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 use Cdb\Exception as CdbException;
  24 use Cdb\Reader as CdbReader;
  25 use Cdb\Writer as CdbWriter;
  26
  27 /**
  28  * Class for caching the contents of localisation files, Messages*.php
  29  * and *.i18n.php.
  30  *
  31  * An instance of this class is available using Language::getLocalisationCache().
  32  *
  33  * The values retrieved from here are merged, containing items from extension
  34  * files, core messages files and the language fallback sequence (e.g. zh-cn ->
  35  * zh-hans -> en ). Some common errors are corrected, for example namespace
  36  * names with spaces instead of underscores, but heavyweight processing, such
  37  * as grammatical transformation, is done by the caller.
  38  */
  39 class LocalisationCache {
  40         const VERSION = 3;
  41
  42         /** Configuration associative array */
  43         private $conf;
  44
  45         /**
  46          * True if recaching should only be done on an explicit call to recache().
  47          * Setting this reduces the overhead of cache freshness checking, which
  48          * requires doing a stat() for every extension i18n file.
  49          */
  50         private $manualRecache = false;
  51
  52         /**
  53          * True to treat all files as expired until they are regenerated by this object.
  54          */
  55         private $forceRecache = false;
  56
  57         /**
  58          * The cache data. 3-d array, where the first key is the language code,
  59          * the second key is the item key e.g. 'messages', and the third key is
  60          * an item specific subkey index. Some items are not arrays and so for those
  61          * items, there are no subkeys.
  62          */
  63         protected $data = array();
  64
  65         /**
  66          * The persistent store object. An instance of LCStore.
  67          *
  68          * @var LCStore
  69          */
  70         private $store;
  71
  72         /**
  73          * A 2-d associative array, code/key, where presence indicates that the item
  74          * is loaded. Value arbitrary.
  75          *
  76          * For split items, if set, this indicates that all of the subitems have been
  77          * loaded.
  78          */
  79         private $loadedItems = array();
  80
  81         /**
  82          * A 3-d associative array, code/key/subkey, where presence indicates that
  83          * the subitem is loaded. Only used for the split items, i.e. messages.
  84          */
  85         private $loadedSubitems = array();
  86
  87         /**
  88          * An array where presence of a key indicates that that language has been
  89          * initialised. Initialisation includes checking for cache expiry and doing
  90          * any necessary updates.
  91          */
  92         private $initialisedLangs = array();
  93
  94         /**
  95          * An array mapping non-existent pseudo-languages to fallback languages. This
  96          * is filled by initShallowFallback() when data is requested from a language
  97          * that lacks a Messages*.php file.
  98          */
  99         private $shallowFallbacks = array();
 100
 101         /**
 102          * An array where the keys are codes that have been recached by this instance.
 103          */
 104         private $recachedLangs = array();
 105
 106         /**
 107          * All item keys
 108          */
 109         static public $allKeys = array(
 110                 'fallback', 'namespaceNames', 'bookstoreList',
 111                 'magicWords', 'messages', 'rtl', 'capitalizeAllNouns', 'digitTransformTable',
 112                 'separatorTransformTable', 'fallback8bitEncoding', 'linkPrefixExtension',
 113                 'linkTrail', 'linkPrefixCharset', 'namespaceAliases',
 114                 'dateFormats', 'datePreferences', 'datePreferenceMigrationMap',
 115                 'defaultDateFormat', 'extraUserToggles', 'specialPageAliases',
 116                 'imageFiles', 'preloadedMessages', 'namespaceGenderAliases',
 117                 'digitGroupingPattern', 'pluralRules', 'pluralRuleTypes', 'compiledPluralRules',
 118         );
 119
 120         /**
 121          * Keys for items which consist of associative arrays, which may be merged
 122          * by a fallback sequence.
 123          */
 124         static public $mergeableMapKeys = array( 'messages', 'namespaceNames',
 125                 'dateFormats', 'imageFiles', 'preloadedMessages'
 126         );
 127
 128         /**
 129          * Keys for items which are a numbered array.
 130          */
 131         static public $mergeableListKeys = array( 'extraUserToggles' );
 132
 133         /**
 134          * Keys for items which contain an array of arrays of equivalent aliases
 135          * for each subitem. The aliases may be merged by a fallback sequence.
 136          */
 137         static public $mergeableAliasListKeys = array( 'specialPageAliases' );
 138
 139         /**
 140          * Keys for items which contain an associative array, and may be merged if
 141          * the primary value contains the special array key "inherit". That array
 142          * key is removed after the first merge.
 143          */
 144         static public $optionalMergeKeys = array( 'bookstoreList' );
 145
 146         /**
 147          * Keys for items that are formatted like $magicWords
 148          */
 149         static public $magicWordKeys = array( 'magicWords' );
 150
 151         /**
 152          * Keys for items where the subitems are stored in the backend separately.
 153          */
 154         static public $splitKeys = array( 'messages' );
 155
 156         /**
 157          * Keys which are loaded automatically by initLanguage()
 158          */
 159         static public $preloadedKeys = array( 'dateFormats', 'namespaceNames' );
 160
 161         /**
 162          * Associative array of cached plural rules. The key is the language code,
 163          * the value is an array of plural rules for that language.
 164          */
 165         private $pluralRules = null;
 166
 167         /**
 168          * Associative array of cached plural rule types. The key is the language
 169          * code, the value is an array of plural rule types for that language. For
 170          * example, $pluralRuleTypes['ar'] = ['zero', 'one', 'two', 'few', 'many'].
 171          * The index for each rule type matches the index for the rule in
 172          * $pluralRules, thus allowing correlation between the two. The reason we
 173          * don't just use the type names as the keys in $pluralRules is because
 174          * Language::convertPlural applies the rules based on numeric order (or
 175          * explicit numeric parameter), not based on the name of the rule type. For
 176          * example, {{plural:count|wordform1|wordform2|wordform3}}, rather than
 177          * {{plural:count|one=wordform1|two=wordform2|many=wordform3}}.
 178          */
 179         private $pluralRuleTypes = null;
 180
 181         private $mergeableKeys = null;
 182
 183         /**
 184          * Constructor.
