includes/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', 'namespaceAliases',
 110                 'dateFormats', 'datePreferences', 'datePreferenceMigrationMap',
 111                 'defaultDateFormat', 'extraUserToggles', 'specialPageAliases',
 112                 'imageFiles', 'preloadedMessages', 'namespaceGenderAliases',
 113                 'digitGroupingPattern', 'pluralRules'
 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', 'pluralRules'
 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 containing plural rules.
 159          */
 160         var $pluralRules = array();
 161
 162         var $mergeableKeys = null;
 163
 164         /**
 165          * Constructor.
 166          * For constructor parameters, see the documentation in DefaultSettings.php
 167          * for $wgLocalisationCacheConf.
 168          *
 169          * @param $conf Array
 170          */
 171         function __construct( $conf ) {
 172                 global $wgCacheDirectory;
 173
 174                 $this->conf = $conf;
 175                 $storeConf = array();
 176                 if ( !empty( $conf['storeClass'] ) ) {
 177                         $storeClass = $conf['storeClass'];
 178                 } else {
 179                         switch ( $conf['store'] ) {
 180                                 case 'files':
 181                                 case 'file':
 182                                         $storeClass = 'LCStore_CDB';
 183                                         break;
 184                                 case 'db':
 185                                         $storeClass = 'LCStore_DB';
 186                                         break;
 187                                 case 'accel':
 188                                         $storeClass = 'LCStore_Accel';
 189                                         break;
 190                                 case 'detect':
 191                                         $storeClass = $wgCacheDirectory ? 'LCStore_CDB' : 'LCStore_DB';
 192                                         break;
 193                                 default:
 194                                         throw new MWException(
 195                                                 'Please set $wgLocalisationCacheConf[\'store\'] to something sensible.' );
 196                         }
 197                 }
 198
 199                 wfDebug( get_class( $this ) . ": using store $storeClass\n" );
 200                 if ( !empty( $conf['storeDirectory'] ) ) {
 201                         $storeConf['directory'] = $conf['storeDirectory'];
 202                 }
 203
 204                 $this->store = new $storeClass( $storeConf );
 205                 foreach ( array( 'manualRecache', 'forceRecache' ) as $var ) {
 206                         if ( isset( $conf[$var] ) ) {
 207                                 $this->$var = $conf[$var];
 208                         }
 209                 }
 210                 $this->readPluralRules();
 211         }
 212
 213         /**
 214          * Returns true if the given key is mergeable, that is, if it is an associative
 215          * array which can be merged through a fallback sequence.
 216          * @param $key
 217          * @return bool
 218          */
 219         public function isMergeableKey( $key ) {
 220                 if ( $this->mergeableKeys === null ) {
 221                         $this->mergeableKeys = array_flip( array_merge(
 222                                 self::$mergeableMapKeys,
 223                                 self::$mergeableListKeys,
 224                                 self::$mergeableAliasListKeys,
 225                                 self::$optionalMergeKeys,
 226                                 self::$magicWordKeys
 227                         ) );
 228                 }
 229                 return isset( $this->mergeableKeys[$key] );
 230         }
 231
 232         /**
 233          * Get a cache item.
 234          *
 235          * Warning: this may be slow for split items (messages), since it will
 236          * need to fetch all of the subitems from the cache individually.
 237          * @param $code
 238          * @param $key
 239          * @return mixed
 240          */
 241         public function getItem( $code, $key ) {
 242                 if ( !isset( $this->loadedItems[$code][$key] ) ) {
 243                         wfProfileIn( __METHOD__ . '-load' );
 244                         $this->loadItem( $code, $key );
 245                         wfProfileOut( __METHOD__ . '-load' );
 246                 }
 247
 248                 if ( $key === 'fallback' && isset( $this->shallowFallbacks[$code] ) ) {
 249                         return $this->shallowFallbacks[$code];
 250                 }
 251
 252                 return $this->data[$code][$key];
 253         }
 254
 255         /**
 256          * Get a subitem, for instance a single message for a given language.
 257          * @param $code
 258          * @param $key
 259          * @param $subkey
 260          * @return null
 261          */
 262         public function getSubitem( $code, $key, $subkey ) {
 263                 if ( !isset( $this->loadedSubitems[$code][$key][$subkey] ) &&
 264                          !isset( $this->loadedItems[$code][$key] ) ) {
 265                         wfProfileIn( __METHOD__ . '-load' );
 266                         $this->loadSubitem( $code, $key, $subkey );
 267                         wfProfileOut( __METHOD__ . '-load' );
 268                 }
 269
 270                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 271                         return $this->data[$code][$key][$subkey];
 272                 } else {
 273                         return null;
 274                 }
 275         }
 276
 277         /**
 278          * Get the list of subitem keys for a given item.
