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 use CLDRPluralRuleParser\Evaluator;
  27
  28 /**
  29  * Class for caching the contents of localisation files, Messages*.php
  30  * and *.i18n.php.
  31  *
  32  * An instance of this class is available using Language::getLocalisationCache().
  33  *
  34  * The values retrieved from here are merged, containing items from extension
  35  * files, core messages files and the language fallback sequence (e.g. zh-cn ->
  36  * zh-hans -> en ). Some common errors are corrected, for example namespace
  37  * names with spaces instead of underscores, but heavyweight processing, such
  38  * as grammatical transformation, is done by the caller.
  39  */
  40 class LocalisationCache {
  41         const VERSION = 4;
  42
  43         /** Configuration associative array */
  44         private $conf;
  45
  46         /**
  47          * True if recaching should only be done on an explicit call to recache().
  48          * Setting this reduces the overhead of cache freshness checking, which
  49          * requires doing a stat() for every extension i18n file.
  50          */
  51         private $manualRecache = false;
  52
  53         /**
  54          * True to treat all files as expired until they are regenerated by this object.
  55          */
  56         private $forceRecache = false;
  57
  58         /**
  59          * The cache data. 3-d array, where the first key is the language code,
  60          * the second key is the item key e.g. 'messages', and the third key is
  61          * an item specific subkey index. Some items are not arrays and so for those
  62          * items, there are no subkeys.
  63          */
  64         protected $data = [];
  65
  66         /**
  67          * The persistent store object. An instance of LCStore.
  68          *
  69          * @var LCStore
  70          */
  71         private $store;
  72
  73         /**
  74          * A 2-d associative array, code/key, where presence indicates that the item
  75          * is loaded. Value arbitrary.
  76          *
  77          * For split items, if set, this indicates that all of the subitems have been
  78          * loaded.
  79          */
  80         private $loadedItems = [];
  81
  82         /**
  83          * A 3-d associative array, code/key/subkey, where presence indicates that
  84          * the subitem is loaded. Only used for the split items, i.e. messages.
  85          */
  86         private $loadedSubitems = [];
  87
  88         /**
  89          * An array where presence of a key indicates that that language has been
  90          * initialised. Initialisation includes checking for cache expiry and doing
  91          * any necessary updates.
  92          */
  93         private $initialisedLangs = [];
  94
  95         /**
  96          * An array mapping non-existent pseudo-languages to fallback languages. This
  97          * is filled by initShallowFallback() when data is requested from a language
  98          * that lacks a Messages*.php file.
  99          */
 100         private $shallowFallbacks = [];
 101
 102         /**
 103          * An array where the keys are codes that have been recached by this instance.
 104          */
 105         private $recachedLangs = [];
 106
 107         /**
 108          * All item keys
 109          */
 110         static public $allKeys = [
 111                 'fallback', 'namespaceNames', 'bookstoreList',
 112                 'magicWords', 'messages', 'rtl', 'capitalizeAllNouns', 'digitTransformTable',
 113                 'separatorTransformTable', 'fallback8bitEncoding', 'linkPrefixExtension',
 114                 'linkTrail', 'linkPrefixCharset', 'namespaceAliases',
 115                 'dateFormats', 'datePreferences', 'datePreferenceMigrationMap',
 116                 'defaultDateFormat', 'extraUserToggles', 'specialPageAliases',
 117                 'imageFiles', 'preloadedMessages', 'namespaceGenderAliases',
 118                 'digitGroupingPattern', 'pluralRules', 'pluralRuleTypes', 'compiledPluralRules',
 119         ];
 120
 121         /**
 122          * Keys for items which consist of associative arrays, which may be merged
 123          * by a fallback sequence.
 124          */
 125         static public $mergeableMapKeys = [ 'messages', 'namespaceNames',
 126                 'namespaceAliases', 'dateFormats', 'imageFiles', 'preloadedMessages'
 127         ];
 128
 129         /**
 130          * Keys for items which are a numbered array.
 131          */
 132         static public $mergeableListKeys = [ 'extraUserToggles' ];
 133
 134         /**
 135          * Keys for items which contain an array of arrays of equivalent aliases
 136          * for each subitem. The aliases may be merged by a fallback sequence.
 137          */
 138         static public $mergeableAliasListKeys = [ 'specialPageAliases' ];
 139
 140         /**
 141          * Keys for items which contain an associative array, and may be merged if
 142          * the primary value contains the special array key "inherit". That array
 143          * key is removed after the first merge.
 144          */
 145         static public $optionalMergeKeys = [ 'bookstoreList' ];
 146
 147         /**
 148          * Keys for items that are formatted like $magicWords
 149          */
 150         static public $magicWordKeys = [ 'magicWords' ];
 151
 152         /**
 153          * Keys for items where the subitems are stored in the backend separately.
 154          */
 155         static public $splitKeys = [ 'messages' ];
 156
 157         /**
 158          * Keys which are loaded automatically by initLanguage()
 159          */
 160         static public $preloadedKeys = [ 'dateFormats', 'namespaceNames' ];
 161
 162         /**
 163          * Associative array of cached plural rules. The key is the language code,
 164          * the value is an array of plural rules for that language.
 165          */
 166         private $pluralRules = null;
 167
 168         /**
 169          * Associative array of cached plural rule types. The key is the language
 170          * code, the value is an array of plural rule types for that language. For
 171          * example, $pluralRuleTypes['ar'] = ['zero', 'one', 'two', 'few', 'many'].
 172          * The index for each rule type matches the index for the rule in
 173          * $pluralRules, thus allowing correlation between the two. The reason we
 174          * don't just use the type names as the keys in $pluralRules is because
 175          * Language::convertPlural applies the rules based on numeric order (or
 176          * explicit numeric parameter), not based on the name of the rule type. For
 177          * example, {{plural:count|wordform1|wordform2|wordform3}}, rather than
 178          * {{plural:count|one=wordform1|two=wordform2|many=wordform3}}.
