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