 279          *
 280          * This is faster than array_keys($lc->getItem(...)) for the items listed in
 281          * self::$splitKeys.
 282          *
 283          * Will return null if the item is not found, or false if the item is not an
 284          * array.
 285          * @param $code
 286          * @param $key
 287          * @return bool|null|string
 288          */
 289         public function getSubitemList( $code, $key ) {
 290                 if ( in_array( $key, self::$splitKeys ) ) {
 291                         return $this->getSubitem( $code, 'list', $key );
 292                 } else {
 293                         $item = $this->getItem( $code, $key );
 294                         if ( is_array( $item ) ) {
 295                                 return array_keys( $item );
 296                         } else {
 297                                 return false;
 298                         }
 299                 }
 300         }
 301
 302         /**
 303          * Load an item into the cache.
 304          * @param $code
 305          * @param $key
 306          */
 307         protected function loadItem( $code, $key ) {
 308                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 309                         $this->initLanguage( $code );
 310                 }
 311
 312                 // Check to see if initLanguage() loaded it for us
 313                 if ( isset( $this->loadedItems[$code][$key] ) ) {
 314                         return;
 315                 }
 316
 317                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 318                         $this->loadItem( $this->shallowFallbacks[$code], $key );
 319                         return;
 320                 }
 321
 322                 if ( in_array( $key, self::$splitKeys ) ) {
 323                         $subkeyList = $this->getSubitem( $code, 'list', $key );
 324                         foreach ( $subkeyList as $subkey ) {
 325                                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 326                                         continue;
 327                                 }
 328                                 $this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
 329                         }
 330                 } else {
 331                         $this->data[$code][$key] = $this->store->get( $code, $key );
 332                 }
 333
 334                 $this->loadedItems[$code][$key] = true;
 335         }
 336
 337         /**
 338          * Load a subitem into the cache
 339          * @param $code
 340          * @param $key
 341          * @param $subkey
 342          * @return
 343          */
 344         protected function loadSubitem( $code, $key, $subkey ) {
 345                 if ( !in_array( $key, self::$splitKeys ) ) {
 346                         $this->loadItem( $code, $key );
 347                         return;
 348                 }
 349
 350                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 351                         $this->initLanguage( $code );
 352                 }
 353
 354                 // Check to see if initLanguage() loaded it for us
 355                 if ( isset( $this->loadedItems[$code][$key] ) ||
 356                          isset( $this->loadedSubitems[$code][$key][$subkey] ) ) {
 357                         return;
 358                 }
 359
 360                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 361                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 362                         return;
 363                 }
 364
 365                 $value = $this->store->get( $code, "$key:$subkey" );
 366                 $this->data[$code][$key][$subkey] = $value;
 367                 $this->loadedSubitems[$code][$key][$subkey] = true;
 368         }
 369
 370         /**
 371          * Returns true if the cache identified by $code is missing or expired.
 372          * @return bool
 373          */
 374         public function isExpired( $code ) {
 375                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 376                         wfDebug( __METHOD__ . "($code): forced reload\n" );
 377                         return true;
 378                 }
 379
 380                 $deps = $this->store->get( $code, 'deps' );
 381                 $keys = $this->store->get( $code, 'list', 'messages' );
 382                 $preload = $this->store->get( $code, 'preload' );
 383                 // Different keys may expire separately, at least in LCStore_Accel
 384                 if ( $deps === null || $keys === null || $preload === null ) {
 385                         wfDebug( __METHOD__ . "($code): cache missing, need to make one\n" );
 386                         return true;
 387                 }
 388
 389                 foreach ( $deps as $dep ) {
 390                         // Because we're unserializing stuff from cache, we
 391                         // could receive objects of classes that don't exist
 392                         // anymore (e.g. uninstalled extensions)
 393                         // When this happens, always expire the cache
 394                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 395                                 wfDebug( __METHOD__ . "($code): cache for $code expired due to " .
 396                                         get_class( $dep ) . "\n" );
 397                                 return true;
 398                         }
 399                 }
 400
 401                 return false;
 402         }
 403
 404         /**
 405          * Initialise a language in this object. Rebuild the cache if necessary.
