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
 563                 // The JSON format only supports messages, none of the other variables, so wrap the data
 564                 return array( 'messages' => $data );
 565         }
 566
 567         /**
 568          * Get the compiled plural rules for a given language from the XML files.
 569          * @since 1.20
 570          */
 571         public function getCompiledPluralRules( $code ) {
 572                 $rules = $this->getPluralRules( $code );
 573                 if ( $rules === null ) {
 574                         return null;
 575                 }
 576                 try {
 577                         $compiledRules = CLDRPluralRuleEvaluator::compile( $rules );
 578                 } catch ( CLDRPluralRuleError $e ) {
 579                         wfDebugLog( 'l10n', $e->getMessage() );
 580
 581                         return array();
 582                 }
 583
 584                 return $compiledRules;
 585         }
 586
 587         /**
 588          * Get the plural rules for a given language from the XML files.
 589          * Cached.
 590          * @since 1.20
 591          */
 592         public function getPluralRules( $code ) {
 593                 if ( $this->pluralRules === null ) {
 594                         $this->loadPluralFiles();
 595                 }
 596                 if ( !isset( $this->pluralRules[$code] ) ) {
 597                         return null;
 598                 } else {
 599                         return $this->pluralRules[$code];
 600                 }
 601         }
 602
 603         /**
 604          * Get the plural rule types for a given language from the XML files.
 605          * Cached.
 606          * @since 1.22
 607          */
 608         public function getPluralRuleTypes( $code ) {
 609                 if ( $this->pluralRuleTypes === null ) {
 610                         $this->loadPluralFiles();
 611                 }
 612                 if ( !isset( $this->pluralRuleTypes[$code] ) ) {
 613                         return null;
 614                 } else {
 615                         return $this->pluralRuleTypes[$code];
 616                 }
 617         }
 618
 619         /**
 620          * Load the plural XML files.
 621          */
 622         protected function loadPluralFiles() {
 623                 global $IP;
 624                 $cldrPlural = "$IP/languages/data/plurals.xml";
 625                 $mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
 626                 // Load CLDR plural rules
 627                 $this->loadPluralFile( $cldrPlural );
 628                 if ( file_exists( $mwPlural ) ) {
 629                         // Override or extend
 630                         $this->loadPluralFile( $mwPlural );
 631                 }
 632         }
 633
 634         /**
 635          * Load a plural XML file with the given filename, compile the relevant
 636          * rules, and save the compiled rules in a process-local cache.
 637          */
 638         protected function loadPluralFile( $fileName ) {
 639                 $doc = new DOMDocument;
 640                 $doc->load( $fileName );
 641                 $rulesets = $doc->getElementsByTagName( "pluralRules" );
 642                 foreach ( $rulesets as $ruleset ) {
 643                         $codes = $ruleset->getAttribute( 'locales' );
 644                         $rules = array();
 645                         $ruleTypes = array();
 646                         $ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
 647                         foreach ( $ruleElements as $elt ) {
 648                                 $ruleType = $elt->getAttribute( 'count' );
 649                                 if ( $ruleType === 'other' ) {
 650                                         // Don't record "other" rules, which have an empty condition
 651                                         continue;
 652                                 }
 653                                 $rules[] = $elt->nodeValue;
 654                                 $ruleTypes[] = $ruleType;
 655                         }
 656                         foreach ( explode( ' ', $codes ) as $code ) {
 657                                 $this->pluralRules[$code] = $rules;
 658                                 $this->pluralRuleTypes[$code] = $ruleTypes;
 659                         }
 660                 }
 661         }
 662
 663         /**
 664          * Read the data from the source files for a given language, and register
 665          * the relevant dependencies in the $deps array. If the localisation
 666          * exists, the data array is returned, otherwise false is returned.