 179          */
 180         private $pluralRuleTypes = null;
 181
 182         private $mergeableKeys = null;
 183
 184         /**
 185          * Constructor.
 186          * For constructor parameters, see the documentation in DefaultSettings.php
 187          * for $wgLocalisationCacheConf.
 188          *
 189          * @param array $conf
 190          * @throws MWException
 191          */
 192         function __construct( $conf ) {
 193                 global $wgCacheDirectory;
 194
 195                 $this->conf = $conf;
 196                 $storeConf = [];
 197                 if ( !empty( $conf['storeClass'] ) ) {
 198                         $storeClass = $conf['storeClass'];
 199                 } else {
 200                         switch ( $conf['store'] ) {
 201                                 case 'files':
 202                                 case 'file':
 203                                         $storeClass = 'LCStoreCDB';
 204                                         break;
 205                                 case 'db':
 206                                         $storeClass = 'LCStoreDB';
 207                                         break;
 208                                 case 'array':
 209                                         $storeClass = 'LCStoreStaticArray';
 210                                         break;
 211                                 case 'detect':
 212                                         if ( !empty( $conf['storeDirectory'] ) ) {
 213                                                 $storeClass = 'LCStoreCDB';
 214                                         } else {
 215                                                 $cacheDir = $wgCacheDirectory ?: wfTempDir();
 216                                                 if ( $cacheDir ) {
 217                                                         $storeConf['directory'] = $cacheDir;
 218                                                         $storeClass = 'LCStoreCDB';
 219                                                 } else {
 220                                                         $storeClass = 'LCStoreDB';
 221                                                 }
 222                                         }
 223                                         break;
 224                                 default:
 225                                         throw new MWException(
 226                                                 'Please set $wgLocalisationCacheConf[\'store\'] to something sensible.' );
 227                         }
 228                 }
 229
 230                 wfDebugLog( 'caches', get_class( $this ) . ": using store $storeClass" );
 231                 if ( !empty( $conf['storeDirectory'] ) ) {
 232                         $storeConf['directory'] = $conf['storeDirectory'];
 233                 }
 234
 235                 $this->store = new $storeClass( $storeConf );
 236                 foreach ( [ 'manualRecache', 'forceRecache' ] as $var ) {
 237                         if ( isset( $conf[$var] ) ) {
 238                                 $this->$var = $conf[$var];
 239                         }
 240                 }
 241         }
 242
 243         /**
 244          * Returns true if the given key is mergeable, that is, if it is an associative
 245          * array which can be merged through a fallback sequence.
 246          * @param string $key
 247          * @return bool
 248          */
 249         public function isMergeableKey( $key ) {
 250                 if ( $this->mergeableKeys === null ) {
 251                         $this->mergeableKeys = array_flip( array_merge(
 252                                 self::$mergeableMapKeys,
 253                                 self::$mergeableListKeys,
 254                                 self::$mergeableAliasListKeys,
 255                                 self::$optionalMergeKeys,
 256                                 self::$magicWordKeys
 257                         ) );
 258                 }
 259
 260                 return isset( $this->mergeableKeys[$key] );
 261         }
 262
 263         /**
 264          * Get a cache item.
 265          *
 266          * Warning: this may be slow for split items (messages), since it will
 267          * need to fetch all of the subitems from the cache individually.
 268          * @param string $code
 269          * @param string $key
 270          * @return mixed
 271          */
 272         public function getItem( $code, $key ) {
 273                 if ( !isset( $this->loadedItems[$code][$key] ) ) {
 274                         $this->loadItem( $code, $key );
 275                 }
 276
 277                 if ( $key === 'fallback' && isset( $this->shallowFallbacks[$code] ) ) {
 278                         return $this->shallowFallbacks[$code];
 279                 }
 280
 281                 return $this->data[$code][$key];
 282         }
 283
 284         /**
 285          * Get a subitem, for instance a single message for a given language.
 286          * @param string $code
 287          * @param string $key
 288          * @param string $subkey
 289          * @return mixed|null
 290          */
 291         public function getSubitem( $code, $key, $subkey ) {
 292                 if ( !isset( $this->loadedSubitems[$code][$key][$subkey] ) &&
 293                         !isset( $this->loadedItems[$code][$key] )
 294                 ) {
 295                         $this->loadSubitem( $code, $key, $subkey );
 296                 }
 297
 298                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 299                         return $this->data[$code][$key][$subkey];
 300                 } else {
 301                         return null;
 302                 }
 303         }
 304
 305         /**
 306          * Get the list of subitem keys for a given item.
 307          *
 308          * This is faster than array_keys($lc->getItem(...)) for the items listed in
 309          * self::$splitKeys.
 310          *
 311          * Will return null if the item is not found, or false if the item is not an
 312          * array.
 313          * @param string $code
 314          * @param string $key
 315          * @return bool|null|string
 316          */
 317         public function getSubitemList( $code, $key ) {
 318                 if ( in_array( $key, self::$splitKeys ) ) {
 319                         return $this->getSubitem( $code, 'list', $key );
 320                 } else {
 321                         $item = $this->getItem( $code, $key );
 322                         if ( is_array( $item ) ) {
 323                                 return array_keys( $item );
 324                         } else {
 325                                 return false;
 326                         }
 327                 }
 328         }
 329
 330         /**
 331          * Load an item into the cache.
