messages with a version.
 433          * @param $memc Bool: Wether to update or not memcache.
 434          * @param $code String: Language code.
 435          * @return False on somekind of error.
 436          */
 437         protected function saveToCaches( $cache, $memc = true, $code = false ) {
 438                 wfProfileIn( __METHOD__ );
 439                 global $wgUseLocalMessageCache, $wgLocalMessageCacheSerialized;
 440
 441                 $cacheKey = wfMemcKey( 'messages', $code );
 442
 443                 if ( $memc ) {
 444                         $success = $this->mMemc->set( $cacheKey, $cache, $this->mExpiry );
 445                 } else {
 446                         $success = true;
 447                 }
 448
 449                 # Save to local cache
 450                 if ( $wgUseLocalMessageCache ) {
 451                         $serialized = serialize( $cache );
 452                         $hash = md5( $serialized );
 453                         $this->mMemc->set( wfMemcKey( 'messages', $code, 'hash' ), $hash, $this->mExpiry );
 454                         if ($wgLocalMessageCacheSerialized) {
 455                                 $this->saveToLocal( $serialized, $hash, $code );
 456                         } else {
 457                                 $this->saveToScript( $cache, $hash, $code );
 458                         }
 459                 }
 460
 461                 wfProfileOut( __METHOD__ );
 462                 return $success;
 463         }
 464
 465         /**
 466          * Represents a write lock on the messages key
 467          *
 468          * @return Boolean: success
 469          */
 470         function lock($key) {
 471                 $lockKey = $key . ':lock';
 472                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 473                         sleep(1);
 474                 }
 475
 476                 return $i >= MSG_WAIT_TIMEOUT;
 477         }
 478
 479         function unlock($key) {
 480                 $lockKey = $key . ':lock';
 481                 $this->mMemc->delete( $lockKey );
 482         }
 483
 484         /**
 485          * Get a message from either the content language or the user language.
 486          *
 487          * @param $key String: the message cache key
 488          * @param $useDB Boolean: get the message from the DB, false to use only
 489          *               the localisation
 490          * @param $langcode String: code of the language to get the message for, if
 491          *                  it is a valid code create a language for that language,
 492          *                  if it is a string but not a valid code then make a basic
 493          *                  language object, if it is a false boolean then use the
 494          *                  current users language (as a fallback for the old
 495          *                  parameter functionality), or if it is a true boolean
 496          *                  then use the wikis content language (also as a
 497          *                  fallback).
 498          * @param $isFullKey Boolean: specifies whether $key is a two part key
 499          *                   "msg/lang".
 500          */
 501         function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {
 502                 global $wgContLanguageCode, $wgContLang;
 503
 504                 if ( !is_string( $key ) ) {
 505                         throw new MWException( "Non-string key given" );
 506                 }
 507
 508                 if ( strval( $key ) === '' ) {
 509                         # Shortcut: the empty key is always missing
 510                         return false;
 511                 }
 512
 513                 $lang = wfGetLangObj( $langcode );
 514                 $langcode = $lang->getCode();
 515
 516                 $message = false;
 517
 518                 # Normalise title-case input (with some inlining)
 519                 $lckey = str_replace( ' ', '_', $key );
 520                 if ( ord( $key ) < 128 ) {
 521                         $lckey[0] = strtolower( $lckey[0] );
 522                         $uckey = ucfirst( $lckey );
 523                 } else {
 524                         $lckey = $wgContLang->lcfirst( $lckey );
 525                         $uckey = $wgContLang->ucfirst( $lckey );
 526                 }
 527
 528                 # Try the MediaWiki namespace
 529                 if( !$this->mDisable && $useDB ) {
 530                         $title = $uckey;
 531                         if(!$isFullKey && ( $langcode != $wgContLanguageCode ) ) {
 532                                 $title .= '/' . $langcode;
 533                         }
 534                         $message = $this->getMsgFromNamespace( $title, $langcode );
 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                 if( $message === false ) {
 547                         $parts = explode( '/', $lckey );
 548                         # We may get calls for things that are http-urls from sidebar
 549                         # Let's not load nonexistent languages for those
 550                         # They usually have more than one slash.
