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 $mDisable, $mExpiry;
  25         var $mKeys, $mParserOptions, $mParser;
  26
  27         // Variable for tracking which variables are loaded
  28         var $mLoadedLanguages = array();
  29
  30         function __construct( $memCached, $useDB, $expiry, /*ignored*/ $memcPrefix ) {
  31                 if ( !$memCached ) {
  32                         $memCached = wfGetCache( CACHE_NONE );
  33                 }
  34
  35                 $this->mMemc = $memCached;
  36                 $this->mDisable = !$useDB;
  37                 $this->mExpiry = $expiry;
  38                 $this->mDisableTransform = false;
  39                 $this->mKeys = false; # initialised on demand
  40                 $this->mParser = null;
  41         }
  42
  43
  44         /**
  45          * ParserOptions is lazy initialised.
  46          */
  47         function getParserOptions() {
  48                 if ( !$this->mParserOptions ) {
  49                         $this->mParserOptions = new ParserOptions;
  50                 }
  51                 return $this->mParserOptions;
  52         }
  53
  54         /**
  55          * Try to load the cache from a local file.
  56          * Actual format of the file depends on the $wgLocalMessageCacheSerialized
  57          * setting.
  58          *
  59          * @param $hash String: the hash of contents, to check validity.
  60          * @param $code Mixed: Optional language code, see documenation of load().
  61          * @return false on failure.
  62          */
  63         function loadFromLocal( $hash, $code ) {
  64                 global $wgCacheDirectory, $wgLocalMessageCacheSerialized;
  65
  66                 $filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
  67
  68                 # Check file existence
  69                 wfSuppressWarnings();
  70                 $file = fopen( $filename, 'r' );
  71                 wfRestoreWarnings();
  72                 if ( !$file ) {
  73                         return false; // No cache file
  74                 }
  75
  76                 if ( $wgLocalMessageCacheSerialized ) {
  77                         // Check to see if the file has the hash specified
  78                         $localHash = fread( $file, 32 );
  79                         if ( $hash === $localHash ) {
  80                                 // All good, get the rest of it
  81                                 $serialized = '';
  82                                 while ( !feof( $file ) ) {
  83                                         $serialized .= fread( $file, 100000 );
  84                                 }
  85                                 fclose( $file );
  86                                 return $this->setCache( unserialize( $serialized ), $code );
  87                         } else {
  88                                 fclose( $file );
  89                                 return false; // Wrong hash
  90                         }
  91                 } else {
  92                         $localHash=substr(fread($file,40),8);
  93                         fclose($file);
  94                         if ($hash!=$localHash) {
  95                                 return false; // Wrong hash
  96                         }
  97
  98                         # Require overwrites the member variable or just shadows it?
  99                         require( $filename );
 100                         return $this->setCache( $this->mCache, $code );
 101                 }
 102         }
 103
 104         /**
 105          * Save the cache to a local file.
 106          */
 107         function saveToLocal( $serialized, $hash, $code ) {
 108                 global $wgCacheDirectory;
 109
 110                 $filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
 111                 wfMkdirParents( $wgCacheDirectory ); // might fail
 112
 113                 wfSuppressWarnings();
 114                 $file = fopen( $filename, 'w' );
 115                 wfRestoreWarnings();
 116
 117                 if ( !$file ) {
 118                         wfDebug( "Unable to open local cache file for writing\n" );
 119                         return;
 120                 }
 121
 122                 fwrite( $file, $hash . $serialized );
 123                 fclose( $file );
 124                 @chmod( $filename, 0666 );
 125         }
 126
 127         function saveToScript( $array, $hash, $code ) {
 128                 global $wgCacheDirectory;
 129
 130                 $filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
 131                 $tempFilename = $filename . '.tmp';
 132                 wfMkdirParents( $wgCacheDirectory ); // might fail
 133
 134                 wfSuppressWarnings();
 135                 $file = fopen( $tempFilename, 'w');
 136                 wfRestoreWarnings();
 137
 138                 if ( !$file ) {
 139                         wfDebug( "Unable to open local cache file for writing\n" );
 140                         return;
 141                 }
 142
 143                 fwrite($file,"<?php\n//$hash\n\n \$this->mCache = array(");
 144
 145                 foreach ($array as $key => $message) {
 146                         $key = $this->escapeForScript($key);
 147                         $messages = $this->escapeForScript($message);
 148                         fwrite($file, "'$key' => '$message',\n");
 149                 }
 150
 151                 fwrite($file,");\n?>");
 152                 fclose($file);
 153                 rename($tempFilename, $filename);
 154         }
 155
 156         function escapeForScript($string) {
 157                 $string = str_replace( '\\', '\\\\', $string );
 158                 $string = str_replace( '\'', '\\\'', $string );
 159                 return $string;
 160         }
 161
 162         /**
 163          * Set the cache to $cache, if it is valid. Otherwise set the cache to false.