 332          * @param string $code
 333          * @param string $key
 334          */
 335         protected function loadItem( $code, $key ) {
 336                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 337                         $this->initLanguage( $code );
 338                 }
 339
 340                 // Check to see if initLanguage() loaded it for us
 341                 if ( isset( $this->loadedItems[$code][$key] ) ) {
 342                         return;
 343                 }
 344
 345                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 346                         $this->loadItem( $this->shallowFallbacks[$code], $key );
 347
 348                         return;
 349                 }
 350
 351                 if ( in_array( $key, self::$splitKeys ) ) {
 352                         $subkeyList = $this->getSubitem( $code, 'list', $key );
 353                         foreach ( $subkeyList as $subkey ) {
 354                                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 355                                         continue;
 356                                 }
 357                                 $this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
 358                         }
 359                 } else {
 360                         $this->data[$code][$key] = $this->store->get( $code, $key );
 361                 }
 362
 363                 $this->loadedItems[$code][$key] = true;
 364         }
 365
 366         /**
 367          * Load a subitem into the cache
 368          * @param string $code
 369          * @param string $key
 370          * @param string $subkey
 371          */
 372         protected function loadSubitem( $code, $key, $subkey ) {
 373                 if ( !in_array( $key, self::$splitKeys ) ) {
 374                         $this->loadItem( $code, $key );
 375
 376                         return;
 377                 }
 378
 379                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 380                         $this->initLanguage( $code );
 381                 }
 382
 383                 // Check to see if initLanguage() loaded it for us
 384                 if ( isset( $this->loadedItems[$code][$key] ) ||
 385                         isset( $this->loadedSubitems[$code][$key][$subkey] )
 386                 ) {
 387                         return;
 388                 }
 389
 390                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 391                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 392
 393                         return;
 394                 }
 395
 396                 $value = $this->store->get( $code, "$key:$subkey" );
 397                 $this->data[$code][$key][$subkey] = $value;
 398                 $this->loadedSubitems[$code][$key][$subkey] = true;
 399         }
 400
 401         /**
 402          * Returns true if the cache identified by $code is missing or expired.
 403          *
 404          * @param string $code
 405          *
 406          * @return bool
 407          */
 408         public function isExpired( $code ) {
 409                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 410                         wfDebug( __METHOD__ . "($code): forced reload\n" );
 411
 412                         return true;
 413                 }
 414
 415                 $deps = $this->store->get( $code, 'deps' );
 416                 $keys = $this->store->get( $code, 'list' );
 417                 $preload = $this->store->get( $code, 'preload' );
 418                 // Different keys may expire separately for some stores
 419                 if ( $deps === null || $keys === null || $preload === null ) {
 420                         wfDebug( __METHOD__ . "($code): cache missing, need to make one\n" );
 421
 422                         return true;
 423                 }
 424
 425                 foreach ( $deps as $dep ) {
 426                         // Because we're unserializing stuff from cache, we
 427                         // could receive objects of classes that don't exist
 428                         // anymore (e.g. uninstalled extensions)
 429                         // When this happens, always expire the cache
 430                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 431                                 wfDebug( __METHOD__ . "($code): cache for $code expired due to " .
 432                                         get_class( $dep ) . "\n" );
 433
 434                                 return true;
 435                         }
 436                 }
 437
 438                 return false;
 439         }
 440
 441         /**
 442          * Initialise a language in this object. Rebuild the cache if necessary.
 443          * @param string $code
 444          * @throws MWException
 445          */
 446         protected function initLanguage( $code ) {
 447                 if ( isset( $this->initialisedLangs[$code] ) ) {
 448                         return;
 449                 }
 450
 451                 $this->initialisedLangs[$code] = true;
 452
 453                 # If the code is of the wrong form for a Messages*.php file, do a shallow fallback
 454                 if ( !Language::isValidBuiltInCode( $code ) ) {
 455                         $this->initShallowFallback( $code, 'en' );
 456
 457                         return;
 458                 }
 459
 460                 # Recache the data if necessary
 461                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 462                         if ( Language::isSupportedLanguage( $code ) ) {
 463                                 $this->recache( $code );
 464                         } elseif ( $code === 'en' ) {
 465                                 throw new MWException( 'MessagesEn.php is missing.' );
 466                         } else {
 467                                 $this->initShallowFallback( $code, 'en' );
 468                         }
 469
 470                         return;
 471                 }
 472
 473                 # Preload some stuff
 474                 $preload = $this->getItem( $code, 'preload' );
 475                 if ( $preload === null ) {
 476                         if ( $this->manualRecache ) {
 477                                 // No Messages*.php file. Do shallow fallback to en.
 478                                 if ( $code === 'en' ) {
 479                                         throw new MWException( 'No localisation cache found for English. ' .
 480                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 481                                 }
 482                                 $this->initShallowFallback( $code, 'en' );
 483
 484                                 return;
 485                         } else {
 486                                 throw new MWException( 'Invalid or missing localisation cache.' );
 487                         }
 488                 }
 489                 $this->data[$code] = $preload;
 490                 foreach ( $preload as $key => $item ) {
 491                         if ( in_array( $key, self::$splitKeys ) ) {
 492                                 foreach ( $item as $subkey => $subitem ) {
 493                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 494                                 }
 495                         } else {
 496                                 $this->loadedItems[$code][$key] = true;
 497                         }
 498                 }
 499         }
 500
 501         /**
 502          * Create a fallback from one language to another, without creating a
 503          * complete persistent cache.
 504          * @param string $primaryCode
 505          * @param string $fallbackCode
 506          */
 507         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 508                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 509                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 510                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 511                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 512         }
 513
 514         /**
 515          * Read a PHP file containing localisation data.
 516          * @param string $_fileName
 517          * @param string $_fileType
 518          * @throws MWException
 519          * @return array
 520          */
 521         protected function readPHPFile( $_fileName, $_fileType ) {
 522                 // Disable APC caching
 523                 MediaWiki\suppressWarnings();
 524                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 525                 MediaWiki\restoreWarnings();
 526
 527                 include $_fileName;
 528
 529                 MediaWiki\suppressWarnings();
 530                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 531                 MediaWiki\restoreWarnings();
 532
 533                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 534                         $data = compact( self::$allKeys );
 535                 } elseif ( $_fileType == 'aliases' ) {
 536                         $data = compact( 'aliases' );
 537                 } else {
 538                         throw new MWException( __METHOD__ . ": Invalid file type: $_fileType" );
 539                 }
 540
 541                 return $data;
 542         }
 543
 544         /**
 545          * Read a JSON file containing localisation messages.
