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', '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          * @return
 358          */
 359         protected function loadSubitem( $code, $key, $subkey ) {
 360                 if ( !in_array( $key, self::$splitKeys ) ) {
 361                         $this->loadItem( $code, $key );
 362                         return;
 363                 }
 364
 365                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 366                         $this->initLanguage( $code );
 367                 }
 368
 369                 // Check to see if initLanguage() loaded it for us
 370                 if ( isset( $this->loadedItems[$code][$key] ) ||
 371                          isset( $this->loadedSubitems[$code][$key][$subkey] ) ) {
 372                         return;
 373                 }
 374
 375                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 376                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 377                         return;
 378                 }
 379
 380                 $value = $this->store->get( $code, "$key:$subkey" );
 381                 $this->data[$code][$key][$subkey] = $value;
 382                 $this->loadedSubitems[$code][$key][$subkey] = true;
 383         }
 384
 385         /**
 386          * Returns true if the cache identified by $code is missing or expired.
 387          * @return bool
 388          */
 389         public function isExpired( $code ) {
 390                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 391                         wfDebug( __METHOD__ . "($code): forced reload\n" );
 392                         return true;
 393                 }
 394
 395                 $deps = $this->store->get( $code, 'deps' );
 396                 $keys = $this->store->get( $code, 'list' );
 397                 $preload = $this->store->get( $code, 'preload' );
 398                 // Different keys may expire separately, at least in LCStore_Accel
 399                 if ( $deps === null || $keys === null || $preload === null ) {
 400                         wfDebug( __METHOD__ . "($code): cache missing, need to make one\n" );
 401                         return true;
 402                 }
 403
 404                 foreach ( $deps as $dep ) {
 405                         // Because we're unserializing stuff from cache, we
 406                         // could receive objects of classes that don't exist
 407                         // anymore (e.g. uninstalled extensions)
 408                         // When this happens, always expire the cache
 409                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 410                                 wfDebug( __METHOD__ . "($code): cache for $code expired due to " .
 411                                         get_class( $dep ) . "\n" );
 412                                 return true;
 413                         }
 414                 }
 415
 416                 return false;
 417         }
 418
 419         /**
 420          * Initialise a language in this object. Rebuild the cache if necessary.
 421          * @param $code
 422          * @throws MWException
 423          */
 424         protected function initLanguage( $code ) {
 425                 if ( isset( $this->initialisedLangs[$code] ) ) {
 426                         return;
 427                 }
 428
 429                 $this->initialisedLangs[$code] = true;
 430
 431                 # If the code is of the wrong form for a Messages*.php file, do a shallow fallback
 432                 if ( !Language::isValidBuiltInCode( $code ) ) {
 433                         $this->initShallowFallback( $code, 'en' );
 434                         return;
 435                 }
 436
 437                 # Recache the data if necessary
 438                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 439                         if ( file_exists( Language::getMessagesFileName( $code ) ) ) {
 440                                 $this->recache( $code );
 441                         } elseif ( $code === 'en' ) {
 442                                 throw new MWException( 'MessagesEn.php is missing.' );
 443                         } else {
 444                                 $this->initShallowFallback( $code, 'en' );
 445                         }
 446                         return;
 447                 }
 448
 449                 # Preload some stuff
 450                 $preload = $this->getItem( $code, 'preload' );
 451                 if ( $preload === null ) {
 452                         if ( $this->manualRecache ) {
 453                                 // No Messages*.php file. Do shallow fallback to en.
 454                                 if ( $code === 'en' ) {
 455                                         throw new MWException( 'No localisation cache found for English. ' .
