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         private $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         private $manualRecache = false;
  47
  48         /**
  49          * True to treat all files as expired until they are regenerated by this object.
  50          */
  51         private $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         protected $data = array();
  60
  61         /**
  62          * The persistent store object. An instance of LCStore.
  63          *
  64          * @var LCStore
  65          */
  66         private $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         private $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         private $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         private $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         private $shallowFallbacks = array();
  96
  97         /**
  98          * An array where the keys are codes that have been recached by this instance.
  99          */
 100         private $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', 'linkPrefixCharset', '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         private $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         private $pluralRuleTypes = null;
 176
 177         private $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 = 'LCStoreCDB';
 199                                         break;
 200                                 case 'db':
 201                                         $storeClass = 'LCStoreDB';
 202                                         break;
 203                                 case 'accel':
 204                                         $storeClass = 'LCStoreAccel';
 205                                         break;
 206                                 case 'detect':
 207                                         $storeClass = $wgCacheDirectory ? 'LCStoreCDB' : 'LCStoreDB';
 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
 245                 return isset( $this->mergeableKeys[$key] );
 246         }
 247
 248         /**
 249          * Get a cache item.
 250          *
 251          * Warning: this may be slow for split items (messages), since it will
 252          * need to fetch all of the subitems from the cache individually.
 253          * @param $code
 254          * @param $key
 255          * @return mixed
 256          */
 257         public function getItem( $code, $key ) {
 258                 if ( !isset( $this->loadedItems[$code][$key] ) ) {
 259                         wfProfileIn( __METHOD__ . '-load' );
 260                         $this->loadItem( $code, $key );
 261                         wfProfileOut( __METHOD__ . '-load' );
 262                 }
 263
 264                 if ( $key === 'fallback' && isset( $this->shallowFallbacks[$code] ) ) {
 265                         return $this->shallowFallbacks[$code];
 266                 }
 267
 268                 return $this->data[$code][$key];
 269         }
 270
 271         /**
 272          * Get a subitem, for instance a single message for a given language.
 273          * @param $code
 274          * @param $key
 275          * @param $subkey
 276          * @return null
 277          */
 278         public function getSubitem( $code, $key, $subkey ) {
 279                 if ( !isset( $this->loadedSubitems[$code][$key][$subkey] ) &&
 280                         !isset( $this->loadedItems[$code][$key] )
 281                 ) {
 282                         wfProfileIn( __METHOD__ . '-load' );
 283                         $this->loadSubitem( $code, $key, $subkey );
 284                         wfProfileOut( __METHOD__ . '-load' );
 285                 }
 286
 287                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 288                         return $this->data[$code][$key][$subkey];
 289                 } else {
 290                         return null;
 291                 }
 292         }
 293
 294         /**
 295          * Get the list of subitem keys for a given item.
 296          *
 297          * This is faster than array_keys($lc->getItem(...)) for the items listed in
 298          * self::$splitKeys.
 299          *
 300          * Will return null if the item is not found, or false if the item is not an
 301          * array.
 302          * @param $code
 303          * @param $key
 304          * @return bool|null|string
 305          */
 306         public function getSubitemList( $code, $key ) {
 307                 if ( in_array( $key, self::$splitKeys ) ) {
 308                         return $this->getSubitem( $code, 'list', $key );
 309                 } else {
 310                         $item = $this->getItem( $code, $key );
 311                         if ( is_array( $item ) ) {
 312                                 return array_keys( $item );
 313                         } else {
 314                                 return false;
 315                         }
 316                 }
 317         }
 318
 319         /**
 320          * Load an item into the cache.
 321          * @param $code
 322          * @param $key
 323          */
 324         protected function loadItem( $code, $key ) {
 325                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 326                         $this->initLanguage( $code );
 327                 }
 328
 329                 // Check to see if initLanguage() loaded it for us
 330                 if ( isset( $this->loadedItems[$code][$key] ) ) {
 331                         return;
 332                 }
 333
 334                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 335                         $this->loadItem( $this->shallowFallbacks[$code], $key );
 336
 337                         return;
 338                 }
 339
 340                 if ( in_array( $key, self::$splitKeys ) ) {
 341                         $subkeyList = $this->getSubitem( $code, 'list', $key );
 342                         foreach ( $subkeyList as $subkey ) {
 343                                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 344                                         continue;
 345                                 }
 346                                 $this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
 347                         }
 348                 } else {
 349                         $this->data[$code][$key] = $this->store->get( $code, $key );
 350                 }
 351
 352                 $this->loadedItems[$code][$key] = true;
 353         }
 354
 355         /**
 356          * Load a subitem into the cache
 357          * @param $code
 358          * @param $key
 359          * @param $subkey
 360          */
 361         protected function loadSubitem( $code, $key, $subkey ) {
 362                 if ( !in_array( $key, self::$splitKeys ) ) {
 363                         $this->loadItem( $code, $key );
 364
 365                         return;
 366                 }
 367
 368                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 369                         $this->initLanguage( $code );
 370                 }
 371
 372                 // Check to see if initLanguage() loaded it for us
 373                 if ( isset( $this->loadedItems[$code][$key] ) ||
 374                         isset( $this->loadedSubitems[$code][$key][$subkey] )
 375                 ) {
 376                         return;
 377                 }
 378
 379                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 380                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 381
 382                         return;
 383                 }
 384
 385                 $value = $this->store->get( $code, "$key:$subkey" );
 386                 $this->data[$code][$key][$subkey] = $value;
 387                 $this->loadedSubitems[$code][$key][$subkey] = true;
 388         }
 389
 390         /**
 391          * Returns true if the cache identified by $code is missing or expired.