 164          */
 165         function setCache( $cache, $code ) {
 166                 if ( isset( $cache['VERSION'] ) && $cache['VERSION'] == MSG_CACHE_VERSION ) {
 167                         $this->mCache[$code] = $cache;
 168                         return true;
 169                 } else {
 170                         return false;
 171                 }
 172         }
 173
 174         /**
 175          * Loads messages from caches or from database in this order:
 176          * (1) local message cache (if $wgUseLocalMessageCache is enabled)
 177          * (2) memcached
 178          * (3) from the database.
 179          *
 180          * When succesfully loading from (2) or (3), all higher level caches are
 181          * updated for the newest version.
 182          *
 183          * Nothing is loaded if  member variable mDisabled is true, either manually
 184          * set by calling code or if message loading fails (is this possible?).
 185          *
 186          * Returns true if cache is already populated or it was succesfully populated,
 187          * or false if populating empty cache fails. Also returns true if MessageCache
 188          * is disabled.
 189          *
 190          * @param $code String: language to which load messages
 191          */
 192         function load( $code = false ) {
 193                 global $wgUseLocalMessageCache;
 194
 195                 if( !is_string( $code ) ) {
 196                         # This isn't really nice, so at least make a note about it and try to
 197                         # fall back
 198                         wfDebug( __METHOD__ . " called without providing a language code\n" );
 199                         $code = 'en';
 200                 }
 201
 202                 # Don't do double loading...
 203                 if ( isset($this->mLoadedLanguages[$code]) ) return true;
 204
 205                 # 8 lines of code just to say (once) that message cache is disabled
 206                 if ( $this->mDisable ) {
 207                         static $shownDisabled = false;
 208                         if ( !$shownDisabled ) {
 209                                 wfDebug( __METHOD__ . ": disabled\n" );
 210                                 $shownDisabled = true;
 211                         }
 212                         return true;
 213                 }
 214
 215                 # Loading code starts
 216                 wfProfileIn( __METHOD__ );
 217                 $success = false; # Keep track of success
 218                 $where = array(); # Debug info, delayed to avoid spamming debug log too much
 219                 $cacheKey = wfMemcKey( 'messages', $code ); # Key in memc for messages
 220
 221
 222                 # (1) local cache
 223                 # Hash of the contents is stored in memcache, to detect if local cache goes
 224                 # out of date (due to update in other thread?)
 225                 if ( $wgUseLocalMessageCache ) {
 226                         wfProfileIn( __METHOD__ . '-fromlocal' );
 227
 228                         $hash = $this->mMemc->get( wfMemcKey( 'messages', $code, 'hash' ) );
 229                         if ( $hash ) {
 230                                 $success = $this->loadFromLocal( $hash, $code );
 231                                 if ( $success ) $where[] = 'got from local cache';
 232                         }
 233                         wfProfileOut( __METHOD__ . '-fromlocal' );
 234                 }
 235
 236                 # (2) memcache
 237                 # Fails if nothing in cache, or in the wrong version.