 185          * For constructor parameters, see the documentation in DefaultSettings.php
 186          * for $wgLocalisationCacheConf.
 187          *
 188          * @param array $conf
 189          * @throws MWException
 190          */
 191         function __construct( $conf ) {
 192                 global $wgCacheDirectory;
 193
 194                 $this->conf = $conf;
 195                 $storeConf = array();
 196                 if ( !empty( $conf['storeClass'] ) ) {
 197                         $storeClass = $conf['storeClass'];
 198                 } else {
 199                         switch ( $conf['store'] ) {
 200                                 case 'files':
 201                                 case 'file':
 202                                         $storeClass = 'LCStoreCDB';
 203                                         break;
 204                                 case 'db':
 205                                         $storeClass = 'LCStoreDB';
 206                                         break;
 207                                 case 'detect':
 208                                         $storeClass = $wgCacheDirectory ? 'LCStoreCDB' : 'LCStoreDB';
 209                                         break;
 210                                 default:
 211                                         throw new MWException(
 212                                                 'Please set $wgLocalisationCacheConf[\'store\'] to something sensible.' );
 213                         }
 214                 }
 215
 216                 wfDebugLog( 'caches', get_class( $this ) . ": using store $storeClass" );
 217                 if ( !empty( $conf['storeDirectory'] ) ) {
 218                         $storeConf['directory'] = $conf['storeDirectory'];
 219                 }
 220
 221                 $this->store = new $storeClass( $storeConf );
 222                 foreach ( array( 'manualRecache', 'forceRecache' ) as $var ) {
 223                         if ( isset( $conf[$var] ) ) {
 224                                 $this->$var = $conf[$var];
 225                         }
 226                 }
 227         }
 228
 229         /**
 230          * Returns true if the given key is mergeable, that is, if it is an associative
 231          * array which can be merged through a fallback sequence.
 232          * @param string $key
 233          * @return bool
 234          */
 235         public function isMergeableKey( $key ) {
 236                 if ( $this->mergeableKeys === null ) {
 237                         $this->mergeableKeys = array_flip( array_merge(
 238                                 self::$mergeableMapKeys,
 239                                 self::$mergeableListKeys,
 240                                 self::$mergeableAliasListKeys,
 241                                 self::$optionalMergeKeys,
 242                                 self::$magicWordKeys
 243                         ) );
 244                 }
 245
 246                 return isset( $this->mergeableKeys[$key] );
 247         }
 248
 249         /**
 250          * Get a cache item.
 251          *
 252          * Warning: this may be slow for split items (messages), since it will
 253          * need to fetch all of the subitems from the cache individually.
 254          * @param string $code
 255          * @param string $key
 256          * @return mixed
 257          */
 258         public function getItem( $code, $key ) {
 259                 if ( !isset( $this->loadedItems[$code][$key] ) ) {
 260                         wfProfileIn( __METHOD__ . '-load' );
 261                         $this->loadItem( $code, $key );
 262                         wfProfileOut( __METHOD__ . '-load' );
 263                 }
 264
 265                 if ( $key === 'fallback' && isset( $this->shallowFallbacks[$code] ) ) {
 266                         return $this->shallowFallbacks[$code];
 267                 }
 268
 269                 return $this->data[$code][$key];
 270         }
 271
 272         /**
 273          * Get a subitem, for instance a single message for a given language.
 274          * @param string $code
 275          * @param string $key
 276          * @param string $subkey
 277          * @return mixed|null
 278          */
 279         public function getSubitem( $code, $key, $subkey ) {
 280                 if ( !isset( $this->loadedSubitems[$code][$key][$subkey] ) &&
 281                         !isset( $this->loadedItems[$code][$key] )
 282                 ) {
 283                         wfProfileIn( __METHOD__ . '-load' );
 284                         $this->loadSubitem( $code, $key, $subkey );
 285                         wfProfileOut( __METHOD__ . '-load' );
 286                 }
 287
 288                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 289                         return $this->data[$code][$key][$subkey];
 290                 } else {
 291                         return null;
 292                 }
 293         }
 294
 295         /**
 296          * Get the list of subitem keys for a given item.
 297          *
 298          * This is faster than array_keys($lc->getItem(...)) for the items listed in
 299          * self::$splitKeys.
 300          *
 301          * Will return null if the item is not found, or false if the item is not an
 302          * array.
 303          * @param string $code
 304          * @param string $key
 305          * @return bool|null|string
 306          */
 307         public function getSubitemList( $code, $key ) {
 308                 if ( in_array( $key, self::$splitKeys ) ) {
 309                         return $this->getSubitem( $code, 'list', $key );
 310                 } else {
 311                         $item = $this->getItem( $code, $key );
 312                         if ( is_array( $item ) ) {
 313                                 return array_keys( $item );
 314                         } else {
 315                                 return false;
 316                         }
 317                 }
 318         }
 319
 320         /**
 321          * Load an item into the cache.
 322          * @param string $code
 323          * @param string $key
 324          */
 325         protected function loadItem( $code, $key ) {
 326                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 327                         $this->initLanguage( $code );
 328                 }
 329
 330                 // Check to see if initLanguage() loaded it for us
 331                 if ( isset( $this->loadedItems[$code][$key] ) ) {
 332                         return;
 333                 }
 334
 335                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 336                         $this->loadItem( $this->shallowFallbacks[$code], $key );
 337
 338                         return;
 339                 }
 340
 341                 if ( in_array( $key, self::$splitKeys ) ) {
 342                         $subkeyList = $this->getSubitem( $code, 'list', $key );
 343                         foreach ( $subkeyList as $subkey ) {
 344                                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 345                                         continue;
 346                                 }
 347                                 $this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
 348                         }
 349                 } else {
 350                         $this->data[$code][$key] = $this->store->get( $code, $key );
 351                 }
 352
 353                 $this->loadedItems[$code][$key] = true;
 354         }
 355
 356         /**
 357          * Load a subitem into the cache
 358          * @param string $code
 359          * @param string $key
 360          * @param string $subkey
 361          */
 362         protected function loadSubitem( $code, $key, $subkey ) {
 363                 if ( !in_array( $key, self::$splitKeys ) ) {
 364                         $this->loadItem( $code, $key );
 365
 366                         return;
 367                 }
 368
 369                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 370                         $this->initLanguage( $code );
 371                 }
 372
 373                 // Check to see if initLanguage() loaded it for us
 374                 if ( isset( $this->loadedItems[$code][$key] ) ||
 375                         isset( $this->loadedSubitems[$code][$key][$subkey] )
 376                 ) {
 377                         return;
 378                 }
 379
 380                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 381                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 382
 383                         return;
 384                 }
 385
 386                 $value = $this->store->get( $code, "$key:$subkey" );
 387                 $this->data[$code][$key][$subkey] = $value;
 388                 $this->loadedSubitems[$code][$key][$subkey] = true;
 389         }
 390
 391         /**
 392          * Returns true if the cache identified by $code is missing or expired.
