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                 // The JSON format only supports messages, none of the other variables, so wrap the data
 563                 return array( 'messages' => $data );
 564         }
 565
 566         /**
 567          * Get the compiled plural rules for a given language from the XML files.
 568          * @since 1.20
 569          * @param string $code
 570          * @return array|null
 571          */
 572         public function getCompiledPluralRules( $code ) {
 573                 $rules = $this->getPluralRules( $code );
 574                 if ( $rules === null ) {
 575                         return null;
 576                 }
 577                 try {
 578                         $compiledRules = CLDRPluralRuleEvaluator::compile( $rules );
 579                 } catch ( CLDRPluralRuleError $e ) {
 580                         wfDebugLog( 'l10n', $e->getMessage() );
 581
 582                         return array();
 583                 }
 584
 585                 return $compiledRules;
 586         }
 587
 588         /**
 589          * Get the plural rules for a given language from the XML files.
 590          * Cached.
 591          * @since 1.20
 592          * @param string $code
 593          * @return array|null
 594          */
 595         public function getPluralRules( $code ) {
 596                 if ( $this->pluralRules === null ) {
 597                         $this->loadPluralFiles();
 598                 }
 599                 if ( !isset( $this->pluralRules[$code] ) ) {
 600                         return null;
 601                 } else {
 602                         return $this->pluralRules[$code];
 603                 }
 604         }
 605
 606         /**
 607          * Get the plural rule types for a given language from the XML files.
 608          * Cached.
 609          * @since 1.22
 610          * @param string $code
 611          * @return array|null
 612          */
 613         public function getPluralRuleTypes( $code ) {
 614                 if ( $this->pluralRuleTypes === null ) {
 615                         $this->loadPluralFiles();
 616                 }
 617                 if ( !isset( $this->pluralRuleTypes[$code] ) ) {
 618                         return null;
 619                 } else {
 620                         return $this->pluralRuleTypes[$code];
 621                 }
 622         }
 623
 624         /**
 625          * Load the plural XML files.
 626          */
 627         protected function loadPluralFiles() {
 628                 global $IP;
 629                 $cldrPlural = "$IP/languages/data/plurals.xml";
 630                 $mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
 631                 // Load CLDR plural rules
 632                 $this->loadPluralFile( $cldrPlural );
 633                 if ( file_exists( $mwPlural ) ) {
 634                         // Override or extend
 635                         $this->loadPluralFile( $mwPlural );
 636                 }
 637         }
 638
 639         /**
 640          * Load a plural XML file with the given filename, compile the relevant
 641          * rules, and save the compiled rules in a process-local cache.
 642          *
 643          * @param string $fileName
 644          * @throws MWException
 645          */
 646         protected function loadPluralFile( $fileName ) {
 647                 // Use file_get_contents instead of DOMDocument::load (T58439)
 648                 $xml = file_get_contents( $fileName );
 649                 if ( !$xml ) {
 650                         throw new MWException( "Unable to read plurals file $fileName" );
 651                 }
 652                 $doc = new DOMDocument;
 653                 $doc->loadXML( $xml );
 654                 $rulesets = $doc->getElementsByTagName( "pluralRules" );
 655                 foreach ( $rulesets as $ruleset ) {
 656                         $codes = $ruleset->getAttribute( 'locales' );
 657                         $rules = array();
 658                         $ruleTypes = array();
 659                         $ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
 660                         foreach ( $ruleElements as $elt ) {
 661                                 $ruleType = $elt->getAttribute( 'count' );
 662                                 if ( $ruleType === 'other' ) {
 663                                         // Don't record "other" rules, which have an empty condition
 664                                         continue;
 665                                 }
 666                                 $rules[] = $elt->nodeValue;
 667                                 $ruleTypes[] = $ruleType;
 668                         }
 669                         foreach ( explode( ' ', $codes ) as $code ) {
 670                                 $this->pluralRules[$code] = $rules;
 671                                 $this->pluralRuleTypes[$code] = $ruleTypes;
 672                         }
 673                 }
 674         }
 675
 676         /**
 677          * Read the data from the source files for a given language, and register
 678          * the relevant dependencies in the $deps array. If the localisation
 679          * exists, the data array is returned, otherwise false is returned.
