includes/cache/LocalisationCache.php

   1 <?php
   2 /**
   3  * Cache of the contents of localisation files.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 use Cdb\Exception as CdbException;
  24 use Cdb\Reader as CdbReader;
  25 use Cdb\Writer as CdbWriter;
  26
  27 /**
  28  * Class for caching the contents of localisation files, Messages*.php
  29  * and *.i18n.php.
  30  *
  31  * An instance of this class is available using Language::getLocalisationCache().
  32  *
  33  * The values retrieved from here are merged, containing items from extension
  34  * files, core messages files and the language fallback sequence (e.g. zh-cn ->
  35  * zh-hans -> en ). Some common errors are corrected, for example namespace
  36  * names with spaces instead of underscores, but heavyweight processing, such
  37  * as grammatical transformation, is done by the caller.
  38  */
  39 class LocalisationCache {
  40         const VERSION = 3;
  41
  42         /** Configuration associative array */
  43         private $conf;
  44
  45         /**
  46          * True if recaching should only be done on an explicit call to recache().
  47          * Setting this reduces the overhead of cache freshness checking, which
  48          * requires doing a stat() for every extension i18n file.
  49          */
  50         private $manualRecache = false;
  51
  52         /**
  53          * True to treat all files as expired until they are regenerated by this object.
  54          */
  55         private $forceRecache = false;
  56
  57         /**
  58          * The cache data. 3-d array, where the first key is the language code,
  59          * the second key is the item key e.g. 'messages', and the third key is
  60          * an item specific subkey index. Some items are not arrays and so for those
  61          * items, there are no subkeys.
  62          */
  63         protected $data = array();
  64
  65         /**
  66          * The persistent store object. An instance of LCStore.
  67          *
  68          * @var LCStore
  69          */
  70         private $store;
  71
  72         /**
  73          * A 2-d associative array, code/key, where presence indicates that the item
  74          * is loaded. Value arbitrary.
  75          *
  76          * For split items, if set, this indicates that all of the subitems have been
  77          * loaded.
  78          */
  79         private $loadedItems = array();
  80
  81         /**
  82          * A 3-d associative array, code/key/subkey, where presence indicates that
  83          * the subitem is loaded. Only used for the split items, i.e. messages.
  84          */
  85         private $loadedSubitems = array();
  86
  87         /**
  88          * An array where presence of a key indicates that that language has been
  89          * initialised. Initialisation includes checking for cache expiry and doing
  90          * any necessary updates.
  91          */
  92         private $initialisedLangs = array();
  93
  94         /**
  95          * An array mapping non-existent pseudo-languages to fallback languages. This
  96          * is filled by initShallowFallback() when data is requested from a language
  97          * that lacks a Messages*.php file.
  98          */
  99         private $shallowFallbacks = array();
 100
 101         /**
 102          * An array where the keys are codes that have been recached by this instance.
 103          */
 104         private $recachedLangs = array();
 105
 106         /**
 107          * All item keys
 108          */
 109         static public $allKeys = array(
 110                 'fallback', 'namespaceNames', 'bookstoreList',
 111                 'magicWords', 'messages', 'rtl', 'capitalizeAllNouns', 'digitTransformTable',
 112                 'separatorTransformTable', 'fallback8bitEncoding', 'linkPrefixExtension',
 113                 'linkTrail', 'linkPrefixCharset', 'namespaceAliases',
 114                 'dateFormats', 'datePreferences', 'datePreferenceMigrationMap',
 115                 'defaultDateFormat', 'extraUserToggles', 'specialPageAliases',
 116                 'imageFiles', 'preloadedMessages', 'namespaceGenderAliases',
 117                 'digitGroupingPattern', 'pluralRules', 'pluralRuleTypes', 'compiledPluralRules',
 118         );
 119
 120         /**
 121          * Keys for items which consist of associative arrays, which may be merged
 122          * by a fallback sequence.
 123          */
 124         static public $mergeableMapKeys = array( 'messages', 'namespaceNames',
 125                 'dateFormats', 'imageFiles', 'preloadedMessages'
 126         );
 127
 128         /**
 129          * Keys for items which are a numbered array.
 130          */
 131         static public $mergeableListKeys = array( 'extraUserToggles' );
 132
 133         /**
 134          * Keys for items which contain an array of arrays of equivalent aliases
 135          * for each subitem. The aliases may be merged by a fallback sequence.
 136          */
 137         static public $mergeableAliasListKeys = array( 'specialPageAliases' );
 138
 139         /**
 140          * Keys for items which contain an associative array, and may be merged if
 141          * the primary value contains the special array key "inherit". That array
 142          * key is removed after the first merge.
 143          */
 144         static public $optionalMergeKeys = array( 'bookstoreList' );
 145
 146         /**
 147          * Keys for items that are formatted like $magicWords
 148          */
 149         static public $magicWordKeys = array( 'magicWords' );
 150
 151         /**
 152          * Keys for items where the subitems are stored in the backend separately.
 153          */
 154         static public $splitKeys = array( 'messages' );
 155
 156         /**
 157          * Keys which are loaded automatically by initLanguage()
 158          */
 159         static public $preloadedKeys = array( 'dateFormats', 'namespaceNames' );
 160
 161         /**
 162          * Associative array of cached plural rules. The key is the language code,
 163          * the value is an array of plural rules for that language.
 164          */
 165         private $pluralRules = null;
 166
 167         /**
 168          * Associative array of cached plural rule types. The key is the language
 169          * code, the value is an array of plural rule types for that language. For
 170          * example, $pluralRuleTypes['ar'] = ['zero', 'one', 'two', 'few', 'many'].
 171          * The index for each rule type matches the index for the rule in
 172          * $pluralRules, thus allowing correlation between the two. The reason we
 173          * don't just use the type names as the keys in $pluralRules is because
 174          * Language::convertPlural applies the rules based on numeric order (or
 175          * explicit numeric parameter), not based on the name of the rule type. For
 176          * example, {{plural:count|wordform1|wordform2|wordform3}}, rather than
 177          * {{plural:count|one=wordform1|two=wordform2|many=wordform3}}.