 667          */
 668         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 669                 global $IP;
 670                 wfProfileIn( __METHOD__ );
 671
 672                 $fileName = Language::getMessagesFileName( $code );
 673                 if ( !file_exists( $fileName ) ) {
 674                         wfProfileOut( __METHOD__ );
 675
 676                         return false;
 677                 }
 678
 679                 $deps[] = new FileDependency( $fileName );
 680                 $data = $this->readPHPFile( $fileName, 'core' );
 681
 682                 # Load CLDR plural rules for JavaScript
 683                 $data['pluralRules'] = $this->getPluralRules( $code );
 684                 # And for PHP
 685                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 686                 # Load plural rule types
 687                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 688
 689                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 690                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 691
 692                 wfProfileOut( __METHOD__ );
 693
 694                 return $data;
 695         }
 696
 697         /**
 698          * Merge two localisation values, a primary and a fallback, overwriting the
 699          * primary value in place.
 700          * @param $key
 701          * @param $value
 702          * @param $fallbackValue
 703          */
 704         protected function mergeItem( $key, &$value, $fallbackValue ) {
 705                 if ( !is_null( $value ) ) {
 706                         if ( !is_null( $fallbackValue ) ) {
 707                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 708                                         $value = $value + $fallbackValue;
 709                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 710                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 711                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 712                                         $value = array_merge_recursive( $value, $fallbackValue );
 713                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 714                                         if ( !empty( $value['inherit'] ) ) {
 715                                                 $value = array_merge( $fallbackValue, $value );
 716                                         }
 717
 718                                         if ( isset( $value['inherit'] ) ) {
 719                                                 unset( $value['inherit'] );
 720                                         }
 721                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 722                                         $this->mergeMagicWords( $value, $fallbackValue );
 723                                 }
 724                         }
 725                 } else {
 726                         $value = $fallbackValue;
 727                 }
 728         }
 729
 730         /**
 731          * @param $value
 732          * @param $fallbackValue
 733          */
 734         protected function mergeMagicWords( &$value, $fallbackValue ) {
 735                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 736                         if ( !isset( $value[$magicName] ) ) {
 737                                 $value[$magicName] = $fallbackInfo;
 738                         } else {
 739                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 740                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 741                                 $synonyms = array_values( array_unique( array_merge(
 742                                         $newSynonyms, $oldSynonyms ) ) );
 743                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 744                         }
 745                 }
 746         }
 747
 748         /**
 749          * Given an array mapping language code to localisation value, such as is
 750          * found in extension *.i18n.php files, iterate through a fallback sequence
 751          * to merge the given data with an existing primary value.
 752          *
 753          * Returns true if any data from the extension array was used, false
 754          * otherwise.
 755          * @param $codeSequence
 756          * @param $key
 757          * @param $value
 758          * @param $fallbackValue
 759          * @return bool
 760          */
 761         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 762                 $used = false;
 763                 foreach ( $codeSequence as $code ) {
 764                         if ( isset( $fallbackValue[$code] ) ) {
 765                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 766                                 $used = true;
 767                         }
 768                 }
 769
 770                 return $used;
 771         }
 772
 773         /**
 774          * Load localisation data for a given language for both core and extensions
 775          * and save it to the persistent cache store and the process cache
 776          * @param $code
 777          * @throws MWException
 778          */
 779         public function recache( $code ) {
 780                 global $wgExtensionMessagesFiles, $wgMessagesDirs;
 781                 wfProfileIn( __METHOD__ );
 782
 783                 if ( !$code ) {
 784                         wfProfileOut( __METHOD__ );
 785                         throw new MWException( "Invalid language code requested" );
 786                 }
 787                 $this->recachedLangs[$code] = true;
 788
 789                 # Initial values
 790                 $initialData = array_combine(
 791                         self::$allKeys,
 792                         array_fill( 0, count( self::$allKeys ), null ) );
 793                 $coreData = $initialData;
 794                 $deps = array();
 795
 796                 # Load the primary localisation from the source file
 797                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 798                 if ( $data === false ) {
 799                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 800                         $coreData['fallback'] = 'en';
 801                 } else {
 802                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 803
 804                         # Merge primary localisation
 805                         foreach ( $data as $key => $value ) {
 806                                 $this->mergeItem( $key, $coreData[$key], $value );
 807                         }
 808                 }
 809
 810                 # Fill in the fallback if it's not there already
 811                 if ( is_null( $coreData['fallback'] ) ) {
 812                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 813                 }
 814                 if ( $coreData['fallback'] === false ) {
 815                         $coreData['fallbackSequence'] = array();
 816                 } else {
 817                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 818                         $len = count( $coreData['fallbackSequence'] );
 819
 820                         # Ensure that the sequence ends at en
 821                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 822                                 $coreData['fallbackSequence'][] = 'en';
 823                         }
 824
 825                         # Load the fallback localisation item by item and merge it
 826                         foreach ( $coreData['fallbackSequence'] as $fbCode ) {
 827                                 # Load the secondary localisation from the source file to
 828                                 # avoid infinite cycles on cyclic fallbacks
 829                                 $fbData = $this->readSourceFilesAndRegisterDeps( $fbCode, $deps );
 830                                 if ( $fbData === false ) {
 831                                         continue;
 832                                 }
 833
 834                                 foreach ( self::$allKeys as $key ) {
 835                                         if ( !isset( $fbData[$key] ) ) {
 836                                                 continue;
 837                                         }
 838
 839                                         if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 840                                                 $this->mergeItem( $key, $coreData[$key], $fbData[$key] );
 841                                         }
 842                                 }
 843                         }
 844                 }
 845
 846                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 847
 848                 # Load the extension localisations
 849                 # This is done after the core because we know the fallback sequence now.