 393          *
 394          * @param string $code
 395          *
 396          * @return bool
 397          */
 398         public function isExpired( $code ) {
 399                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 400                         wfDebug( __METHOD__ . "($code): forced reload\n" );
 401
 402                         return true;
 403                 }
 404
 405                 $deps = $this->store->get( $code, 'deps' );
 406                 $keys = $this->store->get( $code, 'list' );
 407                 $preload = $this->store->get( $code, 'preload' );
 408                 // Different keys may expire separately for some stores
 409                 if ( $deps === null || $keys === null || $preload === null ) {
 410                         wfDebug( __METHOD__ . "($code): cache missing, need to make one\n" );
 411
 412                         return true;
 413                 }
 414
 415                 foreach ( $deps as $dep ) {
 416                         // Because we're unserializing stuff from cache, we
 417                         // could receive objects of classes that don't exist
 418                         // anymore (e.g. uninstalled extensions)
 419                         // When this happens, always expire the cache
 420                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 421                                 wfDebug( __METHOD__ . "($code): cache for $code expired due to " .
 422                                         get_class( $dep ) . "\n" );
 423
 424                                 return true;
 425                         }
 426                 }
 427
 428                 return false;
 429         }
 430
 431         /**
 432          * Initialise a language in this object. Rebuild the cache if necessary.
 433          * @param string $code
 434          * @throws MWException
 435          */
 436         protected function initLanguage( $code ) {
 437                 if ( isset( $this->initialisedLangs[$code] ) ) {
 438                         return;
 439                 }
 440
 441                 $this->initialisedLangs[$code] = true;
 442
 443                 # If the code is of the wrong form for a Messages*.php file, do a shallow fallback
 444                 if ( !Language::isValidBuiltInCode( $code ) ) {
 445                         $this->initShallowFallback( $code, 'en' );
 446
 447                         return;
 448                 }
 449
 450                 # Recache the data if necessary
 451                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 452                         if ( Language::isSupportedLanguage( $code ) ) {
 453                                 $this->recache( $code );
 454                         } elseif ( $code === 'en' ) {
 455                                 throw new MWException( 'MessagesEn.php is missing.' );
 456                         } else {
 457                                 $this->initShallowFallback( $code, 'en' );
 458                         }
 459
 460                         return;
 461                 }
 462
 463                 # Preload some stuff
 464                 $preload = $this->getItem( $code, 'preload' );
 465                 if ( $preload === null ) {
 466                         if ( $this->manualRecache ) {
 467                                 // No Messages*.php file. Do shallow fallback to en.
 468                                 if ( $code === 'en' ) {
 469                                         throw new MWException( 'No localisation cache found for English. ' .
 470                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 471                                 }
 472                                 $this->initShallowFallback( $code, 'en' );
 473
 474                                 return;
 475                         } else {
 476                                 throw new MWException( 'Invalid or missing localisation cache.' );
 477                         }
 478                 }
 479                 $this->data[$code] = $preload;
 480                 foreach ( $preload as $key => $item ) {
 481                         if ( in_array( $key, self::$splitKeys ) ) {
 482                                 foreach ( $item as $subkey => $subitem ) {
 483                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 484                                 }
 485                         } else {
 486                                 $this->loadedItems[$code][$key] = true;
 487                         }
 488                 }
 489         }
 490
 491         /**
 492          * Create a fallback from one language to another, without creating a
 493          * complete persistent cache.
 494          * @param string $primaryCode
 495          * @param string $fallbackCode
 496          */
 497         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 498                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 499                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 500                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 501                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 502         }
 503
 504         /**
 505          * Read a PHP file containing localisation data.
 506          * @param string $_fileName
 507          * @param string $_fileType
 508          * @throws MWException
 509          * @return array
 510          */
 511         protected function readPHPFile( $_fileName, $_fileType ) {
 512                 wfProfileIn( __METHOD__ );
 513                 // Disable APC caching
 514                 wfSuppressWarnings();
 515                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 516                 wfRestoreWarnings();
 517
 518                 include $_fileName;
 519
 520                 wfSuppressWarnings();
 521                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 522                 wfRestoreWarnings();
 523
 524                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 525                         $data = compact( self::$allKeys );
 526                 } elseif ( $_fileType == 'aliases' ) {
 527                         $data = compact( 'aliases' );
 528                 } else {
 529                         wfProfileOut( __METHOD__ );
 530                         throw new MWException( __METHOD__ . ": Invalid file type: $_fileType" );
 531                 }
 532                 wfProfileOut( __METHOD__ );
 533
 534                 return $data;
 535         }
 536
 537         /**
 538          * Read a JSON file containing localisation messages.
 539          * @param string $fileName Name of file to read
 540          * @throws MWException If there is a syntax error in the JSON file
 541          * @return array Array with a 'messages' key, or empty array if the file doesn't exist
 542          */
 543         public function readJSONFile( $fileName ) {
 544                 wfProfileIn( __METHOD__ );
 545
 546                 if ( !is_readable( $fileName ) ) {
 547                         wfProfileOut( __METHOD__ );
 548
 549                         return array();
 550                 }
 551
 552                 $json = file_get_contents( $fileName );
 553                 if ( $json === false ) {
 554                         wfProfileOut( __METHOD__ );
 555
 556                         return array();
 557                 }
 558
 559                 $data = FormatJson::decode( $json, true );
 560                 if ( $data === null ) {
 561                         wfProfileOut( __METHOD__ );
 562
 563                         throw new MWException( __METHOD__ . ": Invalid JSON file: $fileName" );
 564                 }
 565
 566                 // Remove keys starting with '@', they're reserved for metadata and non-message data
 567                 foreach ( $data as $key => $unused ) {
 568                         if ( $key === '' || $key[0] === '@' ) {
 569                                 unset( $data[$key] );
 570                         }
 571                 }
 572
 573                 wfProfileOut( __METHOD__ );
 574
 575                 // The JSON format only supports messages, none of the other variables, so wrap the data
 576                 return array( 'messages' => $data );
 577         }
 578
 579         /**
 580          * Get the compiled plural rules for a given language from the XML files.