 178          */
 179         private $pluralRuleTypes = null;
 180
 181         private $mergeableKeys = null;
 182
 183         /**
 184          * Constructor.
 185          * For constructor parameters, see the documentation in DefaultSettings.php
 186          * for $wgLocalisationCacheConf.
 187          *
 188          * @param array $conf
 189          * @throws MWException
 190          */
 191         function __construct( $conf ) {
 192                 global $wgCacheDirectory;
 193
 194                 $this->conf = $conf;
 195                 $storeConf = array();
 196                 if ( !empty( $conf['storeClass'] ) ) {
 197                         $storeClass = $conf['storeClass'];
 198                 } else {
 199                         switch ( $conf['store'] ) {
 200                                 case 'files':
 201                                 case 'file':
 202                                         $storeClass = 'LCStoreCDB';
 203                                         break;
 204                                 case 'db':
 205                                         $storeClass = 'LCStoreDB';
 206                                         break;
 207                                 case 'detect':
 208                                         $storeClass = $wgCacheDirectory ? 'LCStoreCDB' : 'LCStoreDB';
 209                                         break;
 210                                 default:
 211                                         throw new MWException(
 212                                                 'Please set $wgLocalisationCacheConf[\'store\'] to something sensible.' );
 213                         }
 214                 }
 215
 216                 wfDebugLog( 'caches', get_class( $this ) . ": using store $storeClass" );
 217                 if ( !empty( $conf['storeDirectory'] ) ) {
 218                         $storeConf['directory'] = $conf['storeDirectory'];
 219                 }
 220
 221                 $this->store = new $storeClass( $storeConf );
 222                 foreach ( array( 'manualRecache', 'forceRecache' ) as $var ) {
 223                         if ( isset( $conf[$var] ) ) {
 224                                 $this->$var = $conf[$var];
 225                         }
 226                 }
 227         }
 228
 229         /**
 230          * Returns true if the given key is mergeable, that is, if it is an associative
 231          * array which can be merged through a fallback sequence.
 232          * @param string $key
 233          * @return bool
 234          */
 235         public function isMergeableKey( $key ) {
 236                 if ( $this->mergeableKeys === null ) {
 237                         $this->mergeableKeys = array_flip( array_merge(
 238                                 self::$mergeableMapKeys,
 239                                 self::$mergeableListKeys,
 240                                 self::$mergeableAliasListKeys,
 241                                 self::$optionalMergeKeys,
 242                                 self::$magicWordKeys
 243                         ) );
 244                 }
 245
 246                 return isset( $this->mergeableKeys[$key] );
 247         }
 248
 249         /**
 250          * Get a cache item.
 251          *
 252          * Warning: this may be slow for split items (messages), since it will
 253          * need to fetch all of the subitems from the cache individually.
 254          * @param string $code
 255          * @param string $key
 256          * @return mixed
 257          */
 258         public function getItem( $code, $key ) {
 259                 if ( !isset( $this->loadedItems[$code][$key] ) ) {
 260                         wfProfileIn( __METHOD__ . '-load' );
 261                         $this->loadItem( $code, $key );
 262                         wfProfileOut( __METHOD__ . '-load' );
 263                 }
 264
 265                 if ( $key === 'fallback' && isset( $this->shallowFallbacks[$code] ) ) {
 266                         return $this->shallowFallbacks[$code];
 267                 }
 268
 269                 return $this->data[$code][$key];
 270         }
 271
 272         /**
 273          * Get a subitem, for instance a single message for a given language.
 274          * @param string $code
 275          * @param string $key
 276          * @param string $subkey
 277          * @return mixed|null
 278          */
 279         public function getSubitem( $code, $key, $subkey ) {
 280                 if ( !isset( $this->loadedSubitems[$code][$key][$subkey] ) &&
 281                         !isset( $this->loadedItems[$code][$key] )
 282                 ) {
 283                         wfProfileIn( __METHOD__ . '-load' );
 284                         $this->loadSubitem( $code, $key, $subkey );
 285                         wfProfileOut( __METHOD__ . '-load' );
 286                 }
 287
 288                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 289                         return $this->data[$code][$key][$subkey];
 290                 } else {
 291                         return null;
 292                 }
 293         }
 294
 295         /**
 296          * Get the list of subitem keys for a given item.
 297          *
 298          * This is faster than array_keys($lc->getItem(...)) for the items listed in
 299          * self::$splitKeys.
 300          *
 301          * Will return null if the item is not found, or false if the item is not an
 302          * array.
 303          * @param string $code
 304          * @param string $key
 305          * @return bool|null|string
 306          */
 307         public function getSubitemList( $code, $key ) {
 308                 if ( in_array( $key, self::$splitKeys ) ) {
 309                         return $this->getSubitem( $code, 'list', $key );
 310                 } else {
 311                         $item = $this->getItem( $code, $key );
 312                         if ( is_array( $item ) ) {
 313                                 return array_keys( $item );
 314                         } else {
 315                                 return false;
 316                         }
 317                 }
 318         }
 319
 320         /**
 321          * Load an item into the cache.
 322          * @param string $code
 323          * @param string $key
 324          */
 325         protected function loadItem( $code, $key ) {
 326                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 327                         $this->initLanguage( $code );
 328                 }
 329
 330                 // Check to see if initLanguage() loaded it for us
 331                 if ( isset( $this->loadedItems[$code][$key] ) ) {
 332                         return;
 333                 }
 334
 335                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 336                         $this->loadItem( $this->shallowFallbacks[$code], $key );
 337
 338                         return;
 339                 }
 340
 341                 if ( in_array( $key, self::$splitKeys ) ) {
 342                         $subkeyList = $this->getSubitem( $code, 'list', $key );
 343                         foreach ( $subkeyList as $subkey ) {
 344                                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 345                                         continue;
 346                                 }
 347                                 $this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
 348                         }
 349                 } else {
 350                         $this->data[$code][$key] = $this->store->get( $code, $key );
 351                 }
 352
 353                 $this->loadedItems[$code][$key] = true;
 354         }
 355
 356         /**
 357          * Load a subitem into the cache
 358          * @param string $code
 359          * @param string $key
 360          * @param string $subkey
 361          */
 362         protected function loadSubitem( $code, $key, $subkey ) {
 363                 if ( !in_array( $key, self::$splitKeys ) ) {
 364                         $this->loadItem( $code, $key );
 365
 366                         return;
 367                 }
 368
 369                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 370                         $this->initLanguage( $code );
 371                 }
 372
 373                 // Check to see if initLanguage() loaded it for us
 374                 if ( isset( $this->loadedItems[$code][$key] ) ||
 375                         isset( $this->loadedSubitems[$code][$key][$subkey] )
 376                 ) {
 377                         return;
 378                 }
 379
 380                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 381                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 382
 383                         return;
 384                 }
 385
 386                 $value = $this->store->get( $code, "$key:$subkey" );
 387                 $this->data[$code][$key][$subkey] = $value;
 388                 $this->loadedSubitems[$code][$key][$subkey] = true;
 389         }
 390
 391         /**
 392          * Returns true if the cache identified by $code is missing or expired.