 680          *
 681          * @param string $code
 682          * @param array $deps
 683          * @return array
 684          */
 685         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 686                 global $IP;
 687
 688                 // This reads in the PHP i18n file with non-messages l10n data
 689                 $fileName = Language::getMessagesFileName( $code );
 690                 if ( !file_exists( $fileName ) ) {
 691                         $data = array();
 692                 } else {
 693                         $deps[] = new FileDependency( $fileName );
 694                         $data = $this->readPHPFile( $fileName, 'core' );
 695                 }
 696
 697                 # Load CLDR plural rules for JavaScript
 698                 $data['pluralRules'] = $this->getPluralRules( $code );
 699                 # And for PHP
 700                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 701                 # Load plural rule types
 702                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 703
 704                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 705                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 706
 707                 return $data;
 708         }
 709
 710         /**
 711          * Merge two localisation values, a primary and a fallback, overwriting the
 712          * primary value in place.
 713          * @param string $key
 714          * @param mixed $value
 715          * @param mixed $fallbackValue
 716          */
 717         protected function mergeItem( $key, &$value, $fallbackValue ) {
 718                 if ( !is_null( $value ) ) {
 719                         if ( !is_null( $fallbackValue ) ) {
 720                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 721                                         $value = $value + $fallbackValue;
 722                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 723                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 724                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 725                                         $value = array_merge_recursive( $value, $fallbackValue );
 726                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 727                                         if ( !empty( $value['inherit'] ) ) {
 728                                                 $value = array_merge( $fallbackValue, $value );
 729                                         }
 730
 731                                         if ( isset( $value['inherit'] ) ) {
 732                                                 unset( $value['inherit'] );
 733                                         }
 734                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 735                                         $this->mergeMagicWords( $value, $fallbackValue );
 736                                 }
 737                         }
 738                 } else {
 739                         $value = $fallbackValue;
 740                 }
 741         }
 742
 743         /**
 744          * @param mixed $value
 745          * @param mixed $fallbackValue
 746          */
 747         protected function mergeMagicWords( &$value, $fallbackValue ) {
 748                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 749                         if ( !isset( $value[$magicName] ) ) {
 750                                 $value[$magicName] = $fallbackInfo;
 751                         } else {
 752                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 753                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 754                                 $synonyms = array_values( array_unique( array_merge(
 755                                         $newSynonyms, $oldSynonyms ) ) );
 756                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 757                         }
 758                 }
 759         }
 760
 761         /**
 762          * Given an array mapping language code to localisation value, such as is
 763          * found in extension *.i18n.php files, iterate through a fallback sequence
 764          * to merge the given data with an existing primary value.
 765          *
 766          * Returns true if any data from the extension array was used, false
 767          * otherwise.
 768          * @param array $codeSequence
 769          * @param string $key
 770          * @param mixed $value
 771          * @param mixed $fallbackValue
 772          * @return bool
 773          */
 774         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 775                 $used = false;
 776                 foreach ( $codeSequence as $code ) {
 777                         if ( isset( $fallbackValue[$code] ) ) {
 778                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 779                                 $used = true;
 780                         }
 781                 }
 782
 783                 return $used;
 784         }
 785
 786         /**
 787          * Gets the combined list of messages dirs from
 788          * core and extensions
 789          *
 790          * @since 1.25
 791          * @return array
 792          */
 793         public function getMessagesDirs() {
 794                 global $wgMessagesDirs, $IP;
 795                 return array(
 796                         'core' => "$IP/languages/i18n",
 797                         'api' => "$IP/includes/api/i18n",
 798                         'oojs-ui' => "$IP/resources/lib/oojs-ui/i18n",
 799                 ) + $wgMessagesDirs;
 800         }
 801
 802         /**
 803          * Load localisation data for a given language for both core and extensions
 804          * and save it to the persistent cache store and the process cache
 805          * @param string $code
 806          * @throws MWException
 807          */
 808         public function recache( $code ) {
 809                 global $wgExtensionMessagesFiles;
 810
 811                 if ( !$code ) {
 812                         throw new MWException( "Invalid language code requested" );
 813                 }
 814                 $this->recachedLangs[$code] = true;
 815
 816                 # Initial values
 817                 $initialData = array_combine(
 818                         self::$allKeys,
 819                         array_fill( 0, count( self::$allKeys ), null ) );
 820                 $coreData = $initialData;
 821                 $deps = array();
 822
 823                 # Load the primary localisation from the source file
 824                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 825                 if ( $data === false ) {
 826                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 827                         $coreData['fallback'] = 'en';
 828                 } else {
 829                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 830
 831                         # Merge primary localisation
 832                         foreach ( $data as $key => $value ) {
 833                                 $this->mergeItem( $key, $coreData[$key], $value );
 834                         }
 835                 }