 392          *
 393          * @param string $code
 394          *
 395          * @return bool
 396          */
 397         public function isExpired( $code ) {
 398                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 399                         wfDebug( __METHOD__ . "($code): forced reload\n" );
 400
 401                         return true;
 402                 }
 403
 404                 $deps = $this->store->get( $code, 'deps' );
 405                 $keys = $this->store->get( $code, 'list' );
 406                 $preload = $this->store->get( $code, 'preload' );
 407                 // Different keys may expire separately, at least in LCStoreAccel
 408                 if ( $deps === null || $keys === null || $preload === null ) {
 409                         wfDebug( __METHOD__ . "($code): cache missing, need to make one\n" );
 410
 411                         return true;
 412                 }
 413
 414                 foreach ( $deps as $dep ) {
 415                         // Because we're unserializing stuff from cache, we
 416                         // could receive objects of classes that don't exist
 417                         // anymore (e.g. uninstalled extensions)
 418                         // When this happens, always expire the cache
 419                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 420                                 wfDebug( __METHOD__ . "($code): cache for $code expired due to " .
 421                                         get_class( $dep ) . "\n" );
 422
 423                                 return true;
 424                         }
 425                 }
 426
 427                 return false;
 428         }
 429
 430         /**
 431          * Initialise a language in this object. Rebuild the cache if necessary.
 432          * @param $code
 433          * @throws MWException
 434          */
 435         protected function initLanguage( $code ) {
 436                 if ( isset( $this->initialisedLangs[$code] ) ) {
 437                         return;
 438                 }
 439
 440                 $this->initialisedLangs[$code] = true;
 441
 442                 # If the code is of the wrong form for a Messages*.php file, do a shallow fallback
 443                 if ( !Language::isValidBuiltInCode( $code ) ) {
 444                         $this->initShallowFallback( $code, 'en' );
 445
 446                         return;
 447                 }
 448
 449                 # Recache the data if necessary
 450                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 451                         if ( file_exists( Language::getMessagesFileName( $code ) ) ) {
 452                                 $this->recache( $code );
 453                         } elseif ( $code === 'en' ) {
 454                                 throw new MWException( 'MessagesEn.php is missing.' );
 455                         } else {
 456                                 $this->initShallowFallback( $code, 'en' );
 457                         }
 458
 459                         return;
 460                 }
 461
 462                 # Preload some stuff
 463                 $preload = $this->getItem( $code, 'preload' );
 464                 if ( $preload === null ) {
 465                         if ( $this->manualRecache ) {
 466                                 // No Messages*.php file. Do shallow fallback to en.
 467                                 if ( $code === 'en' ) {
 468                                         throw new MWException( 'No localisation cache found for English. ' .
 469                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 470                                 }
 471                                 $this->initShallowFallback( $code, 'en' );
 472
 473                                 return;
 474                         } else {
 475                                 throw new MWException( 'Invalid or missing localisation cache.' );
 476                         }
 477                 }
 478                 $this->data[$code] = $preload;
 479                 foreach ( $preload as $key => $item ) {
 480                         if ( in_array( $key, self::$splitKeys ) ) {
 481                                 foreach ( $item as $subkey => $subitem ) {
 482                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 483                                 }
 484                         } else {
 485                                 $this->loadedItems[$code][$key] = true;
 486                         }
 487                 }
 488         }
 489
 490         /**
 491          * Create a fallback from one language to another, without creating a
 492          * complete persistent cache.
 493          * @param $primaryCode
 494          * @param $fallbackCode
 495          */
 496         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 497                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 498                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 499                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 500                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 501         }
 502
 503         /**
 504          * Read a PHP file containing localisation data.
 505          * @param $_fileName
 506          * @param $_fileType
 507          * @throws MWException
 508          * @return array
 509          */
 510         protected function readPHPFile( $_fileName, $_fileType ) {
 511                 wfProfileIn( __METHOD__ );
 512                 // Disable APC caching
 513                 wfSuppressWarnings();
 514                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 515                 wfRestoreWarnings();
 516
 517                 include $_fileName;
 518
 519                 wfSuppressWarnings();
 520                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 521                 wfRestoreWarnings();
 522
 523                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 524                         $data = compact( self::$allKeys );
 525                 } elseif ( $_fileType == 'aliases' ) {
 526                         $data = compact( 'aliases' );
 527                 } else {
 528                         wfProfileOut( __METHOD__ );
 529                         throw new MWException( __METHOD__ . ": Invalid file type: $_fileType" );
 530                 }
 531                 wfProfileOut( __METHOD__ );
 532
 533                 return $data;
 534         }
 535
 536         /**
 537          * Read a JSON file containing localisation messages.