 393          *
 394          * @param string $code
 395          *
 396          * @return bool
 397          */
 398         public function isExpired( $code ) {
 399                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 400                         wfDebug( __METHOD__ . "($code): forced reload\n" );
 401
 402                         return true;
 403                 }
 404
 405                 $deps = $this->store->get( $code, 'deps' );
 406                 $keys = $this->store->get( $code, 'list' );
 407                 $preload = $this->store->get( $code, 'preload' );
 408                 // Different keys may expire separately for some stores
 409                 if ( $deps === null || $keys === null || $preload === null ) {
 410                         wfDebug( __METHOD__ . "($code): cache missing, need to make one\n" );
 411
 412                         return true;
 413                 }
 414
 415                 foreach ( $deps as $dep ) {
 416                         // Because we're unserializing stuff from cache, we
 417                         // could receive objects of classes that don't exist
 418                         // anymore (e.g. uninstalled extensions)
 419                         // When this happens, always expire the cache
 420                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 421                                 wfDebug( __METHOD__ . "($code): cache for $code expired due to " .
 422                                         get_class( $dep ) . "\n" );
 423
 424                                 return true;
 425                         }
 426                 }
 427
 428                 return false;
 429         }
 430
 431         /**
 432          * Initialise a language in this object. Rebuild the cache if necessary.
 433          * @param string $code
 434          * @throws MWException
 435          */
 436         protected function initLanguage( $code ) {
 437                 if ( isset( $this->initialisedLangs[$code] ) ) {
 438                         return;
 439                 }
 440
 441                 $this->initialisedLangs[$code] = true;
 442
 443                 # If the code is of the wrong form for a Messages*.php file, do a shallow fallback
 444                 if ( !Language::isValidBuiltInCode( $code ) ) {
 445                         $this->initShallowFallback( $code, 'en' );
 446
 447                         return;
 448                 }
 449
 450                 # Recache the data if necessary
 451                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 452                         if ( Language::isSupportedLanguage( $code ) ) {
 453                                 $this->recache( $code );
 454                         } elseif ( $code === 'en' ) {
 455                                 throw new MWException( 'MessagesEn.php is missing.' );
 456                         } else {
 457                                 $this->initShallowFallback( $code, 'en' );
 458                         }
 459
 460                         return;
 461                 }
 462
 463                 # Preload some stuff
 464                 $preload = $this->getItem( $code, 'preload' );
 465                 if ( $preload === null ) {
 466                         if ( $this->manualRecache ) {
 467                                 // No Messages*.php file. Do shallow fallback to en.
 468                                 if ( $code === 'en' ) {
 469                                         throw new MWException( 'No localisation cache found for English. ' .
 470                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 471                                 }
 472                                 $this->initShallowFallback( $code, 'en' );
 473
 474                                 return;
 475                         } else {
 476                                 throw new MWException( 'Invalid or missing localisation cache.' );
 477                         }
 478                 }
 479                 $this->data[$code] = $preload;
 480                 foreach ( $preload as $key => $item ) {
 481                         if ( in_array( $key, self::$splitKeys ) ) {
 482                                 foreach ( $item as $subkey => $subitem ) {
 483                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 484                                 }
 485                         } else {
 486                                 $this->loadedItems[$code][$key] = true;
 487                         }
 488                 }
 489         }
 490
 491         /**
 492          * Create a fallback from one language to another, without creating a
 493          * complete persistent cache.
 494          * @param string $primaryCode
 495          * @param string $fallbackCode
 496          */
 497         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 498                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 499                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 500                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 501                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 502         }
 503
 504         /**
 505          * Read a PHP file containing localisation data.
 506          * @param string $_fileName
 507          * @param string $_fileType
 508          * @throws MWException
 509          * @return array
 510          */
 511         protected function readPHPFile( $_fileName, $_fileType ) {
 512                 // Disable APC caching
 513                 wfSuppressWarnings();
 514                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 515                 wfRestoreWarnings();
 516
 517                 include $_fileName;
 518
 519                 wfSuppressWarnings();
 520                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 521                 wfRestoreWarnings();
 522
 523                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 524                         $data = compact( self::$allKeys );
 525                 } elseif ( $_fileType == 'aliases' ) {
 526                         $data = compact( 'aliases' );
 527                 } else {
 528                         throw new MWException( __METHOD__ . ": Invalid file type: $_fileType" );
 529                 }
 530
 531                 return $data;
 532         }
 533
 534         /**
 535          * Read a JSON file containing localisation messages.
 536          * @param string $fileName Name of file to read
 537          * @throws MWException If there is a syntax error in the JSON file
 538          * @return array Array with a 'messages' key, or empty array if the file doesn't exist
 539          */
 540         public function readJSONFile( $fileName ) {
 541
 542                 if ( !is_readable( $fileName ) ) {
 543
 544                         return array();
 545                 }
 546
 547                 $json = file_get_contents( $fileName );
 548                 if ( $json === false ) {
 549
 550                         return array();
 551                 }
 552
 553                 $data = FormatJson::decode( $json, true );
 554                 if ( $data === null ) {
 555
 556                         throw new MWException( __METHOD__ . ": Invalid JSON file: $fileName" );
 557                 }
 558
 559                 // Remove keys starting with '@', they're reserved for metadata and non-message data
 560                 foreach ( $data as $key => $unused ) {
 561                         if ( $key === '' || $key[0] === '@' ) {
 562                                 unset( $data[$key] );
 563                         }
 564                 }
 565
 566
 567                 // The JSON format only supports messages, none of the other variables, so wrap the data
 568                 return array( 'messages' => $data );
 569         }
 570
 571         /**
 572          * Get the compiled plural rules for a given language from the XML files.
