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          * @throws MWException
 658          */
 659         protected function loadPluralFile( $fileName ) {
 660                 // Use file_get_contents instead of DOMDocument::load (T58439)
 661                 $xml = file_get_contents( $fileName );
 662                 if ( !$xml ) {
 663                         throw new MWException( "Unable to read plurals file $fileName" );
 664                 }
 665                 $doc = new DOMDocument;
 666                 $doc->loadXML( $xml );
 667                 $rulesets = $doc->getElementsByTagName( "pluralRules" );
 668                 foreach ( $rulesets as $ruleset ) {
 669                         $codes = $ruleset->getAttribute( 'locales' );
 670                         $rules = array();
 671                         $ruleTypes = array();
 672                         $ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
 673                         foreach ( $ruleElements as $elt ) {
 674                                 $ruleType = $elt->getAttribute( 'count' );
 675                                 if ( $ruleType === 'other' ) {
 676                                         // Don't record "other" rules, which have an empty condition
 677                                         continue;
 678                                 }
 679                                 $rules[] = $elt->nodeValue;
 680                                 $ruleTypes[] = $ruleType;
 681                         }
 682                         foreach ( explode( ' ', $codes ) as $code ) {
 683                                 $this->pluralRules[$code] = $rules;
 684                                 $this->pluralRuleTypes[$code] = $ruleTypes;
 685                         }
 686                 }
 687         }
 688
 689         /**
 690          * Read the data from the source files for a given language, and register
 691          * the relevant dependencies in the $deps array. If the localisation
 692          * exists, the data array is returned, otherwise false is returned.
 693          *
 694          * @param string $code
 695          * @param array $deps
 696          * @return array
 697          */
 698         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 699                 global $IP;
 700                 wfProfileIn( __METHOD__ );
 701
 702                 // This reads in the PHP i18n file with non-messages l10n data
 703                 $fileName = Language::getMessagesFileName( $code );
 704                 if ( !file_exists( $fileName ) ) {
 705                         $data = array();
 706                 } else {
 707                         $deps[] = new FileDependency( $fileName );
 708                         $data = $this->readPHPFile( $fileName, 'core' );
 709                 }
 710
 711                 # Load CLDR plural rules for JavaScript
 712                 $data['pluralRules'] = $this->getPluralRules( $code );
 713                 # And for PHP
 714                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 715                 # Load plural rule types
 716                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 717
 718                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 719                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 720
 721                 wfProfileOut( __METHOD__ );
 722
 723                 return $data;
 724         }
 725
 726         /**
 727          * Merge two localisation values, a primary and a fallback, overwriting the
 728          * primary value in place.
 729          * @param string $key
 730          * @param mixed $value
 731          * @param mixed $fallbackValue
 732          */
 733         protected function mergeItem( $key, &$value, $fallbackValue ) {
 734                 if ( !is_null( $value ) ) {
 735                         if ( !is_null( $fallbackValue ) ) {
 736                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 737                                         $value = $value + $fallbackValue;
 738                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 739                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 740                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 741                                         $value = array_merge_recursive( $value, $fallbackValue );
 742                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 743                                         if ( !empty( $value['inherit'] ) ) {
 744                                                 $value = array_merge( $fallbackValue, $value );
 745                                         }
 746
 747                                         if ( isset( $value['inherit'] ) ) {
 748                                                 unset( $value['inherit'] );
 749                                         }
 750                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 751                                         $this->mergeMagicWords( $value, $fallbackValue );
 752                                 }
 753                         }
 754                 } else {
 755                         $value = $fallbackValue;
 756                 }
 757         }
 758
 759         /**
 760          * @param mixed $value
 761          * @param mixed $fallbackValue
 762          */
 763         protected function mergeMagicWords( &$value, $fallbackValue ) {
 764                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 765                         if ( !isset( $value[$magicName] ) ) {
 766                                 $value[$magicName] = $fallbackInfo;
 767                         } else {
 768                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 769                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 770                                 $synonyms = array_values( array_unique( array_merge(
 771                                         $newSynonyms, $oldSynonyms ) ) );
 772                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 773                         }
 774                 }
 775         }
 776
 777         /**
 778          * Given an array mapping language code to localisation value, such as is
 779          * found in extension *.i18n.php files, iterate through a fallback sequence
 780          * to merge the given data with an existing primary value.