 836
 837                 # Fill in the fallback if it's not there already
 838                 if ( is_null( $coreData['fallback'] ) ) {
 839                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 840                 }
 841                 if ( $coreData['fallback'] === false ) {
 842                         $coreData['fallbackSequence'] = array();
 843                 } else {
 844                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 845                         $len = count( $coreData['fallbackSequence'] );
 846
 847                         # Ensure that the sequence ends at en
 848                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 849                                 $coreData['fallbackSequence'][] = 'en';
 850                         }
 851                 }
 852
 853                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 854                 $messageDirs = $this->getMessagesDirs();
 855
 856                 # Load non-JSON localisation data for extensions
 857                 $extensionData = array_combine(
 858                         $codeSequence,
 859                         array_fill( 0, count( $codeSequence ), $initialData ) );
 860                 foreach ( $wgExtensionMessagesFiles as $extension => $fileName ) {
 861                         if ( isset( $messageDirs[$extension] ) ) {
 862                                 # This extension has JSON message data; skip the PHP shim
 863                                 continue;
 864                         }
 865
 866                         $data = $this->readPHPFile( $fileName, 'extension' );
 867                         $used = false;
 868
 869                         foreach ( $data as $key => $item ) {
 870                                 foreach ( $codeSequence as $csCode ) {
 871                                         if ( isset( $item[$csCode] ) ) {
 872                                                 $this->mergeItem( $key, $extensionData[$csCode][$key], $item[$csCode] );
 873                                                 $used = true;
 874                                         }
 875                                 }
 876                         }
 877
 878                         if ( $used ) {
 879                                 $deps[] = new FileDependency( $fileName );
 880                         }
 881                 }
 882
 883                 # Load the localisation data for each fallback, then merge it into the full array
 884                 $allData = $initialData;
 885                 foreach ( $codeSequence as $csCode ) {
 886                         $csData = $initialData;
 887
 888                         # Load core messages and the extension localisations.
 889                         foreach ( $messageDirs as $dirs ) {
 890                                 foreach ( (array)$dirs as $dir ) {
 891                                         $fileName = "$dir/$csCode.json";
 892                                         $data = $this->readJSONFile( $fileName );
 893
 894                                         foreach ( $data as $key => $item ) {
 895                                                 $this->mergeItem( $key, $csData[$key], $item );
 896                                         }
 897
 898                                         $deps[] = new FileDependency( $fileName );
 899                                 }
 900                         }
 901
 902                         # Merge non-JSON extension data
 903                         if ( isset( $extensionData[$csCode] ) ) {
 904                                 foreach ( $extensionData[$csCode] as $key => $item ) {
 905                                         $this->mergeItem( $key, $csData[$key], $item );
 906                                 }
 907                         }
 908
 909                         if ( $csCode === $code ) {
 910                                 # Merge core data into extension data
 911                                 foreach ( $coreData as $key => $item ) {
 912                                         $this->mergeItem( $key, $csData[$key], $item );
 913                                 }
 914                         } else {
 915                                 # Load the secondary localisation from the source file to
 916                                 # avoid infinite cycles on cyclic fallbacks
 917                                 $fbData = $this->readSourceFilesAndRegisterDeps( $csCode, $deps );
 918                                 if ( $fbData !== false ) {
 919                                         # Only merge the keys that make sense to merge
 920                                         foreach ( self::$allKeys as $key ) {
 921                                                 if ( !isset( $fbData[$key] ) ) {
 922                                                         continue;
 923                                                 }
 924
 925                                                 if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 926                                                         $this->mergeItem( $key, $csData[$key], $fbData[$key] );
 927                                                 }
 928                                         }
 929                                 }
 930                         }
 931
 932                         # Allow extensions an opportunity to adjust the data for this
 933                         # fallback
 934                         Hooks::run( 'LocalisationCacheRecacheFallback', array( $this, $csCode, &$csData ) );
 935
 936                         # Merge the data for this fallback into the final array
 937                         if ( $csCode === $code ) {
 938                                 $allData = $csData;
 939                         } else {
 940                                 foreach ( self::$allKeys as $key ) {
 941                                         if ( !isset( $csData[$key] ) ) {
 942                                                 continue;
 943                                         }
 944
 945                                         if ( is_null( $allData[$key] ) || $this->isMergeableKey( $key ) ) {
 946                                                 $this->mergeItem( $key, $allData[$key], $csData[$key] );
 947                                         }
 948                                 }
 949                         }
 950                 }
 951
 952                 # Add cache dependencies for any referenced globals
 953                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 954                 // $wgMessagesDirs is used in LocalisationCache::getMessagesDirs()
 955                 $deps['wgMessagesDirs'] = new GlobalDependency( 'wgMessagesDirs' );
 956                 $deps['version'] = new ConstantDependency( 'LocalisationCache::VERSION' );
 957
 958                 # Add dependencies to the cache entry
 959                 $allData['deps'] = $deps;
 960
 961                 # Replace spaces with underscores in namespace names
 962                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 963
 964                 # And do the same for special page aliases. $page is an array.
