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         private $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         private $manualRecache = false;
  47
  48         /**
  49          * True to treat all files as expired until they are regenerated by this object.
  50          */
  51         private $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         protected $data = array();
  60
  61         /**
  62          * The persistent store object. An instance of LCStore.
  63          *
  64          * @var LCStore
  65          */
  66         private $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         private $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         private $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         private $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         private $shallowFallbacks = array();
  96
  97         /**
  98          * An array where the keys are codes that have been recached by this instance.
  99          */
 100         private $recachedLangs = array();
 101
 102         /**
 103          * All item keys
 104          */
 105         static public $allKeys = array(
 106                 'fallback', 'namespaceNames', 'bookstoreList',
 107                 'magicWords', 'messages', 'rtl', 'capitalizeAllNouns', 'digitTransformTable',
 108                 'separatorTransformTable', 'fallback8bitEncoding', 'linkPrefixExtension',
 109                 'linkTrail', 'linkPrefixCharset', 'namespaceAliases',
 110                 'dateFormats', 'datePreferences', 'datePreferenceMigrationMap',
 111                 'defaultDateFormat', 'extraUserToggles', 'specialPageAliases',
 112                 'imageFiles', 'preloadedMessages', 'namespaceGenderAliases',
 113                 'digitGroupingPattern', 'pluralRules', 'pluralRuleTypes', 'compiledPluralRules',
 114         );
 115
 116         /**
 117          * Keys for items which consist of associative arrays, which may be merged
 118          * by a fallback sequence.
 119          */
 120         static public $mergeableMapKeys = array( 'messages', 'namespaceNames',
 121                 'dateFormats', 'imageFiles', 'preloadedMessages'
 122         );
 123
 124         /**
 125          * Keys for items which are a numbered array.
 126          */
 127         static public $mergeableListKeys = array( 'extraUserToggles' );
 128
 129         /**
 130          * Keys for items which contain an array of arrays of equivalent aliases
 131          * for each subitem. The aliases may be merged by a fallback sequence.
 132          */
 133         static public $mergeableAliasListKeys = array( 'specialPageAliases' );
 134
 135         /**
 136          * Keys for items which contain an associative array, and may be merged if
 137          * the primary value contains the special array key "inherit". That array
 138          * key is removed after the first merge.
 139          */
 140         static public $optionalMergeKeys = array( 'bookstoreList' );
 141
 142         /**
 143          * Keys for items that are formatted like $magicWords
 144          */
 145         static public $magicWordKeys = array( 'magicWords' );
 146
 147         /**
 148          * Keys for items where the subitems are stored in the backend separately.
 149          */
 150         static public $splitKeys = array( 'messages' );
 151
 152         /**
 153          * Keys which are loaded automatically by initLanguage()
 154          */
 155         static public $preloadedKeys = array( 'dateFormats', 'namespaceNames' );
 156
 157         /**
 158          * Associative array of cached plural rules. The key is the language code,
 159          * the value is an array of plural rules for that language.
 160          */
 161         private $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         private $pluralRuleTypes = null;
 176
 177         private $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 = 'LCStoreCDB';
 199                                         break;
 200                                 case 'db':
 201                                         $storeClass = 'LCStoreDB';
 202                                         break;
 203                                 case 'accel':
 204                                         $storeClass = 'LCStoreAccel';
 205                                         break;
 206                                 case 'detect':
 207                                         $storeClass = $wgCacheDirectory ? 'LCStoreCDB' : 'LCStoreDB';
 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
 245                 return isset( $this->mergeableKeys[$key] );
 246         }
 247
 248         /**
 249          * Get a cache item.
 250          *
 251          * Warning: this may be slow for split items (messages), since it will
 252          * need to fetch all of the subitems from the cache individually.
 253          * @param $code
 254          * @param $key
 255          * @return mixed
 256          */
 257         public function getItem( $code, $key ) {
 258                 if ( !isset( $this->loadedItems[$code][$key] ) ) {
 259                         wfProfileIn( __METHOD__ . '-load' );
 260                         $this->loadItem( $code, $key );
 261                         wfProfileOut( __METHOD__ . '-load' );
 262                 }
 263
 264                 if ( $key === 'fallback' && isset( $this->shallowFallbacks[$code] ) ) {
 265                         return $this->shallowFallbacks[$code];
 266                 }
 267
 268                 return $this->data[$code][$key];
 269         }
 270
 271         /**
 272          * Get a subitem, for instance a single message for a given language.