 781          *
 782          * Returns true if any data from the extension array was used, false
 783          * otherwise.
 784          * @param array $codeSequence
 785          * @param string $key
 786          * @param mixed $value
 787          * @param mixed $fallbackValue
 788          * @return bool
 789          */
 790         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 791                 $used = false;
 792                 foreach ( $codeSequence as $code ) {
 793                         if ( isset( $fallbackValue[$code] ) ) {
 794                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 795                                 $used = true;
 796                         }
 797                 }
 798
 799                 return $used;
 800         }
 801
 802         /**
 803          * Gets the combined list of messages dirs from
 804          * core and extensions
 805          *
 806          * @since 1.25
 807          * @return array
 808          */
 809         public function getMessagesDirs() {
 810                 global $wgMessagesDirs, $IP;
 811                 return array(
 812                         'core' => "$IP/languages/i18n",
 813                         'api' => "$IP/includes/api/i18n",
 814                         'oojs-ui' => "$IP/resources/lib/oojs-ui/i18n",
 815                 ) + $wgMessagesDirs;
 816         }
 817
 818         /**
 819          * Load localisation data for a given language for both core and extensions
 820          * and save it to the persistent cache store and the process cache
 821          * @param string $code
 822          * @throws MWException
 823          */
 824         public function recache( $code ) {
 825                 global $wgExtensionMessagesFiles;
 826                 wfProfileIn( __METHOD__ );
 827
 828                 if ( !$code ) {
 829                         wfProfileOut( __METHOD__ );
 830                         throw new MWException( "Invalid language code requested" );
 831                 }
 832                 $this->recachedLangs[$code] = true;
 833
 834                 # Initial values
 835                 $initialData = array_combine(
 836                         self::$allKeys,
 837                         array_fill( 0, count( self::$allKeys ), null ) );
 838                 $coreData = $initialData;
 839                 $deps = array();
 840
 841                 # Load the primary localisation from the source file
 842                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 843                 if ( $data === false ) {
 844                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 845                         $coreData['fallback'] = 'en';
 846                 } else {
 847                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 848
 849                         # Merge primary localisation
 850                         foreach ( $data as $key => $value ) {
 851                                 $this->mergeItem( $key, $coreData[$key], $value );
 852                         }
 853                 }
 854
 855                 # Fill in the fallback if it's not there already
 856                 if ( is_null( $coreData['fallback'] ) ) {
 857                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 858                 }
 859                 if ( $coreData['fallback'] === false ) {
 860                         $coreData['fallbackSequence'] = array();
 861                 } else {
 862                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 863                         $len = count( $coreData['fallbackSequence'] );
 864
 865                         # Ensure that the sequence ends at en
 866                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 867                                 $coreData['fallbackSequence'][] = 'en';
 868                         }
 869                 }
 870
 871                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 872                 $messageDirs = $this->getMessagesDirs();
 873
 874                 wfProfileIn( __METHOD__ . '-fallbacks' );
 875
 876                 # Load non-JSON localisation data for extensions
 877                 $extensionData = array_combine(
 878                         $codeSequence,
 879                         array_fill( 0, count( $codeSequence ), $initialData ) );
 880                 foreach ( $wgExtensionMessagesFiles as $extension => $fileName ) {
 881                         if ( isset( $messageDirs[$extension] ) ) {
 882                                 # This extension has JSON message data; skip the PHP shim
 883                                 continue;
 884                         }
 885
 886                         $data = $this->readPHPFile( $fileName, 'extension' );
 887                         $used = false;
 888
 889                         foreach ( $data as $key => $item ) {
 890                                 foreach ( $codeSequence as $csCode ) {
 891                                         if ( isset( $item[$csCode] ) ) {
 892                                                 $this->mergeItem( $key, $extensionData[$csCode][$key], $item[$csCode] );
 893                                                 $used = true;
 894                                         }
 895                                 }
 896                         }
 897
 898                         if ( $used ) {
 899                                 $deps[] = new FileDependency( $fileName );
 900                         }
 901                 }
 902
 903                 # Load the localisation data for each fallback, then merge it into the full array
 904                 $allData = $initialData;
 905                 foreach ( $codeSequence as $csCode ) {
 906                         $csData = $initialData;
 907
 908                         # Load core messages and the extension localisations.