 551                         if ( count( $parts ) == 2 && $parts[1] !== '' ) {
 552                                 $message = Language::getMessageFor( $parts[0], $parts[1] );
 553                                 if ( is_null( $message ) ) {
 554                                         $message = false;
 555                                 }
 556                         }
 557                 }
 558
 559                 # Is this a custom message? Try the default language in the db...
 560                 if( ($message === false || $message === '-' ) &&
 561                         !$this->mDisable && $useDB &&
 562                         !$isFullKey && ($langcode != $wgContLanguageCode) ) {
 563                         $message = $this->getMsgFromNamespace( $uckey, $wgContLanguageCode );
 564                 }
 565
 566                 # Final fallback
 567                 if( $message === false ) {
 568                         return false;
 569                 }
 570
 571                 # Fix whitespace
 572                 $message = strtr( $message,
 573                         array(
 574                                 # Fix for trailing whitespace, removed by textarea
 575                                 '&#32;' => ' ',
 576                                 # Fix for NBSP, converted to space by firefox
 577                                 '&nbsp;' => "\xc2\xa0",
 578                                 '&#160;' => "\xc2\xa0",
 579                         ) );
 580
 581                 return $message;
 582         }
 583
 584         /**
 585          * Get a message from the MediaWiki namespace, with caching. The key must
 586          * first be converted to two-part lang/msg form if necessary.
 587          *
 588          * @param $title String: Message cache key with initial uppercase letter.
 589          * @param $code String: code denoting the language to try.
 590          */
 591         function getMsgFromNamespace( $title, $code ) {
 592                 $type = false;
 593                 $message = false;
 594
 595                 $this->load( $code );
 596                 if ( isset( $this->mCache[$code][$title] ) ) {
 597                         $entry = $this->mCache[$code][$title];
 598                         if ( substr( $entry, 0, 1 ) === ' ' ) {
 599                                 return substr( $entry, 1 );
 600                         } elseif ( $entry === '!NONEXISTENT' ) {
 601                                 return false;
 602                         }
 603                 }
 604
 605                 # Call message hooks, in case they are defined
 606                 wfRunHooks('MessagesPreLoad', array( $title, &$message ) );
 607                 if ( $message !== false ) {
 608                         return $message;
 609                 }
 610
 611                 # Try the individual message cache
 612                 $titleKey = wfMemcKey( 'messages', 'individual', $title );
 613                 $entry = $this->mMemc->get( $titleKey );
 614                 if ( $entry ) {
 615                         if ( substr( $entry, 0, 1 ) === ' ' ) {
 616                                 $this->mCache[$code][$title] = $entry;
 617                                 return substr( $entry, 1 );
 618                         } elseif ( $entry === '!NONEXISTENT' ) {
 619                                 $this->mCache[$code][$title] = '!NONEXISTENT';
 620                                 return false;
 621                         } else {
 622                                 # Corrupt/obsolete entry, delete it
 623                                 $this->mMemc->delete( $titleKey );
 624                         }
 625                 }
 626
 627                 # Try loading it from the database
 628                 $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
 629                 if ( $revision ) {
 630                         $message = $revision->getText();
 631                         $this->mCache[$code][$title] = ' ' . $message;
 632                         $this->mMemc->set( $titleKey, ' ' . $message, $this->mExpiry );
 633                 } else {
 634                         $this->mCache[$code][$title] = '!NONEXISTENT';
 635                         $this->mMemc->set( $titleKey, '!NONEXISTENT', $this->mExpiry );
 636                 }
 637
 638                 return $message;
 639         }
 640
 641         function transform( $message, $interface = false, $language = null ) {
 642                 // Avoid creating parser if nothing to transform
 643                 if( strpos( $message, '{{' ) === false ) {
 644                         return $message;
 645                 }
 646
 647                 global $wgParser, $wgParserConf;
 648                 if ( !$this->mParser && isset( $wgParser ) ) {
 649                         # Do some initialisation so that we don't have to do it twice
 650                         $wgParser->firstCallInit();
 651                         # Clone it and store it
 652                         $class = $wgParserConf['class'];
 653                         if ( $class == 'Parser_DiffTest' ) {
 654                                 # Uncloneable
 655                                 $this->mParser = new $class( $wgParserConf );
 656                         } else {
 657                                 $this->mParser = clone $wgParser;
 658                         }
 659                         #wfDebug( __METHOD__ . ": following contents triggered transform: $message\n" );
 660                 }
 661                 if ( $this->mParser ) {
 662                         $popts = $this->getParserOptions();
 663                         $popts->setInterfaceMessage( $interface );
 664                         $popts->setTargetLanguage( $language );
 665                         $message = $this->mParser->transformMsg( $message, $popts );
 666                 }
 667                 return $message;
 668         }
 669
 670         function disable() { $this->mDisable = true; }
 671         function enable() { $this->mDisable = false; }
 672
 673         /** @deprecated */
 674         function disableTransform(){
 675                 wfDeprecated( __METHOD__ );
 676         }
 677         function enableTransform() {
 678                 wfDeprecated( __METHOD__ );
 679         }
 680         function setTransform( $x ) {
 681                 wfDeprecated( __METHOD__ );
 682         }
 683         function getTransform() {
 684                 wfDeprecated( __METHOD__ );
 685                 return false;
 686         }
 687
 688         /**
 689          * Clear all stored messages. Mainly used after a mass rebuild.