 581          * @since 1.20
 582          * @param string $code
 583          * @return array|null
 584          */
 585         public function getCompiledPluralRules( $code ) {
 586                 $rules = $this->getPluralRules( $code );
 587                 if ( $rules === null ) {
 588                         return null;
 589                 }
 590                 try {
 591                         $compiledRules = CLDRPluralRuleEvaluator::compile( $rules );
 592                 } catch ( CLDRPluralRuleError $e ) {
 593                         wfDebugLog( 'l10n', $e->getMessage() );
 594
 595                         return array();
 596                 }
 597
 598                 return $compiledRules;
 599         }
 600
 601         /**
 602          * Get the plural rules for a given language from the XML files.
 603          * Cached.
 604          * @since 1.20
 605          * @param string $code
 606          * @return array|null
 607          */
 608         public function getPluralRules( $code ) {
 609                 if ( $this->pluralRules === null ) {
 610                         $this->loadPluralFiles();
 611                 }
 612                 if ( !isset( $this->pluralRules[$code] ) ) {
 613                         return null;
 614                 } else {
 615                         return $this->pluralRules[$code];
 616                 }
 617         }
 618
 619         /**
 620          * Get the plural rule types for a given language from the XML files.
 621          * Cached.
 622          * @since 1.22
 623          * @param string $code
 624          * @return array|null
 625          */
 626         public function getPluralRuleTypes( $code ) {
 627                 if ( $this->pluralRuleTypes === null ) {
 628                         $this->loadPluralFiles();
 629                 }
 630                 if ( !isset( $this->pluralRuleTypes[$code] ) ) {
 631                         return null;
 632                 } else {
 633                         return $this->pluralRuleTypes[$code];
 634                 }
 635         }
 636
 637         /**
 638          * Load the plural XML files.
 639          */
 640         protected function loadPluralFiles() {
 641                 global $IP;
 642                 $cldrPlural = "$IP/languages/data/plurals.xml";
 643                 $mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
 644                 // Load CLDR plural rules
 645                 $this->loadPluralFile( $cldrPlural );
 646                 if ( file_exists( $mwPlural ) ) {
 647                         // Override or extend
 648                         $this->loadPluralFile( $mwPlural );
 649                 }
 650         }
 651
 652         /**
 653          * Load a plural XML file with the given filename, compile the relevant
 654          * rules, and save the compiled rules in a process-local cache.
 655          *
 656          * @param string $fileName
 657          */
 658         protected function loadPluralFile( $fileName ) {
 659                 // Use file_get_contents instead of DOMDocument::load (T58439)
 660                 $xml = file_get_contents( $fileName );
 661                 if ( !$xml ) {
 662                         throw new MWException( "Unable to read plurals file $fileName" );
 663                 }
 664                 $doc = new DOMDocument;
 665                 $doc->loadXML( $xml );
 666                 $rulesets = $doc->getElementsByTagName( "pluralRules" );
 667                 foreach ( $rulesets as $ruleset ) {
 668                         $codes = $ruleset->getAttribute( 'locales' );
 669                         $rules = array();
 670                         $ruleTypes = array();
 671                         $ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
 672                         foreach ( $ruleElements as $elt ) {
 673                                 $ruleType = $elt->getAttribute( 'count' );
 674                                 if ( $ruleType === 'other' ) {
 675                                         // Don't record "other" rules, which have an empty condition
 676                                         continue;
 677                                 }
 678                                 $rules[] = $elt->nodeValue;
 679                                 $ruleTypes[] = $ruleType;
 680                         }
 681                         foreach ( explode( ' ', $codes ) as $code ) {
 682                                 $this->pluralRules[$code] = $rules;
 683                                 $this->pluralRuleTypes[$code] = $ruleTypes;
 684                         }
 685                 }
 686         }
 687
 688         /**
 689          * Read the data from the source files for a given language, and register
 690          * the relevant dependencies in the $deps array. If the localisation
 691          * exists, the data array is returned, otherwise false is returned.
 692          *
 693          * @param string $code
 694          * @param array $deps
 695          * @return array
 696          */
 697         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 698                 global $IP;
 699                 wfProfileIn( __METHOD__ );
 700
 701                 // This reads in the PHP i18n file with non-messages l10n data
 702                 $fileName = Language::getMessagesFileName( $code );
 703                 if ( !file_exists( $fileName ) ) {
 704                         $data = array();
 705                 } else {
 706                         $deps[] = new FileDependency( $fileName );
 707                         $data = $this->readPHPFile( $fileName, 'core' );
 708                 }
 709
 710                 # Load CLDR plural rules for JavaScript
 711                 $data['pluralRules'] = $this->getPluralRules( $code );
 712                 # And for PHP
 713                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 714                 # Load plural rule types
 715                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 716
 717                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 718                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 719
 720                 wfProfileOut( __METHOD__ );
 721
 722                 return $data;
 723         }
 724
 725         /**
 726          * Merge two localisation values, a primary and a fallback, overwriting the
 727          * primary value in place.