 909                         foreach ( $messageDirs as $dirs ) {
 910                                 foreach ( (array)$dirs as $dir ) {
 911                                         $fileName = "$dir/$csCode.json";
 912                                         $data = $this->readJSONFile( $fileName );
 913
 914                                         foreach ( $data as $key => $item ) {
 915                                                 $this->mergeItem( $key, $csData[$key], $item );
 916                                         }
 917
 918                                         $deps[] = new FileDependency( $fileName );
 919                                 }
 920                         }
 921
 922                         # Merge non-JSON extension data
 923                         if ( isset( $extensionData[$csCode] ) ) {
 924                                 foreach ( $extensionData[$csCode] as $key => $item ) {
 925                                         $this->mergeItem( $key, $csData[$key], $item );
 926                                 }
 927                         }
 928
 929                         if ( $csCode === $code ) {
 930                                 # Merge core data into extension data
 931                                 foreach ( $coreData as $key => $item ) {
 932                                         $this->mergeItem( $key, $csData[$key], $item );
 933                                 }
 934                         } else {
 935                                 # Load the secondary localisation from the source file to
 936                                 # avoid infinite cycles on cyclic fallbacks
 937                                 $fbData = $this->readSourceFilesAndRegisterDeps( $csCode, $deps );
 938                                 if ( $fbData !== false ) {
 939                                         # Only merge the keys that make sense to merge
 940                                         foreach ( self::$allKeys as $key ) {
 941                                                 if ( !isset( $fbData[$key] ) ) {
 942                                                         continue;
 943                                                 }
 944
 945                                                 if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 946                                                         $this->mergeItem( $key, $csData[$key], $fbData[$key] );
 947                                                 }
 948                                         }
 949                                 }
 950                         }
 951
 952                         # Allow extensions an opportunity to adjust the data for this
 953                         # fallback
 954                         Hooks::run( 'LocalisationCacheRecacheFallback', array( $this, $csCode, &$csData ) );
 955
 956                         # Merge the data for this fallback into the final array
 957                         if ( $csCode === $code ) {
 958                                 $allData = $csData;
 959                         } else {
 960                                 foreach ( self::$allKeys as $key ) {
 961                                         if ( !isset( $csData[$key] ) ) {
 962                                                 continue;
 963                                         }
 964
 965                                         if ( is_null( $allData[$key] ) || $this->isMergeableKey( $key ) ) {
 966                                                 $this->mergeItem( $key, $allData[$key], $csData[$key] );
 967                                         }
 968                                 }
 969                         }
 970                 }
 971
 972                 wfProfileOut( __METHOD__ . '-fallbacks' );
 973
 974                 # Add cache dependencies for any referenced globals
 975                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 976                 // $wgMessagesDirs is used in LocalisationCache::getMessagesDirs()
 977                 $deps['wgMessagesDirs'] = new GlobalDependency( 'wgMessagesDirs' );
 978                 $deps['version'] = new ConstantDependency( 'LocalisationCache::VERSION' );
 979
 980                 # Add dependencies to the cache entry
 981                 $allData['deps'] = $deps;
 982
 983                 # Replace spaces with underscores in namespace names
 984                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 985
 986                 # And do the same for special page aliases. $page is an array.