 546          * @param string $fileName Name of file to read
 547          * @throws MWException If there is a syntax error in the JSON file
 548          * @return array Array with a 'messages' key, or empty array if the file doesn't exist
 549          */
 550         public function readJSONFile( $fileName ) {
 551
 552                 if ( !is_readable( $fileName ) ) {
 553                         return [];
 554                 }
 555
 556                 $json = file_get_contents( $fileName );
 557                 if ( $json === false ) {
 558                         return [];
 559                 }
 560
 561                 $data = FormatJson::decode( $json, true );
 562                 if ( $data === null ) {
 563
 564                         throw new MWException( __METHOD__ . ": Invalid JSON file: $fileName" );
 565                 }
 566
 567                 // Remove keys starting with '@', they're reserved for metadata and non-message data
 568                 foreach ( $data as $key => $unused ) {
 569                         if ( $key === '' || $key[0] === '@' ) {
 570                                 unset( $data[$key] );
 571                         }
 572                 }
 573
 574                 // The JSON format only supports messages, none of the other variables, so wrap the data
 575                 return [ 'messages' => $data ];
 576         }
 577
 578         /**
 579          * Get the compiled plural rules for a given language from the XML files.
 580          * @since 1.20
 581          * @param string $code
 582          * @return array|null
 583          */
 584         public function getCompiledPluralRules( $code ) {
 585                 $rules = $this->getPluralRules( $code );
 586                 if ( $rules === null ) {
 587                         return null;
 588                 }
 589                 try {
 590                         $compiledRules = Evaluator::compile( $rules );
 591                 } catch ( CLDRPluralRuleError $e ) {
 592                         wfDebugLog( 'l10n', $e->getMessage() );
 593
 594                         return [];
 595                 }
 596
 597                 return $compiledRules;
 598         }
 599
 600         /**
 601          * Get the plural rules for a given language from the XML files.
 602          * Cached.
 603          * @since 1.20
 604          * @param string $code
 605          * @return array|null
 606          */
 607         public function getPluralRules( $code ) {
 608                 if ( $this->pluralRules === null ) {
 609                         $this->loadPluralFiles();
 610                 }
 611                 if ( !isset( $this->pluralRules[$code] ) ) {
 612                         return null;
 613                 } else {
 614                         return $this->pluralRules[$code];
 615                 }
 616         }
 617
 618         /**
 619          * Get the plural rule types for a given language from the XML files.
 620          * Cached.
 621          * @since 1.22
 622          * @param string $code
 623          * @return array|null
 624          */
 625         public function getPluralRuleTypes( $code ) {
 626                 if ( $this->pluralRuleTypes === null ) {
 627                         $this->loadPluralFiles();
 628                 }
 629                 if ( !isset( $this->pluralRuleTypes[$code] ) ) {
 630                         return null;
 631                 } else {
 632                         return $this->pluralRuleTypes[$code];
 633                 }
 634         }
 635
 636         /**
 637          * Load the plural XML files.
 638          */
 639         protected function loadPluralFiles() {
 640                 global $IP;
 641                 $cldrPlural = "$IP/languages/data/plurals.xml";
 642                 $mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
 643                 // Load CLDR plural rules
 644                 $this->loadPluralFile( $cldrPlural );
 645                 if ( file_exists( $mwPlural ) ) {
 646                         // Override or extend
 647                         $this->loadPluralFile( $mwPlural );
 648                 }
 649         }
 650
 651         /**
 652          * Load a plural XML file with the given filename, compile the relevant
 653          * rules, and save the compiled rules in a process-local cache.
 654          *
 655          * @param string $fileName
 656          * @throws MWException
 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 = [];
 670                         $ruleTypes = [];
 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
 700                 // This reads in the PHP i18n file with non-messages l10n data
 701                 $fileName = Language::getMessagesFileName( $code );
 702                 if ( !file_exists( $fileName ) ) {
 703                         $data = [];
 704                 } else {
 705                         $deps[] = new FileDependency( $fileName );
 706                         $data = $this->readPHPFile( $fileName, 'core' );
 707                 }
 708
 709                 # Load CLDR plural rules for JavaScript
 710                 $data['pluralRules'] = $this->getPluralRules( $code );
 711                 # And for PHP
 712                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 713                 # Load plural rule types
 714                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 715
 716                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 717                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 718
 719                 return $data;
 720         }
 721
 722         /**
 723          * Merge two localisation values, a primary and a fallback, overwriting the
 724          * primary value in place.
 725          * @param string $key
 726          * @param mixed $value
 727          * @param mixed $fallbackValue
 728          */
 729         protected function mergeItem( $key, &$value, $fallbackValue ) {
 730                 if ( !is_null( $value ) ) {
 731                         if ( !is_null( $fallbackValue ) ) {
 732                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 733                                         $value = $value + $fallbackValue;
 734                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 735                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 736                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 737                                         $value = array_merge_recursive( $value, $fallbackValue );
 738                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 739                                         if ( !empty( $value['inherit'] ) ) {
 740                                                 $value = array_merge( $fallbackValue, $value );
 741                                         }
 742
 743                                         if ( isset( $value['inherit'] ) ) {
 744                                                 unset( $value['inherit'] );
 745                                         }
 746                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 747                                         $this->mergeMagicWords( $value, $fallbackValue );
 748                                 }
 749                         }
 750                 } else {
 751                         $value = $fallbackValue;
 752                 }
 753         }
 754
 755         /**
 756          * @param mixed $value
 757          * @param mixed $fallbackValue
 758          */
 759         protected function mergeMagicWords( &$value, $fallbackValue ) {
 760                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 761                         if ( !isset( $value[$magicName] ) ) {
 762                                 $value[$magicName] = $fallbackInfo;
 763                         } else {
 764                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 765                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 766                                 $synonyms = array_values( array_unique( array_merge(
 767                                         $newSynonyms, $oldSynonyms ) ) );
 768                                 $value[$magicName] = array_merge( [ $fallbackInfo[0] ], $synonyms );
 769                         }
 770                 }
 771         }
 772
 773         /**
 774          * Given an array mapping language code to localisation value, such as is
 775          * found in extension *.i18n.php files, iterate through a fallback sequence
 776          * to merge the given data with an existing primary value.