 728          * @param string $key
 729          * @param mixed $value
 730          * @param mixed $fallbackValue
 731          */
 732         protected function mergeItem( $key, &$value, $fallbackValue ) {
 733                 if ( !is_null( $value ) ) {
 734                         if ( !is_null( $fallbackValue ) ) {
 735                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 736                                         $value = $value + $fallbackValue;
 737                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 738                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 739                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 740                                         $value = array_merge_recursive( $value, $fallbackValue );
 741                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 742                                         if ( !empty( $value['inherit'] ) ) {
 743                                                 $value = array_merge( $fallbackValue, $value );
 744                                         }
 745
 746                                         if ( isset( $value['inherit'] ) ) {
 747                                                 unset( $value['inherit'] );
 748                                         }
 749                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 750                                         $this->mergeMagicWords( $value, $fallbackValue );
 751                                 }
 752                         }
 753                 } else {
 754                         $value = $fallbackValue;
 755                 }
 756         }
 757
 758         /**
 759          * @param mixed $value
 760          * @param mixed $fallbackValue
 761          */
 762         protected function mergeMagicWords( &$value, $fallbackValue ) {
 763                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 764                         if ( !isset( $value[$magicName] ) ) {
 765                                 $value[$magicName] = $fallbackInfo;
 766                         } else {
 767                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 768                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 769                                 $synonyms = array_values( array_unique( array_merge(
 770                                         $newSynonyms, $oldSynonyms ) ) );
 771                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 772                         }
 773                 }
 774         }
 775
 776         /**
 777          * Given an array mapping language code to localisation value, such as is
 778          * found in extension *.i18n.php files, iterate through a fallback sequence
 779          * to merge the given data with an existing primary value.
 780          *
 781          * Returns true if any data from the extension array was used, false
 782          * otherwise.
 783          * @param array $codeSequence
 784          * @param string $key
 785          * @param mixed $value
 786          * @param mixed $fallbackValue
 787          * @return bool
 788          */
 789         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 790                 $used = false;
 791                 foreach ( $codeSequence as $code ) {
 792                         if ( isset( $fallbackValue[$code] ) ) {
 793                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 794                                 $used = true;
 795                         }
 796                 }
 797
 798                 return $used;
 799         }
 800
 801         /**
 802          * Gets the combined list of messages dirs from
 803          * core and extensions
 804          *
 805          * @since 1.25
 806          * @return array
 807          */
 808         public function getMessagesDirs() {
 809                 global $wgMessagesDirs, $IP;
 810                 return array(
 811                         'core' => "$IP/languages/i18n",
 812                         'api' => "$IP/includes/api/i18n",
 813                         'oojs-ui' => "$IP/resources/lib/oojs-ui/i18n",
 814                 ) + $wgMessagesDirs;
 815         }
 816
 817         /**
 818          * Load localisation data for a given language for both core and extensions
 819          * and save it to the persistent cache store and the process cache
 820          * @param string $code
 821          * @throws MWException
 822          */
 823         public function recache( $code ) {
 824                 global $wgExtensionMessagesFiles;
 825                 wfProfileIn( __METHOD__ );
 826
 827                 if ( !$code ) {
 828                         wfProfileOut( __METHOD__ );
 829                         throw new MWException( "Invalid language code requested" );
 830                 }
 831                 $this->recachedLangs[$code] = true;
 832
 833                 # Initial values
 834                 $initialData = array_combine(
 835                         self::$allKeys,
 836                         array_fill( 0, count( self::$allKeys ), null ) );
 837                 $coreData = $initialData;
 838                 $deps = array();
 839
 840                 # Load the primary localisation from the source file
 841                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 842                 if ( $data === false ) {
 843                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 844                         $coreData['fallback'] = 'en';
 845                 } else {
 846                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 847
 848                         # Merge primary localisation
 849                         foreach ( $data as $key => $value ) {
 850                                 $this->mergeItem( $key, $coreData[$key], $value );
 851                         }
 852                 }
 853
 854                 # Fill in the fallback if it's not there already
 855                 if ( is_null( $coreData['fallback'] ) ) {
 856                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 857                 }
 858                 if ( $coreData['fallback'] === false ) {
 859                         $coreData['fallbackSequence'] = array();
 860                 } else {
 861                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 862                         $len = count( $coreData['fallbackSequence'] );
 863
 864                         # Ensure that the sequence ends at en
 865                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 866                                 $coreData['fallbackSequence'][] = 'en';
 867                         }
 868                 }
 869
 870                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 871                 $messageDirs = $this->getMessagesDirs();
 872
 873                 wfProfileIn( __METHOD__ . '-fallbacks' );
 874
 875                 # Load non-JSON localisation data for extensions
 876                 $extensionData = array_combine(
 877                         $codeSequence,
 878                         array_fill( 0, count( $codeSequence ), $initialData ) );
 879                 foreach ( $wgExtensionMessagesFiles as $extension => $fileName ) {
 880                         if ( isset( $messageDirs[$extension] ) ) {
 881                                 # This extension has JSON message data; skip the PHP shim
 882                                 continue;
 883                         }
 884
 885                         $data = $this->readPHPFile( $fileName, 'extension' );
 886                         $used = false;
 887
 888                         foreach ( $data as $key => $item ) {
 889                                 foreach ( $codeSequence as $csCode ) {
 890                                         if ( isset( $item[$csCode] ) ) {
 891                                                 $this->mergeItem( $key, $extensionData[$csCode][$key], $item[$csCode] );
 892                                                 $used = true;
 893                                         }
 894                                 }
 895                         }
 896
 897                         if ( $used ) {
 898                                 $deps[] = new FileDependency( $fileName );
 899                         }
 900                 }
 901
 902                 # Load the localisation data for each fallback, then merge it into the full array
 903                 $allData = $initialData;
 904                 foreach ( $codeSequence as $csCode ) {
 905                         $csData = $initialData;
 906
 907                         # Load core messages and the extension localisations.
