includes/cache/LocalisationCache.php

   1 <?php
   2 /**
   3  * Cache of the contents of localisation files.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 define( 'MW_LC_VERSION', 2 );
  24
  25 /**
  26  * Class for caching the contents of localisation files, Messages*.php
  27  * and *.i18n.php.
  28  *
  29  * An instance of this class is available using Language::getLocalisationCache().
  30  *
  31  * The values retrieved from here are merged, containing items from extension
  32  * files, core messages files and the language fallback sequence (e.g. zh-cn ->
  33  * zh-hans -> en ). Some common errors are corrected, for example namespace
  34  * names with spaces instead of underscores, but heavyweight processing, such
  35  * as grammatical transformation, is done by the caller.
  36  */
  37 class LocalisationCache {
  38         /** Configuration associative array */
  39         var $conf;
  40
  41         /**
  42          * True if recaching should only be done on an explicit call to recache().
  43          * Setting this reduces the overhead of cache freshness checking, which
  44          * requires doing a stat() for every extension i18n file.
  45          */
  46         var $manualRecache = false;
  47
  48         /**
  49          * True to treat all files as expired until they are regenerated by this object.
  50          */
  51         var $forceRecache = false;
  52
  53         /**
  54          * The cache data. 3-d array, where the first key is the language code,
  55          * the second key is the item key e.g. 'messages', and the third key is
  56          * an item specific subkey index. Some items are not arrays and so for those
  57          * items, there are no subkeys.
  58          */
  59         var $data = array();
  60
  61         /**
  62          * The persistent store object. An instance of LCStore.
  63          *
  64          * @var LCStore
  65          */
  66         var $store;
  67
  68         /**
  69          * A 2-d associative array, code/key, where presence indicates that the item
  70          * is loaded. Value arbitrary.
  71          *
  72          * For split items, if set, this indicates that all of the subitems have been
  73          * loaded.
  74          */
  75         var $loadedItems = array();
  76
  77         /**
  78          * A 3-d associative array, code/key/subkey, where presence indicates that
  79          * the subitem is loaded. Only used for the split items, i.e. messages.
  80          */
  81         var $loadedSubitems = array();
  82
  83         /**
  84          * An array where presence of a key indicates that that language has been
  85          * initialised. Initialisation includes checking for cache expiry and doing
  86          * any necessary updates.
  87          */
  88         var $initialisedLangs = array();
  89
  90         /**
  91          * An array mapping non-existent pseudo-languages to fallback languages. This
  92          * is filled by initShallowFallback() when data is requested from a language
  93          * that lacks a Messages*.php file.
  94          */
  95         var $shallowFallbacks = array();
  96
  97         /**
  98          * An array where the keys are codes that have been recached by this instance.
  99          */
 100         var $recachedLangs = array();
 101
 102         /**
 103          * All item keys
 104          */
 105         static public $allKeys = array(
 106                 'fallback', 'namespaceNames', 'bookstoreList',
 107                 'magicWords', 'messages', 'rtl', 'capitalizeAllNouns', 'digitTransformTable',
 108                 'separatorTransformTable', 'fallback8bitEncoding', 'linkPrefixExtension',
 109                 'linkTrail', 'namespaceAliases',
 110                 'dateFormats', 'datePreferences', 'datePreferenceMigrationMap',
 111                 'defaultDateFormat', 'extraUserToggles', 'specialPageAliases',
 112                 'imageFiles', 'preloadedMessages', 'namespaceGenderAliases',
 113                 'digitGroupingPattern', 'pluralRules', 'pluralRuleTypes', 'compiledPluralRules',
 114         );
 115
 116         /**
 117          * Keys for items which consist of associative arrays, which may be merged
 118          * by a fallback sequence.
 119          */
 120         static public $mergeableMapKeys = array( 'messages', 'namespaceNames',
 121                 'dateFormats', 'imageFiles', 'preloadedMessages'
 122         );
 123
 124         /**
 125          * Keys for items which are a numbered array.
 126          */
 127         static public $mergeableListKeys = array( 'extraUserToggles' );
 128
 129         /**
 130          * Keys for items which contain an array of arrays of equivalent aliases
 131          * for each subitem. The aliases may be merged by a fallback sequence.
 132          */
 133         static public $mergeableAliasListKeys = array( 'specialPageAliases' );
 134
 135         /**
 136          * Keys for items which contain an associative array, and may be merged if
 137          * the primary value contains the special array key "inherit". That array
 138          * key is removed after the first merge.
 139          */
 140         static public $optionalMergeKeys = array( 'bookstoreList' );
 141
 142         /**
 143          * Keys for items that are formatted like $magicWords
 144          */
 145         static public $magicWordKeys = array( 'magicWords' );
 146
 147         /**
 148          * Keys for items where the subitems are stored in the backend separately.
 149          */
 150         static public $splitKeys = array( 'messages' );
 151
 152         /**
 153          * Keys which are loaded automatically by initLanguage()
 154          */
 155         static public $preloadedKeys = array( 'dateFormats', 'namespaceNames' );
 156
 157         /**
 158          * Associative array of cached plural rules. The key is the language code,
 159          * the value is an array of plural rules for that language.
 160          */
 161         var $pluralRules = null;
 162
 163         /**
 164          * Associative array of cached plural rule types. The key is the language
 165          * code, the value is an array of plural rule types for that language. For
 166          * example, $pluralRuleTypes['ar'] = ['zero', 'one', 'two', 'few', 'many'].