 273          * @param $code
 274          * @param $key
 275          * @param $subkey
 276          * @return null
 277          */
 278         public function getSubitem( $code, $key, $subkey ) {
 279                 if ( !isset( $this->loadedSubitems[$code][$key][$subkey] ) &&
 280                         !isset( $this->loadedItems[$code][$key] )
 281                 ) {
 282                         wfProfileIn( __METHOD__ . '-load' );
 283                         $this->loadSubitem( $code, $key, $subkey );
 284                         wfProfileOut( __METHOD__ . '-load' );
 285                 }
 286
 287                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 288                         return $this->data[$code][$key][$subkey];
 289                 } else {
 290                         return null;
 291                 }
 292         }
 293
 294         /**
 295          * Get the list of subitem keys for a given item.
 296          *
 297          * This is faster than array_keys($lc->getItem(...)) for the items listed in
 298          * self::$splitKeys.
 299          *
 300          * Will return null if the item is not found, or false if the item is not an
 301          * array.
 302          * @param $code
 303          * @param $key
 304          * @return bool|null|string
 305          */
 306         public function getSubitemList( $code, $key ) {
 307                 if ( in_array( $key, self::$splitKeys ) ) {
 308                         return $this->getSubitem( $code, 'list', $key );
 309                 } else {
 310                         $item = $this->getItem( $code, $key );
 311                         if ( is_array( $item ) ) {
 312                                 return array_keys( $item );
 313                         } else {
 314                                 return false;
 315                         }
 316                 }
 317         }
 318
 319         /**
 320          * Load an item into the cache.
 321          * @param $code
 322          * @param $key
 323          */
 324         protected function loadItem( $code, $key ) {
 325                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 326                         $this->initLanguage( $code );
 327                 }
 328
 329                 // Check to see if initLanguage() loaded it for us
 330                 if ( isset( $this->loadedItems[$code][$key] ) ) {
 331                         return;
 332                 }
 333
 334                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 335                         $this->loadItem( $this->shallowFallbacks[$code], $key );
 336
 337                         return;
 338                 }
 339
 340                 if ( in_array( $key, self::$splitKeys ) ) {
 341                         $subkeyList = $this->getSubitem( $code, 'list', $key );
 342                         foreach ( $subkeyList as $subkey ) {
 343                                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 344                                         continue;
 345                                 }
 346                                 $this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
 347                         }
 348                 } else {
 349                         $this->data[$code][$key] = $this->store->get( $code, $key );
 350                 }
 351
 352                 $this->loadedItems[$code][$key] = true;
 353         }
 354
 355         /**
 356          * Load a subitem into the cache
 357          * @param $code
 358          * @param $key
 359          * @param $subkey
 360          */
 361         protected function loadSubitem( $code, $key, $subkey ) {
 362                 if ( !in_array( $key, self::$splitKeys ) ) {
 363                         $this->loadItem( $code, $key );
 364
 365                         return;
 366                 }
 367
 368                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 369                         $this->initLanguage( $code );
 370                 }
 371
 372                 // Check to see if initLanguage() loaded it for us
 373                 if ( isset( $this->loadedItems[$code][$key] ) ||
 374                         isset( $this->loadedSubitems[$code][$key][$subkey] )
 375                 ) {
 376                         return;
 377                 }
 378
 379                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 380                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 381
 382                         return;
 383                 }
 384
 385                 $value = $this->store->get( $code, "$key:$subkey" );
 386                 $this->data[$code][$key][$subkey] = $value;
 387                 $this->loadedSubitems[$code][$key][$subkey] = true;
 388         }
 389
 390         /**
 391          * Returns true if the cache identified by $code is missing or expired.
 392          *
 393          * @param string $code
 394          *
 395          * @return bool
 396          */
 397         public function isExpired( $code ) {
 398                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 399                         wfDebug( __METHOD__ . "($code): forced reload\n" );
 400
 401                         return true;
 402                 }
 403
 404                 $deps = $this->store->get( $code, 'deps' );
 405                 $keys = $this->store->get( $code, 'list' );
 406                 $preload = $this->store->get( $code, 'preload' );
 407                 // Different keys may expire separately, at least in LCStoreAccel
 408                 if ( $deps === null || $keys === null || $preload === null ) {
 409                         wfDebug( __METHOD__ . "($code): cache missing, need to make one\n" );
 410
 411                         return true;
 412                 }
 413
 414                 foreach ( $deps as $dep ) {
 415                         // Because we're unserializing stuff from cache, we
 416                         // could receive objects of classes that don't exist
 417                         // anymore (e.g. uninstalled extensions)
 418                         // When this happens, always expire the cache
 419                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 420                                 wfDebug( __METHOD__ . "($code): cache for $code expired due to " .