 406          * @param $code
 407          */
 408         protected function initLanguage( $code ) {
 409                 if ( isset( $this->initialisedLangs[$code] ) ) {
 410                         return;
 411                 }
 412
 413                 $this->initialisedLangs[$code] = true;
 414
 415                 # If the code is of the wrong form for a Messages*.php file, do a shallow fallback
 416                 if ( !Language::isValidBuiltInCode( $code ) ) {
 417                         $this->initShallowFallback( $code, 'en' );
 418                         return;
 419                 }
 420
 421                 # Recache the data if necessary
 422                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 423                         if ( file_exists( Language::getMessagesFileName( $code ) ) ) {
 424                                 $this->recache( $code );
 425                         } elseif ( $code === 'en' ) {
 426                                 throw new MWException( 'MessagesEn.php is missing.' );
 427                         } else {
 428                                 $this->initShallowFallback( $code, 'en' );
 429                         }
 430                         return;
 431                 }
 432
 433                 # Preload some stuff
 434                 $preload = $this->getItem( $code, 'preload' );
 435                 if ( $preload === null ) {
 436                         if ( $this->manualRecache ) {
 437                                 // No Messages*.php file. Do shallow fallback to en.
 438                                 if ( $code === 'en' ) {
 439                                         throw new MWException( 'No localisation cache found for English. ' .
 440                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 441                                 }
 442                                 $this->initShallowFallback( $code, 'en' );
 443                                 return;
 444                         } else {
 445                                 throw new MWException( 'Invalid or missing localisation cache.' );
 446                         }
 447                 }
 448                 $this->data[$code] = $preload;
 449                 foreach ( $preload as $key => $item ) {
 450                         if ( in_array( $key, self::$splitKeys ) ) {
 451                                 foreach ( $item as $subkey => $subitem ) {
 452                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 453                                 }
 454                         } else {
 455                                 $this->loadedItems[$code][$key] = true;
 456                         }
 457                 }
 458         }
 459
 460         /**
 461          * Create a fallback from one language to another, without creating a
 462          * complete persistent cache.
 463          * @param $primaryCode
 464          * @param $fallbackCode
 465          */
 466         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 467                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 468                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 469                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 470                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 471         }
 472
 473         /**
 474          * Read a PHP file containing localisation data.
 475          * @param $_fileName
 476          * @param $_fileType
 477          * @return array
 478          */
 479         protected function readPHPFile( $_fileName, $_fileType ) {
 480                 // Disable APC caching
 481                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 482                 include( $_fileName );
 483                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 484
 485                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 486                         $data = compact( self::$allKeys );
 487                 } elseif ( $_fileType == 'aliases' ) {
 488                         $data = compact( 'aliases' );
 489                 } else {
 490                         throw new MWException( __METHOD__ . ": Invalid file type: $_fileType" );
 491                 }
 492                 return $data;
 493         }
 494         /**
 495          * Read the plural rule xml files.
 496          * First the CLDR xml will be read and it will be extended with
 497          * mediawiki specific tailoring.
 498          * @since 1.20
 499          */
 500         protected function readPluralRules() {
 501                 $CLDRPlural = __DIR__ . "/../languages/data/plurals.xml";
 502                 $MWPlural = __DIR__ . "/../languages/data/plurals-mediawiki.xml";
 503                 # Load CLDR plural rules
 504                 $this->parsePluralXML( $CLDRPlural );
 505                 if ( file_exists( $MWPlural ) ) {
 506                         // override or extend.
 507                         $this->parsePluralXML( $MWPlural );
 508                 }
 509         }
 510
 511         private function parsePluralXML( $xmlFile ) {
 512                 $pluraldoc = new DOMDocument();
 513                 $pluraldoc->load( $xmlFile );
 514                 $rulesets = $pluraldoc->getElementsByTagName( "pluralRules" );
 515                 foreach ( $rulesets as $ruleset ) {
 516                         $codes = $ruleset->getAttribute( 'locales' );
 517                         $parsedRules = array();
 518                         $rules = $ruleset->getElementsByTagName( "pluralRule" );
 519                         foreach ( $rules as $rule ) {
 520                                 $parsedRules[$rule->getAttribute( 'count' )] = $rule->nodeValue;
 521                         }
 522                         foreach ( explode( ' ', $codes ) as $code ) {
 523                                 $this->pluralRules[$code] = $parsedRules;
 524                         }
 525                 }
 526         }
 527
 528         /**
 529          * Merge two localisation values, a primary and a fallback, overwriting the
 530          * primary value in place.