 167          * The index for each rule type matches the index for the rule in
 168          * $pluralRules, thus allowing correlation between the two. The reason we
 169          * don't just use the type names as the keys in $pluralRules is because
 170          * Language::convertPlural applies the rules based on numeric order (or
 171          * explicit numeric parameter), not based on the name of the rule type. For
 172          * example, {{plural:count|wordform1|wordform2|wordform3}}, rather than
 173          * {{plural:count|one=wordform1|two=wordform2|many=wordform3}}.
 174          */
 175         var $pluralRuleTypes = null;
 176
 177         var $mergeableKeys = null;
 178
 179         /**
 180          * Constructor.
 181          * For constructor parameters, see the documentation in DefaultSettings.php
 182          * for $wgLocalisationCacheConf.
 183          *
 184          * @param $conf Array
 185          * @throws MWException
 186          */
 187         function __construct( $conf ) {
 188                 global $wgCacheDirectory;
 189
 190                 $this->conf = $conf;
 191                 $storeConf = array();
 192                 if ( !empty( $conf['storeClass'] ) ) {
 193                         $storeClass = $conf['storeClass'];
 194                 } else {
 195                         switch ( $conf['store'] ) {
 196                                 case 'files':
 197                                 case 'file':
 198                                         $storeClass = 'LCStore_CDB';
 199                                         break;
 200                                 case 'db':
 201                                         $storeClass = 'LCStore_DB';
 202                                         break;
 203                                 case 'accel':
 204                                         $storeClass = 'LCStore_Accel';
 205                                         break;
 206                                 case 'detect':
 207                                         $storeClass = $wgCacheDirectory ? 'LCStore_CDB' : 'LCStore_DB';
 208                                         break;
 209                                 default:
 210                                         throw new MWException(
 211                                                 'Please set $wgLocalisationCacheConf[\'store\'] to something sensible.' );
 212                         }
 213                 }
 214
 215                 wfDebug( get_class( $this ) . ": using store $storeClass\n" );
 216                 if ( !empty( $conf['storeDirectory'] ) ) {
 217                         $storeConf['directory'] = $conf['storeDirectory'];
 218                 }
 219
 220                 $this->store = new $storeClass( $storeConf );
 221                 foreach ( array( 'manualRecache', 'forceRecache' ) as $var ) {
 222                         if ( isset( $conf[$var] ) ) {
 223                                 $this->$var = $conf[$var];
 224                         }
 225                 }
 226         }
 227
 228         /**
 229          * Returns true if the given key is mergeable, that is, if it is an associative
 230          * array which can be merged through a fallback sequence.
 231          * @param $key
 232          * @return bool
 233          */
 234         public function isMergeableKey( $key ) {
 235                 if ( $this->mergeableKeys === null ) {
 236                         $this->mergeableKeys = array_flip( array_merge(
 237                                 self::$mergeableMapKeys,
 238                                 self::$mergeableListKeys,
 239                                 self::$mergeableAliasListKeys,
 240                                 self::$optionalMergeKeys,
 241                                 self::$magicWordKeys
 242                         ) );
 243                 }
 244                 return isset( $this->mergeableKeys[$key] );
 245         }
 246
 247         /**
 248          * Get a cache item.
 249          *
 250          * Warning: this may be slow for split items (messages), since it will
 251          * need to fetch all of the subitems from the cache individually.
 252          * @param $code
 253          * @param $key
 254          * @return mixed
 255          */
 256         public function getItem( $code, $key ) {
 257                 if ( !isset( $this->loadedItems[$code][$key] ) ) {
 258                         wfProfileIn( __METHOD__ . '-load' );
 259                         $this->loadItem( $code, $key );
 260                         wfProfileOut( __METHOD__ . '-load' );
 261                 }
 262
 263                 if ( $key === 'fallback' && isset( $this->shallowFallbacks[$code] ) ) {
 264                         return $this->shallowFallbacks[$code];
 265                 }
 266
 267                 return $this->data[$code][$key];
 268         }
 269
 270         /**
 271          * Get a subitem, for instance a single message for a given language.
 272          * @param $code
 273          * @param $key
 274          * @param $subkey
 275          * @return null
 276          */
 277         public function getSubitem( $code, $key, $subkey ) {
 278                 if ( !isset( $this->loadedSubitems[$code][$key][$subkey] ) &&
 279                          !isset( $this->loadedItems[$code][$key] ) ) {
 280                         wfProfileIn( __METHOD__ . '-load' );
 281                         $this->loadSubitem( $code, $key, $subkey );
 282                         wfProfileOut( __METHOD__ . '-load' );
 283                 }
 284
 285                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 286                         return $this->data[$code][$key][$subkey];
 287                 } else {
 288                         return null;
 289                 }
 290         }
 291
 292         /**
 293          * Get the list of subitem keys for a given item.
 294          *
 295          * This is faster than array_keys($lc->getItem(...)) for the items listed in
 296          * self::$splitKeys.
 297          *
 298          * Will return null if the item is not found, or false if the item is not an
 299          * array.
 300          * @param $code
 301          * @param $key
 302          * @return bool|null|string
 303          */
 304         public function getSubitemList( $code, $key ) {
 305                 if ( in_array( $key, self::$splitKeys ) ) {
 306                         return $this->getSubitem( $code, 'list', $key );
 307                 } else {
 308                         $item = $this->getItem( $code, $key );
 309                         if ( is_array( $item ) ) {
 310                                 return array_keys( $item );
 311                         } else {
 312                                 return false;
 313                         }
 314                 }
 315         }
 316
 317         /**
 318          * Load an item into the cache.