 965                 foreach ( $allData['specialPageAliases'] as &$page ) {
 966                         $page = str_replace( ' ', '_', $page );
 967                 }
 968                 # Decouple the reference to prevent accidental damage
 969                 unset( $page );
 970
 971                 # If there were no plural rules, return an empty array
 972                 if ( $allData['pluralRules'] === null ) {
 973                         $allData['pluralRules'] = array();
 974                 }
 975                 if ( $allData['compiledPluralRules'] === null ) {
 976                         $allData['compiledPluralRules'] = array();
 977                 }
 978                 # If there were no plural rule types, return an empty array
 979                 if ( $allData['pluralRuleTypes'] === null ) {
 980                         $allData['pluralRuleTypes'] = array();
 981                 }
 982
 983                 # Set the list keys
 984                 $allData['list'] = array();
 985                 foreach ( self::$splitKeys as $key ) {
 986                         $allData['list'][$key] = array_keys( $allData[$key] );
 987                 }
 988                 # Run hooks
 989                 $purgeBlobs = true;
 990                 Hooks::run( 'LocalisationCacheRecache', array( $this, $code, &$allData, &$purgeBlobs ) );
 991
 992                 if ( is_null( $allData['namespaceNames'] ) ) {
 993                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
 994                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 995                 }
 996
 997                 # Set the preload key
 998                 $allData['preload'] = $this->buildPreload( $allData );
 999
1000                 # Save to the process cache and register the items loaded
1001                 $this->data[$code] = $allData;
1002                 foreach ( $allData as $key => $item ) {
1003                         $this->loadedItems[$code][$key] = true;
1004                 }
1005
1006                 # Save to the persistent cache
1007                 $this->store->startWrite( $code );
1008                 foreach ( $allData as $key => $value ) {
1009                         if ( in_array( $key, self::$splitKeys ) ) {
1010                                 foreach ( $value as $subkey => $subvalue ) {
1011                                         $this->store->set( "$key:$subkey", $subvalue );
1012                                 }
1013                         } else {
1014                                 $this->store->set( $key, $value );
1015                         }
1016                 }
1017                 $this->store->finishWrite();
1018
1019                 # Clear out the MessageBlobStore
1020                 # HACK: If using a null (i.e. disabled) storage backend, we
1021                 # can't write to the MessageBlobStore either
1022                 if ( $purgeBlobs && !$this->store instanceof LCStoreNull ) {
1023                         MessageBlobStore::getInstance()->clear();
1024                 }
1025
1026         }
1027
1028         /**
1029          * Build the preload item from the given pre-cache data.
1030          *
1031          * The preload item will be loaded automatically, improving performance
1032          * for the commonly-requested items it contains.
1033          * @param array $data
1034          * @return array
1035          */
1036         protected function buildPreload( $data ) {
1037                 $preload = array( 'messages' => array() );
1038                 foreach ( self::$preloadedKeys as $key ) {
1039                         $preload[$key] = $data[$key];
1040                 }
1041
1042                 foreach ( $data['preloadedMessages'] as $subkey ) {
1043                         if ( isset( $data['messages'][$subkey] ) ) {
1044                                 $subitem = $data['messages'][$subkey];
1045                         } else {
1046                                 $subitem = null;
1047                         }
1048                         $preload['messages'][$subkey] = $subitem;
1049                 }
1050
1051                 return $preload;
1052         }
1053
1054         /**
1055          * Unload the data for a given language from the object cache.
