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                 wfProfileIn( __METHOD__ );
 615
 616                 $fileName = Language::getMessagesFileName( $code );
 617                 if ( !file_exists( $fileName ) ) {
 618                         wfProfileOut( __METHOD__ );
 619                         return false;
 620                 }
 621
 622                 $deps[] = new FileDependency( $fileName );
 623                 $data = $this->readPHPFile( $fileName, 'core' );
 624
 625                 # Load CLDR plural rules for JavaScript
 626                 $data['pluralRules'] = $this->getPluralRules( $code );
 627                 # And for PHP
 628                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 629                 # Load plural rule types
 630                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 631
 632                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 633                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 634
 635                 wfProfileOut( __METHOD__ );
 636                 return $data;
 637         }
 638
 639         /**
 640          * Merge two localisation values, a primary and a fallback, overwriting the
 641          * primary value in place.
 642          * @param $key
 643          * @param $value
 644          * @param $fallbackValue
 645          */
 646         protected function mergeItem( $key, &$value, $fallbackValue ) {
 647                 if ( !is_null( $value ) ) {
 648                         if ( !is_null( $fallbackValue ) ) {
 649                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 650                                         $value = $value + $fallbackValue;
 651                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 652                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 653                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 654                                         $value = array_merge_recursive( $value, $fallbackValue );
 655                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 656                                         if ( !empty( $value['inherit'] ) ) {
 657                                                 $value = array_merge( $fallbackValue, $value );
 658                                         }
 659
 660                                         if ( isset( $value['inherit'] ) ) {
 661                                                 unset( $value['inherit'] );
 662                                         }
 663                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 664                                         $this->mergeMagicWords( $value, $fallbackValue );
 665                                 }
 666                         }
 667                 } else {
 668                         $value = $fallbackValue;
 669                 }
 670         }
 671
 672         /**
 673          * @param $value
 674          * @param $fallbackValue
 675          */
 676         protected function mergeMagicWords( &$value, $fallbackValue ) {
 677                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 678                         if ( !isset( $value[$magicName] ) ) {
 679                                 $value[$magicName] = $fallbackInfo;
 680                         } else {
 681                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 682                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 683                                 $synonyms = array_values( array_unique( array_merge(
 684                                         $newSynonyms, $oldSynonyms ) ) );
 685                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 686                         }
 687                 }
 688         }
 689
 690         /**
 691          * Given an array mapping language code to localisation value, such as is
 692          * found in extension *.i18n.php files, iterate through a fallback sequence
 693          * to merge the given data with an existing primary value.
 694          *
 695          * Returns true if any data from the extension array was used, false
 696          * otherwise.
 697          * @param $codeSequence
 698          * @param $key
 699          * @param $value
 700          * @param $fallbackValue
 701          * @return bool
 702          */
 703         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 704                 $used = false;
 705                 foreach ( $codeSequence as $code ) {
 706                         if ( isset( $fallbackValue[$code] ) ) {
 707                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 708                                 $used = true;
 709                         }
 710                 }
 711
 712                 return $used;
 713         }
 714
 715         /**
 716          * Load localisation data for a given language for both core and extensions
 717          * and save it to the persistent cache store and the process cache
 718          * @param $code
 719          * @throws MWException
 720          */
 721         public function recache( $code ) {
 722                 global $wgExtensionMessagesFiles;
 723                 wfProfileIn( __METHOD__ );
 724
 725                 if ( !$code ) {
 726                         throw new MWException( "Invalid language code requested" );
 727                 }
 728                 $this->recachedLangs[$code] = true;
 729
 730                 # Initial values
 731                 $initialData = array_combine(
 732                         self::$allKeys,
 733                         array_fill( 0, count( self::$allKeys ), null ) );
 734                 $coreData = $initialData;
 735                 $deps = array();
 736
 737                 # Load the primary localisation from the source file
 738                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 739                 if ( $data === false ) {
 740                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 741                         $coreData['fallback'] = 'en';
 742                 } else {
 743                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 744
 745                         # Merge primary localisation
 746                         foreach ( $data as $key => $value ) {
 747                                 $this->mergeItem( $key, $coreData[$key], $value );
 748                         }
 749
 750                 }
 751
 752                 # Fill in the fallback if it's not there already
 753                 if ( is_null( $coreData['fallback'] ) ) {
 754                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 755                 }
 756                 if ( $coreData['fallback'] === false ) {
 757                         $coreData['fallbackSequence'] = array();
 758                 } else {
 759                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 760                         $len = count( $coreData['fallbackSequence'] );
 761
 762                         # Ensure that the sequence ends at en
 763                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 764                                 $coreData['fallbackSequence'][] = 'en';
 765                         }
 766
 767                         # Load the fallback localisation item by item and merge it
 768                         foreach ( $coreData['fallbackSequence'] as $fbCode ) {
 769                                 # Load the secondary localisation from the source file to
 770                                 # avoid infinite cycles on cyclic fallbacks
 771                                 $fbData = $this->readSourceFilesAndRegisterDeps( $fbCode, $deps );
 772                                 if ( $fbData === false ) {
 773                                         continue;
 774                                 }
 775
 776                                 foreach ( self::$allKeys as $key ) {
 777                                         if ( !isset( $fbData[$key] ) ) {
 778                                                 continue;
 779                                         }
 780
 781                                         if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 782                                                 $this->mergeItem( $key, $coreData[$key], $fbData[$key] );
 783                                         }
 784                                 }
 785                         }
 786                 }
 787
 788                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 789
 790                 # Load the extension localisations
 791                 # This is done after the core because we know the fallback sequence now.