 987                 foreach ( $allData['specialPageAliases'] as &$page ) {
 988                         $page = str_replace( ' ', '_', $page );
 989                 }
 990                 # Decouple the reference to prevent accidental damage
 991                 unset( $page );
 992
 993                 # If there were no plural rules, return an empty array
 994                 if ( $allData['pluralRules'] === null ) {
 995                         $allData['pluralRules'] = array();
 996                 }
 997                 if ( $allData['compiledPluralRules'] === null ) {
 998                         $allData['compiledPluralRules'] = array();
 999                 }
1000                 # If there were no plural rule types, return an empty array
1001                 if ( $allData['pluralRuleTypes'] === null ) {
1002                         $allData['pluralRuleTypes'] = array();
1003                 }
1004
1005                 # Set the list keys
1006                 $allData['list'] = array();
1007                 foreach ( self::$splitKeys as $key ) {
1008                         $allData['list'][$key] = array_keys( $allData[$key] );
1009                 }
1010                 # Run hooks
1011                 $purgeBlobs = true;
1012                 Hooks::run( 'LocalisationCacheRecache', array( $this, $code, &$allData, &$purgeBlobs ) );
1013
1014                 if ( is_null( $allData['namespaceNames'] ) ) {
1015                         wfProfileOut( __METHOD__ );
1016                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
1017                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
1018                 }
1019
1020                 # Set the preload key
1021                 $allData['preload'] = $this->buildPreload( $allData );
1022
1023                 # Save to the process cache and register the items loaded
1024                 $this->data[$code] = $allData;
1025                 foreach ( $allData as $key => $item ) {
1026                         $this->loadedItems[$code][$key] = true;
1027                 }
1028
1029                 # Save to the persistent cache
1030                 wfProfileIn( __METHOD__ . '-write' );
1031                 $this->store->startWrite( $code );
1032                 foreach ( $allData as $key => $value ) {
1033                         if ( in_array( $key, self::$splitKeys ) ) {
1034                                 foreach ( $value as $subkey => $subvalue ) {
1035                                         $this->store->set( "$key:$subkey", $subvalue );
1036                                 }
1037                         } else {
1038                                 $this->store->set( $key, $value );
1039                         }
1040                 }
1041                 $this->store->finishWrite();
1042                 wfProfileOut( __METHOD__ . '-write' );
1043
1044                 # Clear out the MessageBlobStore
1045                 # HACK: If using a null (i.e. disabled) storage backend, we
1046                 # can't write to the MessageBlobStore either
1047                 if ( $purgeBlobs && !$this->store instanceof LCStoreNull ) {
1048                         MessageBlobStore::getInstance()->clear();
1049                 }
1050
1051                 wfProfileOut( __METHOD__ );
1052         }
1053
1054         /**
1055          * Build the preload item from the given pre-cache data.
1056          *
1057          * The preload item will be loaded automatically, improving performance
1058          * for the commonly-requested items it contains.
1059          * @param array $data
1060          * @return array
1061          */
1062         protected function buildPreload( $data ) {
1063                 $preload = array( 'messages' => array() );
1064                 foreach ( self::$preloadedKeys as $key ) {
1065                         $preload[$key] = $data[$key];
1066                 }
1067
1068                 foreach ( $data['preloadedMessages'] as $subkey ) {
1069                         if ( isset( $data['messages'][$subkey] ) ) {
1070                                 $subitem = $data['messages'][$subkey];
1071                         } else {
1072                                 $subitem = null;
1073                         }
1074                         $preload['messages'][$subkey] = $subitem;
1075                 }
1076
1077                 return $preload;
1078         }
1079
1080         /**
1081          * Unload the data for a given language from the object cache.
1082          * Reduces memory usage.
1083          * @param string $code
1084          */
1085         public function unload( $code ) {
1086                 unset( $this->data[$code] );
1087                 unset( $this->loadedItems[$code] );
1088                 unset( $this->loadedSubitems[$code] );
1089                 unset( $this->initialisedLangs[$code] );
1090                 unset( $this->shallowFallbacks[$code] );
1091
1092                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
1093                         if ( $fbCode === $code ) {
1094                                 $this->unload( $shallowCode );
1095                         }
1096                 }
1097         }
1098
1099         /**
1100          * Unload all data
1101          */
1102         public function unloadAll() {
1103                 foreach ( $this->initialisedLangs as $lang => $unused ) {
1104                         $this->unload( $lang );
1105                 }
1106         }
1107
1108         /**
1109          * Disable the storage backend
1110          */
1111         public function disableBackend() {
1112                 $this->store = new LCStoreNull;
1113                 $this->manualRecache = false;
1114         }
1115 }
1116
1117 /**
1118  * Interface for the persistence layer of LocalisationCache.