 573          * @since 1.20
 574          * @param string $code
 575          * @return array|null
 576          */
 577         public function getCompiledPluralRules( $code ) {
 578                 $rules = $this->getPluralRules( $code );
 579                 if ( $rules === null ) {
 580                         return null;
 581                 }
 582                 try {
 583                         $compiledRules = CLDRPluralRuleEvaluator::compile( $rules );
 584                 } catch ( CLDRPluralRuleError $e ) {
 585                         wfDebugLog( 'l10n', $e->getMessage() );
 586
 587                         return array();
 588                 }
 589
 590                 return $compiledRules;
 591         }
 592
 593         /**
 594          * Get the plural rules for a given language from the XML files.
 595          * Cached.
 596          * @since 1.20
 597          * @param string $code
 598          * @return array|null
 599          */
 600         public function getPluralRules( $code ) {
 601                 if ( $this->pluralRules === null ) {
 602                         $this->loadPluralFiles();
 603                 }
 604                 if ( !isset( $this->pluralRules[$code] ) ) {
 605                         return null;
 606                 } else {
 607                         return $this->pluralRules[$code];
 608                 }
 609         }
 610
 611         /**
 612          * Get the plural rule types for a given language from the XML files.
 613          * Cached.
 614          * @since 1.22
 615          * @param string $code
 616          * @return array|null
 617          */
 618         public function getPluralRuleTypes( $code ) {
 619                 if ( $this->pluralRuleTypes === null ) {
 620                         $this->loadPluralFiles();
 621                 }
 622                 if ( !isset( $this->pluralRuleTypes[$code] ) ) {
 623                         return null;
 624                 } else {
 625                         return $this->pluralRuleTypes[$code];
 626                 }
 627         }
 628
 629         /**
 630          * Load the plural XML files.
 631          */
 632         protected function loadPluralFiles() {
 633                 global $IP;
 634                 $cldrPlural = "$IP/languages/data/plurals.xml";
 635                 $mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
 636                 // Load CLDR plural rules
 637                 $this->loadPluralFile( $cldrPlural );
 638                 if ( file_exists( $mwPlural ) ) {
 639                         // Override or extend
 640                         $this->loadPluralFile( $mwPlural );
 641                 }
 642         }
 643
 644         /**
 645          * Load a plural XML file with the given filename, compile the relevant
 646          * rules, and save the compiled rules in a process-local cache.
 647          *
 648          * @param string $fileName
 649          * @throws MWException
 650          */
 651         protected function loadPluralFile( $fileName ) {
 652                 // Use file_get_contents instead of DOMDocument::load (T58439)
 653                 $xml = file_get_contents( $fileName );
 654                 if ( !$xml ) {
 655                         throw new MWException( "Unable to read plurals file $fileName" );
 656                 }
 657                 $doc = new DOMDocument;
 658                 $doc->loadXML( $xml );
 659                 $rulesets = $doc->getElementsByTagName( "pluralRules" );
 660                 foreach ( $rulesets as $ruleset ) {
 661                         $codes = $ruleset->getAttribute( 'locales' );
 662                         $rules = array();
 663                         $ruleTypes = array();
 664                         $ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
 665                         foreach ( $ruleElements as $elt ) {
 666                                 $ruleType = $elt->getAttribute( 'count' );
 667                                 if ( $ruleType === 'other' ) {
 668                                         // Don't record "other" rules, which have an empty condition
 669                                         continue;
 670                                 }
 671                                 $rules[] = $elt->nodeValue;
 672                                 $ruleTypes[] = $ruleType;
 673                         }
 674                         foreach ( explode( ' ', $codes ) as $code ) {
 675                                 $this->pluralRules[$code] = $rules;
 676                                 $this->pluralRuleTypes[$code] = $ruleTypes;
 677                         }
 678                 }
 679         }
 680
 681         /**
 682          * Read the data from the source files for a given language, and register
 683          * the relevant dependencies in the $deps array. If the localisation
 684          * exists, the data array is returned, otherwise false is returned.
 685          *
 686          * @param string $code
 687          * @param array $deps
 688          * @return array
 689          */
 690         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 691                 global $IP;
 692
 693                 // This reads in the PHP i18n file with non-messages l10n data
 694                 $fileName = Language::getMessagesFileName( $code );
 695                 if ( !file_exists( $fileName ) ) {
 696                         $data = array();
 697                 } else {
 698                         $deps[] = new FileDependency( $fileName );
 699                         $data = $this->readPHPFile( $fileName, 'core' );
 700                 }
 701
 702                 # Load CLDR plural rules for JavaScript
 703                 $data['pluralRules'] = $this->getPluralRules( $code );
 704                 # And for PHP
 705                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 706                 # Load plural rule types
 707                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 708
 709                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 710                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 711
 712
 713                 return $data;
 714         }
 715
 716         /**
 717          * Merge two localisation values, a primary and a fallback, overwriting the
 718          * primary value in place.