 421                                         get_class( $dep ) . "\n" );
 422
 423                                 return true;
 424                         }
 425                 }
 426
 427                 return false;
 428         }
 429
 430         /**
 431          * Initialise a language in this object. Rebuild the cache if necessary.
 432          * @param $code
 433          * @throws MWException
 434          */
 435         protected function initLanguage( $code ) {
 436                 if ( isset( $this->initialisedLangs[$code] ) ) {
 437                         return;
 438                 }
 439
 440                 $this->initialisedLangs[$code] = true;
 441
 442                 # If the code is of the wrong form for a Messages*.php file, do a shallow fallback
 443                 if ( !Language::isValidBuiltInCode( $code ) ) {
 444                         $this->initShallowFallback( $code, 'en' );
 445
 446                         return;
 447                 }
 448
 449                 # Recache the data if necessary
 450                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 451                         if ( file_exists( Language::getMessagesFileName( $code ) ) ) {
 452                                 $this->recache( $code );
 453                         } elseif ( $code === 'en' ) {
 454                                 throw new MWException( 'MessagesEn.php is missing.' );
 455                         } else {
 456                                 $this->initShallowFallback( $code, 'en' );
 457                         }
 458
 459                         return;
 460                 }
 461
 462                 # Preload some stuff
 463                 $preload = $this->getItem( $code, 'preload' );
 464                 if ( $preload === null ) {
 465                         if ( $this->manualRecache ) {
 466                                 // No Messages*.php file. Do shallow fallback to en.
 467                                 if ( $code === 'en' ) {
 468                                         throw new MWException( 'No localisation cache found for English. ' .
 469                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 470                                 }
 471                                 $this->initShallowFallback( $code, 'en' );
 472
 473                                 return;
 474                         } else {
 475                                 throw new MWException( 'Invalid or missing localisation cache.' );
 476                         }
 477                 }
 478                 $this->data[$code] = $preload;
 479                 foreach ( $preload as $key => $item ) {
 480                         if ( in_array( $key, self::$splitKeys ) ) {
 481                                 foreach ( $item as $subkey => $subitem ) {
 482                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 483                                 }
 484                         } else {
 485                                 $this->loadedItems[$code][$key] = true;
 486                         }
 487                 }
 488         }
 489
 490         /**
 491          * Create a fallback from one language to another, without creating a
 492          * complete persistent cache.
 493          * @param $primaryCode
 494          * @param $fallbackCode
 495          */
 496         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 497                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 498                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 499                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 500                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 501         }
 502
 503         /**
 504          * Read a PHP file containing localisation data.
 505          * @param $_fileName
 506          * @param $_fileType
 507          * @throws MWException
 508          * @return array
 509          */
 510         protected function readPHPFile( $_fileName, $_fileType ) {
 511                 wfProfileIn( __METHOD__ );
 512                 // Disable APC caching
 513                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 514                 include $_fileName;
 515                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 516
 517                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 518                         $data = compact( self::$allKeys );
 519                 } elseif ( $_fileType == 'aliases' ) {
 520                         $data = compact( 'aliases' );
 521                 } else {
 522                         wfProfileOut( __METHOD__ );
 523                         throw new MWException( __METHOD__ . ": Invalid file type: $_fileType" );
 524                 }
 525                 wfProfileOut( __METHOD__ );
 526
 527                 return $data;
 528         }
 529
 530         /**
 531          * Get the compiled plural rules for a given language from the XML files.
 532          * @since 1.20
 533          */
 534         public function getCompiledPluralRules( $code ) {
 535                 $rules = $this->getPluralRules( $code );
 536                 if ( $rules === null ) {
 537                         return null;
 538                 }
 539                 try {
 540                         $compiledRules = CLDRPluralRuleEvaluator::compile( $rules );
 541                 } catch ( CLDRPluralRuleError $e ) {
 542                         wfDebugLog( 'l10n', $e->getMessage() . "\n" );
 543
 544                         return array();
 545                 }
 546
 547                 return $compiledRules;
 548         }
 549
 550         /**
 551          * Get the plural rules for a given language from the XML files.