1119  *
1120  * The persistence layer is two-level hierarchical cache. The first level
1121  * is the language, the second level is the item or subitem.
1122  *
1123  * Since the data for a whole language is rebuilt in one operation, it needs
1124  * to have a fast and atomic method for deleting or replacing all of the
1125  * current data for a given language. The interface reflects this bulk update
1126  * operation. Callers writing to the cache must first call startWrite(), then
1127  * will call set() a couple of thousand times, then will call finishWrite()
1128  * to commit the operation. When finishWrite() is called, the cache is
1129  * expected to delete all data previously stored for that language.
1130  *
1131  * The values stored are PHP variables suitable for serialize(). Implementations
1132  * of LCStore are responsible for serializing and unserializing.
1133  */
1134 interface LCStore {
1135         /**
1136          * Get a value.
1137          * @param string $code Language code
1138          * @param string $key Cache key
1139          */
1140         function get( $code, $key );
1141
1142         /**
1143          * Start a write transaction.
1144          * @param string $code Language code
1145          */
1146         function startWrite( $code );
1147
1148         /**
1149          * Finish a write transaction.
1150          */
1151         function finishWrite();
1152
1153         /**
1154          * Set a key to a given value. startWrite() must be called before this
1155          * is called, and finishWrite() must be called afterwards.
1156          * @param string $key
1157          * @param mixed $value
1158          */
1159         function set( $key, $value );
1160 }
1161
1162 /**
1163  * LCStore implementation which uses the standard DB functions to store data.
1164  * This will work on any MediaWiki installation.
1165  */
1166 class LCStoreDB implements LCStore {
1167         private $currentLang;
1168         private $writesDone = false;
1169
1170         /** @var DatabaseBase */
1171         private $dbw;
1172         /** @var array */
1173         private $batch = array();
1174
1175         private $readOnly = false;
1176
1177         public function get( $code, $key ) {
1178                 if ( $this->writesDone ) {
1179                         $db = wfGetDB( DB_MASTER );
1180                 } else {
1181                         $db = wfGetDB( DB_SLAVE );
1182                 }
1183                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1184                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1185                 if ( $row ) {
1186                         return unserialize( $db->decodeBlob( $row->lc_value ) );
1187                 } else {
1188                         return null;
1189                 }
1190         }
1191
1192         public function startWrite( $code ) {
1193                 if ( $this->readOnly ) {
1194                         return;
1195                 } elseif ( !$code ) {
1196                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1197                 }
1198
1199                 $this->dbw = wfGetDB( DB_MASTER );
1200
1201                 $this->currentLang = $code;
1202                 $this->batch = array();
1203         }
1204
1205         public function finishWrite() {
1206                 if ( $this->readOnly ) {
1207                         return;
1208                 } elseif ( is_null( $this->currentLang ) ) {
1209                         throw new MWException( __CLASS__ . ': must call startWrite() before finishWrite()' );
1210                 }
1211
1212                 $this->dbw->begin( __METHOD__ );
1213                 try {
1214                         $this->dbw->delete( 'l10n_cache',
1215                                 array( 'lc_lang' => $this->currentLang ), __METHOD__ );
1216                         foreach ( array_chunk( $this->batch, 500 ) as $rows ) {
1217                                 $this->dbw->insert( 'l10n_cache', $rows, __METHOD__ );
1218                         }
1219                         $this->writesDone = true;
1220                 } catch ( DBQueryError $e ) {
1221                         if ( $this->dbw->wasReadOnlyError() ) {
1222                                 $this->readOnly = true; // just avoid site down time
1223                         } else {
1224                                 throw $e;
1225                         }
1226                 }
1227                 $this->dbw->commit( __METHOD__ );
1228
1229                 $this->currentLang = null;
1230                 $this->batch = array();
1231         }
1232
1233         public function set( $key, $value ) {
1234                 if ( $this->readOnly ) {
1235                         return;
1236                 } elseif ( is_null( $this->currentLang ) ) {
1237                         throw new MWException( __CLASS__ . ': must call startWrite() before set()' );
1238                 }
1239
1240                 $this->batch[] = array(
1241                         'lc_lang' => $this->currentLang,
1242                         'lc_key' => $key,
1243                         'lc_value' => $this->dbw->encodeBlob( serialize( $value ) ) );
1244         }
1245 }
1246
1247 /**
1248  * LCStore implementation which stores data as a collection of CDB files in the
1249  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1250  * will throw an exception.