 719          * @param string $key
 720          * @param mixed $value
 721          * @param mixed $fallbackValue
 722          */
 723         protected function mergeItem( $key, &$value, $fallbackValue ) {
 724                 if ( !is_null( $value ) ) {
 725                         if ( !is_null( $fallbackValue ) ) {
 726                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 727                                         $value = $value + $fallbackValue;
 728                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 729                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 730                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 731                                         $value = array_merge_recursive( $value, $fallbackValue );
 732                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 733                                         if ( !empty( $value['inherit'] ) ) {
 734                                                 $value = array_merge( $fallbackValue, $value );
 735                                         }
 736
 737                                         if ( isset( $value['inherit'] ) ) {
 738                                                 unset( $value['inherit'] );
 739                                         }
 740                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 741                                         $this->mergeMagicWords( $value, $fallbackValue );
 742                                 }
 743                         }
 744                 } else {
 745                         $value = $fallbackValue;
 746                 }
 747         }
 748
 749         /**
 750          * @param mixed $value
 751          * @param mixed $fallbackValue
 752          */
 753         protected function mergeMagicWords( &$value, $fallbackValue ) {
 754                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 755                         if ( !isset( $value[$magicName] ) ) {
 756                                 $value[$magicName] = $fallbackInfo;
 757                         } else {
 758                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 759                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 760                                 $synonyms = array_values( array_unique( array_merge(
 761                                         $newSynonyms, $oldSynonyms ) ) );
 762                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 763                         }
 764                 }
 765         }
 766
 767         /**
 768          * Given an array mapping language code to localisation value, such as is
 769          * found in extension *.i18n.php files, iterate through a fallback sequence
 770          * to merge the given data with an existing primary value.
 771          *
 772          * Returns true if any data from the extension array was used, false
 773          * otherwise.
 774          * @param array $codeSequence
 775          * @param string $key
 776          * @param mixed $value
 777          * @param mixed $fallbackValue
 778          * @return bool
 779          */
 780         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 781                 $used = false;
 782                 foreach ( $codeSequence as $code ) {
 783                         if ( isset( $fallbackValue[$code] ) ) {
 784                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 785                                 $used = true;
 786                         }
 787                 }
 788
 789                 return $used;
 790         }
 791
 792         /**
 793          * Gets the combined list of messages dirs from
 794          * core and extensions
 795          *
 796          * @since 1.25
 797          * @return array
 798          */
 799         public function getMessagesDirs() {
 800                 global $wgMessagesDirs, $IP;
 801                 return array(
 802                         'core' => "$IP/languages/i18n",
 803                         'api' => "$IP/includes/api/i18n",
 804                         'oojs-ui' => "$IP/resources/lib/oojs-ui/i18n",
 805                 ) + $wgMessagesDirs;
 806         }
 807
 808         /**
 809          * Load localisation data for a given language for both core and extensions
 810          * and save it to the persistent cache store and the process cache
 811          * @param string $code
 812          * @throws MWException
 813          */
 814         public function recache( $code ) {
 815                 global $wgExtensionMessagesFiles;
 816
 817                 if ( !$code ) {
 818                         throw new MWException( "Invalid language code requested" );
 819                 }
 820                 $this->recachedLangs[$code] = true;
 821
 822                 # Initial values
 823                 $initialData = array_combine(
 824                         self::$allKeys,
 825                         array_fill( 0, count( self::$allKeys ), null ) );
 826                 $coreData = $initialData;
 827                 $deps = array();
 828
 829                 # Load the primary localisation from the source file
 830                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 831                 if ( $data === false ) {
 832                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 833                         $coreData['fallback'] = 'en';
 834                 } else {
 835                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 836
 837                         # Merge primary localisation
 838                         foreach ( $data as $key => $value ) {
 839                                 $this->mergeItem( $key, $coreData[$key], $value );
 840                         }
 841                 }
 842
 843                 # Fill in the fallback if it's not there already
 844                 if ( is_null( $coreData['fallback'] ) ) {
 845                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 846                 }
 847                 if ( $coreData['fallback'] === false ) {
 848                         $coreData['fallbackSequence'] = array();
 849                 } else {
 850                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 851                         $len = count( $coreData['fallbackSequence'] );
 852
 853                         # Ensure that the sequence ends at en
 854                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 855                                 $coreData['fallbackSequence'][] = 'en';
 856                         }
 857                 }
 858
 859                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 860                 $messageDirs = $this->getMessagesDirs();
 861
 862                 wfProfileIn( __METHOD__ . '-fallbacks' );
 863
 864                 # Load non-JSON localisation data for extensions
 865                 $extensionData = array_combine(
 866                         $codeSequence,
 867                         array_fill( 0, count( $codeSequence ), $initialData ) );
 868                 foreach ( $wgExtensionMessagesFiles as $extension => $fileName ) {
 869                         if ( isset( $messageDirs[$extension] ) ) {
 870                                 # This extension has JSON message data; skip the PHP shim
 871                                 continue;
 872                         }
 873
 874                         $data = $this->readPHPFile( $fileName, 'extension' );
 875                         $used = false;
 876
 877                         foreach ( $data as $key => $item ) {
 878                                 foreach ( $codeSequence as $csCode ) {
 879                                         if ( isset( $item[$csCode] ) ) {
 880                                                 $this->mergeItem( $key, $extensionData[$csCode][$key], $item[$csCode] );
 881                                                 $used = true;
 882                                         }
 883                                 }
 884                         }
 885
 886                         if ( $used ) {
 887                                 $deps[] = new FileDependency( $fileName );
 888                         }
 889                 }
 890
 891                 # Load the localisation data for each fallback, then merge it into the full array
 892                 $allData = $initialData;
 893                 foreach ( $codeSequence as $csCode ) {
 894                         $csData = $initialData;
 895
 896                         # Load core messages and the extension localisations.