 552          * Cached.
 553          * @since 1.20
 554          */
 555         public function getPluralRules( $code ) {
 556                 if ( $this->pluralRules === null ) {
 557                         $this->loadPluralFiles();
 558                 }
 559                 if ( !isset( $this->pluralRules[$code] ) ) {
 560                         return null;
 561                 } else {
 562                         return $this->pluralRules[$code];
 563                 }
 564         }
 565
 566         /**
 567          * Get the plural rule types for a given language from the XML files.
 568          * Cached.
 569          * @since 1.22
 570          */
 571         public function getPluralRuleTypes( $code ) {
 572                 if ( $this->pluralRuleTypes === null ) {
 573                         $this->loadPluralFiles();
 574                 }
 575                 if ( !isset( $this->pluralRuleTypes[$code] ) ) {
 576                         return null;
 577                 } else {
 578                         return $this->pluralRuleTypes[$code];
 579                 }
 580         }
 581
 582         /**
 583          * Load the plural XML files.
 584          */
 585         protected function loadPluralFiles() {
 586                 global $IP;
 587                 $cldrPlural = "$IP/languages/data/plurals.xml";
 588                 $mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
 589                 // Load CLDR plural rules
 590                 $this->loadPluralFile( $cldrPlural );
 591                 if ( file_exists( $mwPlural ) ) {
 592                         // Override or extend
 593                         $this->loadPluralFile( $mwPlural );
 594                 }
 595         }
 596
 597         /**
 598          * Load a plural XML file with the given filename, compile the relevant
 599          * rules, and save the compiled rules in a process-local cache.
 600          */
 601         protected function loadPluralFile( $fileName ) {
 602                 $doc = new DOMDocument;
 603                 $doc->load( $fileName );
 604                 $rulesets = $doc->getElementsByTagName( "pluralRules" );
 605                 foreach ( $rulesets as $ruleset ) {
 606                         $codes = $ruleset->getAttribute( 'locales' );
 607                         $rules = array();
 608                         $ruleTypes = array();
 609                         $ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
 610                         foreach ( $ruleElements as $elt ) {
 611                                 $ruleType = $elt->getAttribute( 'count' );
 612                                 $rules[] = $elt->nodeValue;
 613                                 $ruleTypes[] = $ruleType;
 614                         }
 615                         foreach ( explode( ' ', $codes ) as $code ) {
 616                                 $this->pluralRules[$code] = $rules;
 617                                 $this->pluralRuleTypes[$code] = $ruleTypes;
 618                         }
 619                 }
 620         }
 621
 622         /**
 623          * Read the data from the source files for a given language, and register
 624          * the relevant dependencies in the $deps array. If the localisation
 625          * exists, the data array is returned, otherwise false is returned.
 626          */
 627         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 628                 global $IP;
 629                 wfProfileIn( __METHOD__ );
 630
 631                 $fileName = Language::getMessagesFileName( $code );
 632                 if ( !file_exists( $fileName ) ) {
 633                         wfProfileOut( __METHOD__ );
 634
 635                         return false;
 636                 }
 637
 638                 $deps[] = new FileDependency( $fileName );
 639                 $data = $this->readPHPFile( $fileName, 'core' );
 640
 641                 # Load CLDR plural rules for JavaScript
 642                 $data['pluralRules'] = $this->getPluralRules( $code );
 643                 # And for PHP
 644                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 645                 # Load plural rule types
 646                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 647
 648                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 649                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 650
 651                 wfProfileOut( __METHOD__ );
 652
 653                 return $data;
 654         }
 655
 656         /**
 657          * Merge two localisation values, a primary and a fallback, overwriting the
 658          * primary value in place.