 777          *
 778          * Returns true if any data from the extension array was used, false
 779          * otherwise.
 780          * @param array $codeSequence
 781          * @param string $key
 782          * @param mixed $value
 783          * @param mixed $fallbackValue
 784          * @return bool
 785          */
 786         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 787                 $used = false;
 788                 foreach ( $codeSequence as $code ) {
 789                         if ( isset( $fallbackValue[$code] ) ) {
 790                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 791                                 $used = true;
 792                         }
 793                 }
 794
 795                 return $used;
 796         }
 797
 798         /**
 799          * Gets the combined list of messages dirs from
 800          * core and extensions
 801          *
 802          * @since 1.25
 803          * @return array
 804          */
 805         public function getMessagesDirs() {
 806                 global $wgMessagesDirs, $IP;
 807                 return [
 808                         'core' => "$IP/languages/i18n",
 809                         'api' => "$IP/includes/api/i18n",
 810                         'oojs-ui' => "$IP/resources/lib/oojs-ui/i18n",
 811                 ] + $wgMessagesDirs;
 812         }
 813
 814         /**
 815          * Load localisation data for a given language for both core and extensions
 816          * and save it to the persistent cache store and the process cache
 817          * @param string $code
 818          * @throws MWException
 819          */
 820         public function recache( $code ) {
 821                 global $wgExtensionMessagesFiles;
 822
 823                 if ( !$code ) {
 824                         throw new MWException( "Invalid language code requested" );
 825                 }
 826                 $this->recachedLangs[$code] = true;
 827
 828                 # Initial values
 829                 $initialData = array_fill_keys( self::$allKeys, null );
 830                 $coreData = $initialData;
 831                 $deps = [];
 832
 833                 # Load the primary localisation from the source file
 834                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 835                 if ( $data === false ) {
 836                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 837                         $coreData['fallback'] = 'en';
 838                 } else {
 839                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 840
 841                         # Merge primary localisation
 842                         foreach ( $data as $key => $value ) {
 843                                 $this->mergeItem( $key, $coreData[$key], $value );
 844                         }
 845                 }
 846
 847                 # Fill in the fallback if it's not there already
 848                 if ( is_null( $coreData['fallback'] ) ) {
 849                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 850                 }
 851                 if ( $coreData['fallback'] === false ) {
 852                         $coreData['fallbackSequence'] = [];
 853                 } else {
 854                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 855                         $len = count( $coreData['fallbackSequence'] );
 856
 857                         # Ensure that the sequence ends at en
 858                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 859                                 $coreData['fallbackSequence'][] = 'en';
 860                         }
 861                 }
 862
 863                 $codeSequence = array_merge( [ $code ], $coreData['fallbackSequence'] );
 864                 $messageDirs = $this->getMessagesDirs();
 865
 866                 # Load non-JSON localisation data for extensions
 867                 $extensionData = array_fill_keys( $codeSequence, $initialData );
 868                 foreach ( $wgExtensionMessagesFiles as $extension => $fileName ) {
 869                         if ( isset( $messageDirs[$extension] ) ) {
 870                                 # This extension has JSON message data; skip the PHP shim
 871                                 continue;
 872                         }
 873
 874                         $data = $this->readPHPFile( $fileName, 'extension' );
 875                         $used = false;
 876
 877                         foreach ( $data as $key => $item ) {
 878                                 foreach ( $codeSequence as $csCode ) {
 879                                         if ( isset( $item[$csCode] ) ) {
 880                                                 $this->mergeItem( $key, $extensionData[$csCode][$key], $item[$csCode] );
 881                                                 $used = true;
 882                                         }
 883                                 }
 884                         }
 885
 886                         if ( $used ) {
 887                                 $deps[] = new FileDependency( $fileName );
 888                         }
 889                 }
 890
 891                 # Load the localisation data for each fallback, then merge it into the full array
 892                 $allData = $initialData;
 893                 foreach ( $codeSequence as $csCode ) {
 894                         $csData = $initialData;
 895
 896                         # Load core messages and the extension localisations.
 897                         foreach ( $messageDirs as $dirs ) {
 898                                 foreach ( (array)$dirs as $dir ) {
 899                                         $fileName = "$dir/$csCode.json";
 900                                         $data = $this->readJSONFile( $fileName );
 901
 902                                         foreach ( $data as $key => $item ) {
 903                                                 $this->mergeItem( $key, $csData[$key], $item );
 904                                         }
 905
 906                                         $deps[] = new FileDependency( $fileName );
 907                                 }
 908                         }
 909
 910                         # Merge non-JSON extension data
 911                         if ( isset( $extensionData[$csCode] ) ) {
 912                                 foreach ( $extensionData[$csCode] as $key => $item ) {
 913                                         $this->mergeItem( $key, $csData[$key], $item );
 914                                 }
 915                         }
 916
 917                         if ( $csCode === $code ) {
 918                                 # Merge core data into extension data
 919                                 foreach ( $coreData as $key => $item ) {
 920                                         $this->mergeItem( $key, $csData[$key], $item );
 921                                 }
 922                         } else {
 923                                 # Load the secondary localisation from the source file to
 924                                 # avoid infinite cycles on cyclic fallbacks
 925                                 $fbData = $this->readSourceFilesAndRegisterDeps( $csCode, $deps );
 926                                 if ( $fbData !== false ) {
 927                                         # Only merge the keys that make sense to merge
 928                                         foreach ( self::$allKeys as $key ) {
 929                                                 if ( !isset( $fbData[$key] ) ) {
 930                                                         continue;
 931                                                 }
 932
 933                                                 if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 934                                                         $this->mergeItem( $key, $csData[$key], $fbData[$key] );
 935                                                 }
 936                                         }
 937                                 }
 938                         }
 939
 940                         # Allow extensions an opportunity to adjust the data for this
 941                         # fallback
 942                         Hooks::run( 'LocalisationCacheRecacheFallback', [ $this, $csCode, &$csData ] );
 943
 944                         # Merge the data for this fallback into the final array
 945                         if ( $csCode === $code ) {
 946                                 $allData = $csData;
 947                         } else {
 948                                 foreach ( self::$allKeys as $key ) {
 949                                         if ( !isset( $csData[$key] ) ) {
 950                                                 continue;
 951                                         }
 952
 953                                         if ( is_null( $allData[$key] ) || $this->isMergeableKey( $key ) ) {
 954                                                 $this->mergeItem( $key, $allData[$key], $csData[$key] );
 955                                         }
 956                                 }
 957                         }
 958                 }
 959
 960                 # Add cache dependencies for any referenced globals
 961                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 962                 // $wgMessagesDirs is used in LocalisationCache::getMessagesDirs()
 963                 $deps['wgMessagesDirs'] = new GlobalDependency( 'wgMessagesDirs' );
 964                 $deps['version'] = new ConstantDependency( 'LocalisationCache::VERSION' );
 965
 966                 # Add dependencies to the cache entry
 967                 $allData['deps'] = $deps;
 968
 969                 # Replace spaces with underscores in namespace names
 970                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 971
 972                 # And do the same for special page aliases. $page is an array.