 792                 # But it has a higher precedence for merging so that we can support things
 793                 # like site-specific message overrides.
 794                 wfProfileIn( __METHOD__ . '-extensions' );
 795                 $allData = $initialData;
 796                 foreach ( $wgExtensionMessagesFiles as $fileName ) {
 797                         $data = $this->readPHPFile( $fileName, 'extension' );
 798                         $used = false;
 799
 800                         foreach ( $data as $key => $item ) {
 801                                 if ( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 802                                         $used = true;
 803                                 }
 804                         }
 805
 806                         if ( $used ) {
 807                                 $deps[] = new FileDependency( $fileName );
 808                         }
 809                 }
 810
 811                 # Merge core data into extension data
 812                 foreach ( $coreData as $key => $item ) {
 813                         $this->mergeItem( $key, $allData[$key], $item );
 814                 }
 815                 wfProfileOut( __METHOD__ . '-extensions' );
 816
 817                 # Add cache dependencies for any referenced globals
 818                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 819                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 820
 821                 # Add dependencies to the cache entry
 822                 $allData['deps'] = $deps;
 823
 824                 # Replace spaces with underscores in namespace names
 825                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 826
 827                 # And do the same for special page aliases. $page is an array.
 828                 foreach ( $allData['specialPageAliases'] as &$page ) {
 829                         $page = str_replace( ' ', '_', $page );
 830                 }
 831                 # Decouple the reference to prevent accidental damage
 832                 unset( $page );
 833
 834                 # If there were no plural rules, return an empty array
 835                 if ( $allData['pluralRules'] === null ) {
 836                         $allData['pluralRules'] = array();
 837                 }
 838                 if ( $allData['compiledPluralRules'] === null ) {
 839                         $allData['compiledPluralRules'] = array();
 840                 }
 841                 # If there were no plural rule types, return an empty array
 842                 if ( $allData['pluralRuleTypes'] === null ) {
 843                         $allData['pluralRuleTypes'] = array();
 844                 }
 845
 846                 # Set the list keys
 847                 $allData['list'] = array();
 848                 foreach ( self::$splitKeys as $key ) {
 849                         $allData['list'][$key] = array_keys( $allData[$key] );
 850                 }
 851                 # Run hooks
 852                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData ) );
 853
 854                 if ( is_null( $allData['namespaceNames'] ) ) {
 855                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
 856                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 857                 }
 858
 859                 # Set the preload key
 860                 $allData['preload'] = $this->buildPreload( $allData );
 861
 862                 # Save to the process cache and register the items loaded
 863                 $this->data[$code] = $allData;
 864                 foreach ( $allData as $key => $item ) {
 865                         $this->loadedItems[$code][$key] = true;
 866                 }
 867
 868                 # Save to the persistent cache
 869                 wfProfileIn( __METHOD__ . '-write' );
 870                 $this->store->startWrite( $code );
 871                 foreach ( $allData as $key => $value ) {
 872                         if ( in_array( $key, self::$splitKeys ) ) {
 873                                 foreach ( $value as $subkey => $subvalue ) {
 874                                         $this->store->set( "$key:$subkey", $subvalue );
 875                                 }
 876                         } else {
 877                                 $this->store->set( $key, $value );
 878                         }
 879                 }
 880                 $this->store->finishWrite();
 881                 wfProfileOut( __METHOD__ . '-write' );
 882
 883                 # Clear out the MessageBlobStore
 884                 # HACK: If using a null (i.e. disabled) storage backend, we
 885                 # can't write to the MessageBlobStore either
 886                 if ( !$this->store instanceof LCStore_Null ) {
 887                         MessageBlobStore::clear();
 888                 }
 889
 890                 wfProfileOut( __METHOD__ );
 891         }
 892
 893         /**
 894          * Build the preload item from the given pre-cache data.
