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