 897                         foreach ( $messageDirs as $dirs ) {
 898                                 foreach ( (array)$dirs as $dir ) {
 899                                         $fileName = "$dir/$csCode.json";
 900                                         $data = $this->readJSONFile( $fileName );
 901
 902                                         foreach ( $data as $key => $item ) {
 903                                                 $this->mergeItem( $key, $csData[$key], $item );
 904                                         }
 905
 906                                         $deps[] = new FileDependency( $fileName );
 907                                 }
 908                         }
 909
 910                         # Merge non-JSON extension data
 911                         if ( isset( $extensionData[$csCode] ) ) {
 912                                 foreach ( $extensionData[$csCode] as $key => $item ) {
 913                                         $this->mergeItem( $key, $csData[$key], $item );
 914                                 }
 915                         }
 916
 917                         if ( $csCode === $code ) {
 918                                 # Merge core data into extension data
 919                                 foreach ( $coreData as $key => $item ) {
 920                                         $this->mergeItem( $key, $csData[$key], $item );
 921                                 }
 922                         } else {
 923                                 # Load the secondary localisation from the source file to
 924                                 # avoid infinite cycles on cyclic fallbacks
 925                                 $fbData = $this->readSourceFilesAndRegisterDeps( $csCode, $deps );
 926                                 if ( $fbData !== false ) {
 927                                         # Only merge the keys that make sense to merge
 928                                         foreach ( self::$allKeys as $key ) {
 929                                                 if ( !isset( $fbData[$key] ) ) {
 930                                                         continue;
 931                                                 }
 932
 933                                                 if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 934                                                         $this->mergeItem( $key, $csData[$key], $fbData[$key] );
 935                                                 }
 936                                         }
 937                                 }
 938                         }
 939
 940                         # Allow extensions an opportunity to adjust the data for this
 941                         # fallback
 942                         Hooks::run( 'LocalisationCacheRecacheFallback', array( $this, $csCode, &$csData ) );
 943
 944                         # Merge the data for this fallback into the final array
 945                         if ( $csCode === $code ) {
 946                                 $allData = $csData;
 947                         } else {
 948                                 foreach ( self::$allKeys as $key ) {
 949                                         if ( !isset( $csData[$key] ) ) {
 950                                                 continue;
 951                                         }
 952
 953                                         if ( is_null( $allData[$key] ) || $this->isMergeableKey( $key ) ) {
 954                                                 $this->mergeItem( $key, $allData[$key], $csData[$key] );
 955                                         }
 956                                 }
 957                         }
 958                 }
 959
 960                 wfProfileOut( __METHOD__ . '-fallbacks' );
 961
 962                 # Add cache dependencies for any referenced globals
 963                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 964                 // $wgMessagesDirs is used in LocalisationCache::getMessagesDirs()
 965                 $deps['wgMessagesDirs'] = new GlobalDependency( 'wgMessagesDirs' );
 966                 $deps['version'] = new ConstantDependency( 'LocalisationCache::VERSION' );
 967
 968                 # Add dependencies to the cache entry
 969                 $allData['deps'] = $deps;
 970
 971                 # Replace spaces with underscores in namespace names
 972                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 973
 974                 # And do the same for special page aliases. $page is an array.
 975                 foreach ( $allData['specialPageAliases'] as &$page ) {
 976                         $page = str_replace( ' ', '_', $page );
 977                 }
 978                 # Decouple the reference to prevent accidental damage
 979                 unset( $page );
 980
 981                 # If there were no plural rules, return an empty array
 982                 if ( $allData['pluralRules'] === null ) {
 983                         $allData['pluralRules'] = array();
 984                 }
 985                 if ( $allData['compiledPluralRules'] === null ) {
 986                         $allData['compiledPluralRules'] = array();
 987                 }
 988                 # If there were no plural rule types, return an empty array
 989                 if ( $allData['pluralRuleTypes'] === null ) {
 990                         $allData['pluralRuleTypes'] = array();
 991                 }
 992
 993                 # Set the list keys
 994                 $allData['list'] = array();
 995                 foreach ( self::$splitKeys as $key ) {
 996                         $allData['list'][$key] = array_keys( $allData[$key] );
 997                 }
 998                 # Run hooks
 999                 $purgeBlobs = true;
1000                 Hooks::run( 'LocalisationCacheRecache', array( $this, $code, &$allData, &$purgeBlobs ) );
1001
1002                 if ( is_null( $allData['namespaceNames'] ) ) {
1003                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
1004                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
1005                 }
1006
1007                 # Set the preload key
1008                 $allData['preload'] = $this->buildPreload( $allData );
1009
1010                 # Save to the process cache and register the items loaded
1011                 $this->data[$code] = $allData;
1012                 foreach ( $allData as $key => $item ) {
1013                         $this->loadedItems[$code][$key] = true;
1014                 }
1015
1016                 # Save to the persistent cache
1017                 wfProfileIn( __METHOD__ . '-write' );
1018                 $this->store->startWrite( $code );
1019                 foreach ( $allData as $key => $value ) {
1020                         if ( in_array( $key, self::$splitKeys ) ) {
1021                                 foreach ( $value as $subkey => $subvalue ) {
1022                                         $this->store->set( "$key:$subkey", $subvalue );
1023                                 }
1024                         } else {
1025                                 $this->store->set( $key, $value );
1026                         }
1027                 }
1028                 $this->store->finishWrite();
1029                 wfProfileOut( __METHOD__ . '-write' );
1030
1031                 # Clear out the MessageBlobStore
1032                 # HACK: If using a null (i.e. disabled) storage backend, we
1033                 # can't write to the MessageBlobStore either
1034                 if ( $purgeBlobs && !$this->store instanceof LCStoreNull ) {
1035                         MessageBlobStore::getInstance()->clear();
1036                 }
1037
1038         }
1039
1040         /**
1041          * Build the preload item from the given pre-cache data.
1042          *
1043          * The preload item will be loaded automatically, improving performance
1044          * for the commonly-requested items it contains.
1045          * @param array $data
1046          * @return array
1047          */
1048         protected function buildPreload( $data ) {
1049                 $preload = array( 'messages' => array() );
1050                 foreach ( self::$preloadedKeys as $key ) {
1051                         $preload[$key] = $data[$key];
1052                 }
1053
1054                 foreach ( $data['preloadedMessages'] as $subkey ) {
1055                         if ( isset( $data['messages'][$subkey] ) ) {
1056                                 $subitem = $data['messages'][$subkey];
1057                         } else {
1058                                 $subitem = null;
1059                         }
1060                         $preload['messages'][$subkey] = $subitem;
1061                 }
1062
1063                 return $preload;
1064         }
1065
1066         /**
1067          * Unload the data for a given language from the object cache.
1068          * Reduces memory usage.