 690          */
 691         function clear() {
 692                 $langs = Language::getLanguageNames( false );
 693                 foreach ( array_keys($langs) as $code ) {
 694                         # Global cache
 695                         $this->mMemc->delete( wfMemcKey( 'messages', $code ) );
 696                         # Invalidate all local caches
 697                         $this->mMemc->delete( wfMemcKey( 'messages', $code, 'hash' ) );
 698                 }
 699         }
 700
 701         /**
 702          * Add a message to the cache
 703          * @deprecated Use $wgExtensionMessagesFiles
 704          *
 705          * @param $key Mixed
 706          * @param $value Mixed
 707          * @param $lang String: the messages language, English by default
 708          */
 709         function addMessage( $key, $value, $lang = 'en' ) {
 710                 wfDeprecated( __METHOD__ );
 711                 $lc = Language::getLocalisationCache();
 712                 $lc->addLegacyMessages( array( $lang => array( $key => $value ) ) );
 713         }
 714
 715         /**
 716          * Add an associative array of message to the cache
 717          * @deprecated Use $wgExtensionMessagesFiles
 718          *
 719          * @param $messages Array: an associative array of key => values to be added
 720          * @param $lang String: the messages language, English by default
 721          */
 722         function addMessages( $messages, $lang = 'en' ) {
 723                 wfDeprecated( __METHOD__ );
 724                 $lc = Language::getLocalisationCache();
 725                 $lc->addLegacyMessages( array( $lang => $messages ) );
 726         }
 727
 728         /**
 729          * Add a 2-D array of messages by lang. Useful for extensions.
 730          * @deprecated Use $wgExtensionMessagesFiles
 731          *
 732          * @param $messages Array: the array to be added
 733          */
 734         function addMessagesByLang( $messages ) {
 735                 wfDeprecated( __METHOD__ );
 736                 $lc = Language::getLocalisationCache();
 737                 $lc->addLegacyMessages( $messages );
 738         }
 739
 740         /**
 741          * Set a hook for addMessagesByLang()
 742          */
 743         function setExtensionMessagesHook( $callback ) {
 744                 $this->mAddMessagesHook = $callback;
 745         }
 746
 747         /**
 748          * @deprecated
 749          */
 750         function loadAllMessages( $lang = false ) {
 751         }
 752
 753         /**
 754          * @deprecated
 755          */
 756         function loadMessagesFile( $filename, $langcode = false ) {
 757         }
 758
 759         public function figureMessage( $key ) {
 760                 global $wgContLanguageCode;
 761                 $pieces = explode( '/', $key );
 762                 if( count( $pieces ) < 2 )
 763                         return array( $key, $wgContLanguageCode );
 764
 765                 $lang = array_pop( $pieces );
 766                 $validCodes = Language::getLanguageNames();
 767                 if( !array_key_exists( $lang, $validCodes ) )
 768                         return array( $key, $wgContLanguageCode );
 769
 770                 $message = implode( '/', $pieces );
 771                 return array( $message, $lang );
 772         }
 773
 774 }