 908                         foreach ( $messageDirs as $dirs ) {
 909                                 foreach ( (array)$dirs as $dir ) {
 910                                         $fileName = "$dir/$csCode.json";
 911                                         $data = $this->readJSONFile( $fileName );
 912
 913                                         foreach ( $data as $key => $item ) {
 914                                                 $this->mergeItem( $key, $csData[$key], $item );
 915                                         }
 916
 917                                         $deps[] = new FileDependency( $fileName );
 918                                 }
 919                         }
 920
 921                         # Merge non-JSON extension data
 922                         if ( isset( $extensionData[$csCode] ) ) {
 923                                 foreach ( $extensionData[$csCode] as $key => $item ) {
 924                                         $this->mergeItem( $key, $csData[$key], $item );
 925                                 }
 926                         }
 927
 928                         if ( $csCode === $code ) {
 929                                 # Merge core data into extension data
 930                                 foreach ( $coreData as $key => $item ) {
 931                                         $this->mergeItem( $key, $csData[$key], $item );
 932                                 }
 933                         } else {
 934                                 # Load the secondary localisation from the source file to
 935                                 # avoid infinite cycles on cyclic fallbacks
 936                                 $fbData = $this->readSourceFilesAndRegisterDeps( $csCode, $deps );
 937                                 if ( $fbData !== false ) {
 938                                         # Only merge the keys that make sense to merge
 939                                         foreach ( self::$allKeys as $key ) {
 940                                                 if ( !isset( $fbData[$key] ) ) {
 941                                                         continue;
 942                                                 }
 943
 944                                                 if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 945                                                         $this->mergeItem( $key, $csData[$key], $fbData[$key] );
 946                                                 }
 947                                         }
 948                                 }
 949                         }
 950
 951                         # Allow extensions an opportunity to adjust the data for this
 952                         # fallback
 953                         Hooks::run( 'LocalisationCacheRecacheFallback', array( $this, $csCode, &$csData ) );
 954
 955                         # Merge the data for this fallback into the final array
 956                         if ( $csCode === $code ) {
 957                                 $allData = $csData;
 958                         } else {
 959                                 foreach ( self::$allKeys as $key ) {
 960                                         if ( !isset( $csData[$key] ) ) {
 961                                                 continue;
 962                                         }
 963
 964                                         if ( is_null( $allData[$key] ) || $this->isMergeableKey( $key ) ) {
 965                                                 $this->mergeItem( $key, $allData[$key], $csData[$key] );
 966                                         }
 967                                 }
 968                         }
 969                 }
 970
 971                 wfProfileOut( __METHOD__ . '-fallbacks' );
 972
 973                 # Add cache dependencies for any referenced globals
 974                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 975                 // $wgMessagesDirs is used in LocalisationCache::getMessagesDirs()
 976                 $deps['wgMessagesDirs'] = new GlobalDependency( 'wgMessagesDirs' );
 977                 $deps['version'] = new ConstantDependency( 'LocalisationCache::VERSION' );
 978
 979                 # Add dependencies to the cache entry
 980                 $allData['deps'] = $deps;
 981
 982                 # Replace spaces with underscores in namespace names
 983                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 984
 985                 # And do the same for special page aliases. $page is an array.
 986                 foreach ( $allData['specialPageAliases'] as &$page ) {
 987                         $page = str_replace( ' ', '_', $page );
 988                 }
 989                 # Decouple the reference to prevent accidental damage
 990                 unset( $page );
 991
 992                 # If there were no plural rules, return an empty array
 993                 if ( $allData['pluralRules'] === null ) {
 994                         $allData['pluralRules'] = array();
 995                 }
 996                 if ( $allData['compiledPluralRules'] === null ) {
 997                         $allData['compiledPluralRules'] = array();
 998                 }
 999                 # If there were no plural rule types, return an empty array
1000                 if ( $allData['pluralRuleTypes'] === null ) {
1001                         $allData['pluralRuleTypes'] = array();
1002                 }
1003
1004                 # Set the list keys
1005                 $allData['list'] = array();
1006                 foreach ( self::$splitKeys as $key ) {
1007                         $allData['list'][$key] = array_keys( $allData[$key] );
1008                 }
1009                 # Run hooks
1010                 $purgeBlobs = true;
1011                 Hooks::run( 'LocalisationCacheRecache', array( $this, $code, &$allData, &$purgeBlobs ) );
1012
1013                 if ( is_null( $allData['namespaceNames'] ) ) {
1014                         wfProfileOut( __METHOD__ );
1015                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
1016                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
1017                 }
1018
1019                 # Set the preload key
1020                 $allData['preload'] = $this->buildPreload( $allData );
1021
1022                 # Save to the process cache and register the items loaded
1023                 $this->data[$code] = $allData;
1024                 foreach ( $allData as $key => $item ) {
1025                         $this->loadedItems[$code][$key] = true;
1026                 }
1027
1028                 # Save to the persistent cache
1029                 wfProfileIn( __METHOD__ . '-write' );
1030                 $this->store->startWrite( $code );
1031                 foreach ( $allData as $key => $value ) {
1032                         if ( in_array( $key, self::$splitKeys ) ) {
1033                                 foreach ( $value as $subkey => $subvalue ) {
1034                                         $this->store->set( "$key:$subkey", $subvalue );
1035                                 }
1036                         } else {
1037                                 $this->store->set( $key, $value );
1038                         }
1039                 }
1040                 $this->store->finishWrite();
1041                 wfProfileOut( __METHOD__ . '-write' );
1042
1043                 # Clear out the MessageBlobStore
1044                 # HACK: If using a null (i.e. disabled) storage backend, we
1045                 # can't write to the MessageBlobStore either
1046                 if ( $purgeBlobs && !$this->store instanceof LCStoreNull ) {
1047                         MessageBlobStore::getInstance()->clear();
1048                 }
1049
1050                 wfProfileOut( __METHOD__ );
1051         }
1052
1053         /**
1054          * Build the preload item from the given pre-cache data.
1055          *
1056          * The preload item will be loaded automatically, improving performance
1057          * for the commonly-requested items it contains.
1058          * @param array $data
1059          * @return array
1060          */
1061         protected function buildPreload( $data ) {
1062                 $preload = array( 'messages' => array() );
1063                 foreach ( self::$preloadedKeys as $key ) {
1064                         $preload[$key] = $data[$key];
1065                 }
1066
1067                 foreach ( $data['preloadedMessages'] as $subkey ) {
1068                         if ( isset( $data['messages'][$subkey] ) ) {
1069                                 $subitem = $data['messages'][$subkey];
1070                         } else {
1071                                 $subitem = null;
1072                         }
1073                         $preload['messages'][$subkey] = $subitem;
1074                 }
1075
1076                 return $preload;
1077         }
1078
1079         /**
1080          * Unload the data for a given language from the object cache.
1081          * Reduces memory usage.