 850                 # But it has a higher precedence for merging so that we can support things
 851                 # like site-specific message overrides.
 852                 wfProfileIn( __METHOD__ . '-extensions' );
 853                 $allData = $initialData;
 854                 foreach ( $wgMessagesDirs as $dirs ) {
 855                         foreach ( (array)$dirs as $dir ) {
 856                                 foreach ( $codeSequence as $csCode ) {
 857                                         $fileName = "$dir/$csCode.json";
 858                                         $data = $this->readJSONFile( $fileName );
 859
 860                                         foreach ( $data as $key => $item ) {
 861                                                 $this->mergeItem( $key, $allData[$key], $item );
 862                                         }
 863
 864                                         $deps[] = new FileDependency( $fileName );
 865                                 }
 866                         }
 867                 }
 868
 869                 foreach ( $wgExtensionMessagesFiles as $extension => $fileName ) {
 870                         $data = $this->readPHPFile( $fileName, 'extension' );
 871                         $used = false;
 872
 873                         foreach ( $data as $key => $item ) {
 874                                 if ( $key === 'messages' && isset( $wgMessagesDirs[$extension] ) ) {
 875                                         # For backwards compatibility, ignore messages from extensions in
 876                                         # $wgExtensionMessagesFiles that are also present in $wgMessagesDirs.
 877                                         # This allows extensions to use both and be backwards compatible.
 878                                         # Variables other than $messages still need to be supported though.
 879                                         continue;
 880                                 }
 881                                 if ( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 882                                         $used = true;
 883                                 }
 884                         }
 885
 886                         if ( $used ) {
 887                                 $deps[] = new FileDependency( $fileName );
 888                         }
 889                 }
 890
 891                 # Merge core data into extension data
 892                 foreach ( $coreData as $key => $item ) {
 893                         $this->mergeItem( $key, $allData[$key], $item );
 894                 }
 895                 wfProfileOut( __METHOD__ . '-extensions' );
 896
 897                 # Add cache dependencies for any referenced globals
 898                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 899                 $deps['wgMessagesDirs'] = new GlobalDependency( 'wgMessagesDirs' );
 900                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 901
 902                 # Add dependencies to the cache entry
 903                 $allData['deps'] = $deps;
 904
 905                 # Replace spaces with underscores in namespace names
 906                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 907
 908                 # And do the same for special page aliases. $page is an array.