 659          * @param $key
 660          * @param $value
 661          * @param $fallbackValue
 662          */
 663         protected function mergeItem( $key, &$value, $fallbackValue ) {
 664                 if ( !is_null( $value ) ) {
 665                         if ( !is_null( $fallbackValue ) ) {
 666                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 667                                         $value = $value + $fallbackValue;
 668                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 669                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 670                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 671                                         $value = array_merge_recursive( $value, $fallbackValue );
 672                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 673                                         if ( !empty( $value['inherit'] ) ) {
 674                                                 $value = array_merge( $fallbackValue, $value );
 675                                         }
 676
 677                                         if ( isset( $value['inherit'] ) ) {
 678                                                 unset( $value['inherit'] );
 679                                         }
 680                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 681                                         $this->mergeMagicWords( $value, $fallbackValue );
 682                                 }
 683                         }
 684                 } else {
 685                         $value = $fallbackValue;
 686                 }
 687         }
 688
 689         /**
 690          * @param $value
 691          * @param $fallbackValue
 692          */
 693         protected function mergeMagicWords( &$value, $fallbackValue ) {
 694                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 695                         if ( !isset( $value[$magicName] ) ) {
 696                                 $value[$magicName] = $fallbackInfo;
 697                         } else {
 698                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 699                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 700                                 $synonyms = array_values( array_unique( array_merge(
 701                                         $newSynonyms, $oldSynonyms ) ) );
 702                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 703                         }
 704                 }
 705         }
 706
 707         /**
 708          * Given an array mapping language code to localisation value, such as is
 709          * found in extension *.i18n.php files, iterate through a fallback sequence
 710          * to merge the given data with an existing primary value.
 711          *
 712          * Returns true if any data from the extension array was used, false
 713          * otherwise.
 714          * @param $codeSequence
 715          * @param $key
 716          * @param $value
 717          * @param $fallbackValue
 718          * @return bool
 719          */
 720         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 721                 $used = false;
 722                 foreach ( $codeSequence as $code ) {
 723                         if ( isset( $fallbackValue[$code] ) ) {
 724                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 725                                 $used = true;
 726                         }
 727                 }
 728
 729                 return $used;
 730         }
 731
 732         /**
 733          * Load localisation data for a given language for both core and extensions
 734          * and save it to the persistent cache store and the process cache
 735          * @param $code
 736          * @throws MWException
 737          */
 738         public function recache( $code ) {
 739                 global $wgExtensionMessagesFiles;
 740                 wfProfileIn( __METHOD__ );
 741
 742                 if ( !$code ) {
 743                         wfProfileOut( __METHOD__ );
 744                         throw new MWException( "Invalid language code requested" );
 745                 }
 746                 $this->recachedLangs[$code] = true;
 747
 748                 # Initial values
 749                 $initialData = array_combine(
 750                         self::$allKeys,
 751                         array_fill( 0, count( self::$allKeys ), null ) );
 752                 $coreData = $initialData;
 753                 $deps = array();
 754
 755                 # Load the primary localisation from the source file
 756                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 757                 if ( $data === false ) {
 758                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 759                         $coreData['fallback'] = 'en';
 760                 } else {
 761                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 762
 763                         # Merge primary localisation
 764                         foreach ( $data as $key => $value ) {
 765                                 $this->mergeItem( $key, $coreData[$key], $value );
 766                         }
 767                 }
 768
 769                 # Fill in the fallback if it's not there already
 770                 if ( is_null( $coreData['fallback'] ) ) {
 771                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 772                 }
 773                 if ( $coreData['fallback'] === false ) {
 774                         $coreData['fallbackSequence'] = array();
 775                 } else {
 776                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 777                         $len = count( $coreData['fallbackSequence'] );
 778
 779                         # Ensure that the sequence ends at en
 780                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 781                                 $coreData['fallbackSequence'][] = 'en';
 782                         }
 783
 784                         # Load the fallback localisation item by item and merge it
 785                         foreach ( $coreData['fallbackSequence'] as $fbCode ) {
 786                                 # Load the secondary localisation from the source file to
 787                                 # avoid infinite cycles on cyclic fallbacks
 788                                 $fbData = $this->readSourceFilesAndRegisterDeps( $fbCode, $deps );
 789                                 if ( $fbData === false ) {
 790                                         continue;
 791                                 }
 792
 793                                 foreach ( self::$allKeys as $key ) {
 794                                         if ( !isset( $fbData[$key] ) ) {
 795                                                 continue;
 796                                         }
 797
 798                                         if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 799                                                 $this->mergeItem( $key, $coreData[$key], $fbData[$key] );
 800                                         }
 801                                 }
 802                         }
 803                 }
 804
 805                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 806
 807                 # Load the extension localisations
 808                 # This is done after the core because we know the fallback sequence now.