 538          * @param string $fileName Name of file to read
 539          * @throws MWException if there is a syntax error in the JSON file
 540          * @return array with a 'messages' key, or empty array if the file doesn't exist
 541          */
 542         protected function readJSONFile( $fileName ) {
 543                 wfProfileIn( __METHOD__ );
 544                 if ( !is_readable( $fileName ) ) {
 545                         return array();
 546                 }
 547
 548                 $json = file_get_contents( $fileName );
 549                 if ( $json === false ) {
 550                         return array();
 551                 }
 552                 $data = FormatJson::decode( $json, true );
 553                 if ( $data === null ) {
 554                         throw new MWException( __METHOD__ . ": Invalid JSON file: $fileName" );
 555                 }
 556                 // Remove keys starting with '@', they're reserved for metadata and non-message data
 557                 foreach ( $data as $key => $unused ) {
 558                         if ( $key === '' || $key[0] === '@' ) {
 559                                 unset( $data[$key] );
 560                         }
 561                 }
 562                 // The JSON format only supports messages, none of the other variables, so wrap the data
 563                 return array( 'messages' => $data );
 564         }
 565
 566         /**
 567          * Get the compiled plural rules for a given language from the XML files.
 568          * @since 1.20
 569          */
 570         public function getCompiledPluralRules( $code ) {
 571                 $rules = $this->getPluralRules( $code );
 572                 if ( $rules === null ) {
 573                         return null;
 574                 }
 575                 try {
 576                         $compiledRules = CLDRPluralRuleEvaluator::compile( $rules );
 577                 } catch ( CLDRPluralRuleError $e ) {
 578                         wfDebugLog( 'l10n', $e->getMessage() . "\n" );
 579
 580                         return array();
 581                 }
 582
 583                 return $compiledRules;
 584         }
 585
 586         /**
 587          * Get the plural rules for a given language from the XML files.
 588          * Cached.
 589          * @since 1.20
 590          */
 591         public function getPluralRules( $code ) {
 592                 if ( $this->pluralRules === null ) {
 593                         $this->loadPluralFiles();
 594                 }
 595                 if ( !isset( $this->pluralRules[$code] ) ) {
 596                         return null;
 597                 } else {
 598                         return $this->pluralRules[$code];
 599                 }
 600         }
 601
 602         /**
 603          * Get the plural rule types for a given language from the XML files.
 604          * Cached.
 605          * @since 1.22
 606          */
 607         public function getPluralRuleTypes( $code ) {
 608                 if ( $this->pluralRuleTypes === null ) {
 609                         $this->loadPluralFiles();
 610                 }
 611                 if ( !isset( $this->pluralRuleTypes[$code] ) ) {
 612                         return null;
 613                 } else {
 614                         return $this->pluralRuleTypes[$code];
 615                 }
 616         }
 617
 618         /**
 619          * Load the plural XML files.
 620          */
 621         protected function loadPluralFiles() {
 622                 global $IP;
 623                 $cldrPlural = "$IP/languages/data/plurals.xml";
 624                 $mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
 625                 // Load CLDR plural rules
 626                 $this->loadPluralFile( $cldrPlural );
 627                 if ( file_exists( $mwPlural ) ) {
 628                         // Override or extend
 629                         $this->loadPluralFile( $mwPlural );
 630                 }
 631         }
 632
 633         /**
 634          * Load a plural XML file with the given filename, compile the relevant
 635          * rules, and save the compiled rules in a process-local cache.
 636          */
 637         protected function loadPluralFile( $fileName ) {
 638                 $doc = new DOMDocument;
 639                 $doc->load( $fileName );
 640                 $rulesets = $doc->getElementsByTagName( "pluralRules" );
 641                 foreach ( $rulesets as $ruleset ) {
 642                         $codes = $ruleset->getAttribute( 'locales' );
 643                         $rules = array();
 644                         $ruleTypes = array();
 645                         $ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
 646                         foreach ( $ruleElements as $elt ) {
 647                                 $ruleType = $elt->getAttribute( 'count' );
 648                                 if ( $ruleType === 'other' ) {
 649                                         // Don't record "other" rules, which have an empty condition
 650                                         continue;
 651                                 }
 652                                 $rules[] = $elt->nodeValue;
 653                                 $ruleTypes[] = $ruleType;
 654                         }
 655                         foreach ( explode( ' ', $codes ) as $code ) {
 656                                 $this->pluralRules[$code] = $rules;
 657                                 $this->pluralRuleTypes[$code] = $ruleTypes;
 658                         }
 659                 }
 660         }
 661
 662         /**
 663          * Read the data from the source files for a given language, and register
 664          * the relevant dependencies in the $deps array. If the localisation
 665          * exists, the data array is returned, otherwise false is returned.