1056          * Reduces memory usage.
1057          * @param string $code
1058          */
1059         public function unload( $code ) {
1060                 unset( $this->data[$code] );
1061                 unset( $this->loadedItems[$code] );
1062                 unset( $this->loadedSubitems[$code] );
1063                 unset( $this->initialisedLangs[$code] );
1064                 unset( $this->shallowFallbacks[$code] );
1065
1066                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
1067                         if ( $fbCode === $code ) {
1068                                 $this->unload( $shallowCode );
1069                         }
1070                 }
1071         }
1072
1073         /**
1074          * Unload all data
1075          */
1076         public function unloadAll() {
1077                 foreach ( $this->initialisedLangs as $lang => $unused ) {
1078                         $this->unload( $lang );
1079                 }
1080         }
1081
1082         /**
1083          * Disable the storage backend
1084          */
1085         public function disableBackend() {
1086                 $this->store = new LCStoreNull;
1087                 $this->manualRecache = false;
1088         }
1089 }
1090
1091 /**
1092  * Interface for the persistence layer of LocalisationCache.
1093  *
1094  * The persistence layer is two-level hierarchical cache. The first level
1095  * is the language, the second level is the item or subitem.
1096  *
1097  * Since the data for a whole language is rebuilt in one operation, it needs
1098  * to have a fast and atomic method for deleting or replacing all of the
1099  * current data for a given language. The interface reflects this bulk update
1100  * operation. Callers writing to the cache must first call startWrite(), then
1101  * will call set() a couple of thousand times, then will call finishWrite()
1102  * to commit the operation. When finishWrite() is called, the cache is
1103  * expected to delete all data previously stored for that language.
1104  *
1105  * The values stored are PHP variables suitable for serialize(). Implementations
1106  * of LCStore are responsible for serializing and unserializing.
1107  */
1108 interface LCStore {
1109         /**
1110          * Get a value.
1111          * @param string $code Language code
1112          * @param string $key Cache key
1113          */
1114         function get( $code, $key );
1115
1116         /**
1117          * Start a write transaction.
1118          * @param string $code Language code
1119          */
1120         function startWrite( $code );
1121
1122         /**
1123          * Finish a write transaction.
1124          */
1125         function finishWrite();
1126
1127         /**
1128          * Set a key to a given value. startWrite() must be called before this
1129          * is called, and finishWrite() must be called afterwards.
1130          * @param string $key
1131          * @param mixed $value
1132          */
1133         function set( $key, $value );
1134 }
1135
1136 /**
1137  * LCStore implementation which uses the standard DB functions to store data.
1138  * This will work on any MediaWiki installation.
1139  */
1140 class LCStoreDB implements LCStore {
1141         private $currentLang;
1142         private $writesDone = false;
1143
1144         /** @var DatabaseBase */
1145         private $dbw;
1146         /** @var array */
1147         private $batch = array();
1148
1149         private $readOnly = false;
1150
1151         public function get( $code, $key ) {
1152                 if ( $this->writesDone ) {
1153                         $db = wfGetDB( DB_MASTER );
1154                 } else {
1155                         $db = wfGetDB( DB_SLAVE );
1156                 }
1157                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1158                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1159                 if ( $row ) {
1160                         return unserialize( $db->decodeBlob( $row->lc_value ) );
1161                 } else {
1162                         return null;
1163                 }
1164         }
1165
1166         public function startWrite( $code ) {
1167                 if ( $this->readOnly ) {
1168                         return;
1169                 } elseif ( !$code ) {
1170                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1171                 }
1172
1173                 $this->dbw = wfGetDB( DB_MASTER );
1174
1175                 $this->currentLang = $code;
1176                 $this->batch = array();
1177         }
1178
1179         public function finishWrite() {
1180                 if ( $this->readOnly ) {
1181                         return;
1182                 } elseif ( is_null( $this->currentLang ) ) {