1069          * @param string $code
1070          */
1071         public function unload( $code ) {
1072                 unset( $this->data[$code] );
1073                 unset( $this->loadedItems[$code] );
1074                 unset( $this->loadedSubitems[$code] );
1075                 unset( $this->initialisedLangs[$code] );
1076                 unset( $this->shallowFallbacks[$code] );
1077
1078                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
1079                         if ( $fbCode === $code ) {
1080                                 $this->unload( $shallowCode );
1081                         }
1082                 }
1083         }
1084
1085         /**
1086          * Unload all data
1087          */
1088         public function unloadAll() {
1089                 foreach ( $this->initialisedLangs as $lang => $unused ) {
1090                         $this->unload( $lang );
1091                 }
1092         }
1093
1094         /**
1095          * Disable the storage backend
1096          */
1097         public function disableBackend() {
1098                 $this->store = new LCStoreNull;
1099                 $this->manualRecache = false;
1100         }
1101 }
1102
1103 /**
1104  * Interface for the persistence layer of LocalisationCache.
1105  *
1106  * The persistence layer is two-level hierarchical cache. The first level
1107  * is the language, the second level is the item or subitem.
1108  *
1109  * Since the data for a whole language is rebuilt in one operation, it needs
1110  * to have a fast and atomic method for deleting or replacing all of the
1111  * current data for a given language. The interface reflects this bulk update
1112  * operation. Callers writing to the cache must first call startWrite(), then
1113  * will call set() a couple of thousand times, then will call finishWrite()
1114  * to commit the operation. When finishWrite() is called, the cache is
1115  * expected to delete all data previously stored for that language.
1116  *
1117  * The values stored are PHP variables suitable for serialize(). Implementations
1118  * of LCStore are responsible for serializing and unserializing.
1119  */
1120 interface LCStore {
1121         /**
1122          * Get a value.
1123          * @param string $code Language code
1124          * @param string $key Cache key
1125          */
1126         function get( $code, $key );
1127
1128         /**
1129          * Start a write transaction.
1130          * @param string $code Language code
1131          */
1132         function startWrite( $code );
1133
1134         /**
1135          * Finish a write transaction.
1136          */
1137         function finishWrite();
1138
1139         /**
1140          * Set a key to a given value. startWrite() must be called before this
1141          * is called, and finishWrite() must be called afterwards.
1142          * @param string $key
1143          * @param mixed $value
1144          */
1145         function set( $key, $value );
1146 }
1147
1148 /**
1149  * LCStore implementation which uses the standard DB functions to store data.
1150  * This will work on any MediaWiki installation.
1151  */
1152 class LCStoreDB implements LCStore {
1153         private $currentLang;
1154         private $writesDone = false;
1155
1156         /** @var DatabaseBase */
1157         private $dbw;
1158         /** @var array */
1159         private $batch = array();
1160
1161         private $readOnly = false;
1162
1163         public function get( $code, $key ) {
1164                 if ( $this->writesDone ) {
1165                         $db = wfGetDB( DB_MASTER );
1166                 } else {
1167                         $db = wfGetDB( DB_SLAVE );
1168                 }
1169                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1170                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1171                 if ( $row ) {
1172                         return unserialize( $db->decodeBlob( $row->lc_value ) );
1173                 } else {
1174                         return null;
1175                 }
1176         }
1177
1178         public function startWrite( $code ) {
1179                 if ( $this->readOnly ) {
1180                         return;
1181                 } elseif ( !$code ) {
1182                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1183                 }
1184
1185                 $this->dbw = wfGetDB( DB_MASTER );
1186
1187                 $this->currentLang = $code;
1188                 $this->batch = array();
1189         }
1190
1191         public function finishWrite() {
1192                 if ( $this->readOnly ) {
1193                         return;
1194                 } elseif ( is_null( $this->currentLang ) ) {
1195                         throw new MWException( __CLASS__ . ': must call startWrite() before finishWrite()' );
1196                 }
1197
1198                 $this->dbw->begin( __METHOD__ );
1199                 try {
1200                         $this->dbw->delete( 'l10n_cache',
1201                                 array( 'lc_lang' => $this->currentLang ), __METHOD__ );
1202                         foreach ( array_chunk( $this->batch, 500 ) as $rows ) {
1203                                 $this->dbw->insert( 'l10n_cache', $rows, __METHOD__ );
1204                         }
1205                         $this->writesDone = true;
1206                 } catch ( DBQueryError $e ) {
1207                         if ( $this->dbw->wasReadOnlyError() ) {
1208                                 $this->readOnly = true; // just avoid site down time
1209                         } else {
1210                                 throw $e;
1211                         }
1212                 }
1213                 $this->dbw->commit( __METHOD__ );
1214
1215                 $this->currentLang = null;
1216                 $this->batch = array();
1217         }
1218
1219         public function set( $key, $value ) {
1220                 if ( $this->readOnly ) {
1221                         return;
1222                 } elseif ( is_null( $this->currentLang ) ) {
1223                         throw new MWException( __CLASS__ . ': must call startWrite() before set()' );
1224                 }
1225
1226                 $this->batch[] = array(
1227                         'lc_lang' => $this->currentLang,
1228                         'lc_key' => $key,
1229                         'lc_value' => $this->dbw->encodeBlob( serialize( $value ) ) );
1230         }
1231 }
1232
1233 /**
1234  * LCStore implementation which stores data as a collection of CDB files in the
1235  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1236  * will throw an exception.
1237  *
1238  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1239  * the directory is on a local filesystem and there is ample kernel cache
1240  * space. The performance advantage is greater when the DBA extension is
1241  * available than it is with the PHP port.