 456                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 457                                 }
 458                                 $this->initShallowFallback( $code, 'en' );
 459                                 return;
 460                         } else {
 461                                 throw new MWException( 'Invalid or missing localisation cache.' );
 462                         }
 463                 }
 464                 $this->data[$code] = $preload;
 465                 foreach ( $preload as $key => $item ) {
 466                         if ( in_array( $key, self::$splitKeys ) ) {
 467                                 foreach ( $item as $subkey => $subitem ) {
 468                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 469                                 }
 470                         } else {
 471                                 $this->loadedItems[$code][$key] = true;
 472                         }
 473                 }
 474         }
 475
 476         /**
 477          * Create a fallback from one language to another, without creating a
 478          * complete persistent cache.
 479          * @param $primaryCode
 480          * @param $fallbackCode
 481          */
 482         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 483                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 484                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 485                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 486                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 487         }
 488
 489         /**
 490          * Read a PHP file containing localisation data.
 491          * @param $_fileName
 492          * @param $_fileType
 493          * @throws MWException
 494          * @return array
 495          */
 496         protected function readPHPFile( $_fileName, $_fileType ) {
 497                 // Disable APC caching
 498                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 499                 include( $_fileName );
 500                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 501
 502                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 503                         $data = compact( self::$allKeys );
 504                 } elseif ( $_fileType == 'aliases' ) {
 505                         $data = compact( 'aliases' );
 506                 } else {
 507                         throw new MWException( __METHOD__ . ": Invalid file type: $_fileType" );
 508                 }
 509                 return $data;
 510         }
 511
 512         /**
 513          * Get the compiled plural rules for a given language from the XML files.
 514          * @since 1.20
 515          */
 516         public function getCompiledPluralRules( $code ) {
 517                 $rules = $this->getPluralRules( $code );
 518                 if ( $rules === null ) {
 519                         return null;
 520                 }
 521                 try {
 522                         $compiledRules = CLDRPluralRuleEvaluator::compile( $rules );
 523                 } catch( CLDRPluralRuleError $e ) {
 524                         wfDebugLog( 'l10n', $e->getMessage() . "\n" );
 525                         return array();
 526                 }
 527                 return $compiledRules;
 528         }
 529
 530         /**
 531          * Get the plural rules for a given language from the XML files.
 532          * Cached.
 533          * @since 1.20
 534          */
 535         public function getPluralRules( $code ) {
 536                 if ( $this->pluralRules === null ) {
 537                         $this->loadPluralFiles();
 538                 }
 539                 if ( !isset( $this->pluralRules[$code] ) ) {
 540                         return null;
 541                 } else {
 542                         return $this->pluralRules[$code];
 543                 }
 544         }
 545
 546         /**
 547          * Get the plural rule types for a given language from the XML files.
 548          * Cached.
 549          * @since 1.21
 550          */
 551         public function getPluralRuleTypes( $code ) {
 552                 if ( $this->pluralRuleTypes === null ) {
 553                         $this->loadPluralFiles();
 554                 }
 555                 if ( !isset( $this->pluralRuleTypes[$code] ) ) {
 556                         return null;
 557                 } else {
 558                         return $this->pluralRuleTypes[$code];
 559                 }
 560         }
 561
 562         /**
 563          * Load the plural XML files.
 564          */
 565         protected function loadPluralFiles() {
 566                 global $IP;
 567                 $cldrPlural = "$IP/languages/data/plurals.xml";
 568                 $mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
 569                 // Load CLDR plural rules
 570                 $this->loadPluralFile( $cldrPlural );
 571                 if ( file_exists( $mwPlural ) ) {
 572                         // Override or extend
 573                         $this->loadPluralFile( $mwPlural );
 574                 }
 575         }
 576
 577         /**
 578          * Load a plural XML file with the given filename, compile the relevant
 579          * rules, and save the compiled rules in a process-local cache.