 319          * @param $code
 320          * @param $key
 321          */
 322         protected function loadItem( $code, $key ) {
 323                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 324                         $this->initLanguage( $code );
 325                 }
 326
 327                 // Check to see if initLanguage() loaded it for us
 328                 if ( isset( $this->loadedItems[$code][$key] ) ) {
 329                         return;
 330                 }
 331
 332                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 333                         $this->loadItem( $this->shallowFallbacks[$code], $key );
 334                         return;
 335                 }
 336
 337                 if ( in_array( $key, self::$splitKeys ) ) {
 338                         $subkeyList = $this->getSubitem( $code, 'list', $key );
 339                         foreach ( $subkeyList as $subkey ) {
 340                                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 341                                         continue;
 342                                 }
 343                                 $this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
 344                         }
 345                 } else {
 346                         $this->data[$code][$key] = $this->store->get( $code, $key );
 347                 }
 348
 349                 $this->loadedItems[$code][$key] = true;
 350         }
 351
 352         /**
 353          * Load a subitem into the cache
 354          * @param $code
 355          * @param $key
 356          * @param $subkey
 357          */
 358         protected function loadSubitem( $code, $key, $subkey ) {
 359                 if ( !in_array( $key, self::$splitKeys ) ) {
 360                         $this->loadItem( $code, $key );
 361                         return;
 362                 }
 363
 364                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 365                         $this->initLanguage( $code );
 366                 }
 367
 368                 // Check to see if initLanguage() loaded it for us
 369                 if ( isset( $this->loadedItems[$code][$key] ) ||
 370                          isset( $this->loadedSubitems[$code][$key][$subkey] ) ) {
 371                         return;
 372                 }
 373
 374                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 375                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 376                         return;
 377                 }
 378
 379                 $value = $this->store->get( $code, "$key:$subkey" );
 380                 $this->data[$code][$key][$subkey] = $value;
 381                 $this->loadedSubitems[$code][$key][$subkey] = true;
 382         }
 383
 384         /**
 385          * Returns true if the cache identified by $code is missing or expired.
 386          *
 387          * @param string $code
 388          *
 389          * @return bool
 390          */
 391         public function isExpired( $code ) {
 392                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 393                         wfDebug( __METHOD__ . "($code): forced reload\n" );
 394                         return true;
 395                 }
 396
 397                 $deps = $this->store->get( $code, 'deps' );
 398                 $keys = $this->store->get( $code, 'list' );
 399                 $preload = $this->store->get( $code, 'preload' );
 400                 // Different keys may expire separately, at least in LCStore_Accel
 401                 if ( $deps === null || $keys === null || $preload === null ) {
 402                         wfDebug( __METHOD__ . "($code): cache missing, need to make one\n" );
 403                         return true;
 404                 }
 405
 406                 foreach ( $deps as $dep ) {
 407                         // Because we're unserializing stuff from cache, we
 408                         // could receive objects of classes that don't exist
 409                         // anymore (e.g. uninstalled extensions)
 410                         // When this happens, always expire the cache
 411                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 412                                 wfDebug( __METHOD__ . "($code): cache for $code expired due to " .
 413                                         get_class( $dep ) . "\n" );
 414                                 return true;
 415                         }
 416                 }
 417
 418                 return false;
 419         }
 420
 421         /**
 422          * Initialise a language in this object. Rebuild the cache if necessary.
 423          * @param $code
 424          * @throws MWException
 425          */
 426         protected function initLanguage( $code ) {
 427                 if ( isset( $this->initialisedLangs[$code] ) ) {
 428                         return;
 429                 }
 430
 431                 $this->initialisedLangs[$code] = true;
 432
 433                 # If the code is of the wrong form for a Messages*.php file, do a shallow fallback
 434                 if ( !Language::isValidBuiltInCode( $code ) ) {
 435                         $this->initShallowFallback( $code, 'en' );
 436                         return;
 437                 }
 438
 439                 # Recache the data if necessary
 440                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 441                         if ( file_exists( Language::getMessagesFileName( $code ) ) ) {
 442                                 $this->recache( $code );
 443                         } elseif ( $code === 'en' ) {
 444                                 throw new MWException( 'MessagesEn.php is missing.' );
 445                         } else {
 446                                 $this->initShallowFallback( $code, 'en' );
 447                         }
 448                         return;
 449                 }
 450
 451                 # Preload some stuff
 452                 $preload = $this->getItem( $code, 'preload' );
 453                 if ( $preload === null ) {
 454                         if ( $this->manualRecache ) {
 455                                 // No Messages*.php file. Do shallow fallback to en.
 456                                 if ( $code === 'en' ) {
 457                                         throw new MWException( 'No localisation cache found for English. ' .
 458                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 459                                 }
 460                                 $this->initShallowFallback( $code, 'en' );
 461                                 return;
 462                         } else {
 463                                 throw new MWException( 'Invalid or missing localisation cache.' );
 464                         }
 465                 }
 466                 $this->data[$code] = $preload;
 467                 foreach ( $preload as $key => $item ) {
 468                         if ( in_array( $key, self::$splitKeys ) ) {
 469                                 foreach ( $item as $subkey => $subitem ) {
 470                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 471                                 }
 472                         } else {
 473                                 $this->loadedItems[$code][$key] = true;
 474                         }
 475                 }
 476         }
 477
 478         /**
 479          * Create a fallback from one language to another, without creating a
 480          * complete persistent cache.