 895          *
 896          * The preload item will be loaded automatically, improving performance
 897          * for the commonly-requested items it contains.
 898          * @param $data
 899          * @return array
 900          */
 901         protected function buildPreload( $data ) {
 902                 $preload = array( 'messages' => array() );
 903                 foreach ( self::$preloadedKeys as $key ) {
 904                         $preload[$key] = $data[$key];
 905                 }
 906
 907                 foreach ( $data['preloadedMessages'] as $subkey ) {
 908                         if ( isset( $data['messages'][$subkey] ) ) {
 909                                 $subitem = $data['messages'][$subkey];
 910                         } else {
 911                                 $subitem = null;
 912                         }
 913                         $preload['messages'][$subkey] = $subitem;
 914                 }
 915
 916                 return $preload;
 917         }
 918
 919         /**
 920          * Unload the data for a given language from the object cache.
 921          * Reduces memory usage.
 922          * @param $code
 923          */
 924         public function unload( $code ) {
 925                 unset( $this->data[$code] );
 926                 unset( $this->loadedItems[$code] );
 927                 unset( $this->loadedSubitems[$code] );
 928                 unset( $this->initialisedLangs[$code] );
 929
 930                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
 931                         if ( $fbCode === $code ) {
 932                                 $this->unload( $shallowCode );
 933                         }
 934                 }
 935         }
 936
 937         /**
 938          * Unload all data
 939          */
 940         public function unloadAll() {
 941                 foreach ( $this->initialisedLangs as $lang => $unused ) {
 942                         $this->unload( $lang );
 943                 }
 944         }
 945
 946         /**
 947          * Disable the storage backend
 948          */
 949         public function disableBackend() {
 950                 $this->store = new LCStore_Null;
 951                 $this->manualRecache = false;
 952         }
 953 }
 954
 955 /**
 956  * Interface for the persistence layer of LocalisationCache.
 957  *
 958  * The persistence layer is two-level hierarchical cache. The first level
 959  * is the language, the second level is the item or subitem.
 960  *
 961  * Since the data for a whole language is rebuilt in one operation, it needs
 962  * to have a fast and atomic method for deleting or replacing all of the
 963  * current data for a given language. The interface reflects this bulk update
 964  * operation. Callers writing to the cache must first call startWrite(), then
 965  * will call set() a couple of thousand times, then will call finishWrite()
 966  * to commit the operation. When finishWrite() is called, the cache is
 967  * expected to delete all data previously stored for that language.
 968  *
 969  * The values stored are PHP variables suitable for serialize(). Implementations
 970  * of LCStore are responsible for serializing and unserializing.
 971  */
 972 interface LCStore {
 973         /**
 974          * Get a value.
 975          * @param string $code Language code
 976          * @param string $key Cache key
 977          */
 978         function get( $code, $key );
 979
 980         /**
 981          * Start a write transaction.
 982          * @param string $code Language code
 983          */
 984         function startWrite( $code );
 985
 986         /**
 987          * Finish a write transaction.
 988          */
 989         function finishWrite();
 990
 991         /**
 992          * Set a key to a given value. startWrite() must be called before this
 993          * is called, and finishWrite() must be called afterwards.
 994          * @param string $key
 995          * @param mixed $value
 996          */
 997         function set( $key, $value );
 998 }
 999
1000 /**
1001  * LCStore implementation which uses PHP accelerator to store data.
1002  * This will work if one of XCache, WinCache or APC cacher is configured.
1003  * (See ObjectCache.php)
1004  */
1005 class LCStore_Accel implements LCStore {
1006         var $currentLang;
1007         var $keys;
1008
1009         public function __construct() {
1010                 $this->cache = wfGetCache( CACHE_ACCEL );
1011         }
1012
1013         public function get( $code, $key ) {
1014                 $k = wfMemcKey( 'l10n', $code, 'k', $key );
1015                 $r = $this->cache->get( $k );
1016                 return $r === false ? null : $r;
1017         }
1018
1019         public function startWrite( $code ) {
1020                 $k = wfMemcKey( 'l10n', $code, 'l' );
1021                 $keys = $this->cache->get( $k );
1022                 if ( $keys ) {
1023                         foreach ( $keys as $k ) {
1024                                 $this->cache->delete( $k );
1025                         }
1026                 }
1027                 $this->currentLang = $code;
1028                 $this->keys = array();
1029         }
1030
1031         public function finishWrite() {
1032                 if ( $this->currentLang ) {
1033                         $k = wfMemcKey( 'l10n', $this->currentLang, 'l' );
1034                         $this->cache->set( $k, array_keys( $this->keys ) );
1035                 }
1036                 $this->currentLang = null;
1037                 $this->keys = array();
1038         }
1039
1040         public function set( $key, $value ) {
1041                 if ( $this->currentLang ) {
1042                         $k = wfMemcKey( 'l10n', $this->currentLang, 'k', $key );
1043                         $this->keys[$k] = true;
1044                         $this->cache->set( $k, $value );
1045                 }
1046         }
1047 }
1048
1049 /**
1050  * LCStore implementation which uses the standard DB functions to store data.