 580          */
 581         protected function loadPluralFile( $fileName ) {
 582                 $doc = new DOMDocument;
 583                 $doc->load( $fileName );
 584                 $rulesets = $doc->getElementsByTagName( "pluralRules" );
 585                 foreach ( $rulesets as $ruleset ) {
 586                         $codes = $ruleset->getAttribute( 'locales' );
 587                         $rules = array();
 588                         $ruleTypes = array();
 589                         $ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
 590                         foreach ( $ruleElements as $elt ) {
 591                                 $ruleType = $elt->getAttribute( 'count' );
 592                                 $rules[] = $elt->nodeValue;
 593                                 $ruleTypes[] = $ruleType;
 594                         }
 595                         foreach ( explode( ' ', $codes ) as $code ) {
 596                                 $this->pluralRules[$code] = $rules;
 597                                 $this->pluralRuleTypes[$code] = $ruleTypes;
 598                         }
 599                 }
 600         }
 601
 602         /**
 603          * Read the data from the source files for a given language, and register
 604          * the relevant dependencies in the $deps array. If the localisation
 605          * exists, the data array is returned, otherwise false is returned.
 606          */
 607         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 608                 global $IP;
 609
 610                 $fileName = Language::getMessagesFileName( $code );
 611                 if ( !file_exists( $fileName ) ) {
 612                         return false;
 613                 }
 614
 615                 $deps[] = new FileDependency( $fileName );
 616                 $data = $this->readPHPFile( $fileName, 'core' );
 617
 618                 # Load CLDR plural rules for JavaScript
 619                 $data['pluralRules'] = $this->getPluralRules( $code );
 620                 # And for PHP
 621                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 622                 # Load plural rule types
 623                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 624
 625                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 626                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 627
 628                 return $data;
 629         }
 630
 631         /**
 632          * Merge two localisation values, a primary and a fallback, overwriting the
 633          * primary value in place.
 634          * @param $key
 635          * @param $value
 636          * @param $fallbackValue
 637          */
 638         protected function mergeItem( $key, &$value, $fallbackValue ) {
 639                 if ( !is_null( $value ) ) {
 640                         if ( !is_null( $fallbackValue ) ) {
 641                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 642                                         $value = $value + $fallbackValue;
 643                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 644                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 645                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 646                                         $value = array_merge_recursive( $value, $fallbackValue );
 647                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 648                                         if ( !empty( $value['inherit'] ) ) {
 649                                                 $value = array_merge( $fallbackValue, $value );
 650                                         }
 651
 652                                         if ( isset( $value['inherit'] ) ) {
 653                                                 unset( $value['inherit'] );
 654                                         }
 655                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 656                                         $this->mergeMagicWords( $value, $fallbackValue );
 657                                 }
 658                         }
 659                 } else {
 660                         $value = $fallbackValue;
 661                 }
 662         }
 663
 664         /**
 665          * @param $value
 666          * @param $fallbackValue
 667          */
 668         protected function mergeMagicWords( &$value, $fallbackValue ) {
 669                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 670                         if ( !isset( $value[$magicName] ) ) {
 671                                 $value[$magicName] = $fallbackInfo;
 672                         } else {
 673                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 674                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 675                                 $synonyms = array_values( array_unique( array_merge(
 676                                         $newSynonyms, $oldSynonyms ) ) );
 677                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 678                         }
 679                 }
 680         }
 681
 682         /**
 683          * Given an array mapping language code to localisation value, such as is
 684          * found in extension *.i18n.php files, iterate through a fallback sequence
 685          * to merge the given data with an existing primary value.
 686          *
 687          * Returns true if any data from the extension array was used, false
 688          * otherwise.