 909                 foreach ( $allData['specialPageAliases'] as &$page ) {
 910                         $page = str_replace( ' ', '_', $page );
 911                 }
 912                 # Decouple the reference to prevent accidental damage
 913                 unset( $page );
 914
 915                 # If there were no plural rules, return an empty array
 916                 if ( $allData['pluralRules'] === null ) {
 917                         $allData['pluralRules'] = array();
 918                 }
 919                 if ( $allData['compiledPluralRules'] === null ) {
 920                         $allData['compiledPluralRules'] = array();
 921                 }
 922                 # If there were no plural rule types, return an empty array
 923                 if ( $allData['pluralRuleTypes'] === null ) {
 924                         $allData['pluralRuleTypes'] = array();
 925                 }
 926
 927                 # Set the list keys
 928                 $allData['list'] = array();
 929                 foreach ( self::$splitKeys as $key ) {
 930                         $allData['list'][$key] = array_keys( $allData[$key] );
 931                 }
 932                 # Run hooks
 933                 $purgeBlobs = true;
 934                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData, &$purgeBlobs ) );
 935
 936                 if ( is_null( $allData['namespaceNames'] ) ) {
 937                         wfProfileOut( __METHOD__ );
 938                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
 939                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 940                 }
 941
 942                 # Set the preload key
 943                 $allData['preload'] = $this->buildPreload( $allData );
 944
 945                 # Save to the process cache and register the items loaded
 946                 $this->data[$code] = $allData;
 947                 foreach ( $allData as $key => $item ) {
 948                         $this->loadedItems[$code][$key] = true;
 949                 }
 950
 951                 # Save to the persistent cache
 952                 wfProfileIn( __METHOD__ . '-write' );
 953                 $this->store->startWrite( $code );
 954                 foreach ( $allData as $key => $value ) {
 955                         if ( in_array( $key, self::$splitKeys ) ) {
 956                                 foreach ( $value as $subkey => $subvalue ) {
 957                                         $this->store->set( "$key:$subkey", $subvalue );
 958                                 }
 959                         } else {
 960                                 $this->store->set( $key, $value );
 961                         }
 962                 }
 963                 $this->store->finishWrite();
 964                 wfProfileOut( __METHOD__ . '-write' );
 965
 966                 # Clear out the MessageBlobStore
 967                 # HACK: If using a null (i.e. disabled) storage backend, we
 968                 # can't write to the MessageBlobStore either
 969                 if ( $purgeBlobs && !$this->store instanceof LCStoreNull ) {
 970                         MessageBlobStore::clear();
 971                 }
 972
 973                 wfProfileOut( __METHOD__ );
 974         }
 975
 976         /**
 977          * Build the preload item from the given pre-cache data.
 978          *
 979          * The preload item will be loaded automatically, improving performance
 980          * for the commonly-requested items it contains.
 981          * @param $data
 982          * @return array
 983          */
 984         protected function buildPreload( $data ) {
 985                 $preload = array( 'messages' => array() );
 986                 foreach ( self::$preloadedKeys as $key ) {
 987                         $preload[$key] = $data[$key];
 988                 }
 989
 990                 foreach ( $data['preloadedMessages'] as $subkey ) {
 991                         if ( isset( $data['messages'][$subkey] ) ) {
 992                                 $subitem = $data['messages'][$subkey];
 993                         } else {
 994                                 $subitem = null;
 995                         }
 996                         $preload['messages'][$subkey] = $subitem;
 997                 }
 998
 999                 return $preload;
1000         }
1001
1002         /**
1003          * Unload the data for a given language from the object cache.
1004          * Reduces memory usage.
1005          * @param $code
1006          */
1007         public function unload( $code ) {
1008                 unset( $this->data[$code] );
1009                 unset( $this->loadedItems[$code] );
1010                 unset( $this->loadedSubitems[$code] );
1011                 unset( $this->initialisedLangs[$code] );
1012                 unset( $this->shallowFallbacks[$code] );
1013
1014                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
1015                         if ( $fbCode === $code ) {
1016                                 $this->unload( $shallowCode );
1017                         }
1018                 }
1019         }
1020
1021         /**
1022          * Unload all data
1023          */
1024         public function unloadAll() {
1025                 foreach ( $this->initialisedLangs as $lang => $unused ) {
1026                         $this->unload( $lang );
1027                 }
1028         }
1029
1030         /**
1031          * Disable the storage backend
1032          */
1033         public function disableBackend() {
1034                 $this->store = new LCStoreNull;
1035                 $this->manualRecache = false;
1036         }
1037 }
1038
1039 /**
1040  * Interface for the persistence layer of LocalisationCache.
1041  *
1042  * The persistence layer is two-level hierarchical cache. The first level
1043  * is the language, the second level is the item or subitem.