 531          * @param $key
 532          * @param $value
 533          * @param $fallbackValue
 534          */
 535         protected function mergeItem( $key, &$value, $fallbackValue ) {
 536                 if ( !is_null( $value ) ) {
 537                         if ( !is_null( $fallbackValue ) ) {
 538                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 539                                         $value = $value + $fallbackValue;
 540                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 541                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 542                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 543                                         $value = array_merge_recursive( $value, $fallbackValue );
 544                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 545                                         if ( !empty( $value['inherit'] ) )  {
 546                                                 $value = array_merge( $fallbackValue, $value );
 547                                         }
 548
 549                                         if ( isset( $value['inherit'] ) ) {
 550                                                 unset( $value['inherit'] );
 551                                         }
 552                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 553                                         $this->mergeMagicWords( $value, $fallbackValue );
 554                                 }
 555                         }
 556                 } else {
 557                         $value = $fallbackValue;
 558                 }
 559         }
 560
 561         /**
 562          * @param $value
 563          * @param $fallbackValue
 564          */
 565         protected function mergeMagicWords( &$value, $fallbackValue ) {
 566                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 567                         if ( !isset( $value[$magicName] ) ) {
 568                                 $value[$magicName] = $fallbackInfo;
 569                         } else {
 570                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 571                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 572                                 $synonyms = array_values( array_unique( array_merge(
 573                                         $newSynonyms, $oldSynonyms ) ) );
 574                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 575                         }
 576                 }
 577         }
 578
 579         /**
 580          * Given an array mapping language code to localisation value, such as is
 581          * found in extension *.i18n.php files, iterate through a fallback sequence
 582          * to merge the given data with an existing primary value.
 583          *
 584          * Returns true if any data from the extension array was used, false
 585          * otherwise.
 586          * @param $codeSequence
 587          * @param $key
 588          * @param $value
 589          * @param $fallbackValue
 590          * @return bool
 591          */
 592         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 593                 $used = false;
 594                 foreach ( $codeSequence as $code ) {
 595                         if ( isset( $fallbackValue[$code] ) ) {
 596                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 597                                 $used = true;
 598                         }
 599                 }
 600
 601                 return $used;
 602         }
 603
 604         /**
 605          * Load localisation data for a given language for both core and extensions
 606          * and save it to the persistent cache store and the process cache
 607          * @param $code
 608          */
 609         public function recache( $code ) {
 610                 global $wgExtensionMessagesFiles;
 611                 wfProfileIn( __METHOD__ );
 612
 613                 if ( !$code ) {
 614                         throw new MWException( "Invalid language code requested" );
 615                 }
 616                 $this->recachedLangs[$code] = true;
 617
 618                 # Initial values
 619                 $initialData = array_combine(
 620                         self::$allKeys,
 621                         array_fill( 0, count( self::$allKeys ), null ) );
 622                 $coreData = $initialData;
 623                 $deps = array();
 624
 625                 # Load the primary localisation from the source file
 626                 $fileName = Language::getMessagesFileName( $code );
 627                 if ( !file_exists( $fileName ) ) {
 628                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 629                         $coreData['fallback'] = 'en';
 630                 } else {
 631                         $deps[] = new FileDependency( $fileName );
 632                         $data = $this->readPHPFile( $fileName, 'core' );
 633                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 634
 635                         # Merge primary localisation
 636                         foreach ( $data as $key => $value ) {
 637                                 $this->mergeItem( $key, $coreData[$key], $value );
 638                         }
 639
 640                 }
 641
 642                 # Fill in the fallback if it's not there already
 643                 if ( is_null( $coreData['fallback'] ) ) {
 644                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 645                 }
 646                 if ( $coreData['fallback'] === false ) {
 647                         $coreData['fallbackSequence'] = array();
 648                 } else {
 649                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 650                         $len = count( $coreData['fallbackSequence'] );
 651
 652                         # Ensure that the sequence ends at en
 653                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 654                                 $coreData['fallbackSequence'][] = 'en';
 655                         }
 656
 657                         # Load the fallback localisation item by item and merge it
 658                         foreach ( $coreData['fallbackSequence'] as $fbCode ) {
 659                                 # Load the secondary localisation from the source file to
 660                                 # avoid infinite cycles on cyclic fallbacks
 661                                 $fbFilename = Language::getMessagesFileName( $fbCode );
 662
 663                                 if ( !file_exists( $fbFilename ) ) {
 664                                         continue;
 665                                 }
 666
 667                                 $deps[] = new FileDependency( $fbFilename );
 668                                 $fbData = $this->readPHPFile( $fbFilename, 'core' );
 669
 670                                 foreach ( self::$allKeys as $key ) {
 671                                         if ( !isset( $fbData[$key] ) ) {
 672                                                 continue;
 673                                         }
 674
 675                                         if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 676                                                 $this->mergeItem( $key, $coreData[$key], $fbData[$key] );
 677                                         }
 678                                 }
 679                         }
 680                 }
 681
 682                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 683
 684                 # Load the extension localisations
 685                 # This is done after the core because we know the fallback sequence now.