1082          * @param string $code
1083          */
1084         public function unload( $code ) {
1085                 unset( $this->data[$code] );
1086                 unset( $this->loadedItems[$code] );
1087                 unset( $this->loadedSubitems[$code] );
1088                 unset( $this->initialisedLangs[$code] );
1089                 unset( $this->shallowFallbacks[$code] );
1090
1091                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
1092                         if ( $fbCode === $code ) {
1093                                 $this->unload( $shallowCode );
1094                         }
1095                 }
1096         }
1097
1098         /**
1099          * Unload all data
1100          */
1101         public function unloadAll() {
1102                 foreach ( $this->initialisedLangs as $lang => $unused ) {
1103                         $this->unload( $lang );
1104                 }
1105         }
1106
1107         /**
1108          * Disable the storage backend
1109          */
1110         public function disableBackend() {
1111                 $this->store = new LCStoreNull;
1112                 $this->manualRecache = false;
1113         }
1114 }
1115
1116 /**
1117  * Interface for the persistence layer of LocalisationCache.
1118  *
1119  * The persistence layer is two-level hierarchical cache. The first level
1120  * is the language, the second level is the item or subitem.
1121  *
1122  * Since the data for a whole language is rebuilt in one operation, it needs
1123  * to have a fast and atomic method for deleting or replacing all of the
1124  * current data for a given language. The interface reflects this bulk update
1125  * operation. Callers writing to the cache must first call startWrite(), then
1126  * will call set() a couple of thousand times, then will call finishWrite()
1127  * to commit the operation. When finishWrite() is called, the cache is
1128  * expected to delete all data previously stored for that language.
1129  *
1130  * The values stored are PHP variables suitable for serialize(). Implementations
1131  * of LCStore are responsible for serializing and unserializing.
1132  */
1133 interface LCStore {
1134         /**
1135          * Get a value.
1136          * @param string $code Language code
1137          * @param string $key Cache key
1138          */
1139         function get( $code, $key );
1140
1141         /**
1142          * Start a write transaction.
1143          * @param string $code Language code
1144          */
1145         function startWrite( $code );
1146
1147         /**
1148          * Finish a write transaction.
1149          */
1150         function finishWrite();
1151
1152         /**
1153          * Set a key to a given value. startWrite() must be called before this
1154          * is called, and finishWrite() must be called afterwards.
1155          * @param string $key
1156          * @param mixed $value
1157          */
1158         function set( $key, $value );
1159 }
1160
1161 /**
1162  * LCStore implementation which uses the standard DB functions to store data.
1163  * This will work on any MediaWiki installation.
1164  */
1165 class LCStoreDB implements LCStore {
1166         private $currentLang;
1167         private $writesDone = false;
1168
1169         /** @var DatabaseBase */
1170         private $dbw;
1171         /** @var array */
1172         private $batch = array();
1173
1174         private $readOnly = false;
1175
1176         public function get( $code, $key ) {
1177                 if ( $this->writesDone ) {
1178                         $db = wfGetDB( DB_MASTER );
1179                 } else {
1180                         $db = wfGetDB( DB_SLAVE );
1181                 }
1182                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1183                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1184                 if ( $row ) {
1185                         return unserialize( $db->decodeBlob( $row->lc_value ) );
1186                 } else {
1187                         return null;
1188                 }
1189         }
1190
1191         public function startWrite( $code ) {
1192                 if ( $this->readOnly ) {
1193                         return;
1194                 } elseif ( !$code ) {
1195                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1196                 }
1197
1198                 $this->dbw = wfGetDB( DB_MASTER );
1199
1200                 $this->currentLang = $code;
1201                 $this->batch = array();
1202         }
1203
1204         public function finishWrite() {
1205                 if ( $this->readOnly ) {
1206                         return;
1207                 } elseif ( is_null( $this->currentLang ) ) {
1208                         throw new MWException( __CLASS__ . ': must call startWrite() before finishWrite()' );
1209                 }
1210
1211                 $this->dbw->begin( __METHOD__ );
1212                 try {
1213                         $this->dbw->delete( 'l10n_cache',
1214                                 array( 'lc_lang' => $this->currentLang ), __METHOD__ );
1215                         foreach ( array_chunk( $this->batch, 500 ) as $rows ) {
1216                                 $this->dbw->insert( 'l10n_cache', $rows, __METHOD__ );
1217                         }
1218                         $this->writesDone = true;
1219                 } catch ( DBQueryError $e ) {
1220                         if ( $this->dbw->wasReadOnlyError() ) {
1221                                 $this->readOnly = true; // just avoid site down time
1222                         } else {
1223                                 throw $e;
1224                         }
1225                 }
1226                 $this->dbw->commit( __METHOD__ );
1227
1228                 $this->currentLang = null;
1229                 $this->batch = array();
1230         }
1231
1232         public function set( $key, $value ) {
1233                 if ( $this->readOnly ) {
1234                         return;
1235                 } elseif ( is_null( $this->currentLang ) ) {
1236                         throw new MWException( __CLASS__ . ': must call startWrite() before set()' );
1237                 }
1238
1239                 $this->batch[] = array(
1240                         'lc_lang' => $this->currentLang,
1241                         'lc_key' => $key,
1242                         'lc_value' => $this->dbw->encodeBlob( serialize( $value ) ) );
1243         }
1244 }
1245
1246 /**
1247  * LCStore implementation which stores data as a collection of CDB files in the
1248  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1249  * will throw an exception.
1250  *
1251  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1252  * the directory is on a local filesystem and there is ample kernel cache
1253  * space. The performance advantage is greater when the DBA extension is
1254  * available than it is with the PHP port.