 809                 # But it has a higher precedence for merging so that we can support things
 810                 # like site-specific message overrides.
 811                 wfProfileIn( __METHOD__ . '-extensions' );
 812                 $allData = $initialData;
 813                 foreach ( $wgExtensionMessagesFiles as $fileName ) {
 814                         $data = $this->readPHPFile( $fileName, 'extension' );
 815                         $used = false;
 816
 817                         foreach ( $data as $key => $item ) {
 818                                 if ( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 819                                         $used = true;
 820                                 }
 821                         }
 822
 823                         if ( $used ) {
 824                                 $deps[] = new FileDependency( $fileName );
 825                         }
 826                 }
 827
 828                 # Merge core data into extension data
 829                 foreach ( $coreData as $key => $item ) {
 830                         $this->mergeItem( $key, $allData[$key], $item );
 831                 }
 832                 wfProfileOut( __METHOD__ . '-extensions' );
 833
 834                 # Add cache dependencies for any referenced globals
 835                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 836                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 837
 838                 # Add dependencies to the cache entry
 839                 $allData['deps'] = $deps;
 840
 841                 # Replace spaces with underscores in namespace names
 842                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 843
 844                 # And do the same for special page aliases. $page is an array.
 845                 foreach ( $allData['specialPageAliases'] as &$page ) {
 846                         $page = str_replace( ' ', '_', $page );
 847                 }
 848                 # Decouple the reference to prevent accidental damage
 849                 unset( $page );
 850
 851                 # If there were no plural rules, return an empty array
 852                 if ( $allData['pluralRules'] === null ) {
 853                         $allData['pluralRules'] = array();
 854                 }
 855                 if ( $allData['compiledPluralRules'] === null ) {
 856                         $allData['compiledPluralRules'] = array();
 857                 }
 858                 # If there were no plural rule types, return an empty array
 859                 if ( $allData['pluralRuleTypes'] === null ) {
 860                         $allData['pluralRuleTypes'] = array();
 861                 }
 862
 863                 # Set the list keys
 864                 $allData['list'] = array();
 865                 foreach ( self::$splitKeys as $key ) {
 866                         $allData['list'][$key] = array_keys( $allData[$key] );
 867                 }
 868                 # Run hooks
 869                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData ) );
 870
 871                 if ( is_null( $allData['namespaceNames'] ) ) {
 872                         wfProfileOut( __METHOD__ );
 873                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
 874                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 875                 }
 876
 877                 # Set the preload key
 878                 $allData['preload'] = $this->buildPreload( $allData );
 879
 880                 # Save to the process cache and register the items loaded
 881                 $this->data[$code] = $allData;
 882                 foreach ( $allData as $key => $item ) {
 883                         $this->loadedItems[$code][$key] = true;
 884                 }
 885
 886                 # Save to the persistent cache
 887                 wfProfileIn( __METHOD__ . '-write' );
 888                 $this->store->startWrite( $code );
 889                 foreach ( $allData as $key => $value ) {
 890                         if ( in_array( $key, self::$splitKeys ) ) {
 891                                 foreach ( $value as $subkey => $subvalue ) {
 892                                         $this->store->set( "$key:$subkey", $subvalue );
 893                                 }
 894                         } else {
 895                                 $this->store->set( $key, $value );
 896                         }
 897                 }
 898                 $this->store->finishWrite();
 899                 wfProfileOut( __METHOD__ . '-write' );
 900
 901                 # Clear out the MessageBlobStore
 902                 # HACK: If using a null (i.e. disabled) storage backend, we
 903                 # can't write to the MessageBlobStore either
 904                 if ( !$this->store instanceof LCStoreNull ) {
 905                         MessageBlobStore::clear();
 906                 }
 907
 908                 wfProfileOut( __METHOD__ );
 909         }
 910
 911         /**
 912          * Build the preload item from the given pre-cache data.
 913          *
 914          * The preload item will be loaded automatically, improving performance
 915          * for the commonly-requested items it contains.
 916          * @param $data
 917          * @return array
 918          */
 919         protected function buildPreload( $data ) {
 920                 $preload = array( 'messages' => array() );
 921                 foreach ( self::$preloadedKeys as $key ) {
 922                         $preload[$key] = $data[$key];
 923                 }
 924
 925                 foreach ( $data['preloadedMessages'] as $subkey ) {
 926                         if ( isset( $data['messages'][$subkey] ) ) {
 927                                 $subitem = $data['messages'][$subkey];
 928                         } else {
 929                                 $subitem = null;
 930                         }
 931                         $preload['messages'][$subkey] = $subitem;
 932                 }
 933
 934                 return $preload;
 935         }
 936
 937         /**
 938          * Unload the data for a given language from the object cache.