 689          * @param $codeSequence
 690          * @param $key
 691          * @param $value
 692          * @param $fallbackValue
 693          * @return bool
 694          */
 695         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 696                 $used = false;
 697                 foreach ( $codeSequence as $code ) {
 698                         if ( isset( $fallbackValue[$code] ) ) {
 699                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 700                                 $used = true;
 701                         }
 702                 }
 703
 704                 return $used;
 705         }
 706
 707         /**
 708          * Load localisation data for a given language for both core and extensions
 709          * and save it to the persistent cache store and the process cache
 710          * @param $code
 711          * @throws MWException
 712          */
 713         public function recache( $code ) {
 714                 global $wgExtensionMessagesFiles;
 715                 wfProfileIn( __METHOD__ );
 716
 717                 if ( !$code ) {
 718                         throw new MWException( "Invalid language code requested" );
 719                 }
 720                 $this->recachedLangs[$code] = true;
 721
 722                 # Initial values
 723                 $initialData = array_combine(
 724                         self::$allKeys,
 725                         array_fill( 0, count( self::$allKeys ), null ) );
 726                 $coreData = $initialData;
 727                 $deps = array();
 728
 729                 # Load the primary localisation from the source file
 730                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 731                 if ( $data === false ) {
 732                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 733                         $coreData['fallback'] = 'en';
 734                 } else {
 735                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 736
 737                         # Merge primary localisation
 738                         foreach ( $data as $key => $value ) {
 739                                 $this->mergeItem( $key, $coreData[$key], $value );
 740                         }
 741
 742                 }
 743
 744                 # Fill in the fallback if it's not there already
 745                 if ( is_null( $coreData['fallback'] ) ) {
 746                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 747                 }
 748                 if ( $coreData['fallback'] === false ) {
 749                         $coreData['fallbackSequence'] = array();
 750                 } else {
 751                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 752                         $len = count( $coreData['fallbackSequence'] );
 753
 754                         # Ensure that the sequence ends at en
 755                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 756                                 $coreData['fallbackSequence'][] = 'en';
 757                         }
 758
 759                         # Load the fallback localisation item by item and merge it
 760                         foreach ( $coreData['fallbackSequence'] as $fbCode ) {
 761                                 # Load the secondary localisation from the source file to
 762                                 # avoid infinite cycles on cyclic fallbacks
 763                                 $fbData = $this->readSourceFilesAndRegisterDeps( $fbCode, $deps );
 764                                 if ( $fbData === false ) {
 765                                         continue;
 766                                 }
 767
 768                                 foreach ( self::$allKeys as $key ) {
 769                                         if ( !isset( $fbData[$key] ) ) {
 770                                                 continue;
 771                                         }
 772
 773                                         if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 774                                                 $this->mergeItem( $key, $coreData[$key], $fbData[$key] );
 775                                         }
 776                                 }
 777                         }
 778                 }
 779
 780                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 781
 782                 # Load the extension localisations
 783                 # This is done after the core because we know the fallback sequence now.
 784                 # But it has a higher precedence for merging so that we can support things
 785                 # like site-specific message overrides.
 786                 $allData = $initialData;
 787                 foreach ( $wgExtensionMessagesFiles as $fileName ) {
 788                         $data = $this->readPHPFile( $fileName, 'extension' );
 789                         $used = false;
 790
 791                         foreach ( $data as $key => $item ) {
 792                                 if ( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 793                                         $used = true;
 794                                 }
 795                         }
 796
 797                         if ( $used ) {
 798                                 $deps[] = new FileDependency( $fileName );
 799                         }
 800                 }
 801
 802                 # Merge core data into extension data
 803                 foreach ( $coreData as $key => $item ) {
 804                         $this->mergeItem( $key, $allData[$key], $item );
 805                 }
 806
 807                 # Add cache dependencies for any referenced globals
 808                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 809                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 810
 811                 # Add dependencies to the cache entry
 812                 $allData['deps'] = $deps;
 813
 814                 # Replace spaces with underscores in namespace names
 815                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 816
 817                 # And do the same for special page aliases. $page is an array.