 686                 # But it has a higher precedence for merging so that we can support things
 687                 # like site-specific message overrides.
 688                 $allData = $initialData;
 689                 foreach ( $wgExtensionMessagesFiles as $fileName ) {
 690                         $data = $this->readPHPFile( $fileName, 'extension' );
 691                         $used = false;
 692
 693                         foreach ( $data as $key => $item ) {
 694                                 if ( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 695                                         $used = true;
 696                                 }
 697                         }
 698
 699                         if ( $used ) {
 700                                 $deps[] = new FileDependency( $fileName );
 701                         }
 702                 }
 703
 704                 # Merge core data into extension data
 705                 foreach ( $coreData as $key => $item ) {
 706                         $this->mergeItem( $key, $allData[$key], $item );
 707                 }
 708
 709                 # Add cache dependencies for any referenced globals
 710                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 711                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 712
 713                 # Add dependencies to the cache entry
 714                 $allData['deps'] = $deps;
 715
 716                 # Replace spaces with underscores in namespace names
 717                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 718
 719                 # And do the same for special page aliases. $page is an array.
 720                 foreach ( $allData['specialPageAliases'] as &$page ) {
 721                         $page = str_replace( ' ', '_', $page );
 722                 }
 723                 # Decouple the reference to prevent accidental damage
 724                 unset( $page );
 725
 726                 # Set the list keys
 727                 $allData['list'] = array();
 728                 foreach ( self::$splitKeys as $key ) {
 729                         $allData['list'][$key] = array_keys( $allData[$key] );
 730                 }
 731                 # Load CLDR plural rules
 732                 if ( isset( $this->pluralRules[$code] ) ) {
 733                         $allData['pluralRules'] = $this->pluralRules[$code];
 734                 }
 735                 # Run hooks
 736                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData ) );
 737
 738                 if ( is_null( $allData['namespaceNames'] ) ) {
 739                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
 740                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 741                 }
 742
 743                 # Set the preload key
 744                 $allData['preload'] = $this->buildPreload( $allData );
 745
 746                 # Save to the process cache and register the items loaded
 747                 $this->data[$code] = $allData;
 748                 foreach ( $allData as $key => $item ) {
 749                         $this->loadedItems[$code][$key] = true;
 750                 }
 751
 752                 # Save to the persistent cache
 753                 $this->store->startWrite( $code );
 754                 foreach ( $allData as $key => $value ) {
 755                         if ( in_array( $key, self::$splitKeys ) ) {
 756                                 foreach ( $value as $subkey => $subvalue ) {
 757                                         $this->store->set( "$key:$subkey", $subvalue );
 758                                 }
 759                         } else {
 760                                 $this->store->set( $key, $value );
 761                         }
 762                 }
 763                 $this->store->finishWrite();
 764
 765                 # Clear out the MessageBlobStore
 766                 # HACK: If using a null (i.e. disabled) storage backend, we
 767                 # can't write to the MessageBlobStore either
 768                 if ( !$this->store instanceof LCStore_Null ) {
 769                         MessageBlobStore::clear();
 770                 }
 771
 772                 wfProfileOut( __METHOD__ );
 773         }
 774
 775         /**
 776          * Build the preload item from the given pre-cache data.
 777          *
 778          * The preload item will be loaded automatically, improving performance
 779          * for the commonly-requested items it contains.