 481          * @param $primaryCode
 482          * @param $fallbackCode
 483          */
 484         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 485                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 486                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 487                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 488                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 489         }
 490
 491         /**
 492          * Read a PHP file containing localisation data.
 493          * @param $_fileName
 494          * @param $_fileType
 495          * @throws MWException
 496          * @return array
 497          */
 498         protected function readPHPFile( $_fileName, $_fileType ) {
 499                 wfProfileIn( __METHOD__ );
 500                 // Disable APC caching
 501                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 502                 include( $_fileName );
 503                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 504
 505                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 506                         $data = compact( self::$allKeys );
 507                 } elseif ( $_fileType == 'aliases' ) {
 508                         $data = compact( 'aliases' );
 509                 } else {
 510                         wfProfileOut( __METHOD__ );
 511                         throw new MWException( __METHOD__ . ": Invalid file type: $_fileType" );
 512                 }
 513                 wfProfileOut( __METHOD__ );
 514                 return $data;
 515         }
 516
 517         /**
 518          * Get the compiled plural rules for a given language from the XML files.
 519          * @since 1.20
 520          */
 521         public function getCompiledPluralRules( $code ) {
 522                 $rules = $this->getPluralRules( $code );
 523                 if ( $rules === null ) {
 524                         return null;
 525                 }
 526                 try {
 527                         $compiledRules = CLDRPluralRuleEvaluator::compile( $rules );
 528                 } catch( CLDRPluralRuleError $e ) {
 529                         wfDebugLog( 'l10n', $e->getMessage() . "\n" );
 530                         return array();
 531                 }
 532                 return $compiledRules;
 533         }
 534
 535         /**
 536          * Get the plural rules for a given language from the XML files.
 537          * Cached.
 538          * @since 1.20
 539          */
 540         public function getPluralRules( $code ) {
 541                 if ( $this->pluralRules === null ) {
 542                         $this->loadPluralFiles();
 543                 }
 544                 if ( !isset( $this->pluralRules[$code] ) ) {
 545                         return null;
 546                 } else {
 547                         return $this->pluralRules[$code];
 548                 }
 549         }
 550
 551         /**
 552          * Get the plural rule types for a given language from the XML files.
 553          * Cached.
 554          * @since 1.21
 555          */
 556         public function getPluralRuleTypes( $code ) {
 557                 if ( $this->pluralRuleTypes === null ) {
 558                         $this->loadPluralFiles();
 559                 }
 560                 if ( !isset( $this->pluralRuleTypes[$code] ) ) {
 561                         return null;
 562                 } else {
 563                         return $this->pluralRuleTypes[$code];
 564                 }
 565         }
 566
 567         /**
 568          * Load the plural XML files.
 569          */
 570         protected function loadPluralFiles() {
 571                 global $IP;
 572                 $cldrPlural = "$IP/languages/data/plurals.xml";
 573                 $mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
 574                 // Load CLDR plural rules
 575                 $this->loadPluralFile( $cldrPlural );
 576                 if ( file_exists( $mwPlural ) ) {
 577                         // Override or extend
 578                         $this->loadPluralFile( $mwPlural );
 579                 }
 580         }
 581
 582         /**
 583          * Load a plural XML file with the given filename, compile the relevant
 584          * rules, and save the compiled rules in a process-local cache.
 585          */
 586         protected function loadPluralFile( $fileName ) {
 587                 $doc = new DOMDocument;
 588                 $doc->load( $fileName );
 589                 $rulesets = $doc->getElementsByTagName( "pluralRules" );
 590                 foreach ( $rulesets as $ruleset ) {
 591                         $codes = $ruleset->getAttribute( 'locales' );
 592                         $rules = array();
 593                         $ruleTypes = array();
 594                         $ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
 595                         foreach ( $ruleElements as $elt ) {
 596                                 $ruleType = $elt->getAttribute( 'count' );
 597                                 $rules[] = $elt->nodeValue;
 598                                 $ruleTypes[] = $ruleType;
 599                         }
 600                         foreach ( explode( ' ', $codes ) as $code ) {
 601                                 $this->pluralRules[$code] = $rules;
 602                                 $this->pluralRuleTypes[$code] = $ruleTypes;
 603                         }
 604                 }
 605         }
 606
 607         /**
 608          * Read the data from the source files for a given language, and register
 609          * the relevant dependencies in the $deps array. If the localisation
 610          * exists, the data array is returned, otherwise false is returned.
 611          */
 612         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 613                 global $IP;
 614
 615                 wfProfileIn( __METHOD__ );
 616                 $fileName = Language::getMessagesFileName( $code );
 617                 if ( !file_exists( $fileName ) ) {
 618                         return false;
 619                 }
 620
 621                 $deps[] = new FileDependency( $fileName );
 622                 $data = $this->readPHPFile( $fileName, 'core' );
 623
 624                 # Load CLDR plural rules for JavaScript
 625                 $data['pluralRules'] = $this->getPluralRules( $code );
 626                 # And for PHP
 627                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 628                 # Load plural rule types
 629                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 630
 631                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 632                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 633                 wfProfileOut( __METHOD__ );
 634
 635                 return $data;
 636         }
 637
 638         /**
 639          * Merge two localisation values, a primary and a fallback, overwriting the
 640          * primary value in place.