 818                 foreach ( $allData['specialPageAliases'] as &$page ) {
 819                         $page = str_replace( ' ', '_', $page );
 820                 }
 821                 # Decouple the reference to prevent accidental damage
 822                 unset( $page );
 823
 824                 # If there were no plural rules, return an empty array
 825                 if ( $allData['pluralRules'] === null ) {
 826                         $allData['pluralRules'] = array();
 827                 }
 828                 if ( $allData['compiledPluralRules'] === null ) {
 829                         $allData['compiledPluralRules'] = array();
 830                 }
 831                 # If there were no plural rule types, return an empty array
 832                 if ( $allData['pluralRuleTypes'] === null ) {
 833                         $allData['pluralRuleTypes'] = array();
 834                 }
 835
 836                 # Set the list keys
 837                 $allData['list'] = array();
 838                 foreach ( self::$splitKeys as $key ) {
 839                         $allData['list'][$key] = array_keys( $allData[$key] );
 840                 }
 841                 # Run hooks
 842                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData ) );
 843
 844                 if ( is_null( $allData['namespaceNames'] ) ) {
 845                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
 846                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 847                 }
 848
 849                 # Set the preload key
 850                 $allData['preload'] = $this->buildPreload( $allData );
 851
 852                 # Save to the process cache and register the items loaded
 853                 $this->data[$code] = $allData;
 854                 foreach ( $allData as $key => $item ) {
 855                         $this->loadedItems[$code][$key] = true;
 856                 }
 857
 858                 # Save to the persistent cache
 859                 $this->store->startWrite( $code );
 860                 foreach ( $allData as $key => $value ) {
 861                         if ( in_array( $key, self::$splitKeys ) ) {
 862                                 foreach ( $value as $subkey => $subvalue ) {
 863                                         $this->store->set( "$key:$subkey", $subvalue );
 864                                 }
 865                         } else {
 866                                 $this->store->set( $key, $value );
 867                         }
 868                 }
 869                 $this->store->finishWrite();
 870
 871                 # Clear out the MessageBlobStore
 872                 # HACK: If using a null (i.e. disabled) storage backend, we
 873                 # can't write to the MessageBlobStore either
 874                 if ( !$this->store instanceof LCStore_Null ) {
 875                         MessageBlobStore::clear();
 876                 }
 877
 878                 wfProfileOut( __METHOD__ );
 879         }
 880
 881         /**
 882          * Build the preload item from the given pre-cache data.
 883          *
 884          * The preload item will be loaded automatically, improving performance
 885          * for the commonly-requested items it contains.
 886          * @param $data
 887          * @return array
 888          */
 889         protected function buildPreload( $data ) {
 890                 $preload = array( 'messages' => array() );
 891                 foreach ( self::$preloadedKeys as $key ) {
 892                         $preload[$key] = $data[$key];
 893                 }
 894
 895                 foreach ( $data['preloadedMessages'] as $subkey ) {
 896                         if ( isset( $data['messages'][$subkey] ) ) {
 897                                 $subitem = $data['messages'][$subkey];
 898                         } else {
 899                                 $subitem = null;
 900                         }
 901                         $preload['messages'][$subkey] = $subitem;
 902                 }
 903
 904                 return $preload;
 905         }
 906
 907         /**
 908          * Unload the data for a given language from the object cache.
 909          * Reduces memory usage.
 910          * @param $code
 911          */
 912         public function unload( $code ) {
 913                 unset( $this->data[$code] );
 914                 unset( $this->loadedItems[$code] );
 915                 unset( $this->loadedSubitems[$code] );
 916                 unset( $this->initialisedLangs[$code] );
 917
 918                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
 919                         if ( $fbCode === $code ) {
 920                                 $this->unload( $shallowCode );
 921                         }
 922                 }
 923         }
 924
 925         /**
 926          * Unload all data
 927          */
 928         public function unloadAll() {
 929                 foreach ( $this->initialisedLangs as $lang => $unused ) {
 930                         $this->unload( $lang );
 931                 }
 932         }
 933
 934         /**
 935          * Disable the storage backend
 936          */
 937         public function disableBackend() {
 938                 $this->store = new LCStore_Null;
 939                 $this->manualRecache = false;
 940         }
 941 }
 942
 943 /**
 944  * Interface for the persistence layer of LocalisationCache.
 945  *
 946  * The persistence layer is two-level hierarchical cache. The first level
 947  * is the language, the second level is the item or subitem.