 780          * @param $data
 781          * @return array
 782          */
 783         protected function buildPreload( $data ) {
 784                 $preload = array( 'messages' => array() );
 785                 foreach ( self::$preloadedKeys as $key ) {
 786                         $preload[$key] = $data[$key];
 787                 }
 788
 789                 foreach ( $data['preloadedMessages'] as $subkey ) {
 790                         if ( isset( $data['messages'][$subkey] ) ) {
 791                                 $subitem = $data['messages'][$subkey];
 792                         } else {
 793                                 $subitem = null;
 794                         }
 795                         $preload['messages'][$subkey] = $subitem;
 796                 }
 797
 798                 return $preload;
 799         }
 800
 801         /**
 802          * Unload the data for a given language from the object cache.
 803          * Reduces memory usage.
 804          * @param $code
 805          */
 806         public function unload( $code ) {
 807                 unset( $this->data[$code] );
 808                 unset( $this->loadedItems[$code] );
 809                 unset( $this->loadedSubitems[$code] );
 810                 unset( $this->initialisedLangs[$code] );
 811
 812                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
 813                         if ( $fbCode === $code ) {
 814                                 $this->unload( $shallowCode );
 815                         }
 816                 }
 817         }
 818
 819         /**
 820          * Unload all data
 821          */
 822         public function unloadAll() {
 823                 foreach ( $this->initialisedLangs as $lang => $unused ) {
 824                         $this->unload( $lang );
 825                 }
 826         }
 827
 828         /**
 829          * Disable the storage backend
 830          */
 831         public function disableBackend() {
 832                 $this->store = new LCStore_Null;
 833                 $this->manualRecache = false;
 834         }
 835 }
 836
 837 /**
 838  * Interface for the persistence layer of LocalisationCache.
 839  *
 840  * The persistence layer is two-level hierarchical cache. The first level
 841  * is the language, the second level is the item or subitem.
 842  *
 843  * Since the data for a whole language is rebuilt in one operation, it needs
 844  * to have a fast and atomic method for deleting or replacing all of the
 845  * current data for a given language. The interface reflects this bulk update
 846  * operation. Callers writing to the cache must first call startWrite(), then
 847  * will call set() a couple of thousand times, then will call finishWrite()
 848  * to commit the operation. When finishWrite() is called, the cache is
 849  * expected to delete all data previously stored for that language.
 850  *
 851  * The values stored are PHP variables suitable for serialize(). Implementations
 852  * of LCStore are responsible for serializing and unserializing.
 853  */
 854 interface LCStore {
 855         /**
 856          * Get a value.
 857          * @param $code string Language code
 858          * @param $key string Cache key
 859          */
 860         function get( $code, $key );
 861
 862         /**
 863          * Start a write transaction.
 864          * @param $code Language code
 865          */
 866         function startWrite( $code );
 867
 868         /**
 869          * Finish a write transaction.
 870          */
 871         function finishWrite();
 872
 873         /**
 874          * Set a key to a given value. startWrite() must be called before this
 875          * is called, and finishWrite() must be called afterwards.
 876          * @param $key
 877          * @param $value
 878          */
 879         function set( $key, $value );
 880 }
 881
 882 /**
 883  * LCStore implementation which uses PHP accelerator to store data.
 884  * This will work if one of XCache, WinCache or APC cacher is configured.
 885  * (See ObjectCache.php)
 886  */
 887 class LCStore_Accel implements LCStore {
 888         var $currentLang;
 889         var $keys;
 890
 891         public function __construct() {
 892                 $this->cache = wfGetCache( CACHE_ACCEL );
 893         }
 894
 895         public function get( $code, $key ) {
 896                 $k = wfMemcKey( 'l10n', $code, 'k', $key );
 897                 $r = $this->cache->get( $k );
 898                 return $r === false ? null : $r;
 899         }
 900
 901         public function startWrite( $code ) {
 902                 $k = wfMemcKey( 'l10n', $code, 'l' );
 903                 $keys = $this->cache->get( $k );
 904                 if ( $keys ) {
 905                         foreach ( $keys as $k ) {
 906                                 $this->cache->delete( $k );
 907                         }
 908                 }
 909                 $this->currentLang = $code;
 910                 $this->keys = array();
 911         }
 912
 913         public function finishWrite() {
 914                 if ( $this->currentLang ) {
 915                         $k = wfMemcKey( 'l10n', $this->currentLang, 'l' );
 916                         $this->cache->set( $k, array_keys( $this->keys ) );
 917                 }
 918                 $this->currentLang = null;
 919                 $this->keys = array();
 920         }
 921
 922         public function set( $key, $value ) {
 923                 if ( $this->currentLang ) {
 924                         $k = wfMemcKey( 'l10n', $this->currentLang, 'k', $key );
 925                         $this->keys[$k] = true;
 926                         $this->cache->set( $k, $value );
 927                 }
 928         }
 929 }
 930
 931 /**
 932  * LCStore implementation which uses the standard DB functions to store data.