1044  *
1045  * Since the data for a whole language is rebuilt in one operation, it needs
1046  * to have a fast and atomic method for deleting or replacing all of the
1047  * current data for a given language. The interface reflects this bulk update
1048  * operation. Callers writing to the cache must first call startWrite(), then
1049  * will call set() a couple of thousand times, then will call finishWrite()
1050  * to commit the operation. When finishWrite() is called, the cache is
1051  * expected to delete all data previously stored for that language.
1052  *
1053  * The values stored are PHP variables suitable for serialize(). Implementations
1054  * of LCStore are responsible for serializing and unserializing.
1055  */
1056 interface LCStore {
1057         /**
1058          * Get a value.
1059          * @param string $code Language code
1060          * @param string $key Cache key
1061          */
1062         function get( $code, $key );
1063
1064         /**
1065          * Start a write transaction.
1066          * @param string $code Language code
1067          */
1068         function startWrite( $code );
1069
1070         /**
1071          * Finish a write transaction.
1072          */
1073         function finishWrite();
1074
1075         /**
1076          * Set a key to a given value. startWrite() must be called before this
1077          * is called, and finishWrite() must be called afterwards.
1078          * @param string $key
1079          * @param mixed $value
1080          */
1081         function set( $key, $value );
1082 }
1083
1084 /**
1085  * LCStore implementation which uses PHP accelerator to store data.
1086  * This will work if one of XCache, WinCache or APC cacher is configured.
1087  * (See ObjectCache.php)
1088  */
1089 class LCStoreAccel implements LCStore {
1090         private $currentLang;
1091         private $keys;
1092
1093         public function __construct() {
1094                 $this->cache = wfGetCache( CACHE_ACCEL );
1095         }
1096
1097         public function get( $code, $key ) {
1098                 $k = wfMemcKey( 'l10n', $code, 'k', $key );
1099                 $r = $this->cache->get( $k );
1100
1101                 return $r === false ? null : $r;
1102         }
1103
1104         public function startWrite( $code ) {
1105                 $k = wfMemcKey( 'l10n', $code, 'l' );
1106                 $keys = $this->cache->get( $k );
1107                 if ( $keys ) {
1108                         foreach ( $keys as $k ) {
1109                                 $this->cache->delete( $k );
1110                         }
1111                 }
1112                 $this->currentLang = $code;
1113                 $this->keys = array();
1114         }
1115
1116         public function finishWrite() {
1117                 if ( $this->currentLang ) {
1118                         $k = wfMemcKey( 'l10n', $this->currentLang, 'l' );
1119                         $this->cache->set( $k, array_keys( $this->keys ) );
1120                 }
1121                 $this->currentLang = null;
1122                 $this->keys = array();
1123         }
1124
1125         public function set( $key, $value ) {
1126                 if ( $this->currentLang ) {
1127                         $k = wfMemcKey( 'l10n', $this->currentLang, 'k', $key );
1128                         $this->keys[$k] = true;
1129                         $this->cache->set( $k, $value );
1130                 }
1131         }
1132 }
1133
1134 /**
1135  * LCStore implementation which uses the standard DB functions to store data.
1136  * This will work on any MediaWiki installation.