1183                         throw new MWException( __CLASS__ . ': must call startWrite() before finishWrite()' );
1184                 }
1185
1186                 $this->dbw->begin( __METHOD__ );
1187                 try {
1188                         $this->dbw->delete( 'l10n_cache',
1189                                 array( 'lc_lang' => $this->currentLang ), __METHOD__ );
1190                         foreach ( array_chunk( $this->batch, 500 ) as $rows ) {
1191                                 $this->dbw->insert( 'l10n_cache', $rows, __METHOD__ );
1192                         }
1193                         $this->writesDone = true;
1194                 } catch ( DBQueryError $e ) {
1195                         if ( $this->dbw->wasReadOnlyError() ) {
1196                                 $this->readOnly = true; // just avoid site down time
1197                         } else {
1198                                 throw $e;
1199                         }
1200                 }
1201                 $this->dbw->commit( __METHOD__ );
1202
1203                 $this->currentLang = null;
1204                 $this->batch = array();
1205         }
1206
1207         public function set( $key, $value ) {
1208                 if ( $this->readOnly ) {
1209                         return;
1210                 } elseif ( is_null( $this->currentLang ) ) {
1211                         throw new MWException( __CLASS__ . ': must call startWrite() before set()' );
1212                 }
1213
1214                 $this->batch[] = array(
1215                         'lc_lang' => $this->currentLang,
1216                         'lc_key' => $key,
1217                         'lc_value' => $this->dbw->encodeBlob( serialize( $value ) ) );
1218         }
1219 }
1220
1221 /**
1222  * LCStore implementation which stores data as a collection of CDB files in the
1223  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1224  * will throw an exception.
1225  *
1226  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1227  * the directory is on a local filesystem and there is ample kernel cache
1228  * space. The performance advantage is greater when the DBA extension is
1229  * available than it is with the PHP port.
1230  *
1231  * See Cdb.php and http://cr.yp.to/cdb.html
1232  */
1233 class LCStoreCDB implements LCStore {
1234         /** @var CdbReader[] */
1235         private $readers;
1236
1237         /** @var CdbWriter */
1238         private $writer;
1239
1240         /** @var string Current language code */
1241         private $currentLang;
1242
1243         /** @var bool|string Cache directory. False if not set */
1244         private $directory;
1245
1246         function __construct( $conf = array() ) {
1247                 global $wgCacheDirectory;
1248
1249                 if ( isset( $conf['directory'] ) ) {
1250                         $this->directory = $conf['directory'];
1251                 } else {
1252                         $this->directory = $wgCacheDirectory;
1253                 }
1254         }
1255
1256         public function get( $code, $key ) {
1257                 if ( !isset( $this->readers[$code] ) ) {
1258                         $fileName = $this->getFileName( $code );
1259
1260                         $this->readers[$code] = false;
1261                         if ( file_exists( $fileName ) ) {
1262                                 try {
1263                                         $this->readers[$code] = CdbReader::open( $fileName );
1264                                 } catch ( CdbException $e ) {
1265                                         wfDebug( __METHOD__ . ": unable to open cdb file for reading\n" );
1266                                 }
1267                         }
1268                 }
1269
1270                 if ( !$this->readers[$code] ) {
1271                         return null;
1272                 } else {
1273                         $value = false;
1274                         try {
1275                                 $value = $this->readers[$code]->get( $key );
1276                         } catch ( CdbException $e ) {
1277                                 wfDebug( __METHOD__ . ": CdbException caught, error message was "
1278                                         . $e->getMessage() . "\n" );
1279                         }
1280                         if ( $value === false ) {
1281                                 return null;
1282                         }
1283
1284                         return unserialize( $value );
1285                 }
1286         }
1287
1288         public function startWrite( $code ) {
1289                 if ( !file_exists( $this->directory ) ) {
1290                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1291                                 throw new MWException( "Unable to create the localisation store " .