 238                 if ( !$success ) {
 239                         wfProfileIn( __METHOD__ . '-fromcache' );
 240                         $cache = $this->mMemc->get( $cacheKey );
 241                         $success = $this->setCache( $cache, $code );
 242                         if ( $success ) {
 243                                 $where[] = 'got from global cache';
 244                                 $this->saveToCaches( $cache, false, $code );
 245                         }
 246                         wfProfileOut( __METHOD__ . '-fromcache' );
 247                 }
 248
 249
 250                 # (3)
 251                 # Nothing in caches... so we need create one and store it in caches
 252                 if ( !$success ) {
 253                         $where[] = 'cache is empty';
 254                         $where[] = 'loading from database';
 255
 256                         $this->lock($cacheKey);
 257
 258                         # Limit the concurrency of loadFromDB to a single process
 259                         # This prevents the site from going down when the cache expires
 260                         $statusKey = wfMemcKey( 'messages', $code, 'status' );
 261                         $success = $this->mMemc->add( $statusKey, 'loading', MSG_LOAD_TIMEOUT );
 262                         if ( $success ) {
 263                                 $cache = $this->loadFromDB( $code );
 264                                 $success = $this->setCache( $cache, $code );
 265                         }
 266                         if ( $success ) {
 267                                 $success = $this->saveToCaches( $cache, true, $code );
 268                                 if ( $success ) {
 269                                         $this->mMemc->delete( $statusKey );
 270                                 } else {
 271                                         $this->mMemc->set( $statusKey, 'error', 60*5 );
 272                                         wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
 273                                 }
 274                         }
 275                         $this->unlock($cacheKey);
 276                 }
 277
 278                 if ( !$success ) {
 279                         # Bad luck... this should not happen
 280                         $where[] = 'loading FAILED - cache is disabled';
 281                         $info = implode( ', ', $where );
 282                         wfDebug( __METHOD__ . ": Loading $code... $info\n" );
 283                         $this->mDisable = true;
 284                         $this->mCache = false;
 285                 } else {
 286                         # All good, just record the success
 287                         $info = implode( ', ', $where );
 288                         wfDebug( __METHOD__ . ": Loading $code... $info\n" );
 289                         $this->mLoadedLanguages[$code] = true;
 290                 }
 291                 wfProfileOut( __METHOD__ );
 292                 return $success;
 293         }
 294
 295         /**
 296          * Loads cacheable messages from the database. Messages bigger than
 297          * $wgMaxMsgCacheEntrySize are assigned a special value, and are loaded
 298          * on-demand from the database later.
 299          *
 300          * @param $code Optional language code, see documenation of load().
 301          * @return Array: Loaded messages for storing in caches.
 302          */
 303         function loadFromDB( $code = false ) {
 304                 wfProfileIn( __METHOD__ );
 305                 global $wgMaxMsgCacheEntrySize, $wgContLanguageCode;
 306                 $dbr = wfGetDB( DB_SLAVE );
 307                 $cache = array();
 308
 309                 # Common conditions
 310                 $conds = array(
 311                         'page_is_redirect' => 0,
 312                         'page_namespace' => NS_MEDIAWIKI,
 313                 );
 314
 315                 if ( $code ) {
 316                         # Is this fast enough. Should not matter if the filtering is done in the
 317                         # database or in code.
 318                         if ( $code !== $wgContLanguageCode ) {
 319                                 # Messages for particular language
 320                                 $conds[] = 'page_title' . $dbr->buildLike( $dbr->anyString(), "/$code" );
 321                         } else {
 322                                 # Effectively disallows use of '/' character in NS_MEDIAWIKI for uses
 323                                 # other than language code.