1051  * This will work on any MediaWiki installation.
1052  */
1053 class LCStore_DB implements LCStore {
1054         var $currentLang;
1055         var $writesDone = false;
1056
1057         /**
1058          * @var DatabaseBase
1059          */
1060         var $dbw;
1061         var $batch;
1062         var $readOnly = false;
1063
1064         public function get( $code, $key ) {
1065                 if ( $this->writesDone ) {
1066                         $db = wfGetDB( DB_MASTER );
1067                 } else {
1068                         $db = wfGetDB( DB_SLAVE );
1069                 }
1070                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1071                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1072                 if ( $row ) {
1073                         return unserialize( $row->lc_value );
1074                 } else {
1075                         return null;
1076                 }
1077         }
1078
1079         public function startWrite( $code ) {
1080                 if ( $this->readOnly ) {
1081                         return;
1082                 }
1083
1084                 if ( !$code ) {
1085                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1086                 }
1087
1088                 $this->dbw = wfGetDB( DB_MASTER );
1089                 try {
1090                         $this->dbw->begin( __METHOD__ );
1091                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
1092                 } catch ( DBQueryError $e ) {
1093                         if ( $this->dbw->wasReadOnlyError() ) {
1094                                 $this->readOnly = true;
1095                                 $this->dbw->rollback( __METHOD__ );
1096                                 return;
1097                         } else {
1098                                 throw $e;
1099                         }
1100                 }
1101
1102                 $this->currentLang = $code;
1103                 $this->batch = array();
1104         }
1105
1106         public function finishWrite() {
1107                 if ( $this->readOnly ) {
1108                         return;
1109                 }
1110
1111                 if ( $this->batch ) {
1112                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1113                 }
1114
1115                 $this->dbw->commit( __METHOD__ );
1116                 $this->currentLang = null;
1117                 $this->dbw = null;
1118                 $this->batch = array();
1119                 $this->writesDone = true;
1120         }
1121
1122         public function set( $key, $value ) {
1123                 if ( $this->readOnly ) {
1124                         return;
1125                 }
1126
1127                 if ( is_null( $this->currentLang ) ) {
1128                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1129                 }
1130
1131                 $this->batch[] = array(
1132                         'lc_lang' => $this->currentLang,
1133                         'lc_key' => $key,
1134                         'lc_value' => serialize( $value ) );
1135
1136                 if ( count( $this->batch ) >= 100 ) {
1137                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1138                         $this->batch = array();
1139                 }
1140         }
1141 }
1142
1143 /**
1144  * LCStore implementation which stores data as a collection of CDB files in the
1145  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1146  * will throw an exception.
1147  *
1148  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1149  * the directory is on a local filesystem and there is ample kernel cache
1150  * space. The performance advantage is greater when the DBA extension is
1151  * available than it is with the PHP port.
1152  *
1153  * See Cdb.php and http://cr.yp.to/cdb.html
1154  */
1155 class LCStore_CDB implements LCStore {
1156         var $readers, $writer, $currentLang, $directory;
1157
1158         function __construct( $conf = array() ) {
1159                 global $wgCacheDirectory;
1160
1161                 if ( isset( $conf['directory'] ) ) {
1162                         $this->directory = $conf['directory'];
1163                 } else {
1164                         $this->directory = $wgCacheDirectory;
1165                 }
1166         }
1167
1168         public function get( $code, $key ) {
1169                 if ( !isset( $this->readers[$code] ) ) {
1170                         $fileName = $this->getFileName( $code );
1171
1172                         if ( !file_exists( $fileName ) ) {
1173                                 $this->readers[$code] = false;
1174                         } else {
1175                                 $this->readers[$code] = CdbReader::open( $fileName );
1176                         }
1177                 }
1178
1179                 if ( !$this->readers[$code] ) {
1180                         return null;
1181                 } else {
1182                         $value = $this->readers[$code]->get( $key );
1183
1184                         if ( $value === false ) {
1185                                 return null;
1186                         }
1187                         return unserialize( $value );
1188                 }
1189         }
1190
1191         public function startWrite( $code ) {
1192                 if ( !file_exists( $this->directory ) ) {
1193                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1194                                 throw new MWException( "Unable to create the localisation store " .