1137  */
1138 class LCStoreDB implements LCStore {
1139         private $currentLang;
1140         private $writesDone = false;
1141
1142         /**
1143          * @var DatabaseBase
1144          */
1145         private $dbw;
1146         private $batch;
1147         private $readOnly = false;
1148
1149         public function get( $code, $key ) {
1150                 if ( $this->writesDone ) {
1151                         $db = wfGetDB( DB_MASTER );
1152                 } else {
1153                         $db = wfGetDB( DB_SLAVE );
1154                 }
1155                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1156                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1157                 if ( $row ) {
1158                         return unserialize( $row->lc_value );
1159                 } else {
1160                         return null;
1161                 }
1162         }
1163
1164         public function startWrite( $code ) {
1165                 if ( $this->readOnly ) {
1166                         return;
1167                 }
1168
1169                 if ( !$code ) {
1170                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1171                 }
1172
1173                 $this->dbw = wfGetDB( DB_MASTER );
1174                 try {
1175                         $this->dbw->begin( __METHOD__ );
1176                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
1177                 } catch ( DBQueryError $e ) {
1178                         if ( $this->dbw->wasReadOnlyError() ) {
1179                                 $this->readOnly = true;
1180                                 $this->dbw->rollback( __METHOD__ );
1181
1182                                 return;
1183                         } else {
1184                                 throw $e;
1185                         }
1186                 }
1187
1188                 $this->currentLang = $code;
1189                 $this->batch = array();
1190         }
1191
1192         public function finishWrite() {
1193                 if ( $this->readOnly ) {
1194                         return;
1195                 }
1196
1197                 if ( $this->batch ) {
1198                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1199                 }
1200
1201                 $this->dbw->commit( __METHOD__ );
1202                 $this->currentLang = null;
1203                 $this->dbw = null;
1204                 $this->batch = array();
1205                 $this->writesDone = true;
1206         }
1207
1208         public function set( $key, $value ) {
1209                 if ( $this->readOnly ) {
1210                         return;
1211                 }
1212
1213                 if ( is_null( $this->currentLang ) ) {
1214                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1215                 }
1216
1217                 $this->batch[] = array(
1218                         'lc_lang' => $this->currentLang,
1219                         'lc_key' => $key,
1220                         'lc_value' => serialize( $value ) );
1221
1222                 if ( count( $this->batch ) >= 100 ) {
1223                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1224                         $this->batch = array();
1225                 }
1226         }
1227 }
1228
1229 /**
1230  * LCStore implementation which stores data as a collection of CDB files in the
1231  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1232  * will throw an exception.
1233  *
1234  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1235  * the directory is on a local filesystem and there is ample kernel cache
1236  * space. The performance advantage is greater when the DBA extension is
1237  * available than it is with the PHP port.
1238  *
1239  * See Cdb.php and http://cr.yp.to/cdb.html
1240  */
1241 class LCStoreCDB implements LCStore {
1242         /** @var CdbReader[] */
1243         private $readers;
1244
1245         /** @var CdbWriter */
1246         private $writer;
1247
1248         /** @var string Current language code */
1249         private $currentLang;
1250
1251         /** @var bool|string Cache directory. False if not set */
1252         private $directory;
1253
1254         function __construct( $conf = array() ) {
1255                 global $wgCacheDirectory;
1256
1257                 if ( isset( $conf['directory'] ) ) {
1258                         $this->directory = $conf['directory'];
1259                 } else {
1260                         $this->directory = $wgCacheDirectory;
1261                 }
1262         }
1263
1264         public function get( $code, $key ) {
1265                 if ( !isset( $this->readers[$code] ) ) {
1266                         $fileName = $this->getFileName( $code );
1267
1268                         $this->readers[$code] = false;
1269                         if ( file_exists( $fileName ) ) {
1270                                 try {
1271                                         $this->readers[$code] = CdbReader::open( $fileName );
1272                                 } catch ( CdbException $e ) {
1273                                         wfDebug( __METHOD__ . ": unable to open cdb file for reading" );
1274                                 }
1275                         }
1276                 }
1277
1278                 if ( !$this->readers[$code] ) {
1279                         return null;
1280                 } else {
1281                         $value = false;
1282                         try {
1283                                 $value = $this->readers[$code]->get( $key );
1284                         } catch ( CdbException $e ) {
1285                                 wfDebug( __METHOD__ . ": CdbException caught, error message was "
1286                                         . $e->getMessage() );
1287                         }
1288                         if ( $value === false ) {
1289                                 return null;
1290                         }
1291
1292                         return unserialize( $value );
1293                 }
1294         }
1295
1296         public function startWrite( $code ) {
1297                 if ( !file_exists( $this->directory ) ) {
1298                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1299                                 throw new MWException( "Unable to create the localisation store " .