 324                                 $conds[] = 'page_title NOT' . $dbr->buildLike( $dbr->anyString(), '/', $dbr->anyString() );
 325                         }
 326                 }
 327
 328                 # Conditions to fetch oversized pages to ignore them
 329                 $bigConds = $conds;
 330                 $bigConds[] = 'page_len > ' . intval( $wgMaxMsgCacheEntrySize );
 331
 332                 # Load titles for all oversized pages in the MediaWiki namespace
 333                 $res = $dbr->select( 'page', 'page_title', $bigConds, __METHOD__ . "($code)-big" );
 334                 while ( $row = $dbr->fetchObject( $res ) ) {
 335                         $cache[$row->page_title] = '!TOO BIG';
 336                 }
 337                 $dbr->freeResult( $res );
 338
 339                 # Conditions to load the remaining pages with their contents
 340                 $smallConds = $conds;
 341                 $smallConds[] = 'page_latest=rev_id';
 342                 $smallConds[] = 'rev_text_id=old_id';
 343                 $smallConds[] = 'page_len <= ' . intval( $wgMaxMsgCacheEntrySize );
 344
 345                 $res = $dbr->select( array( 'page', 'revision', 'text' ),
 346                         array( 'page_title', 'old_text', 'old_flags' ),
 347                         $smallConds, __METHOD__ . "($code)-small" );
 348
 349                 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
 350                         $cache[$row->page_title] = ' ' . Revision::getRevisionText( $row );
 351                 }
 352                 $dbr->freeResult( $res );
 353
 354                 $cache['VERSION'] = MSG_CACHE_VERSION;
 355                 wfProfileOut( __METHOD__ );
 356                 return $cache;
 357         }
 358
 359         /**
 360          * Updates cache as necessary when message page is changed
 361          *
 362          * @param $title String: name of the page changed.
 363          * @param $text Mixed: new contents of the page.
 364          */
 365         public function replace( $title, $text ) {
 366                 global $wgMaxMsgCacheEntrySize;
 367                 wfProfileIn( __METHOD__ );
 368
 369
 370                 list( , $code ) = $this->figureMessage( $title );
 371
 372                 $cacheKey = wfMemcKey( 'messages', $code );
 373                 $this->load($code);
 374                 $this->lock($cacheKey);
 375
 376                 if ( is_array($this->mCache[$code]) ) {
 377                         $titleKey = wfMemcKey( 'messages', 'individual', $title );
 378
 379                         if ( $text === false ) {
 380                                 # Article was deleted
 381                                 unset( $this->mCache[$code][$title] );
 382                                 $this->mMemc->delete( $titleKey );
 383
 384                         } elseif ( strlen( $text ) > $wgMaxMsgCacheEntrySize ) {
 385                                 # Check for size
 386                                 $this->mCache[$code][$title] = '!TOO BIG';
 387                                 $this->mMemc->set( $titleKey, ' ' . $text, $this->mExpiry );
 388
 389                         } else {
 390                                 $this->mCache[$code][$title] = ' ' . $text;
 391                                 $this->mMemc->delete( $titleKey );
 392                         }
 393
 394                         # Update caches
 395                         $this->saveToCaches( $this->mCache[$code], true, $code );
 396                 }
 397                 $this->unlock($cacheKey);
 398
 399                 // Also delete cached sidebar... just in case it is affected
 400                 global $parserMemc;
 401                 $codes = array( $code );
 402                 if ( $code === 'en'  ) {
 403                         // Delete all sidebars, like for example on action=purge on the
 404                         // sidebar messages
 405                         $codes = array_keys( Language::getLanguageNames() );
 406                 }
 407
 408                 foreach ( $codes as $code ) {
 409                         $sidebarKey = wfMemcKey( 'sidebar', $code );
 410                         $parserMemc->delete( $sidebarKey );
 411                 }
 412
 413                 wfRunHooks( "MessageCacheReplace", array( $title, $text ) );
 414
 415                 wfProfileOut( __METHOD__ );
 416         }
 417
 418         /**
 419          * Shortcut to update caches.
 420          *
 421          * @param $cache Array: cached messages with a version.
 422          * @param $memc Bool: Wether to update or not memcache.
 423          * @param $code String: Language code.
 424          * @return False on somekind of error.