 641          * @param $key
 642          * @param $value
 643          * @param $fallbackValue
 644          */
 645         protected function mergeItem( $key, &$value, $fallbackValue ) {
 646                 if ( !is_null( $value ) ) {
 647                         if ( !is_null( $fallbackValue ) ) {
 648                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 649                                         $value = $value + $fallbackValue;
 650                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 651                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 652                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 653                                         $value = array_merge_recursive( $value, $fallbackValue );
 654                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 655                                         if ( !empty( $value['inherit'] ) ) {
 656                                                 $value = array_merge( $fallbackValue, $value );
 657                                         }
 658
 659                                         if ( isset( $value['inherit'] ) ) {
 660                                                 unset( $value['inherit'] );
 661                                         }
 662                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 663                                         $this->mergeMagicWords( $value, $fallbackValue );
 664                                 }
 665                         }
 666                 } else {
 667                         $value = $fallbackValue;
 668                 }
 669         }
 670
 671         /**
 672          * @param $value
 673          * @param $fallbackValue
 674          */
 675         protected function mergeMagicWords( &$value, $fallbackValue ) {
 676                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 677                         if ( !isset( $value[$magicName] ) ) {
 678                                 $value[$magicName] = $fallbackInfo;
 679                         } else {
 680                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 681                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 682                                 $synonyms = array_values( array_unique( array_merge(
 683                                         $newSynonyms, $oldSynonyms ) ) );
 684                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 685                         }
 686                 }
 687         }
 688
 689         /**
 690          * Given an array mapping language code to localisation value, such as is
 691          * found in extension *.i18n.php files, iterate through a fallback sequence
 692          * to merge the given data with an existing primary value.
 693          *
 694          * Returns true if any data from the extension array was used, false
 695          * otherwise.
 696          * @param $codeSequence
 697          * @param $key
 698          * @param $value
 699          * @param $fallbackValue
 700          * @return bool
 701          */
 702         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 703                 $used = false;
 704                 foreach ( $codeSequence as $code ) {
 705                         if ( isset( $fallbackValue[$code] ) ) {
 706                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 707                                 $used = true;
 708                         }
 709                 }
 710
 711                 return $used;
 712         }
 713
 714         /**
 715          * Load localisation data for a given language for both core and extensions
 716          * and save it to the persistent cache store and the process cache
 717          * @param $code
 718          * @throws MWException
 719          */
 720         public function recache( $code ) {
 721                 global $wgExtensionMessagesFiles;
 722                 wfProfileIn( __METHOD__ );
 723
 724                 if ( !$code ) {
 725                         throw new MWException( "Invalid language code requested" );
 726                 }
 727                 $this->recachedLangs[$code] = true;
 728
 729                 # Initial values
 730                 $initialData = array_combine(
 731                         self::$allKeys,
 732                         array_fill( 0, count( self::$allKeys ), null ) );
 733                 $coreData = $initialData;
 734                 $deps = array();
 735
 736                 # Load the primary localisation from the source file
 737                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 738                 if ( $data === false ) {
 739                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 740                         $coreData['fallback'] = 'en';
 741                 } else {
 742                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 743
 744                         # Merge primary localisation
 745                         foreach ( $data as $key => $value ) {
 746                                 $this->mergeItem( $key, $coreData[$key], $value );
 747                         }
 748
 749                 }
 750
 751                 # Fill in the fallback if it's not there already
 752                 if ( is_null( $coreData['fallback'] ) ) {
 753                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 754                 }
 755                 if ( $coreData['fallback'] === false ) {
 756                         $coreData['fallbackSequence'] = array();
 757                 } else {
 758                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 759                         $len = count( $coreData['fallbackSequence'] );
 760
 761                         # Ensure that the sequence ends at en
 762                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 763                                 $coreData['fallbackSequence'][] = 'en';
 764                         }
 765
 766                         # Load the fallback localisation item by item and merge it
 767                         foreach ( $coreData['fallbackSequence'] as $fbCode ) {
 768                                 # Load the secondary localisation from the source file to
 769                                 # avoid infinite cycles on cyclic fallbacks
 770                                 $fbData = $this->readSourceFilesAndRegisterDeps( $fbCode, $deps );
 771                                 if ( $fbData === false ) {
 772                                         continue;
 773                                 }
 774
 775                                 foreach ( self::$allKeys as $key ) {
 776                                         if ( !isset( $fbData[$key] ) ) {
 777                                                 continue;
 778                                         }
 779
 780                                         if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 781                                                 $this->mergeItem( $key, $coreData[$key], $fbData[$key] );
 782                                         }
 783                                 }
 784                         }
 785                 }
 786
 787                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 788
 789                 # Load the extension localisations
 790                 # This is done after the core because we know the fallback sequence now.
 791                 # But it has a higher precedence for merging so that we can support things
 792                 # like site-specific message overrides.
 793                 wfProfileIn( __METHOD__ . '-extensions' );
 794                 $allData = $initialData;
 795                 foreach ( $wgExtensionMessagesFiles as $fileName ) {
 796                         $data = $this->readPHPFile( $fileName, 'extension' );
 797                         $used = false;
 798
 799                         foreach ( $data as $key => $item ) {
 800                                 if ( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 801                                         $used = true;
 802                                 }
 803                         }
 804
 805                         if ( $used ) {
 806                                 $deps[] = new FileDependency( $fileName );
 807                         }
 808                 }
 809
 810                 # Merge core data into extension data
 811                 foreach ( $coreData as $key => $item ) {
 812                         $this->mergeItem( $key, $allData[$key], $item );
 813                 }
 814                 wfProfileOut( __METHOD__ . '-extensions' );
 815
 816                 # Add cache dependencies for any referenced globals
 817                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 818                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 819
 820                 # Add dependencies to the cache entry
 821                 $allData['deps'] = $deps;
 822
 823                 # Replace spaces with underscores in namespace names
 824                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 825
 826                 # And do the same for special page aliases. $page is an array.