1300                                         "directory \"{$this->directory}\"" );
1301                         }
1302                 }
1303
1304                 // Close reader to stop permission errors on write
1305                 if ( !empty( $this->readers[$code] ) ) {
1306                         $this->readers[$code]->close();
1307                 }
1308
1309                 try {
1310                         $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1311                 } catch ( CdbException $e ) {
1312                         throw new MWException( $e->getMessage() );
1313                 }
1314                 $this->currentLang = $code;
1315         }
1316
1317         public function finishWrite() {
1318                 // Close the writer
1319                 try {
1320                         $this->writer->close();
1321                 } catch ( CdbException $e ) {
1322                         throw new MWException( $e->getMessage() );
1323                 }
1324                 $this->writer = null;
1325                 unset( $this->readers[$this->currentLang] );
1326                 $this->currentLang = null;
1327         }
1328
1329         public function set( $key, $value ) {
1330                 if ( is_null( $this->writer ) ) {
1331                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1332                 }
1333                 try {
1334                         $this->writer->set( $key, serialize( $value ) );
1335                 } catch ( CdbException $e ) {
1336                         throw new MWException( $e->getMessage() );
1337                 }
1338         }
1339
1340         protected function getFileName( $code ) {
1341                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1342                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1343                 }
1344
1345                 return "{$this->directory}/l10n_cache-$code.cdb";
1346         }
1347 }
1348
1349 /**
1350  * Null store backend, used to avoid DB errors during install
1351  */
1352 class LCStoreNull implements LCStore {
1353         public function get( $code, $key ) {
1354                 return null;
1355         }
1356
1357         public function startWrite( $code ) {
1358         }
1359
1360         public function finishWrite() {
1361         }
1362
1363         public function set( $key, $value ) {
1364         }
1365 }
1366
1367 /**
1368  * A localisation cache optimised for loading large amounts of data for many
1369  * languages. Used by rebuildLocalisationCache.php.
1370  */
1371 class LocalisationCacheBulkLoad extends LocalisationCache {
1372         /**
1373          * A cache of the contents of data files.
1374          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1375          */
1376         private $fileCache = array();
1377
1378         /**
1379          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1380          * to keep the most recently used language codes at the end of the array, and
1381          * the language codes that are ready to be deleted at the beginning.
1382          */
1383         private $mruLangs = array();
1384
1385         /**
1386          * Maximum number of languages that may be loaded into $this->data
1387          */
1388         private $maxLoadedLangs = 10;
1389
1390         /**
1391          * @param $fileName
1392          * @param $fileType
1393          * @return array|mixed
1394          */
1395         protected function readPHPFile( $fileName, $fileType ) {
1396                 $serialize = $fileType === 'core';
1397                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1398                         $data = parent::readPHPFile( $fileName, $fileType );
1399
1400                         if ( $serialize ) {
1401                                 $encData = serialize( $data );
1402                         } else {
1403                                 $encData = $data;
1404                         }
1405
1406                         $this->fileCache[$fileName][$fileType] = $encData;
1407
1408                         return $data;
1409                 } elseif ( $serialize ) {
1410                         return unserialize( $this->fileCache[$fileName][$fileType] );
1411                 } else {
1412                         return $this->fileCache[$fileName][$fileType];
1413                 }
1414         }
1415
1416         /**
1417          * @param $code
1418          * @param $key
1419          * @return mixed
1420          */
1421         public function getItem( $code, $key ) {
1422                 unset( $this->mruLangs[$code] );
1423                 $this->mruLangs[$code] = true;
1424
1425                 return parent::getItem( $code, $key );
1426         }
1427
1428         /**
1429          * @param $code
1430          * @param $key
1431          * @param $subkey
1432          * @return
1433          */
1434         public function getSubitem( $code, $key, $subkey ) {
1435                 unset( $this->mruLangs[$code] );
1436                 $this->mruLangs[$code] = true;
1437
1438                 return parent::getSubitem( $code, $key, $subkey );
1439         }
1440
1441         /**
1442          * @param $code
1443          */
1444         public function recache( $code ) {
1445                 parent::recache( $code );
1446                 unset( $this->mruLangs[$code] );
1447                 $this->mruLangs[$code] = true;
1448                 $this->trimCache();
1449         }
1450
1451         /**
1452          * @param $code
1453          */
1454         public function unload( $code ) {
1455                 unset( $this->mruLangs[$code] );
1456                 parent::unload( $code );
1457         }
1458
1459         /**
1460          * Unload cached languages until there are less than $this->maxLoadedLangs
1461          */
1462         protected function trimCache() {
1463                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1464                         reset( $this->mruLangs );
1465                         $code = key( $this->mruLangs );
1466                         wfDebug( __METHOD__ . ": unloading $code\n" );
1467                         $this->unload( $code );
1468                 }
1469         }
1470 }