1195                                         "directory \"{$this->directory}\"" );
1196                         }
1197                 }
1198
1199                 // Close reader to stop permission errors on write
1200                 if ( !empty( $this->readers[$code] ) ) {
1201                         $this->readers[$code]->close();
1202                 }
1203
1204                 $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1205                 $this->currentLang = $code;
1206         }
1207
1208         public function finishWrite() {
1209                 // Close the writer
1210                 $this->writer->close();
1211                 $this->writer = null;
1212                 unset( $this->readers[$this->currentLang] );
1213                 $this->currentLang = null;
1214         }
1215
1216         public function set( $key, $value ) {
1217                 if ( is_null( $this->writer ) ) {
1218                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1219                 }
1220                 $this->writer->set( $key, serialize( $value ) );
1221         }
1222
1223         protected function getFileName( $code ) {
1224                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1225                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1226                 }
1227                 return "{$this->directory}/l10n_cache-$code.cdb";
1228         }
1229 }
1230
1231 /**
1232  * Null store backend, used to avoid DB errors during install
1233  */
1234 class LCStore_Null implements LCStore {
1235         public function get( $code, $key ) {
1236                 return null;
1237         }
1238
1239         public function startWrite( $code ) {}
1240         public function finishWrite() {}
1241         public function set( $key, $value ) {}
1242 }
1243
1244 /**
1245  * A localisation cache optimised for loading large amounts of data for many
1246  * languages. Used by rebuildLocalisationCache.php.
1247  */
1248 class LocalisationCache_BulkLoad extends LocalisationCache {
1249         /**
1250          * A cache of the contents of data files.
1251          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1252          */
1253         var $fileCache = array();
1254
1255         /**
1256          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1257          * to keep the most recently used language codes at the end of the array, and
1258          * the language codes that are ready to be deleted at the beginning.
1259          */
1260         var $mruLangs = array();
1261
1262         /**
1263          * Maximum number of languages that may be loaded into $this->data
1264          */
1265         var $maxLoadedLangs = 10;
1266
1267         /**
1268          * @param $fileName
1269          * @param $fileType
1270          * @return array|mixed
1271          */
1272         protected function readPHPFile( $fileName, $fileType ) {
1273                 $serialize = $fileType === 'core';
1274                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1275                         $data = parent::readPHPFile( $fileName, $fileType );
1276
1277                         if ( $serialize ) {
1278                                 $encData = serialize( $data );
1279                         } else {
1280                                 $encData = $data;
1281                         }
1282
1283                         $this->fileCache[$fileName][$fileType] = $encData;
1284
1285                         return $data;
1286                 } elseif ( $serialize ) {
1287                         return unserialize( $this->fileCache[$fileName][$fileType] );
1288                 } else {
1289                         return $this->fileCache[$fileName][$fileType];
1290                 }
1291         }
1292
1293         /**
1294          * @param $code
1295          * @param $key
1296          * @return mixed
1297          */
1298         public function getItem( $code, $key ) {
1299                 unset( $this->mruLangs[$code] );
1300                 $this->mruLangs[$code] = true;
1301                 return parent::getItem( $code, $key );
1302         }
1303
1304         /**
1305          * @param $code
1306          * @param $key
1307          * @param $subkey
1308          * @return
1309          */
1310         public function getSubitem( $code, $key, $subkey ) {
1311                 unset( $this->mruLangs[$code] );
1312                 $this->mruLangs[$code] = true;
1313                 return parent::getSubitem( $code, $key, $subkey );
1314         }
1315
1316         /**
1317          * @param $code
1318          */
1319         public function recache( $code ) {
1320                 parent::recache( $code );
1321                 unset( $this->mruLangs[$code] );
1322                 $this->mruLangs[$code] = true;
1323                 $this->trimCache();
1324         }
1325
1326         /**
1327          * @param $code
1328          */
1329         public function unload( $code ) {
1330                 unset( $this->mruLangs[$code] );
1331                 parent::unload( $code );
1332         }
1333
1334         /**
1335          * Unload cached languages until there are less than $this->maxLoadedLangs
1336          */
1337         protected function trimCache() {
1338                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1339                         reset( $this->mruLangs );
1340                         $code = key( $this->mruLangs );
1341                         wfDebug( __METHOD__ . ": unloading $code\n" );
1342                         $this->unload( $code );
1343                 }
1344         }
1345 }