 948  *
 949  * Since the data for a whole language is rebuilt in one operation, it needs
 950  * to have a fast and atomic method for deleting or replacing all of the
 951  * current data for a given language. The interface reflects this bulk update
 952  * operation. Callers writing to the cache must first call startWrite(), then
 953  * will call set() a couple of thousand times, then will call finishWrite()
 954  * to commit the operation. When finishWrite() is called, the cache is
 955  * expected to delete all data previously stored for that language.
 956  *
 957  * The values stored are PHP variables suitable for serialize(). Implementations
 958  * of LCStore are responsible for serializing and unserializing.
 959  */
 960 interface LCStore {
 961         /**
 962          * Get a value.
 963          * @param string $code Language code
 964          * @param string $key Cache key
 965          */
 966         function get( $code, $key );
 967
 968         /**
 969          * Start a write transaction.
 970          * @param $code Language code
 971          */
 972         function startWrite( $code );
 973
 974         /**
 975          * Finish a write transaction.
 976          */
 977         function finishWrite();
 978
 979         /**
 980          * Set a key to a given value. startWrite() must be called before this
 981          * is called, and finishWrite() must be called afterwards.
 982          * @param $key
 983          * @param $value
 984          */
 985         function set( $key, $value );
 986 }
 987
 988 /**
 989  * LCStore implementation which uses PHP accelerator to store data.
 990  * This will work if one of XCache, WinCache or APC cacher is configured.
 991  * (See ObjectCache.php)
 992  */
 993 class LCStore_Accel implements LCStore {
 994         var $currentLang;
 995         var $keys;
 996
 997         public function __construct() {
 998                 $this->cache = wfGetCache( CACHE_ACCEL );
 999         }
1000
1001         public function get( $code, $key ) {
1002                 $k = wfMemcKey( 'l10n', $code, 'k', $key );
1003                 $r = $this->cache->get( $k );
1004                 return $r === false ? null : $r;
1005         }
1006
1007         public function startWrite( $code ) {
1008                 $k = wfMemcKey( 'l10n', $code, 'l' );
1009                 $keys = $this->cache->get( $k );
1010                 if ( $keys ) {
1011                         foreach ( $keys as $k ) {
1012                                 $this->cache->delete( $k );
1013                         }
1014                 }
1015                 $this->currentLang = $code;
1016                 $this->keys = array();
1017         }
1018
1019         public function finishWrite() {
1020                 if ( $this->currentLang ) {
1021                         $k = wfMemcKey( 'l10n', $this->currentLang, 'l' );
1022                         $this->cache->set( $k, array_keys( $this->keys ) );
1023                 }
1024                 $this->currentLang = null;
1025                 $this->keys = array();
1026         }
1027
1028         public function set( $key, $value ) {
1029                 if ( $this->currentLang ) {
1030                         $k = wfMemcKey( 'l10n', $this->currentLang, 'k', $key );
1031                         $this->keys[$k] = true;
1032                         $this->cache->set( $k, $value );
1033                 }
1034         }
1035 }
1036
1037 /**
1038  * LCStore implementation which uses the standard DB functions to store data.
1039  * This will work on any MediaWiki installation.