1242  *
1243  * See Cdb.php and http://cr.yp.to/cdb.html
1244  */
1245 class LCStoreCDB implements LCStore {
1246         /** @var CdbReader[] */
1247         private $readers;
1248
1249         /** @var CdbWriter */
1250         private $writer;
1251
1252         /** @var string Current language code */
1253         private $currentLang;
1254
1255         /** @var bool|string Cache directory. False if not set */
1256         private $directory;
1257
1258         function __construct( $conf = array() ) {
1259                 global $wgCacheDirectory;
1260
1261                 if ( isset( $conf['directory'] ) ) {
1262                         $this->directory = $conf['directory'];
1263                 } else {
1264                         $this->directory = $wgCacheDirectory;
1265                 }
1266         }
1267
1268         public function get( $code, $key ) {
1269                 if ( !isset( $this->readers[$code] ) ) {
1270                         $fileName = $this->getFileName( $code );
1271
1272                         $this->readers[$code] = false;
1273                         if ( file_exists( $fileName ) ) {
1274                                 try {
1275                                         $this->readers[$code] = CdbReader::open( $fileName );
1276                                 } catch ( CdbException $e ) {
1277                                         wfDebug( __METHOD__ . ": unable to open cdb file for reading\n" );
1278                                 }
1279                         }
1280                 }
1281
1282                 if ( !$this->readers[$code] ) {
1283                         return null;
1284                 } else {
1285                         $value = false;
1286                         try {
1287                                 $value = $this->readers[$code]->get( $key );
1288                         } catch ( CdbException $e ) {
1289                                 wfDebug( __METHOD__ . ": CdbException caught, error message was "
1290                                         . $e->getMessage() . "\n" );
1291                         }
1292                         if ( $value === false ) {
1293                                 return null;
1294                         }
1295
1296                         return unserialize( $value );
1297                 }
1298         }
1299
1300         public function startWrite( $code ) {
1301                 if ( !file_exists( $this->directory ) ) {
1302                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1303                                 throw new MWException( "Unable to create the localisation store " .
1304                                         "directory \"{$this->directory}\"" );
1305                         }
1306                 }
1307
1308                 // Close reader to stop permission errors on write
1309                 if ( !empty( $this->readers[$code] ) ) {
1310                         $this->readers[$code]->close();
1311                 }
1312
1313                 try {
1314                         $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1315                 } catch ( CdbException $e ) {
1316                         throw new MWException( $e->getMessage() );
1317                 }
1318                 $this->currentLang = $code;
1319         }
1320
1321         public function finishWrite() {
1322                 // Close the writer
1323                 try {
1324                         $this->writer->close();
1325                 } catch ( CdbException $e ) {
1326                         throw new MWException( $e->getMessage() );
1327                 }
1328                 $this->writer = null;
1329                 unset( $this->readers[$this->currentLang] );
1330                 $this->currentLang = null;
1331         }
1332
1333         public function set( $key, $value ) {
1334                 if ( is_null( $this->writer ) ) {
1335                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1336                 }
1337                 try {
1338                         $this->writer->set( $key, serialize( $value ) );
1339                 } catch ( CdbException $e ) {
1340                         throw new MWException( $e->getMessage() );
1341                 }
1342         }
1343
1344         protected function getFileName( $code ) {
1345                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1346                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1347                 }
1348
1349                 return "{$this->directory}/l10n_cache-$code.cdb";
1350         }
1351 }
1352
1353 /**
1354  * Null store backend, used to avoid DB errors during install
1355  */
1356 class LCStoreNull implements LCStore {
1357         public function get( $code, $key ) {
1358                 return null;
1359         }
1360
1361         public function startWrite( $code ) {
1362         }
1363
1364         public function finishWrite() {
1365         }
1366
1367         public function set( $key, $value ) {
1368         }
1369 }
1370
1371 /**
1372  * A localisation cache optimised for loading large amounts of data for many
1373  * languages. Used by rebuildLocalisationCache.php.
1374  */
1375 class LocalisationCacheBulkLoad extends LocalisationCache {
1376         /**
1377          * A cache of the contents of data files.
1378          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1379          */
1380         private $fileCache = array();
1381
1382         /**
1383          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1384          * to keep the most recently used language codes at the end of the array, and
1385          * the language codes that are ready to be deleted at the beginning.
1386          */
1387         private $mruLangs = array();
1388
1389         /**
1390          * Maximum number of languages that may be loaded into $this->data
1391          */
1392         private $maxLoadedLangs = 10;
1393
1394         /**
1395          * @param string $fileName
1396          * @param string $fileType
1397          * @return array|mixed
1398          */
1399         protected function readPHPFile( $fileName, $fileType ) {
1400                 $serialize = $fileType === 'core';
1401                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1402                         $data = parent::readPHPFile( $fileName, $fileType );
1403
1404                         if ( $serialize ) {
1405                                 $encData = serialize( $data );
1406                         } else {
1407                                 $encData = $data;
1408                         }
1409
1410                         $this->fileCache[$fileName][$fileType] = $encData;
1411
1412                         return $data;
1413                 } elseif ( $serialize ) {
1414                         return unserialize( $this->fileCache[$fileName][$fileType] );
1415                 } else {
1416                         return $this->fileCache[$fileName][$fileType];
1417                 }
1418         }
1419
1420         /**
1421          * @param string $code
1422          * @param string $key
1423          * @return mixed
1424          */
1425         public function getItem( $code, $key ) {
1426                 unset( $this->mruLangs[$code] );
1427                 $this->mruLangs[$code] = true;
1428
1429                 return parent::getItem( $code, $key );
1430         }
1431
1432         /**
1433          * @param string $code
1434          * @param string $key
1435          * @param string $subkey
1436          * @return mixed
1437          */
1438         public function getSubitem( $code, $key, $subkey ) {
1439                 unset( $this->mruLangs[$code] );
1440                 $this->mruLangs[$code] = true;
1441
1442                 return parent::getSubitem( $code, $key, $subkey );
1443         }
1444
1445         /**
1446          * @param string $code
1447          */
1448         public function recache( $code ) {
1449                 parent::recache( $code );
1450                 unset( $this->mruLangs[$code] );
1451                 $this->mruLangs[$code] = true;
1452                 $this->trimCache();
1453         }
1454
1455         /**
1456          * @param string $code
1457          */
1458         public function unload( $code ) {
1459                 unset( $this->mruLangs[$code] );
1460                 parent::unload( $code );
1461         }
1462
1463         /**
1464          * Unload cached languages until there are less than $this->maxLoadedLangs
1465          */
1466         protected function trimCache() {
1467                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1468                         reset( $this->mruLangs );
1469                         $code = key( $this->mruLangs );
1470                         wfDebug( __METHOD__ . ": unloading $code\n" );
1471                         $this->unload( $code );
1472                 }
1473         }
1474 }