 973                 foreach ( $allData['specialPageAliases'] as &$page ) {
 974                         $page = str_replace( ' ', '_', $page );
 975                 }
 976                 # Decouple the reference to prevent accidental damage
 977                 unset( $page );
 978
 979                 # If there were no plural rules, return an empty array
 980                 if ( $allData['pluralRules'] === null ) {
 981                         $allData['pluralRules'] = [];
 982                 }
 983                 if ( $allData['compiledPluralRules'] === null ) {
 984                         $allData['compiledPluralRules'] = [];
 985                 }
 986                 # If there were no plural rule types, return an empty array
 987                 if ( $allData['pluralRuleTypes'] === null ) {
 988                         $allData['pluralRuleTypes'] = [];
 989                 }
 990
 991                 # Set the list keys
 992                 $allData['list'] = [];
 993                 foreach ( self::$splitKeys as $key ) {
 994                         $allData['list'][$key] = array_keys( $allData[$key] );
 995                 }
 996                 # Run hooks
 997                 $purgeBlobs = true;
 998                 Hooks::run( 'LocalisationCacheRecache', [ $this, $code, &$allData, &$purgeBlobs ] );
 999
1000                 if ( is_null( $allData['namespaceNames'] ) ) {
1001                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
1002                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
1003                 }
1004
1005                 # Set the preload key
1006                 $allData['preload'] = $this->buildPreload( $allData );
1007
1008                 # Save to the process cache and register the items loaded
1009                 $this->data[$code] = $allData;
1010                 foreach ( $allData as $key => $item ) {
1011                         $this->loadedItems[$code][$key] = true;
1012                 }
1013
1014                 # Save to the persistent cache
1015                 $this->store->startWrite( $code );
1016                 foreach ( $allData as $key => $value ) {
1017                         if ( in_array( $key, self::$splitKeys ) ) {
1018                                 foreach ( $value as $subkey => $subvalue ) {
1019                                         $this->store->set( "$key:$subkey", $subvalue );
1020                                 }
1021                         } else {
1022                                 $this->store->set( $key, $value );
1023                         }
1024                 }
1025                 $this->store->finishWrite();
1026
1027                 # Clear out the MessageBlobStore
1028                 # HACK: If using a null (i.e. disabled) storage backend, we
1029                 # can't write to the MessageBlobStore either
1030                 if ( $purgeBlobs && !$this->store instanceof LCStoreNull ) {
1031                         $blobStore = new MessageBlobStore();
1032                         $blobStore->clear();
1033                 }
1034
1035         }
1036
1037         /**
1038          * Build the preload item from the given pre-cache data.
1039          *
1040          * The preload item will be loaded automatically, improving performance
1041          * for the commonly-requested items it contains.
1042          * @param array $data
1043          * @return array
1044          */
1045         protected function buildPreload( $data ) {
1046                 $preload = [ 'messages' => [] ];
1047                 foreach ( self::$preloadedKeys as $key ) {
1048                         $preload[$key] = $data[$key];
1049                 }
1050
1051                 foreach ( $data['preloadedMessages'] as $subkey ) {
1052                         if ( isset( $data['messages'][$subkey] ) ) {
1053                                 $subitem = $data['messages'][$subkey];
1054                         } else {
1055                                 $subitem = null;
1056                         }
1057                         $preload['messages'][$subkey] = $subitem;
1058                 }
1059
1060                 return $preload;
1061         }
1062
1063         /**
1064          * Unload the data for a given language from the object cache.
1065          * Reduces memory usage.
1066          * @param string $code
1067          */
1068         public function unload( $code ) {
1069                 unset( $this->data[$code] );
1070                 unset( $this->loadedItems[$code] );
1071                 unset( $this->loadedSubitems[$code] );
1072                 unset( $this->initialisedLangs[$code] );
1073                 unset( $this->shallowFallbacks[$code] );
1074
1075                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
1076                         if ( $fbCode === $code ) {
1077                                 $this->unload( $shallowCode );
1078                         }
1079                 }
1080         }
1081
1082         /**
1083          * Unload all data
1084          */
1085         public function unloadAll() {
1086                 foreach ( $this->initialisedLangs as $lang => $unused ) {
1087                         $this->unload( $lang );
1088                 }
1089         }
1090
1091         /**
1092          * Disable the storage backend
1093          */
1094         public function disableBackend() {
1095                 $this->store = new LCStoreNull;
1096                 $this->manualRecache = false;
1097         }
1098 }
1099
1100 /**
1101  * Interface for the persistence layer of LocalisationCache.