 666          */
 667         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 668                 global $IP;
 669                 wfProfileIn( __METHOD__ );
 670
 671                 $fileName = Language::getMessagesFileName( $code );
 672                 if ( !file_exists( $fileName ) ) {
 673                         wfProfileOut( __METHOD__ );
 674
 675                         return false;
 676                 }
 677
 678                 $deps[] = new FileDependency( $fileName );
 679                 $data = $this->readPHPFile( $fileName, 'core' );
 680
 681                 # Load CLDR plural rules for JavaScript
 682                 $data['pluralRules'] = $this->getPluralRules( $code );
 683                 # And for PHP
 684                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 685                 # Load plural rule types
 686                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 687
 688                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 689                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 690
 691                 wfProfileOut( __METHOD__ );
 692
 693                 return $data;
 694         }
 695
 696         /**
 697          * Merge two localisation values, a primary and a fallback, overwriting the
 698          * primary value in place.
 699          * @param $key
 700          * @param $value
 701          * @param $fallbackValue
 702          */
 703         protected function mergeItem( $key, &$value, $fallbackValue ) {
 704                 if ( !is_null( $value ) ) {
 705                         if ( !is_null( $fallbackValue ) ) {
 706                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 707                                         $value = $value + $fallbackValue;
 708                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 709                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 710                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 711                                         $value = array_merge_recursive( $value, $fallbackValue );
 712                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 713                                         if ( !empty( $value['inherit'] ) ) {
 714                                                 $value = array_merge( $fallbackValue, $value );
 715                                         }
 716
 717                                         if ( isset( $value['inherit'] ) ) {
 718                                                 unset( $value['inherit'] );
 719                                         }
 720                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 721                                         $this->mergeMagicWords( $value, $fallbackValue );
 722                                 }
 723                         }
 724                 } else {
 725                         $value = $fallbackValue;
 726                 }
 727         }
 728
 729         /**
 730          * @param $value
 731          * @param $fallbackValue
 732          */
 733         protected function mergeMagicWords( &$value, $fallbackValue ) {
 734                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 735                         if ( !isset( $value[$magicName] ) ) {
 736                                 $value[$magicName] = $fallbackInfo;
 737                         } else {
 738                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 739                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 740                                 $synonyms = array_values( array_unique( array_merge(
 741                                         $newSynonyms, $oldSynonyms ) ) );
 742                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 743                         }
 744                 }
 745         }
 746
 747         /**
 748          * Given an array mapping language code to localisation value, such as is
 749          * found in extension *.i18n.php files, iterate through a fallback sequence
 750          * to merge the given data with an existing primary value.
 751          *
 752          * Returns true if any data from the extension array was used, false
 753          * otherwise.
 754          * @param $codeSequence
 755          * @param $key
 756          * @param $value
 757          * @param $fallbackValue
 758          * @return bool
 759          */
 760         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 761                 $used = false;
 762                 foreach ( $codeSequence as $code ) {
 763                         if ( isset( $fallbackValue[$code] ) ) {
 764                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 765                                 $used = true;
 766                         }
 767                 }
 768
 769                 return $used;
 770         }
 771
 772         /**
 773          * Load localisation data for a given language for both core and extensions
 774          * and save it to the persistent cache store and the process cache
 775          * @param $code
 776          * @throws MWException
 777          */
 778         public function recache( $code ) {
 779                 global $wgExtensionMessagesFiles, $wgMessagesDirs;
 780                 wfProfileIn( __METHOD__ );
 781
 782                 if ( !$code ) {
 783                         wfProfileOut( __METHOD__ );
 784                         throw new MWException( "Invalid language code requested" );
 785                 }
 786                 $this->recachedLangs[$code] = true;
 787
 788                 # Initial values
 789                 $initialData = array_combine(
 790                         self::$allKeys,
 791                         array_fill( 0, count( self::$allKeys ), null ) );
 792                 $coreData = $initialData;
 793                 $deps = array();
 794
 795                 # Load the primary localisation from the source file
 796                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 797                 if ( $data === false ) {
 798                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 799                         $coreData['fallback'] = 'en';
 800                 } else {
 801                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 802
 803                         # Merge primary localisation
 804                         foreach ( $data as $key => $value ) {
 805                                 $this->mergeItem( $key, $coreData[$key], $value );
 806                         }
 807                 }
 808
 809                 # Fill in the fallback if it's not there already
 810                 if ( is_null( $coreData['fallback'] ) ) {
 811                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 812                 }
 813                 if ( $coreData['fallback'] === false ) {
 814                         $coreData['fallbackSequence'] = array();
 815                 } else {
 816                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 817                         $len = count( $coreData['fallbackSequence'] );
 818
 819                         # Ensure that the sequence ends at en
 820                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 821                                 $coreData['fallbackSequence'][] = 'en';
 822                         }
 823
 824                         # Load the fallback localisation item by item and merge it
 825                         foreach ( $coreData['fallbackSequence'] as $fbCode ) {
 826                                 # Load the secondary localisation from the source file to
 827                                 # avoid infinite cycles on cyclic fallbacks
 828                                 $fbData = $this->readSourceFilesAndRegisterDeps( $fbCode, $deps );
 829                                 if ( $fbData === false ) {
 830                                         continue;
 831                                 }
 832
 833                                 foreach ( self::$allKeys as $key ) {
 834                                         if ( !isset( $fbData[$key] ) ) {
 835                                                 continue;
 836                                         }
 837
 838                                         if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 839                                                 $this->mergeItem( $key, $coreData[$key], $fbData[$key] );
 840                                         }
 841                                 }
 842                         }
 843                 }
 844
 845                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 846
 847                 # Load the extension localisations
 848                 # This is done after the core because we know the fallback sequence now.