 827                 foreach ( $allData['specialPageAliases'] as &$page ) {
 828                         $page = str_replace( ' ', '_', $page );
 829                 }
 830                 # Decouple the reference to prevent accidental damage
 831                 unset( $page );
 832
 833                 # If there were no plural rules, return an empty array
 834                 if ( $allData['pluralRules'] === null ) {
 835                         $allData['pluralRules'] = array();
 836                 }
 837                 if ( $allData['compiledPluralRules'] === null ) {
 838                         $allData['compiledPluralRules'] = array();
 839                 }
 840                 # If there were no plural rule types, return an empty array
 841                 if ( $allData['pluralRuleTypes'] === null ) {
 842                         $allData['pluralRuleTypes'] = array();
 843                 }
 844
 845                 # Set the list keys
 846                 $allData['list'] = array();
 847                 foreach ( self::$splitKeys as $key ) {
 848                         $allData['list'][$key] = array_keys( $allData[$key] );
 849                 }
 850                 # Run hooks
 851                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData ) );
 852
 853                 if ( is_null( $allData['namespaceNames'] ) ) {
 854                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
 855                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 856                 }
 857
 858                 # Set the preload key
 859                 $allData['preload'] = $this->buildPreload( $allData );
 860
 861                 # Save to the process cache and register the items loaded
 862                 $this->data[$code] = $allData;
 863                 foreach ( $allData as $key => $item ) {
 864                         $this->loadedItems[$code][$key] = true;
 865                 }
 866
 867                 # Save to the persistent cache
 868                 wfProfileIn( __METHOD__ . '-write' );
 869                 $this->store->startWrite( $code );
 870                 foreach ( $allData as $key => $value ) {
 871                         if ( in_array( $key, self::$splitKeys ) ) {
 872                                 foreach ( $value as $subkey => $subvalue ) {
 873                                         $this->store->set( "$key:$subkey", $subvalue );
 874                                 }
 875                         } else {
 876                                 $this->store->set( $key, $value );
 877                         }
 878                 }
 879                 $this->store->finishWrite();
 880                 wfProfileOut( __METHOD__ . '-write' );
 881
 882                 # Clear out the MessageBlobStore
 883                 # HACK: If using a null (i.e. disabled) storage backend, we
 884                 # can't write to the MessageBlobStore either
 885                 if ( !$this->store instanceof LCStore_Null ) {
 886                         MessageBlobStore::clear();
 887                 }
 888
 889                 wfProfileOut( __METHOD__ );
 890         }
 891
 892         /**
 893          * Build the preload item from the given pre-cache data.
 894          *
 895          * The preload item will be loaded automatically, improving performance
 896          * for the commonly-requested items it contains.
 897          * @param $data
 898          * @return array
 899          */
 900         protected function buildPreload( $data ) {
 901                 $preload = array( 'messages' => array() );
 902                 foreach ( self::$preloadedKeys as $key ) {
 903                         $preload[$key] = $data[$key];
 904                 }
 905
 906                 foreach ( $data['preloadedMessages'] as $subkey ) {
 907                         if ( isset( $data['messages'][$subkey] ) ) {
 908                                 $subitem = $data['messages'][$subkey];
 909                         } else {
 910                                 $subitem = null;
 911                         }
 912                         $preload['messages'][$subkey] = $subitem;
 913                 }
 914
 915                 return $preload;
 916         }
 917
 918         /**
 919          * Unload the data for a given language from the object cache.
 920          * Reduces memory usage.
 921          * @param $code
 922          */
 923         public function unload( $code ) {
 924                 unset( $this->data[$code] );
 925                 unset( $this->loadedItems[$code] );
 926                 unset( $this->loadedSubitems[$code] );
 927                 unset( $this->initialisedLangs[$code] );
 928
 929                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
 930                         if ( $fbCode === $code ) {
 931                                 $this->unload( $shallowCode );
 932                         }
 933                 }
 934         }
 935
 936         /**
 937          * Unload all data
 938          */
 939         public function unloadAll() {
 940                 foreach ( $this->initialisedLangs as $lang => $unused ) {
 941                         $this->unload( $lang );
 942                 }
 943         }
 944
 945         /**
 946          * Disable the storage backend
 947          */
 948         public function disableBackend() {
 949                 $this->store = new LCStore_Null;
 950                 $this->manualRecache = false;
 951         }
 952 }
 953
 954 /**
 955  * Interface for the persistence layer of LocalisationCache.
 956  *
 957  * The persistence layer is two-level hierarchical cache. The first level
 958  * is the language, the second level is the item or subitem.
 959  *
 960  * Since the data for a whole language is rebuilt in one operation, it needs
 961  * to have a fast and atomic method for deleting or replacing all of the
 962  * current data for a given language. The interface reflects this bulk update
 963  * operation. Callers writing to the cache must first call startWrite(), then
 964  * will call set() a couple of thousand times, then will call finishWrite()
 965  * to commit the operation. When finishWrite() is called, the cache is
 966  * expected to delete all data previously stored for that language.
 967  *
 968  * The values stored are PHP variables suitable for serialize(). Implementations
 969  * of LCStore are responsible for serializing and unserializing.
 970  */
 971 interface LCStore {
 972         /**
 973          * Get a value.