1102  *
1103  * The persistence layer is two-level hierarchical cache. The first level
1104  * is the language, the second level is the item or subitem.
1105  *
1106  * Since the data for a whole language is rebuilt in one operation, it needs
1107  * to have a fast and atomic method for deleting or replacing all of the
1108  * current data for a given language. The interface reflects this bulk update
1109  * operation. Callers writing to the cache must first call startWrite(), then
1110  * will call set() a couple of thousand times, then will call finishWrite()
1111  * to commit the operation. When finishWrite() is called, the cache is
1112  * expected to delete all data previously stored for that language.
1113  *
1114  * The values stored are PHP variables suitable for serialize(). Implementations
1115  * of LCStore are responsible for serializing and unserializing.
1116  */
1117 interface LCStore {
1118         /**
1119          * Get a value.
1120          * @param string $code Language code
1121          * @param string $key Cache key
1122          */
1123         function get( $code, $key );
1124
1125         /**
1126          * Start a write transaction.
1127          * @param string $code Language code
1128          */
1129         function startWrite( $code );
1130
1131         /**
1132          * Finish a write transaction.
1133          */
1134         function finishWrite();
1135
1136         /**
1137          * Set a key to a given value. startWrite() must be called before this
1138          * is called, and finishWrite() must be called afterwards.
1139          * @param string $key
1140          * @param mixed $value
1141          */
1142         function set( $key, $value );
1143 }
1144
1145 /**
1146  * LCStore implementation which uses the standard DB functions to store data.
1147  * This will work on any MediaWiki installation.
1148  */
1149 class LCStoreDB implements LCStore {
1150         /** @var string */
1151         private $currentLang;
1152         /** @var bool */
1153         private $writesDone = false;
1154         /** @var IDatabase */
1155         private $dbw;
1156         /** @var array */
1157         private $batch = [];
1158         /** @var bool */
1159         private $readOnly = false;
1160
1161         public function get( $code, $key ) {
1162                 if ( $this->writesDone && $this->dbw ) {
1163                         $db = $this->dbw; // see the changes in finishWrite()
1164                 } else {
1165                         $db = wfGetDB( DB_SLAVE );
1166                 }
1167
1168                 $value = $db->selectField(
1169                         'l10n_cache',
1170                         'lc_value',
1171                         [ 'lc_lang' => $code, 'lc_key' => $key ],
1172                         __METHOD__
1173                 );
1174
1175                 return ( $value !== false ) ? unserialize( $db->decodeBlob( $value ) ) : null;
1176         }
1177
1178         public function startWrite( $code ) {
1179                 if ( $this->readOnly ) {
1180                         return;
1181                 } elseif ( !$code ) {
1182                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1183                 }
1184
1185                 $this->dbw = wfGetDB( DB_MASTER );
1186                 $this->readOnly = $this->dbw->isReadOnly();
1187
1188                 $this->currentLang = $code;
1189                 $this->batch = [];
1190         }
1191
1192         public function finishWrite() {
1193                 if ( $this->readOnly ) {
1194                         return;
1195                 } elseif ( is_null( $this->currentLang ) ) {
1196                         throw new MWException( __CLASS__ . ': must call startWrite() before finishWrite()' );
1197                 }
1198
1199                 $this->dbw->startAtomic( __METHOD__ );
1200                 try {
1201                         $this->dbw->delete(
1202                                 'l10n_cache',
1203                                 [ 'lc_lang' => $this->currentLang ],
1204                                 __METHOD__
1205                         );
1206                         foreach ( array_chunk( $this->batch, 500 ) as $rows ) {
1207                                 $this->dbw->insert( 'l10n_cache', $rows, __METHOD__ );
1208                         }
1209                         $this->writesDone = true;
1210                 } catch ( DBQueryError $e ) {
1211                         if ( $this->dbw->wasReadOnlyError() ) {
1212                                 $this->readOnly = true; // just avoid site down time
1213                         } else {
1214                                 throw $e;
1215                         }
1216                 }
1217                 $this->dbw->endAtomic( __METHOD__ );
1218
1219                 $this->currentLang = null;
1220                 $this->batch = [];
1221         }
1222
1223         public function set( $key, $value ) {
1224                 if ( $this->readOnly ) {
1225                         return;
1226                 } elseif ( is_null( $this->currentLang ) ) {
1227                         throw new MWException( __CLASS__ . ': must call startWrite() before set()' );
1228                 }
1229
1230                 $this->batch[] = [
1231                         'lc_lang' => $this->currentLang,
1232                         'lc_key' => $key,
1233                         'lc_value' => $this->dbw->encodeBlob( serialize( $value ) )
1234                 ];
1235         }
1236 }
1237
1238 /**
1239  * LCStore implementation which stores data as a collection of CDB files in the
1240  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1241  * will throw an exception.
1242  *
1243  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1244  * the directory is on a local filesystem and there is ample kernel cache
1245  * space. The performance advantage is greater when the DBA extension is
1246  * available than it is with the PHP port.