 425          */
 426         protected function saveToCaches( $cache, $memc = true, $code = false ) {
 427                 wfProfileIn( __METHOD__ );
 428                 global $wgUseLocalMessageCache, $wgLocalMessageCacheSerialized;
 429
 430                 $cacheKey = wfMemcKey( 'messages', $code );
 431
 432                 if ( $memc ) {
 433                         $success = $this->mMemc->set( $cacheKey, $cache, $this->mExpiry );
 434                 } else {
 435                         $success = true;
 436                 }
 437
 438                 # Save to local cache
 439                 if ( $wgUseLocalMessageCache ) {
 440                         $serialized = serialize( $cache );
 441                         $hash = md5( $serialized );
 442                         $this->mMemc->set( wfMemcKey( 'messages', $code, 'hash' ), $hash, $this->mExpiry );
 443                         if ($wgLocalMessageCacheSerialized) {
 444                                 $this->saveToLocal( $serialized, $hash, $code );
 445                         } else {
 446                                 $this->saveToScript( $cache, $hash, $code );
 447                         }
 448                 }
 449
 450                 wfProfileOut( __METHOD__ );
 451                 return $success;
 452         }
 453
 454         /**
 455          * Represents a write lock on the messages key
 456          *
 457          * @return Boolean: success
 458          */
 459         function lock($key) {
 460                 $lockKey = $key . ':lock';
 461                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 462                         sleep(1);
 463                 }
 464
 465                 return $i >= MSG_WAIT_TIMEOUT;
 466         }
 467
 468         function unlock($key) {
 469                 $lockKey = $key . ':lock';
 470                 $this->mMemc->delete( $lockKey );
 471         }
 472
 473         /**
 474          * Get a message from either the content language or the user language.
 475          *
 476          * @param $key String: the message cache key
 477          * @param $useDB Boolean: get the message from the DB, false to use only
 478          *               the localisation
 479          * @param $langcode String: code of the language to get the message for, if
 480          *                  it is a valid code create a language for that language,
 481          *                  if it is a string but not a valid code then make a basic
 482          *                  language object, if it is a false boolean then use the
 483          *                  current users language (as a fallback for the old
 484          *                  parameter functionality), or if it is a true boolean
 485          *                  then use the wikis content language (also as a
 486          *                  fallback).
 487          * @param $isFullKey Boolean: specifies whether $key is a two part key
 488          *                   "msg/lang".
 489          */
 490         function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {
 491                 global $wgContLanguageCode, $wgContLang;
 492
 493                 if ( !is_string( $key ) ) {
 494                         throw new MWException( "Non-string key given" );
 495                 }
 496
 497                 if ( strval( $key ) === '' ) {
 498                         # Shortcut: the empty key is always missing
 499                         return false;
 500                 }
 501
 502                 $lang = wfGetLangObj( $langcode );
 503                 $langcode = $lang->getCode();
 504
 505                 $message = false;
 506
 507                 # Normalise title-case input (with some inlining)
 508                 $lckey = str_replace( ' ', '_', $key );
 509                 if ( ord( $key ) < 128 ) {
 510                         $lckey[0] = strtolower( $lckey[0] );
 511                         $uckey = ucfirst( $lckey );
 512                 } else {
 513                         $lckey = $wgContLang->lcfirst( $lckey );
 514                         $uckey = $wgContLang->ucfirst( $lckey );
 515                 }
 516
 517                 # Try the MediaWiki namespace
 518                 if( !$this->mDisable && $useDB ) {
 519                         $title = $uckey;
 520                         if(!$isFullKey && ( $langcode != $wgContLanguageCode ) ) {
 521                                 $title .= '/' . $langcode;
 522                         }
 523                         $message = $this->getMsgFromNamespace( $title, $langcode );
 524                 }
 525
 526                 # Try the array in the language object
 527                 if ( $message === false ) {
 528                         $message = $lang->getMessage( $lckey );
 529                         if ( is_null( $message ) ) {
 530                                 $message = false;
 531                         }
 532                 }
 533
 534                 # Try the array of another language
 535                 if( $message === false ) {
 536                         $parts = explode( '/', $lckey );
 537                         # We may get calls for things that are http-urls from sidebar
 538                         # Let's not load nonexistent languages for those
 539                         # They usually have more than one slash.
 540                         if ( count( $parts ) == 2 && $parts[1] !== '' ) {
 541                                 $message = Language::getMessageFor( $parts[0], $parts[1] );
 542                                 if ( is_null( $message ) ) {
 543                                         $message = false;
 544                                 }
 545                         }
 546                 }
 547
 548                 # Is this a custom message? Try the default language in the db...