1040  */
1041 class LCStore_DB implements LCStore {
1042         var $currentLang;
1043         var $writesDone = false;
1044
1045         /**
1046          * @var DatabaseBase
1047          */
1048         var $dbw;
1049         var $batch;
1050         var $readOnly = false;
1051
1052         public function get( $code, $key ) {
1053                 if ( $this->writesDone ) {
1054                         $db = wfGetDB( DB_MASTER );
1055                 } else {
1056                         $db = wfGetDB( DB_SLAVE );
1057                 }
1058                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1059                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1060                 if ( $row ) {
1061                         return unserialize( $row->lc_value );
1062                 } else {
1063                         return null;
1064                 }
1065         }
1066
1067         public function startWrite( $code ) {
1068                 if ( $this->readOnly ) {
1069                         return;
1070                 }
1071
1072                 if ( !$code ) {
1073                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1074                 }
1075
1076                 $this->dbw = wfGetDB( DB_MASTER );
1077                 try {
1078                         $this->dbw->begin( __METHOD__ );
1079                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
1080                 } catch ( DBQueryError $e ) {
1081                         if ( $this->dbw->wasReadOnlyError() ) {
1082                                 $this->readOnly = true;
1083                                 $this->dbw->rollback( __METHOD__ );
1084                                 return;
1085                         } else {
1086                                 throw $e;
1087                         }
1088                 }
1089
1090                 $this->currentLang = $code;
1091                 $this->batch = array();
1092         }
1093
1094         public function finishWrite() {
1095                 if ( $this->readOnly ) {
1096                         return;
1097                 }
1098
1099                 if ( $this->batch ) {
1100                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1101                 }
1102
1103                 $this->dbw->commit( __METHOD__ );
1104                 $this->currentLang = null;
1105                 $this->dbw = null;
1106                 $this->batch = array();
1107                 $this->writesDone = true;
1108         }
1109
1110         public function set( $key, $value ) {
1111                 if ( $this->readOnly ) {
1112                         return;
1113                 }
1114
1115                 if ( is_null( $this->currentLang ) ) {
1116                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1117                 }
1118
1119                 $this->batch[] = array(
1120                         'lc_lang' => $this->currentLang,
1121                         'lc_key' => $key,
1122                         'lc_value' => serialize( $value ) );
1123
1124                 if ( count( $this->batch ) >= 100 ) {
1125                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1126                         $this->batch = array();
1127                 }
1128         }
1129 }
1130
1131 /**
1132  * LCStore implementation which stores data as a collection of CDB files in the
1133  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1134  * will throw an exception.
1135  *
1136  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1137  * the directory is on a local filesystem and there is ample kernel cache
1138  * space. The performance advantage is greater when the DBA extension is
1139  * available than it is with the PHP port.
1140  *
1141  * See Cdb.php and http://cr.yp.to/cdb.html
1142  */
1143 class LCStore_CDB implements LCStore {
1144         var $readers, $writer, $currentLang, $directory;
1145
1146         function __construct( $conf = array() ) {
1147                 global $wgCacheDirectory;
1148
1149                 if ( isset( $conf['directory'] ) ) {
1150                         $this->directory = $conf['directory'];
1151                 } else {
1152                         $this->directory = $wgCacheDirectory;
1153                 }
1154         }
1155
1156         public function get( $code, $key ) {
1157                 if ( !isset( $this->readers[$code] ) ) {
1158                         $fileName = $this->getFileName( $code );
1159
1160                         if ( !file_exists( $fileName ) ) {
1161                                 $this->readers[$code] = false;
1162                         } else {
1163                                 $this->readers[$code] = CdbReader::open( $fileName );
1164                         }
1165                 }
1166
1167                 if ( !$this->readers[$code] ) {
1168                         return null;
1169                 } else {
1170                         $value = $this->readers[$code]->get( $key );
1171
1172                         if ( $value === false ) {
1173                                 return null;
1174                         }
1175                         return unserialize( $value );
1176                 }
1177         }
1178
1179         public function startWrite( $code ) {
1180                 if ( !file_exists( $this->directory ) ) {
1181                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1182                                 throw new MWException( "Unable to create the localisation store " .