1251  *
1252  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1253  * the directory is on a local filesystem and there is ample kernel cache
1254  * space. The performance advantage is greater when the DBA extension is
1255  * available than it is with the PHP port.
1256  *
1257  * See Cdb.php and http://cr.yp.to/cdb.html
1258  */
1259 class LCStoreCDB implements LCStore {
1260         /** @var CdbReader[] */
1261         private $readers;
1262
1263         /** @var CdbWriter */
1264         private $writer;
1265
1266         /** @var string Current language code */
1267         private $currentLang;
1268
1269         /** @var bool|string Cache directory. False if not set */
1270         private $directory;
1271
1272         function __construct( $conf = array() ) {
1273                 global $wgCacheDirectory;
1274
1275                 if ( isset( $conf['directory'] ) ) {
1276                         $this->directory = $conf['directory'];
1277                 } else {
1278                         $this->directory = $wgCacheDirectory;
1279                 }
1280         }
1281
1282         public function get( $code, $key ) {
1283                 if ( !isset( $this->readers[$code] ) ) {
1284                         $fileName = $this->getFileName( $code );
1285
1286                         $this->readers[$code] = false;
1287                         if ( file_exists( $fileName ) ) {
1288                                 try {
1289                                         $this->readers[$code] = CdbReader::open( $fileName );
1290                                 } catch ( CdbException $e ) {
1291                                         wfDebug( __METHOD__ . ": unable to open cdb file for reading\n" );
1292                                 }
1293                         }
1294                 }
1295
1296                 if ( !$this->readers[$code] ) {
1297                         return null;
1298                 } else {
1299                         $value = false;
1300                         try {
1301                                 $value = $this->readers[$code]->get( $key );
1302                         } catch ( CdbException $e ) {
1303                                 wfDebug( __METHOD__ . ": CdbException caught, error message was "
1304                                         . $e->getMessage() . "\n" );
1305                         }
1306                         if ( $value === false ) {
1307                                 return null;
1308                         }
1309
1310                         return unserialize( $value );
1311                 }
1312         }
1313
1314         public function startWrite( $code ) {
1315                 if ( !file_exists( $this->directory ) ) {
1316                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1317                                 throw new MWException( "Unable to create the localisation store " .