 549                 if( ($message === false || $message === '-' ) &&
 550                         !$this->mDisable && $useDB &&
 551                         !$isFullKey && ($langcode != $wgContLanguageCode) ) {
 552                         $message = $this->getMsgFromNamespace( $uckey, $wgContLanguageCode );
 553                 }
 554
 555                 # Final fallback
 556                 if( $message === false ) {
 557                         return false;
 558                 }
 559
 560                 # Fix whitespace
 561                 $message = strtr( $message,
 562                         array(
 563                                 # Fix for trailing whitespace, removed by textarea
 564                                 '&#32;' => ' ',
 565                                 # Fix for NBSP, converted to space by firefox
 566                                 '&nbsp;' => "\xc2\xa0",
 567                                 '&#160;' => "\xc2\xa0",
 568                         ) );
 569
 570                 return $message;
 571         }
 572
 573         /**
 574          * Get a message from the MediaWiki namespace, with caching. The key must
 575          * first be converted to two-part lang/msg form if necessary.
 576          *
 577          * @param $title String: Message cache key with initial uppercase letter.
 578          * @param $code String: code denoting the language to try.
 579          */
 580         function getMsgFromNamespace( $title, $code ) {
 581                 $type = false;
 582                 $message = false;
 583
 584                 $this->load( $code );
 585                 if (isset( $this->mCache[$code][$title] ) ) {
 586                         $entry = $this->mCache[$code][$title];
 587                         $type = substr( $entry, 0, 1 );
 588                         if ( $type == ' ' ) {
 589                                 return substr( $entry, 1 );
 590                         }
 591                 }
 592
 593                 # Call message hooks, in case they are defined
 594                 wfRunHooks('MessagesPreLoad', array( $title, &$message ) );
 595                 if ( $message !== false ) {
 596                         return $message;
 597                 }
 598
 599                 # If there is no cache entry and no placeholder, it doesn't exist
 600                 if ( $type !== '!' ) {
 601                         return false;
 602                 }
 603
 604                 $titleKey = wfMemcKey( 'messages', 'individual', $title );
 605
 606                 # Try the individual message cache
 607                 $entry = $this->mMemc->get( $titleKey );
 608                 if ( $entry ) {
 609                         $type = substr( $entry, 0, 1 );
 610
 611                         if ( $type === ' ' ) {
 612                                 # Ok!
 613                                 $message = substr( $entry, 1 );
 614                                 $this->mCache[$code][$title] = $entry;
 615                                 return $message;
 616                         } elseif ( $entry === '!NONEXISTENT' ) {
 617                                 return false;
 618                         } else {
 619                                 # Corrupt/obsolete entry, delete it
 620                                 $this->mMemc->delete( $titleKey );
 621                         }
 622                 }
 623
 624                 # Try loading it from the DB
 625                 $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
 626                 if( $revision ) {
 627                         $message = $revision->getText();
 628                         $this->mCache[$code][$title] = ' ' . $message;
 629                         $this->mMemc->set( $titleKey, ' ' . $message, $this->mExpiry );
 630                 } else {
 631                         # Negative caching
 632                         # Use some special text instead of false, because false gets converted to '' somewhere
 633                         $this->mMemc->set( $titleKey, '!NONEXISTENT', $this->mExpiry );
 634                         $this->mCache[$code][$title] = false;
 635                 }
 636                 return $message;
 637         }
 638
 639         function transform( $message, $interface = false, $language = null ) {
 640                 // Avoid creating parser if nothing to transform
 641                 if( strpos( $message, '{{' ) === false ) {
 642                         return $message;
 643                 }
 644
 645                 global $wgParser, $wgParserConf;
 646                 if ( !$this->mParser && isset( $wgParser ) ) {
 647                         # Do some initialisation so that we don't have to do it twice
 648                         $wgParser->firstCallInit();
 649                         # Clone it and store it
 650                         $class = $wgParserConf['class'];
 651                         if ( $class == 'Parser_DiffTest' ) {
 652                                 # Uncloneable
 653                                 $this->mParser = new $class( $wgParserConf );
 654                         } else {
 655                                 $this->mParser = clone $wgParser;
 656                         }
 657                         #wfDebug( __METHOD__ . ": following contents triggered transform: $message\n" );
 658                 }
 659                 if ( $this->mParser ) {
 660                         $popts = $this->getParserOptions();
 661                         $popts->setInterfaceMessage( $interface );
 662                         $popts->setTargetLanguage( $language );
 663                         $message = $this->mParser->transformMsg( $message, $popts );
 664                 }
 665                 return $message;
 666         }
 667
 668         function disable() { $this->mDisable = true; }
 669         function enable() { $this->mDisable = false; }
 670
 671         /** @deprecated */
 672         function disableTransform(){
 673                 wfDeprecated( __METHOD__ );
 674         }
 675         function enableTransform() {
 676                 wfDeprecated( __METHOD__ );
 677         }
 678         function setTransform( $x ) {
 679                 wfDeprecated( __METHOD__ );
 680         }
 681         function getTransform() {
 682                 wfDeprecated( __METHOD__ );
 683                 return false;
 684         }
 685
 686         /**
 687          * Clear all stored messages. Mainly used after a mass rebuild.