1183                                         "directory \"{$this->directory}\"" );
1184                         }
1185                 }
1186
1187                 // Close reader to stop permission errors on write
1188                 if ( !empty( $this->readers[$code] ) ) {
1189                         $this->readers[$code]->close();
1190                 }
1191
1192                 $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1193                 $this->currentLang = $code;
1194         }
1195
1196         public function finishWrite() {
1197                 // Close the writer
1198                 $this->writer->close();
1199                 $this->writer = null;
1200                 unset( $this->readers[$this->currentLang] );
1201                 $this->currentLang = null;
1202         }
1203
1204         public function set( $key, $value ) {
1205                 if ( is_null( $this->writer ) ) {
1206                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1207                 }
1208                 $this->writer->set( $key, serialize( $value ) );
1209         }
1210
1211         protected function getFileName( $code ) {
1212                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1213                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1214                 }
1215                 return "{$this->directory}/l10n_cache-$code.cdb";
1216         }
1217 }
1218
1219 /**
1220  * Null store backend, used to avoid DB errors during install
1221  */
1222 class LCStore_Null implements LCStore {
1223         public function get( $code, $key ) {
1224                 return null;
1225         }
1226
1227         public function startWrite( $code ) {}
1228         public function finishWrite() {}
1229         public function set( $key, $value ) {}
1230 }
1231
1232 /**
1233  * A localisation cache optimised for loading large amounts of data for many
1234  * languages. Used by rebuildLocalisationCache.php.
1235  */
1236 class LocalisationCache_BulkLoad extends LocalisationCache {
1237         /**
1238          * A cache of the contents of data files.
1239          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1240          */
1241         var $fileCache = array();
1242
1243         /**
1244          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1245          * to keep the most recently used language codes at the end of the array, and
1246          * the language codes that are ready to be deleted at the beginning.
1247          */
1248         var $mruLangs = array();
1249
1250         /**
1251          * Maximum number of languages that may be loaded into $this->data
1252          */
1253         var $maxLoadedLangs = 10;
1254
1255         /**
1256          * @param $fileName
1257          * @param $fileType
1258          * @return array|mixed
1259          */
1260         protected function readPHPFile( $fileName, $fileType ) {
1261                 $serialize = $fileType === 'core';
1262                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1263                         $data = parent::readPHPFile( $fileName, $fileType );
1264
1265                         if ( $serialize ) {
1266                                 $encData = serialize( $data );
1267                         } else {
1268                                 $encData = $data;
1269                         }
1270
1271                         $this->fileCache[$fileName][$fileType] = $encData;
1272
1273                         return $data;
1274                 } elseif ( $serialize ) {
1275                         return unserialize( $this->fileCache[$fileName][$fileType] );
1276                 } else {
1277                         return $this->fileCache[$fileName][$fileType];
1278                 }
1279         }
1280
1281         /**
1282          * @param $code
1283          * @param $key
1284          * @return mixed
1285          */
1286         public function getItem( $code, $key ) {
1287                 unset( $this->mruLangs[$code] );
1288                 $this->mruLangs[$code] = true;
1289                 return parent::getItem( $code, $key );
1290         }
1291
1292         /**
1293          * @param $code
1294          * @param $key
1295          * @param $subkey
1296          * @return
1297          */
1298         public function getSubitem( $code, $key, $subkey ) {
1299                 unset( $this->mruLangs[$code] );
1300                 $this->mruLangs[$code] = true;
1301                 return parent::getSubitem( $code, $key, $subkey );
1302         }
1303
1304         /**
1305          * @param $code
1306          */
1307         public function recache( $code ) {
1308                 parent::recache( $code );
1309                 unset( $this->mruLangs[$code] );
1310                 $this->mruLangs[$code] = true;
1311                 $this->trimCache();
1312         }
1313
1314         /**
1315          * @param $code
1316          */
1317         public function unload( $code ) {
1318                 unset( $this->mruLangs[$code] );
1319                 parent::unload( $code );
1320         }
1321
1322         /**
1323          * Unload cached languages until there are less than $this->maxLoadedLangs
1324          */
1325         protected function trimCache() {
1326                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1327                         reset( $this->mruLangs );
1328                         $code = key( $this->mruLangs );
1329                         wfDebug( __METHOD__ . ": unloading $code\n" );
1330                         $this->unload( $code );
1331                 }
1332         }
1333 }