 974          * @param string $code Language code
 975          * @param string $key Cache key
 976          */
 977         function get( $code, $key );
 978
 979         /**
 980          * Start a write transaction.
 981          * @param string $code Language code
 982          */
 983         function startWrite( $code );
 984
 985         /**
 986          * Finish a write transaction.
 987          */
 988         function finishWrite();
 989
 990         /**
 991          * Set a key to a given value. startWrite() must be called before this
 992          * is called, and finishWrite() must be called afterwards.
 993          * @param string $key
 994          * @param mixed $value
 995          */
 996         function set( $key, $value );
 997 }
 998
 999 /**
1000  * LCStore implementation which uses PHP accelerator to store data.
1001  * This will work if one of XCache, WinCache or APC cacher is configured.
1002  * (See ObjectCache.php)
1003  */
1004 class LCStore_Accel implements LCStore {
1005         var $currentLang;
1006         var $keys;
1007
1008         public function __construct() {
1009                 $this->cache = wfGetCache( CACHE_ACCEL );
1010         }
1011
1012         public function get( $code, $key ) {
1013                 $k = wfMemcKey( 'l10n', $code, 'k', $key );
1014                 $r = $this->cache->get( $k );
1015                 return $r === false ? null : $r;
1016         }
1017
1018         public function startWrite( $code ) {
1019                 $k = wfMemcKey( 'l10n', $code, 'l' );
1020                 $keys = $this->cache->get( $k );
1021                 if ( $keys ) {
1022                         foreach ( $keys as $k ) {
1023                                 $this->cache->delete( $k );
1024                         }
1025                 }
1026                 $this->currentLang = $code;
1027                 $this->keys = array();
1028         }
1029
1030         public function finishWrite() {
1031                 if ( $this->currentLang ) {
1032                         $k = wfMemcKey( 'l10n', $this->currentLang, 'l' );
1033                         $this->cache->set( $k, array_keys( $this->keys ) );
1034                 }
1035                 $this->currentLang = null;
1036                 $this->keys = array();
1037         }
1038
1039         public function set( $key, $value ) {
1040                 if ( $this->currentLang ) {
1041                         $k = wfMemcKey( 'l10n', $this->currentLang, 'k', $key );
1042                         $this->keys[$k] = true;
1043                         $this->cache->set( $k, $value );
1044                 }
1045         }
1046 }
1047
1048 /**
1049  * LCStore implementation which uses the standard DB functions to store data.
1050  * This will work on any MediaWiki installation.
1051  */
1052 class LCStore_DB implements LCStore {
1053         var $currentLang;
1054         var $writesDone = false;
1055
1056         /**
1057          * @var DatabaseBase
1058          */
1059         var $dbw;
1060         var $batch;
1061         var $readOnly = false;
1062
1063         public function get( $code, $key ) {
1064                 if ( $this->writesDone ) {
1065                         $db = wfGetDB( DB_MASTER );
1066                 } else {
1067                         $db = wfGetDB( DB_SLAVE );
1068                 }
1069                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1070                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1071                 if ( $row ) {
1072                         return unserialize( $row->lc_value );
1073                 } else {
1074                         return null;
1075                 }
1076         }
1077
1078         public function startWrite( $code ) {
1079                 if ( $this->readOnly ) {
1080                         return;
1081                 }
1082
1083                 if ( !$code ) {
1084                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1085                 }
1086
1087                 $this->dbw = wfGetDB( DB_MASTER );
1088                 try {
1089                         $this->dbw->begin( __METHOD__ );
1090                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
1091                 } catch ( DBQueryError $e ) {
1092                         if ( $this->dbw->wasReadOnlyError() ) {
1093                                 $this->readOnly = true;
1094                                 $this->dbw->rollback( __METHOD__ );
1095                                 return;
1096                         } else {
1097                                 throw $e;
1098                         }
1099                 }
1100
1101                 $this->currentLang = $code;
1102                 $this->batch = array();
1103         }
1104
1105         public function finishWrite() {
1106                 if ( $this->readOnly ) {
1107                         return;
1108                 }
1109
1110                 if ( $this->batch ) {
1111                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1112                 }
1113
1114                 $this->dbw->commit( __METHOD__ );
1115                 $this->currentLang = null;
1116                 $this->dbw = null;
1117                 $this->batch = array();
1118                 $this->writesDone = true;
1119         }
1120
1121         public function set( $key, $value ) {
1122                 if ( $this->readOnly ) {
1123                         return;
1124                 }
1125
1126                 if ( is_null( $this->currentLang ) ) {
1127                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1128                 }
1129
1130                 $this->batch[] = array(
1131                         'lc_lang' => $this->currentLang,
1132                         'lc_key' => $key,
1133                         'lc_value' => serialize( $value ) );
1134
1135                 if ( count( $this->batch ) >= 100 ) {
1136                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1137                         $this->batch = array();
1138                 }
1139         }
1140 }
1141
1142 /**
1143  * LCStore implementation which stores data as a collection of CDB files in the
1144  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1145  * will throw an exception.
1146  *
1147  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1148  * the directory is on a local filesystem and there is ample kernel cache
1149  * space. The performance advantage is greater when the DBA extension is
1150  * available than it is with the PHP port.