 688          */
 689         function clear() {
 690                 $langs = Language::getLanguageNames( false );
 691                 foreach ( array_keys($langs) as $code ) {
 692                         # Global cache
 693                         $this->mMemc->delete( wfMemcKey( 'messages', $code ) );
 694                         # Invalidate all local caches
 695                         $this->mMemc->delete( wfMemcKey( 'messages', $code, 'hash' ) );
 696                 }
 697         }
 698
 699         /**
 700          * Add a message to the cache
 701          * @deprecated Use $wgExtensionMessagesFiles
 702          *
 703          * @param $key Mixed
 704          * @param $value Mixed
 705          * @param $lang String: the messages language, English by default
 706          */
 707         function addMessage( $key, $value, $lang = 'en' ) {
 708                 wfDeprecated( __METHOD__ );
 709                 $lc = Language::getLocalisationCache();
 710                 $lc->addLegacyMessages( array( $lang => array( $key => $value ) ) );
 711         }
 712
 713         /**
 714          * Add an associative array of message to the cache
 715          * @deprecated Use $wgExtensionMessagesFiles
 716          *
 717          * @param $messages Array: an associative array of key => values to be added
 718          * @param $lang String: the messages language, English by default
 719          */
 720         function addMessages( $messages, $lang = 'en' ) {
 721                 wfDeprecated( __METHOD__ );
 722                 $lc = Language::getLocalisationCache();
 723                 $lc->addLegacyMessages( array( $lang => $messages ) );
 724         }
 725
 726         /**
 727          * Add a 2-D array of messages by lang. Useful for extensions.
 728          * @deprecated Use $wgExtensionMessagesFiles
 729          *
 730          * @param $messages Array: the array to be added
 731          */
 732         function addMessagesByLang( $messages ) {
 733                 wfDeprecated( __METHOD__ );
 734                 $lc = Language::getLocalisationCache();
 735                 $lc->addLegacyMessages( $messages );
 736         }
 737
 738         /**
 739          * Set a hook for addMessagesByLang()
 740          */
 741         function setExtensionMessagesHook( $callback ) {
 742                 $this->mAddMessagesHook = $callback;
 743         }
 744
 745         /**
 746          * @deprecated
 747          */
 748         function loadAllMessages( $lang = false ) {
 749         }
 750
 751         /**
 752          * @deprecated
 753          */
 754         function loadMessagesFile( $filename, $langcode = false ) {
 755         }
 756
 757         public function figureMessage( $key ) {
 758                 global $wgContLanguageCode;
 759                 $pieces = explode( '/', $key );
 760                 if( count( $pieces ) < 2 )
 761                         return array( $key, $wgContLanguageCode );
 762
 763                 $lang = array_pop( $pieces );
 764                 $validCodes = Language::getLanguageNames();
 765                 if( !array_key_exists( $lang, $validCodes ) )
 766                         return array( $key, $wgContLanguageCode );
 767
 768                 $message = implode( '/', $pieces );
 769                 return array( $message, $lang );
 770         }
 771
 772 }