 849                 # But it has a higher precedence for merging so that we can support things
 850                 # like site-specific message overrides.
 851                 wfProfileIn( __METHOD__ . '-extensions' );
 852                 $allData = $initialData;
 853                 foreach ( $wgMessagesDirs as $dirs ) {
 854                         foreach ( (array)$dirs as $dir ) {
 855                                 foreach ( $codeSequence as $csCode ) {
 856                                         $fileName = "$dir/$csCode.json";
 857                                         $data = $this->readJSONFile( $fileName );
 858
 859                                         foreach ( $data as $key => $item ) {
 860                                                 $this->mergeItem( $key, $allData[$key], $item );
 861                                         }
 862
 863                                         $deps[] = new FileDependency( $fileName );
 864                                 }
 865                         }
 866                 }
 867
 868                 foreach ( $wgExtensionMessagesFiles as $extension => $fileName ) {
 869                         $data = $this->readPHPFile( $fileName, 'extension' );
 870                         $used = false;
 871
 872                         foreach ( $data as $key => $item ) {
 873                                 if ( $key === 'messages' && isset( $wgMessagesDirs[$extension] ) ) {
 874                                         # For backwards compatibility, ignore messages from extensions in
 875                                         # $wgExtensionMessagesFiles that are also present in $wgMessagesDirs.
 876                                         # This allows extensions to use both and be backwards compatible.
 877                                         # Variables other than $messages still need to be supported though.
 878                                         continue;
 879                                 }
 880                                 if ( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 881                                         $used = true;
 882                                 }
 883                         }
 884
 885                         if ( $used ) {
 886                                 $deps[] = new FileDependency( $fileName );
 887                         }
 888                 }
 889
 890                 # Merge core data into extension data
 891                 foreach ( $coreData as $key => $item ) {
 892                         $this->mergeItem( $key, $allData[$key], $item );
 893                 }
 894                 wfProfileOut( __METHOD__ . '-extensions' );
 895
 896                 # Add cache dependencies for any referenced globals
 897                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 898                 $deps['wgMessagesDirs'] = new GlobalDependency( 'wgMessagesDirs' );
 899                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 900
 901                 # Add dependencies to the cache entry
 902                 $allData['deps'] = $deps;
 903
 904                 # Replace spaces with underscores in namespace names
 905                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 906
 907                 # And do the same for special page aliases. $page is an array.
 908                 foreach ( $allData['specialPageAliases'] as &$page ) {
 909                         $page = str_replace( ' ', '_', $page );
 910                 }
 911                 # Decouple the reference to prevent accidental damage
 912                 unset( $page );
 913
 914                 # If there were no plural rules, return an empty array
 915                 if ( $allData['pluralRules'] === null ) {
 916                         $allData['pluralRules'] = array();
 917                 }
 918                 if ( $allData['compiledPluralRules'] === null ) {
 919                         $allData['compiledPluralRules'] = array();
 920                 }
 921                 # If there were no plural rule types, return an empty array
 922                 if ( $allData['pluralRuleTypes'] === null ) {
 923                         $allData['pluralRuleTypes'] = array();
 924                 }
 925
 926                 # Set the list keys
 927                 $allData['list'] = array();
 928                 foreach ( self::$splitKeys as $key ) {
 929                         $allData['list'][$key] = array_keys( $allData[$key] );
 930                 }
 931                 # Run hooks
 932                 $purgeBlobs = true;
 933                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData, &$purgeBlobs ) );
 934
 935                 if ( is_null( $allData['namespaceNames'] ) ) {
 936                         wfProfileOut( __METHOD__ );
 937                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
 938                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 939                 }
 940
 941                 # Set the preload key
 942                 $allData['preload'] = $this->buildPreload( $allData );
 943
 944                 # Save to the process cache and register the items loaded
 945                 $this->data[$code] = $allData;
 946                 foreach ( $allData as $key => $item ) {
 947                         $this->loadedItems[$code][$key] = true;
 948                 }
 949
 950                 # Save to the persistent cache
 951                 wfProfileIn( __METHOD__ . '-write' );
 952                 $this->store->startWrite( $code );
 953                 foreach ( $allData as $key => $value ) {
 954                         if ( in_array( $key, self::$splitKeys ) ) {
 955                                 foreach ( $value as $subkey => $subvalue ) {
 956                                         $this->store->set( "$key:$subkey", $subvalue );
 957                                 }
 958                         } else {
 959                                 $this->store->set( $key, $value );
 960                         }
 961                 }
 962                 $this->store->finishWrite();
 963                 wfProfileOut( __METHOD__ . '-write' );
 964
 965                 # Clear out the MessageBlobStore
 966                 # HACK: If using a null (i.e. disabled) storage backend, we
 967                 # can't write to the MessageBlobStore either
 968                 if ( $purgeBlobs && !$this->store instanceof LCStoreNull ) {
 969                         MessageBlobStore::clear();
 970                 }
 971
 972                 wfProfileOut( __METHOD__ );
 973         }
 974
 975         /**
 976          * Build the preload item from the given pre-cache data.