1247  *
1248  * See Cdb.php and http://cr.yp.to/cdb.html
1249  */
1250 class LCStoreCDB implements LCStore {
1251         /** @var CdbReader[] */
1252         private $readers;
1253
1254         /** @var CdbWriter */
1255         private $writer;
1256
1257         /** @var string Current language code */
1258         private $currentLang;
1259
1260         /** @var bool|string Cache directory. False if not set */
1261         private $directory;
1262
1263         function __construct( $conf = [] ) {
1264                 global $wgCacheDirectory;
1265
1266                 if ( isset( $conf['directory'] ) ) {
1267                         $this->directory = $conf['directory'];
1268                 } else {
1269                         $this->directory = $wgCacheDirectory;
1270                 }
1271         }
1272
1273         public function get( $code, $key ) {
1274                 if ( !isset( $this->readers[$code] ) ) {
1275                         $fileName = $this->getFileName( $code );
1276
1277                         $this->readers[$code] = false;
1278                         if ( file_exists( $fileName ) ) {
1279                                 try {
1280                                         $this->readers[$code] = CdbReader::open( $fileName );
1281                                 } catch ( CdbException $e ) {
1282                                         wfDebug( __METHOD__ . ": unable to open cdb file for reading\n" );
1283                                 }
1284                         }
1285                 }
1286
1287                 if ( !$this->readers[$code] ) {
1288                         return null;
1289                 } else {
1290                         $value = false;
1291                         try {
1292                                 $value = $this->readers[$code]->get( $key );
1293                         } catch ( CdbException $e ) {
1294                                 wfDebug( __METHOD__ . ": CdbException caught, error message was "
1295                                         . $e->getMessage() . "\n" );
1296                         }
1297                         if ( $value === false ) {
1298                                 return null;
1299                         }
1300
1301                         return unserialize( $value );
1302                 }
1303         }
1304
1305         public function startWrite( $code ) {
1306                 if ( !file_exists( $this->directory ) ) {
1307                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1308                                 throw new MWException( "Unable to create the localisation store " .
1309                                         "directory \"{$this->directory}\"" );
1310                         }
1311                 }
1312
1313                 // Close reader to stop permission errors on write
1314                 if ( !empty( $this->readers[$code] ) ) {
1315                         $this->readers[$code]->close();
1316                 }
1317
1318                 try {
1319                         $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1320                 } catch ( CdbException $e ) {
1321                         throw new MWException( $e->getMessage() );
1322                 }
1323                 $this->currentLang = $code;
1324         }
1325
1326         public function finishWrite() {
1327                 // Close the writer
1328                 try {
1329                         $this->writer->close();
1330                 } catch ( CdbException $e ) {
1331                         throw new MWException( $e->getMessage() );
1332                 }
1333                 $this->writer = null;
1334                 unset( $this->readers[$this->currentLang] );
1335                 $this->currentLang = null;
1336         }
1337
1338         public function set( $key, $value ) {
1339                 if ( is_null( $this->writer ) ) {
1340                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1341                 }
1342                 try {
1343                         $this->writer->set( $key, serialize( $value ) );
1344                 } catch ( CdbException $e ) {
1345                         throw new MWException( $e->getMessage() );
1346                 }
1347         }
1348
1349         protected function getFileName( $code ) {
1350                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1351                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1352                 }
1353
1354                 return "{$this->directory}/l10n_cache-$code.cdb";
1355         }
1356 }
1357
1358 /**
1359  * Null store backend, used to avoid DB errors during install
1360  */
1361 class LCStoreNull implements LCStore {
1362         public function get( $code, $key ) {
1363                 return null;
1364         }
1365
1366         public function startWrite( $code ) {
1367         }
1368
1369         public function finishWrite() {
1370         }
1371
1372         public function set( $key, $value ) {
1373         }
1374 }
1375
1376 /**
1377  * A localisation cache optimised for loading large amounts of data for many
1378  * languages. Used by rebuildLocalisationCache.php.
1379  */
1380 class LocalisationCacheBulkLoad extends LocalisationCache {
1381         /**
1382          * A cache of the contents of data files.
1383          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1384          */
1385         private $fileCache = [];
1386
1387         /**
1388          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1389          * to keep the most recently used language codes at the end of the array, and
1390          * the language codes that are ready to be deleted at the beginning.
1391          */
1392         private $mruLangs = [];
1393
1394         /**
1395          * Maximum number of languages that may be loaded into $this->data
1396          */
1397         private $maxLoadedLangs = 10;
1398
1399         /**
1400          * @param string $fileName
1401          * @param string $fileType
1402          * @return array|mixed
1403          */
1404         protected function readPHPFile( $fileName, $fileType ) {
1405                 $serialize = $fileType === 'core';
1406                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1407                         $data = parent::readPHPFile( $fileName, $fileType );
1408
1409                         if ( $serialize ) {
1410                                 $encData = serialize( $data );
1411                         } else {
1412                                 $encData = $data;
1413                         }
1414
1415                         $this->fileCache[$fileName][$fileType] = $encData;
1416
1417                         return $data;
1418                 } elseif ( $serialize ) {
1419                         return unserialize( $this->fileCache[$fileName][$fileType] );
1420                 } else {
1421                         return $this->fileCache[$fileName][$fileType];
1422                 }
1423         }
1424
1425         /**
1426          * @param string $code
1427          * @param string $key
1428          * @return mixed
1429          */
1430         public function getItem( $code, $key ) {
1431                 unset( $this->mruLangs[$code] );
1432                 $this->mruLangs[$code] = true;
1433
1434                 return parent::getItem( $code, $key );
1435         }
1436
1437         /**
1438          * @param string $code
1439          * @param string $key
1440          * @param string $subkey
1441          * @return mixed
1442          */
1443         public function getSubitem( $code, $key, $subkey ) {
1444                 unset( $this->mruLangs[$code] );
1445                 $this->mruLangs[$code] = true;
1446
1447                 return parent::getSubitem( $code, $key, $subkey );
1448         }
1449
1450         /**
1451          * @param string $code
1452          */
1453         public function recache( $code ) {
1454                 parent::recache( $code );
1455                 unset( $this->mruLangs[$code] );
1456                 $this->mruLangs[$code] = true;
1457                 $this->trimCache();
1458         }
1459
1460         /**
1461          * @param string $code
1462          */
1463         public function unload( $code ) {
1464                 unset( $this->mruLangs[$code] );
1465                 parent::unload( $code );
1466         }
1467
1468         /**
1469          * Unload cached languages until there are less than $this->maxLoadedLangs
1470          */
1471         protected function trimCache() {
1472                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1473                         reset( $this->mruLangs );
1474                         $code = key( $this->mruLangs );
1475                         wfDebug( __METHOD__ . ": unloading $code\n" );
1476                         $this->unload( $code );
1477                 }
1478         }
1479 }