 933  * This will work on any MediaWiki installation.
 934  */
 935 class LCStore_DB implements LCStore {
 936         var $currentLang;
 937         var $writesDone = false;
 938
 939         /**
 940          * @var DatabaseBase
 941          */
 942         var $dbw;
 943         var $batch;
 944         var $readOnly = false;
 945
 946         public function get( $code, $key ) {
 947                 if ( $this->writesDone ) {
 948                         $db = wfGetDB( DB_MASTER );
 949                 } else {
 950                         $db = wfGetDB( DB_SLAVE );
 951                 }
 952                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
 953                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
 954                 if ( $row ) {
 955                         return unserialize( $row->lc_value );
 956                 } else {
 957                         return null;
 958                 }
 959         }
 960
 961         public function startWrite( $code ) {
 962                 if ( $this->readOnly ) {
 963                         return;
 964                 }
 965
 966                 if ( !$code ) {
 967                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
 968                 }
 969
 970                 $this->dbw = wfGetDB( DB_MASTER );
 971                 try {
 972                         $this->dbw->begin( __METHOD__ );
 973                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
 974                 } catch ( DBQueryError $e ) {
 975                         if ( $this->dbw->wasReadOnlyError() ) {
 976                                 $this->readOnly = true;
 977                                 $this->dbw->rollback( __METHOD__ );
 978                                 $this->dbw->ignoreErrors( false );
 979                                 return;
 980                         } else {
 981                                 throw $e;
 982                         }
 983                 }
 984
 985                 $this->currentLang = $code;
 986                 $this->batch = array();
 987         }
 988
 989         public function finishWrite() {
 990                 if ( $this->readOnly ) {
 991                         return;
 992                 }
 993
 994                 if ( $this->batch ) {
 995                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
 996                 }
 997
 998                 $this->dbw->commit( __METHOD__ );
 999                 $this->currentLang = null;
1000                 $this->dbw = null;
1001                 $this->batch = array();
1002                 $this->writesDone = true;
1003         }
1004
1005         public function set( $key, $value ) {
1006                 if ( $this->readOnly ) {
1007                         return;
1008                 }
1009
1010                 if ( is_null( $this->currentLang ) ) {
1011                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1012                 }
1013
1014                 $this->batch[] = array(
1015                         'lc_lang' => $this->currentLang,
1016                         'lc_key' => $key,
1017                         'lc_value' => serialize( $value ) );
1018
1019                 if ( count( $this->batch ) >= 100 ) {
1020                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1021                         $this->batch = array();
1022                 }
1023         }
1024 }
1025
1026 /**
1027  * LCStore implementation which stores data as a collection of CDB files in the
1028  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1029  * will throw an exception.
1030  *
1031  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1032  * the directory is on a local filesystem and there is ample kernel cache
1033  * space. The performance advantage is greater when the DBA extension is
1034  * available than it is with the PHP port.
1035  *
1036  * See Cdb.php and http://cr.yp.to/cdb.html
1037  */
1038 class LCStore_CDB implements LCStore {
1039         var $readers, $writer, $currentLang, $directory;
1040
1041         function __construct( $conf = array() ) {
1042                 global $wgCacheDirectory;
1043
1044                 if ( isset( $conf['directory'] ) ) {
1045                         $this->directory = $conf['directory'];
1046                 } else {
1047                         $this->directory = $wgCacheDirectory;
1048                 }
1049         }
1050
1051         public function get( $code, $key ) {
1052                 if ( !isset( $this->readers[$code] ) ) {
1053                         $fileName = $this->getFileName( $code );
1054
1055                         if ( !file_exists( $fileName ) ) {
1056                                 $this->readers[$code] = false;
1057                         } else {
1058                                 $this->readers[$code] = CdbReader::open( $fileName );
1059                         }
1060                 }
1061
1062                 if ( !$this->readers[$code] ) {
1063                         return null;
1064                 } else {
1065                         $value = $this->readers[$code]->get( $key );
1066
1067                         if ( $value === false ) {
1068                                 return null;
1069                         }
1070                         return unserialize( $value );
1071                 }
1072         }
1073
1074         public function startWrite( $code ) {
1075                 if ( !file_exists( $this->directory ) ) {
1076                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1077                                 throw new MWException( "Unable to create the localisation store " .