 977          *
 978          * The preload item will be loaded automatically, improving performance
 979          * for the commonly-requested items it contains.
 980          * @param $data
 981          * @return array
 982          */
 983         protected function buildPreload( $data ) {
 984                 $preload = array( 'messages' => array() );
 985                 foreach ( self::$preloadedKeys as $key ) {
 986                         $preload[$key] = $data[$key];
 987                 }
 988
 989                 foreach ( $data['preloadedMessages'] as $subkey ) {
 990                         if ( isset( $data['messages'][$subkey] ) ) {
 991                                 $subitem = $data['messages'][$subkey];
 992                         } else {
 993                                 $subitem = null;
 994                         }
 995                         $preload['messages'][$subkey] = $subitem;
 996                 }
 997
 998                 return $preload;
 999         }
1000
1001         /**
1002          * Unload the data for a given language from the object cache.
1003          * Reduces memory usage.
1004          * @param $code
1005          */
1006         public function unload( $code ) {
1007                 unset( $this->data[$code] );
1008                 unset( $this->loadedItems[$code] );
1009                 unset( $this->loadedSubitems[$code] );
1010                 unset( $this->initialisedLangs[$code] );
1011                 unset( $this->shallowFallbacks[$code] );
1012
1013                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
1014                         if ( $fbCode === $code ) {
1015                                 $this->unload( $shallowCode );
1016                         }
1017                 }
1018         }
1019
1020         /**
1021          * Unload all data
1022          */
1023         public function unloadAll() {
1024                 foreach ( $this->initialisedLangs as $lang => $unused ) {
1025                         $this->unload( $lang );
1026                 }
1027         }
1028
1029         /**
1030          * Disable the storage backend
1031          */
1032         public function disableBackend() {
1033                 $this->store = new LCStoreNull;
1034                 $this->manualRecache = false;
1035         }
1036 }
1037
1038 /**
1039  * Interface for the persistence layer of LocalisationCache.
1040  *
1041  * The persistence layer is two-level hierarchical cache. The first level
1042  * is the language, the second level is the item or subitem.
1043  *
1044  * Since the data for a whole language is rebuilt in one operation, it needs
1045  * to have a fast and atomic method for deleting or replacing all of the
1046  * current data for a given language. The interface reflects this bulk update
1047  * operation. Callers writing to the cache must first call startWrite(), then
1048  * will call set() a couple of thousand times, then will call finishWrite()
1049  * to commit the operation. When finishWrite() is called, the cache is
1050  * expected to delete all data previously stored for that language.
1051  *
1052  * The values stored are PHP variables suitable for serialize(). Implementations
1053  * of LCStore are responsible for serializing and unserializing.
1054  */
1055 interface LCStore {
1056         /**
1057          * Get a value.
1058          * @param string $code Language code
1059          * @param string $key Cache key
1060          */
1061         function get( $code, $key );
1062
1063         /**
1064          * Start a write transaction.
1065          * @param string $code Language code
1066          */
1067         function startWrite( $code );
1068
1069         /**
1070          * Finish a write transaction.
1071          */
1072         function finishWrite();
1073
1074         /**
1075          * Set a key to a given value. startWrite() must be called before this
1076          * is called, and finishWrite() must be called afterwards.
1077          * @param string $key
1078          * @param mixed $value
1079          */
1080         function set( $key, $value );
1081 }
1082
1083 /**
1084  * LCStore implementation which uses PHP accelerator to store data.
1085  * This will work if one of XCache, WinCache or APC cacher is configured.
1086  * (See ObjectCache.php)
1087  */
1088 class LCStoreAccel implements LCStore {
1089         private $currentLang;
1090         private $keys;
1091
1092         public function __construct() {
1093                 $this->cache = wfGetCache( CACHE_ACCEL );
1094         }
1095
1096         public function get( $code, $key ) {
1097                 $k = wfMemcKey( 'l10n', $code, 'k', $key );
1098                 $r = $this->cache->get( $k );
1099
1100                 return $r === false ? null : $r;
1101         }
1102
1103         public function startWrite( $code ) {
1104                 $k = wfMemcKey( 'l10n', $code, 'l' );
1105                 $keys = $this->cache->get( $k );
1106                 if ( $keys ) {
1107                         foreach ( $keys as $k ) {
1108                                 $this->cache->delete( $k );
1109                         }
1110                 }
1111                 $this->currentLang = $code;
1112                 $this->keys = array();
1113         }
1114
1115         public function finishWrite() {
1116                 if ( $this->currentLang ) {
1117                         $k = wfMemcKey( 'l10n', $this->currentLang, 'l' );
1118                         $this->cache->set( $k, array_keys( $this->keys ) );
1119                 }
1120                 $this->currentLang = null;
1121                 $this->keys = array();
1122         }
1123
1124         public function set( $key, $value ) {
1125                 if ( $this->currentLang ) {
1126                         $k = wfMemcKey( 'l10n', $this->currentLang, 'k', $key );
1127                         $this->keys[$k] = true;
1128                         $this->cache->set( $k, $value );
1129                 }
1130         }
1131 }
1132
1133 /**
1134  * LCStore implementation which uses the standard DB functions to store data.