1292                                         "directory \"{$this->directory}\"" );
1293                         }
1294                 }
1295
1296                 // Close reader to stop permission errors on write
1297                 if ( !empty( $this->readers[$code] ) ) {
1298                         $this->readers[$code]->close();
1299                 }
1300
1301                 try {
1302                         $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1303                 } catch ( CdbException $e ) {
1304                         throw new MWException( $e->getMessage() );
1305                 }
1306                 $this->currentLang = $code;
1307         }
1308
1309         public function finishWrite() {
1310                 // Close the writer
1311                 try {
1312                         $this->writer->close();
1313                 } catch ( CdbException $e ) {
1314                         throw new MWException( $e->getMessage() );
1315                 }
1316                 $this->writer = null;
1317                 unset( $this->readers[$this->currentLang] );
1318                 $this->currentLang = null;
1319         }
1320
1321         public function set( $key, $value ) {
1322                 if ( is_null( $this->writer ) ) {
1323                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1324                 }
1325                 try {
1326                         $this->writer->set( $key, serialize( $value ) );
1327                 } catch ( CdbException $e ) {
1328                         throw new MWException( $e->getMessage() );
1329                 }
1330         }
1331
1332         protected function getFileName( $code ) {
1333                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1334                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1335                 }
1336
1337                 return "{$this->directory}/l10n_cache-$code.cdb";
1338         }
1339 }
1340
1341 /**
1342  * Null store backend, used to avoid DB errors during install
1343  */
1344 class LCStoreNull implements LCStore {
1345         public function get( $code, $key ) {
1346                 return null;
1347         }
1348
1349         public function startWrite( $code ) {
1350         }
1351
1352         public function finishWrite() {
1353         }
1354
1355         public function set( $key, $value ) {
1356         }
1357 }
1358
1359 /**
1360  * A localisation cache optimised for loading large amounts of data for many
1361  * languages. Used by rebuildLocalisationCache.php.
1362  */
1363 class LocalisationCacheBulkLoad extends LocalisationCache {
1364         /**
1365          * A cache of the contents of data files.
1366          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1367          */
1368         private $fileCache = array();
1369
1370         /**
1371          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1372          * to keep the most recently used language codes at the end of the array, and
1373          * the language codes that are ready to be deleted at the beginning.
1374          */
1375         private $mruLangs = array();
1376
1377         /**
1378          * Maximum number of languages that may be loaded into $this->data
1379          */
1380         private $maxLoadedLangs = 10;
1381
1382         /**
1383          * @param string $fileName
1384          * @param string $fileType
1385          * @return array|mixed
1386          */
1387         protected function readPHPFile( $fileName, $fileType ) {
1388                 $serialize = $fileType === 'core';
1389                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1390                         $data = parent::readPHPFile( $fileName, $fileType );
1391
1392                         if ( $serialize ) {
1393                                 $encData = serialize( $data );
1394                         } else {
1395                                 $encData = $data;
1396                         }
1397
1398                         $this->fileCache[$fileName][$fileType] = $encData;
1399
1400                         return $data;
1401                 } elseif ( $serialize ) {
1402                         return unserialize( $this->fileCache[$fileName][$fileType] );
1403                 } else {
1404                         return $this->fileCache[$fileName][$fileType];
1405                 }
1406         }
1407
1408         /**
1409          * @param string $code
1410          * @param string $key
1411          * @return mixed
1412          */
1413         public function getItem( $code, $key ) {
1414                 unset( $this->mruLangs[$code] );
1415                 $this->mruLangs[$code] = true;
1416
1417                 return parent::getItem( $code, $key );
1418         }
1419
1420         /**
1421          * @param string $code
1422          * @param string $key
1423          * @param string $subkey
1424          * @return mixed
1425          */
1426         public function getSubitem( $code, $key, $subkey ) {
1427                 unset( $this->mruLangs[$code] );
1428                 $this->mruLangs[$code] = true;
1429
1430                 return parent::getSubitem( $code, $key, $subkey );
1431         }
1432
1433         /**
1434          * @param string $code
1435          */
1436         public function recache( $code ) {
1437                 parent::recache( $code );
1438                 unset( $this->mruLangs[$code] );
1439                 $this->mruLangs[$code] = true;
1440                 $this->trimCache();
1441         }
1442
1443         /**
1444          * @param string $code
1445          */
1446         public function unload( $code ) {
1447                 unset( $this->mruLangs[$code] );
1448                 parent::unload( $code );
1449         }
1450
1451         /**
1452          * Unload cached languages until there are less than $this->maxLoadedLangs
1453          */
1454         protected function trimCache() {
1455                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1456                         reset( $this->mruLangs );
1457                         $code = key( $this->mruLangs );
1458                         wfDebug( __METHOD__ . ": unloading $code\n" );
1459                         $this->unload( $code );
1460                 }
1461         }
1462 }