1078                                         "directory \"{$this->directory}\"" );
1079                         }
1080                 }
1081
1082                 // Close reader to stop permission errors on write
1083                 if ( !empty( $this->readers[$code] ) ) {
1084                         $this->readers[$code]->close();
1085                 }
1086
1087                 $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1088                 $this->currentLang = $code;
1089         }
1090
1091         public function finishWrite() {
1092                 // Close the writer
1093                 $this->writer->close();
1094                 $this->writer = null;
1095                 unset( $this->readers[$this->currentLang] );
1096                 $this->currentLang = null;
1097         }
1098
1099         public function set( $key, $value ) {
1100                 if ( is_null( $this->writer ) ) {
1101                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1102                 }
1103                 $this->writer->set( $key, serialize( $value ) );
1104         }
1105
1106         protected function getFileName( $code ) {
1107                 if ( !$code || strpos( $code, '/' ) !== false ) {
1108                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1109                 }
1110                 return "{$this->directory}/l10n_cache-$code.cdb";
1111         }
1112 }
1113
1114 /**
1115  * Null store backend, used to avoid DB errors during install
1116  */
1117 class LCStore_Null implements LCStore {
1118         public function get( $code, $key ) {
1119                 return null;
1120         }
1121
1122         public function startWrite( $code ) {}
1123         public function finishWrite() {}
1124         public function set( $key, $value ) {}
1125 }
1126
1127 /**
1128  * A localisation cache optimised for loading large amounts of data for many
1129  * languages. Used by rebuildLocalisationCache.php.
1130  */
1131 class LocalisationCache_BulkLoad extends LocalisationCache {
1132         /**
1133          * A cache of the contents of data files.
1134          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1135          */
1136         var $fileCache = array();
1137
1138         /**
1139          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1140          * to keep the most recently used language codes at the end of the array, and
1141          * the language codes that are ready to be deleted at the beginning.
1142          */
1143         var $mruLangs = array();
1144
1145         /**
1146          * Maximum number of languages that may be loaded into $this->data
1147          */
1148         var $maxLoadedLangs = 10;
1149
1150         /**
1151          * @param $fileName
1152          * @param $fileType
1153          * @return array|mixed
1154          */
1155         protected function readPHPFile( $fileName, $fileType ) {
1156                 $serialize = $fileType === 'core';
1157                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1158                         $data = parent::readPHPFile( $fileName, $fileType );
1159
1160                         if ( $serialize ) {
1161                                 $encData = serialize( $data );
1162                         } else {
1163                                 $encData = $data;
1164                         }
1165
1166                         $this->fileCache[$fileName][$fileType] = $encData;
1167
1168                         return $data;
1169                 } elseif ( $serialize ) {
1170                         return unserialize( $this->fileCache[$fileName][$fileType] );
1171                 } else {
1172                         return $this->fileCache[$fileName][$fileType];
1173                 }
1174         }
1175
1176         /**
1177          * @param $code
1178          * @param $key
1179          * @return mixed
1180          */
1181         public function getItem( $code, $key ) {
1182                 unset( $this->mruLangs[$code] );
1183                 $this->mruLangs[$code] = true;
1184                 return parent::getItem( $code, $key );
1185         }
1186
1187         /**
1188          * @param $code
1189          * @param $key
1190          * @param $subkey
1191          * @return
1192          */
1193         public function getSubitem( $code, $key, $subkey ) {
1194                 unset( $this->mruLangs[$code] );
1195                 $this->mruLangs[$code] = true;
1196                 return parent::getSubitem( $code, $key, $subkey );
1197         }
1198
1199         /**
1200          * @param $code
1201          */
1202         public function recache( $code ) {
1203                 parent::recache( $code );
1204                 unset( $this->mruLangs[$code] );
1205                 $this->mruLangs[$code] = true;
1206                 $this->trimCache();
1207         }
1208
1209         /**
1210          * @param $code
1211          */
1212         public function unload( $code ) {
1213                 unset( $this->mruLangs[$code] );
1214                 parent::unload( $code );
1215         }
1216
1217         /**
1218          * Unload cached languages until there are less than $this->maxLoadedLangs
1219          */
1220         protected function trimCache() {
1221                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1222                         reset( $this->mruLangs );
1223                         $code = key( $this->mruLangs );
1224                         wfDebug( __METHOD__ . ": unloading $code\n" );
1225                         $this->unload( $code );
1226                 }
1227         }
1228
1229 }