1135  * This will work on any MediaWiki installation.
1136  */
1137 class LCStoreDB implements LCStore {
1138         private $currentLang;
1139         private $writesDone = false;
1140
1141         /**
1142          * @var DatabaseBase
1143          */
1144         private $dbw;
1145         private $batch;
1146         private $readOnly = false;
1147
1148         public function get( $code, $key ) {
1149                 if ( $this->writesDone ) {
1150                         $db = wfGetDB( DB_MASTER );
1151                 } else {
1152                         $db = wfGetDB( DB_SLAVE );
1153                 }
1154                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1155                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1156                 if ( $row ) {
1157                         return unserialize( $row->lc_value );
1158                 } else {
1159                         return null;
1160                 }
1161         }
1162
1163         public function startWrite( $code ) {
1164                 if ( $this->readOnly ) {
1165                         return;
1166                 }
1167
1168                 if ( !$code ) {
1169                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1170                 }
1171
1172                 $this->dbw = wfGetDB( DB_MASTER );
1173                 try {
1174                         $this->dbw->begin( __METHOD__ );
1175                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
1176                 } catch ( DBQueryError $e ) {
1177                         if ( $this->dbw->wasReadOnlyError() ) {
1178                                 $this->readOnly = true;
1179                                 $this->dbw->rollback( __METHOD__ );
1180
1181                                 return;
1182                         } else {
1183                                 throw $e;
1184                         }
1185                 }
1186
1187                 $this->currentLang = $code;
1188                 $this->batch = array();
1189         }
1190
1191         public function finishWrite() {
1192                 if ( $this->readOnly ) {
1193                         return;
1194                 }
1195
1196                 if ( $this->batch ) {
1197                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1198                 }
1199
1200                 $this->dbw->commit( __METHOD__ );
1201                 $this->currentLang = null;
1202                 $this->dbw = null;
1203                 $this->batch = array();
1204                 $this->writesDone = true;
1205         }
1206
1207         public function set( $key, $value ) {
1208                 if ( $this->readOnly ) {
1209                         return;
1210                 }
1211
1212                 if ( is_null( $this->currentLang ) ) {
1213                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1214                 }
1215
1216                 $this->batch[] = array(
1217                         'lc_lang' => $this->currentLang,
1218                         'lc_key' => $key,
1219                         'lc_value' => serialize( $value ) );
1220
1221                 if ( count( $this->batch ) >= 100 ) {
1222                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1223                         $this->batch = array();
1224                 }
1225         }
1226 }
1227
1228 /**
1229  * LCStore implementation which stores data as a collection of CDB files in the
1230  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1231  * will throw an exception.
1232  *
1233  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1234  * the directory is on a local filesystem and there is ample kernel cache
1235  * space. The performance advantage is greater when the DBA extension is
1236  * available than it is with the PHP port.
1237  *
1238  * See Cdb.php and http://cr.yp.to/cdb.html
1239  */
1240 class LCStoreCDB implements LCStore {
1241         /** @var CdbReader[] */
1242         private $readers;
1243
1244         /** @var CdbWriter */
1245         private $writer;
1246
1247         /** @var string Current language code */
1248         private $currentLang;
1249
1250         /** @var bool|string Cache directory. False if not set */
1251         private $directory;
1252
1253         function __construct( $conf = array() ) {
1254                 global $wgCacheDirectory;
1255
1256                 if ( isset( $conf['directory'] ) ) {
1257                         $this->directory = $conf['directory'];
1258                 } else {
1259                         $this->directory = $wgCacheDirectory;
1260                 }
1261         }
1262
1263         public function get( $code, $key ) {
1264                 if ( !isset( $this->readers[$code] ) ) {
1265                         $fileName = $this->getFileName( $code );
1266
1267                         $this->readers[$code] = false;
1268                         if ( file_exists( $fileName ) ) {
1269                                 try {
1270                                         $this->readers[$code] = CdbReader::open( $fileName );
1271                                 } catch ( CdbException $e ) {
1272                                         wfDebug( __METHOD__ . ": unable to open cdb file for reading" );
1273                                 }
1274                         }
1275                 }
1276
1277                 if ( !$this->readers[$code] ) {
1278                         return null;
1279                 } else {
1280                         $value = false;
1281                         try {
1282                                 $value = $this->readers[$code]->get( $key );
1283                         } catch ( CdbException $e ) {
1284                                 wfDebug( __METHOD__ . ": CdbException caught, error message was "
1285                                         . $e->getMessage() );
1286                         }
1287                         if ( $value === false ) {
1288                                 return null;
1289                         }
1290
1291                         return unserialize( $value );
1292                 }
1293         }
1294
1295         public function startWrite( $code ) {
1296                 if ( !file_exists( $this->directory ) ) {
1297                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1298                                 throw new MWException( "Unable to create the localisation store " .