1151  *
1152  * See Cdb.php and http://cr.yp.to/cdb.html
1153  */
1154 class LCStore_CDB implements LCStore {
1155         var $readers, $writer, $currentLang, $directory;
1156
1157         function __construct( $conf = array() ) {
1158                 global $wgCacheDirectory;
1159
1160                 if ( isset( $conf['directory'] ) ) {
1161                         $this->directory = $conf['directory'];
1162                 } else {
1163                         $this->directory = $wgCacheDirectory;
1164                 }
1165         }
1166
1167         public function get( $code, $key ) {
1168                 if ( !isset( $this->readers[$code] ) ) {
1169                         $fileName = $this->getFileName( $code );
1170
1171                         if ( !file_exists( $fileName ) ) {
1172                                 $this->readers[$code] = false;
1173                         } else {
1174                                 $this->readers[$code] = CdbReader::open( $fileName );
1175                         }
1176                 }
1177
1178                 if ( !$this->readers[$code] ) {
1179                         return null;
1180                 } else {
1181                         $value = $this->readers[$code]->get( $key );
1182
1183                         if ( $value === false ) {
1184                                 return null;
1185                         }
1186                         return unserialize( $value );
1187                 }
1188         }
1189
1190         public function startWrite( $code ) {
1191                 if ( !file_exists( $this->directory ) ) {
1192                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1193                                 throw new MWException( "Unable to create the localisation store " .
1194                                         "directory \"{$this->directory}\"" );
1195                         }
1196                 }
1197
1198                 // Close reader to stop permission errors on write
1199                 if ( !empty( $this->readers[$code] ) ) {
1200                         $this->readers[$code]->close();
1201                 }
1202
1203                 $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1204                 $this->currentLang = $code;
1205         }
1206
1207         public function finishWrite() {
1208                 // Close the writer
1209                 $this->writer->close();
1210                 $this->writer = null;
1211                 unset( $this->readers[$this->currentLang] );
1212                 $this->currentLang = null;
1213         }
1214
1215         public function set( $key, $value ) {
1216                 if ( is_null( $this->writer ) ) {
1217                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1218                 }
1219                 $this->writer->set( $key, serialize( $value ) );
1220         }
1221
1222         protected function getFileName( $code ) {
1223                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1224                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1225                 }
1226                 return "{$this->directory}/l10n_cache-$code.cdb";
1227         }
1228 }
1229
1230 /**
1231  * Null store backend, used to avoid DB errors during install
1232  */
1233 class LCStore_Null implements LCStore {
1234         public function get( $code, $key ) {
1235                 return null;
1236         }
1237
1238         public function startWrite( $code ) {}
1239         public function finishWrite() {}
1240         public function set( $key, $value ) {}
1241 }
1242
1243 /**
1244  * A localisation cache optimised for loading large amounts of data for many
1245  * languages. Used by rebuildLocalisationCache.php.
1246  */
1247 class LocalisationCache_BulkLoad extends LocalisationCache {
1248         /**
1249          * A cache of the contents of data files.
1250          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1251          */
1252         var $fileCache = array();
1253
1254         /**
1255          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1256          * to keep the most recently used language codes at the end of the array, and
1257          * the language codes that are ready to be deleted at the beginning.
1258          */
1259         var $mruLangs = array();
1260
1261         /**
1262          * Maximum number of languages that may be loaded into $this->data
1263          */
1264         var $maxLoadedLangs = 10;
1265
1266         /**
1267          * @param $fileName
1268          * @param $fileType
1269          * @return array|mixed
1270          */
1271         protected function readPHPFile( $fileName, $fileType ) {
1272                 $serialize = $fileType === 'core';
1273                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1274                         $data = parent::readPHPFile( $fileName, $fileType );
1275
1276                         if ( $serialize ) {
1277                                 $encData = serialize( $data );
1278                         } else {
1279                                 $encData = $data;
1280                         }
1281
1282                         $this->fileCache[$fileName][$fileType] = $encData;
1283
1284                         return $data;
1285                 } elseif ( $serialize ) {
1286                         return unserialize( $this->fileCache[$fileName][$fileType] );
1287                 } else {
1288                         return $this->fileCache[$fileName][$fileType];
1289                 }
1290         }
1291
1292         /**
1293          * @param $code
1294          * @param $key
1295          * @return mixed
1296          */
1297         public function getItem( $code, $key ) {
1298                 unset( $this->mruLangs[$code] );
1299                 $this->mruLangs[$code] = true;
1300                 return parent::getItem( $code, $key );
1301         }
1302
1303         /**
1304          * @param $code
1305          * @param $key
1306          * @param $subkey
1307          * @return
1308          */
1309         public function getSubitem( $code, $key, $subkey ) {
1310                 unset( $this->mruLangs[$code] );
1311                 $this->mruLangs[$code] = true;
1312                 return parent::getSubitem( $code, $key, $subkey );
1313         }
1314
1315         /**
1316          * @param $code
1317          */
1318         public function recache( $code ) {
1319                 parent::recache( $code );
1320                 unset( $this->mruLangs[$code] );
1321                 $this->mruLangs[$code] = true;
1322                 $this->trimCache();
1323         }
1324
1325         /**
1326          * @param $code
1327          */
1328         public function unload( $code ) {
1329                 unset( $this->mruLangs[$code] );
1330                 parent::unload( $code );
1331         }
1332
1333         /**
1334          * Unload cached languages until there are less than $this->maxLoadedLangs
1335          */
1336         protected function trimCache() {
1337                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1338                         reset( $this->mruLangs );
1339                         $code = key( $this->mruLangs );
1340                         wfDebug( __METHOD__ . ": unloading $code\n" );
1341                         $this->unload( $code );
1342                 }
1343         }
1344 }