1255  *
1256  * See Cdb.php and http://cr.yp.to/cdb.html
1257  */
1258 class LCStoreCDB implements LCStore {
1259         /** @var CdbReader[] */
1260         private $readers;
1261
1262         /** @var CdbWriter */
1263         private $writer;
1264
1265         /** @var string Current language code */
1266         private $currentLang;
1267
1268         /** @var bool|string Cache directory. False if not set */
1269         private $directory;
1270
1271         function __construct( $conf = array() ) {
1272                 global $wgCacheDirectory;
1273
1274                 if ( isset( $conf['directory'] ) ) {
1275                         $this->directory = $conf['directory'];
1276                 } else {
1277                         $this->directory = $wgCacheDirectory;
1278                 }
1279         }
1280
1281         public function get( $code, $key ) {
1282                 if ( !isset( $this->readers[$code] ) ) {
1283                         $fileName = $this->getFileName( $code );
1284
1285                         $this->readers[$code] = false;
1286                         if ( file_exists( $fileName ) ) {
1287                                 try {
1288                                         $this->readers[$code] = CdbReader::open( $fileName );
1289                                 } catch ( CdbException $e ) {
1290                                         wfDebug( __METHOD__ . ": unable to open cdb file for reading\n" );
1291                                 }
1292                         }
1293                 }
1294
1295                 if ( !$this->readers[$code] ) {
1296                         return null;
1297                 } else {
1298                         $value = false;
1299                         try {
1300                                 $value = $this->readers[$code]->get( $key );
1301                         } catch ( CdbException $e ) {
1302                                 wfDebug( __METHOD__ . ": CdbException caught, error message was "
1303                                         . $e->getMessage() . "\n" );
1304                         }
1305                         if ( $value === false ) {
1306                                 return null;
1307                         }
1308
1309                         return unserialize( $value );
1310                 }
1311         }
1312
1313         public function startWrite( $code ) {
1314                 if ( !file_exists( $this->directory ) ) {
1315                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1316                                 throw new MWException( "Unable to create the localisation store " .
1317                                         "directory \"{$this->directory}\"" );
1318                         }
1319                 }
1320
1321                 // Close reader to stop permission errors on write
1322                 if ( !empty( $this->readers[$code] ) ) {
1323                         $this->readers[$code]->close();
1324                 }
1325
1326                 try {
1327                         $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1328                 } catch ( CdbException $e ) {
1329                         throw new MWException( $e->getMessage() );
1330                 }
1331                 $this->currentLang = $code;
1332         }
1333
1334         public function finishWrite() {
1335                 // Close the writer
1336                 try {
1337                         $this->writer->close();
1338                 } catch ( CdbException $e ) {
1339                         throw new MWException( $e->getMessage() );
1340                 }
1341                 $this->writer = null;
1342                 unset( $this->readers[$this->currentLang] );
1343                 $this->currentLang = null;
1344         }
1345
1346         public function set( $key, $value ) {
1347                 if ( is_null( $this->writer ) ) {
1348                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1349                 }
1350                 try {
1351                         $this->writer->set( $key, serialize( $value ) );
1352                 } catch ( CdbException $e ) {
1353                         throw new MWException( $e->getMessage() );
1354                 }
1355         }
1356
1357         protected function getFileName( $code ) {
1358                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1359                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1360                 }
1361
1362                 return "{$this->directory}/l10n_cache-$code.cdb";
1363         }
1364 }
1365
1366 /**
1367  * Null store backend, used to avoid DB errors during install
1368  */
1369 class LCStoreNull implements LCStore {
1370         public function get( $code, $key ) {
1371                 return null;
1372         }
1373
1374         public function startWrite( $code ) {
1375         }
1376
1377         public function finishWrite() {
1378         }
1379
1380         public function set( $key, $value ) {
1381         }
1382 }
1383
1384 /**
1385  * A localisation cache optimised for loading large amounts of data for many
1386  * languages. Used by rebuildLocalisationCache.php.
1387  */
1388 class LocalisationCacheBulkLoad extends LocalisationCache {
1389         /**
1390          * A cache of the contents of data files.
1391          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1392          */
1393         private $fileCache = array();
1394
1395         /**
1396          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1397          * to keep the most recently used language codes at the end of the array, and
1398          * the language codes that are ready to be deleted at the beginning.
1399          */
1400         private $mruLangs = array();
1401
1402         /**
1403          * Maximum number of languages that may be loaded into $this->data
1404          */
1405         private $maxLoadedLangs = 10;
1406
1407         /**
1408          * @param string $fileName
1409          * @param string $fileType
1410          * @return array|mixed
1411          */
1412         protected function readPHPFile( $fileName, $fileType ) {
1413                 $serialize = $fileType === 'core';
1414                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1415                         $data = parent::readPHPFile( $fileName, $fileType );
1416
1417                         if ( $serialize ) {
1418                                 $encData = serialize( $data );
1419                         } else {
1420                                 $encData = $data;
1421                         }
1422
1423                         $this->fileCache[$fileName][$fileType] = $encData;
1424
1425                         return $data;
1426                 } elseif ( $serialize ) {
1427                         return unserialize( $this->fileCache[$fileName][$fileType] );
1428                 } else {
1429                         return $this->fileCache[$fileName][$fileType];
1430                 }
1431         }
1432
1433         /**
1434          * @param string $code
1435          * @param string $key
1436          * @return mixed
1437          */
1438         public function getItem( $code, $key ) {
1439                 unset( $this->mruLangs[$code] );
1440                 $this->mruLangs[$code] = true;
1441
1442                 return parent::getItem( $code, $key );
1443         }
1444
1445         /**
1446          * @param string $code
1447          * @param string $key
1448          * @param string $subkey
1449          * @return mixed
1450          */
1451         public function getSubitem( $code, $key, $subkey ) {
1452                 unset( $this->mruLangs[$code] );
1453                 $this->mruLangs[$code] = true;
1454
1455                 return parent::getSubitem( $code, $key, $subkey );
1456         }
1457
1458         /**
1459          * @param string $code
1460          */
1461         public function recache( $code ) {
1462                 parent::recache( $code );
1463                 unset( $this->mruLangs[$code] );
1464                 $this->mruLangs[$code] = true;
1465                 $this->trimCache();
1466         }
1467
1468         /**
1469          * @param string $code
1470          */
1471         public function unload( $code ) {
1472                 unset( $this->mruLangs[$code] );
1473                 parent::unload( $code );
1474         }
1475
1476         /**
1477          * Unload cached languages until there are less than $this->maxLoadedLangs
1478          */
1479         protected function trimCache() {
1480                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1481                         reset( $this->mruLangs );
1482                         $code = key( $this->mruLangs );
1483                         wfDebug( __METHOD__ . ": unloading $code\n" );
1484                         $this->unload( $code );
1485                 }
1486         }
1487 }