1299                                         "directory \"{$this->directory}\"" );
1300                         }
1301                 }
1302
1303                 // Close reader to stop permission errors on write
1304                 if ( !empty( $this->readers[$code] ) ) {
1305                         $this->readers[$code]->close();
1306                 }
1307
1308                 try {
1309                         $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1310                 } catch ( CdbException $e ) {
1311                         throw new MWException( $e->getMessage() );
1312                 }
1313                 $this->currentLang = $code;
1314         }
1315
1316         public function finishWrite() {
1317                 // Close the writer
1318                 try {
1319                         $this->writer->close();
1320                 } catch ( CdbException $e ) {
1321                         throw new MWException( $e->getMessage() );
1322                 }
1323                 $this->writer = null;
1324                 unset( $this->readers[$this->currentLang] );
1325                 $this->currentLang = null;
1326         }
1327
1328         public function set( $key, $value ) {
1329                 if ( is_null( $this->writer ) ) {
1330                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1331                 }
1332                 try {
1333                         $this->writer->set( $key, serialize( $value ) );
1334                 } catch ( CdbException $e ) {
1335                         throw new MWException( $e->getMessage() );
1336                 }
1337         }
1338
1339         protected function getFileName( $code ) {
1340                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1341                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1342                 }
1343
1344                 return "{$this->directory}/l10n_cache-$code.cdb";
1345         }
1346 }
1347
1348 /**
1349  * Null store backend, used to avoid DB errors during install
1350  */
1351 class LCStoreNull implements LCStore {
1352         public function get( $code, $key ) {
1353                 return null;
1354         }
1355
1356         public function startWrite( $code ) {
1357         }
1358
1359         public function finishWrite() {
1360         }
1361
1362         public function set( $key, $value ) {
1363         }
1364 }
1365
1366 /**
1367  * A localisation cache optimised for loading large amounts of data for many
1368  * languages. Used by rebuildLocalisationCache.php.
1369  */
1370 class LocalisationCacheBulkLoad extends LocalisationCache {
1371         /**
1372          * A cache of the contents of data files.
1373          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1374          */
1375         private $fileCache = array();
1376
1377         /**
1378          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1379          * to keep the most recently used language codes at the end of the array, and
1380          * the language codes that are ready to be deleted at the beginning.
1381          */
1382         private $mruLangs = array();
1383
1384         /**
1385          * Maximum number of languages that may be loaded into $this->data
1386          */
1387         private $maxLoadedLangs = 10;
1388
1389         /**
1390          * @param $fileName
1391          * @param $fileType
1392          * @return array|mixed
1393          */
1394         protected function readPHPFile( $fileName, $fileType ) {
1395                 $serialize = $fileType === 'core';
1396                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1397                         $data = parent::readPHPFile( $fileName, $fileType );
1398
1399                         if ( $serialize ) {
1400                                 $encData = serialize( $data );
1401                         } else {
1402                                 $encData = $data;
1403                         }
1404
1405                         $this->fileCache[$fileName][$fileType] = $encData;
1406
1407                         return $data;
1408                 } elseif ( $serialize ) {
1409                         return unserialize( $this->fileCache[$fileName][$fileType] );
1410                 } else {
1411                         return $this->fileCache[$fileName][$fileType];
1412                 }
1413         }
1414
1415         /**
1416          * @param $code
1417          * @param $key
1418          * @return mixed
1419          */
1420         public function getItem( $code, $key ) {
1421                 unset( $this->mruLangs[$code] );
1422                 $this->mruLangs[$code] = true;
1423
1424                 return parent::getItem( $code, $key );
1425         }
1426
1427         /**
1428          * @param $code
1429          * @param $key
1430          * @param $subkey
1431          * @return
1432          */
1433         public function getSubitem( $code, $key, $subkey ) {
1434                 unset( $this->mruLangs[$code] );
1435                 $this->mruLangs[$code] = true;
1436
1437                 return parent::getSubitem( $code, $key, $subkey );
1438         }
1439
1440         /**
1441          * @param $code
1442          */
1443         public function recache( $code ) {
1444                 parent::recache( $code );
1445                 unset( $this->mruLangs[$code] );
1446                 $this->mruLangs[$code] = true;
1447                 $this->trimCache();
1448         }
1449
1450         /**
1451          * @param $code
1452          */
1453         public function unload( $code ) {
1454                 unset( $this->mruLangs[$code] );
1455                 parent::unload( $code );
1456         }
1457
1458         /**
1459          * Unload cached languages until there are less than $this->maxLoadedLangs
1460          */
1461         protected function trimCache() {
1462                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1463                         reset( $this->mruLangs );
1464                         $code = key( $this->mruLangs );
1465                         wfDebug( __METHOD__ . ": unloading $code\n" );
1466                         $this->unload( $code );
1467                 }
1468         }
1469 }