1318                                         "directory \"{$this->directory}\"" );
1319                         }
1320                 }
1321
1322                 // Close reader to stop permission errors on write
1323                 if ( !empty( $this->readers[$code] ) ) {
1324                         $this->readers[$code]->close();
1325                 }
1326
1327                 try {
1328                         $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1329                 } catch ( CdbException $e ) {
1330                         throw new MWException( $e->getMessage() );
1331                 }
1332                 $this->currentLang = $code;
1333         }
1334
1335         public function finishWrite() {
1336                 // Close the writer
1337                 try {
1338                         $this->writer->close();
1339                 } catch ( CdbException $e ) {
1340                         throw new MWException( $e->getMessage() );
1341                 }
1342                 $this->writer = null;
1343                 unset( $this->readers[$this->currentLang] );
1344                 $this->currentLang = null;
1345         }
1346
1347         public function set( $key, $value ) {
1348                 if ( is_null( $this->writer ) ) {
1349                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1350                 }
1351                 try {
1352                         $this->writer->set( $key, serialize( $value ) );
1353                 } catch ( CdbException $e ) {
1354                         throw new MWException( $e->getMessage() );
1355                 }
1356         }
1357
1358         protected function getFileName( $code ) {
1359                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1360                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1361                 }
1362
1363                 return "{$this->directory}/l10n_cache-$code.cdb";
1364         }
1365 }
1366
1367 /**
1368  * Null store backend, used to avoid DB errors during install
1369  */
1370 class LCStoreNull implements LCStore {
1371         public function get( $code, $key ) {
1372                 return null;
1373         }
1374
1375         public function startWrite( $code ) {
1376         }
1377
1378         public function finishWrite() {
1379         }
1380
1381         public function set( $key, $value ) {
1382         }
1383 }
1384
1385 /**
1386  * A localisation cache optimised for loading large amounts of data for many
1387  * languages. Used by rebuildLocalisationCache.php.
1388  */
1389 class LocalisationCacheBulkLoad extends LocalisationCache {
1390         /**
1391          * A cache of the contents of data files.
1392          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1393          */
1394         private $fileCache = array();
1395
1396         /**
1397          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1398          * to keep the most recently used language codes at the end of the array, and
1399          * the language codes that are ready to be deleted at the beginning.
1400          */
1401         private $mruLangs = array();
1402
1403         /**
1404          * Maximum number of languages that may be loaded into $this->data
1405          */
1406         private $maxLoadedLangs = 10;
1407
1408         /**
1409          * @param string $fileName
1410          * @param string $fileType
1411          * @return array|mixed
1412          */
1413         protected function readPHPFile( $fileName, $fileType ) {
1414                 $serialize = $fileType === 'core';
1415                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1416                         $data = parent::readPHPFile( $fileName, $fileType );
1417
1418                         if ( $serialize ) {
1419                                 $encData = serialize( $data );
1420                         } else {
1421                                 $encData = $data;
1422                         }
1423
1424                         $this->fileCache[$fileName][$fileType] = $encData;
1425
1426                         return $data;
1427                 } elseif ( $serialize ) {
1428                         return unserialize( $this->fileCache[$fileName][$fileType] );
1429                 } else {
1430                         return $this->fileCache[$fileName][$fileType];
1431                 }
1432         }
1433
1434         /**
1435          * @param string $code
1436          * @param string $key
1437          * @return mixed
1438          */
1439         public function getItem( $code, $key ) {
1440                 unset( $this->mruLangs[$code] );
1441                 $this->mruLangs[$code] = true;
1442
1443                 return parent::getItem( $code, $key );
1444         }
1445
1446         /**
1447          * @param string $code
1448          * @param string $key
1449          * @param string $subkey
1450          * @return mixed
1451          */
1452         public function getSubitem( $code, $key, $subkey ) {
1453                 unset( $this->mruLangs[$code] );
1454                 $this->mruLangs[$code] = true;
1455
1456                 return parent::getSubitem( $code, $key, $subkey );
1457         }
1458
1459         /**
1460          * @param string $code
1461          */
1462         public function recache( $code ) {
1463                 parent::recache( $code );
1464                 unset( $this->mruLangs[$code] );
1465                 $this->mruLangs[$code] = true;
1466                 $this->trimCache();
1467         }
1468
1469         /**
1470          * @param string $code
1471          */
1472         public function unload( $code ) {
1473                 unset( $this->mruLangs[$code] );
1474                 parent::unload( $code );
1475         }
1476
1477         /**
1478          * Unload cached languages until there are less than $this->maxLoadedLangs
1479          */
1480         protected function trimCache() {
1481                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1482                         reset( $this->mruLangs );
1483                         $code = key( $this->mruLangs );
1484                         wfDebug( __METHOD__ . ": unloading $code\n" );
1485                         $this->unload( $code );
1486                 }
1487         }
1488 }