 939          * Reduces memory usage.
 940          * @param $code
 941          */
 942         public function unload( $code ) {
 943                 unset( $this->data[$code] );
 944                 unset( $this->loadedItems[$code] );
 945                 unset( $this->loadedSubitems[$code] );
 946                 unset( $this->initialisedLangs[$code] );
 947                 unset( $this->shallowFallbacks[$code] );
 948
 949                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
 950                         if ( $fbCode === $code ) {
 951                                 $this->unload( $shallowCode );
 952                         }
 953                 }
 954         }
 955
 956         /**
 957          * Unload all data
 958          */
 959         public function unloadAll() {
 960                 foreach ( $this->initialisedLangs as $lang => $unused ) {
 961                         $this->unload( $lang );
 962                 }
 963         }
 964
 965         /**
 966          * Disable the storage backend
 967          */
 968         public function disableBackend() {
 969                 $this->store = new LCStoreNull;
 970                 $this->manualRecache = false;
 971         }
 972 }
 973
 974 /**
 975  * Interface for the persistence layer of LocalisationCache.
 976  *
 977  * The persistence layer is two-level hierarchical cache. The first level
 978  * is the language, the second level is the item or subitem.
 979  *
 980  * Since the data for a whole language is rebuilt in one operation, it needs
 981  * to have a fast and atomic method for deleting or replacing all of the
 982  * current data for a given language. The interface reflects this bulk update
 983  * operation. Callers writing to the cache must first call startWrite(), then
 984  * will call set() a couple of thousand times, then will call finishWrite()
 985  * to commit the operation. When finishWrite() is called, the cache is
 986  * expected to delete all data previously stored for that language.
 987  *
 988  * The values stored are PHP variables suitable for serialize(). Implementations
 989  * of LCStore are responsible for serializing and unserializing.
 990  */
 991 interface LCStore {
 992         /**
 993          * Get a value.
 994          * @param string $code Language code
 995          * @param string $key Cache key
 996          */
 997         function get( $code, $key );
 998
 999         /**
1000          * Start a write transaction.
1001          * @param string $code Language code
1002          */
1003         function startWrite( $code );
1004
1005         /**
1006          * Finish a write transaction.
1007          */
1008         function finishWrite();
1009
1010         /**
1011          * Set a key to a given value. startWrite() must be called before this
1012          * is called, and finishWrite() must be called afterwards.
1013          * @param string $key
1014          * @param mixed $value
1015          */
1016         function set( $key, $value );
1017 }
1018
1019 /**
1020  * LCStore implementation which uses PHP accelerator to store data.
1021  * This will work if one of XCache, WinCache or APC cacher is configured.
1022  * (See ObjectCache.php)
1023  */
1024 class LCStoreAccel implements LCStore {
1025         private $currentLang;
1026         private $keys;
1027
1028         public function __construct() {
1029                 $this->cache = wfGetCache( CACHE_ACCEL );
1030         }
1031
1032         public function get( $code, $key ) {
1033                 $k = wfMemcKey( 'l10n', $code, 'k', $key );
1034                 $r = $this->cache->get( $k );
1035
1036                 return $r === false ? null : $r;
1037         }
1038
1039         public function startWrite( $code ) {
1040                 $k = wfMemcKey( 'l10n', $code, 'l' );
1041                 $keys = $this->cache->get( $k );
1042                 if ( $keys ) {
1043                         foreach ( $keys as $k ) {
1044                                 $this->cache->delete( $k );
1045                         }
1046                 }
1047                 $this->currentLang = $code;
1048                 $this->keys = array();
1049         }
1050
1051         public function finishWrite() {
1052                 if ( $this->currentLang ) {
1053                         $k = wfMemcKey( 'l10n', $this->currentLang, 'l' );
1054                         $this->cache->set( $k, array_keys( $this->keys ) );
1055                 }
1056                 $this->currentLang = null;
1057                 $this->keys = array();
1058         }
1059
1060         public function set( $key, $value ) {
1061                 if ( $this->currentLang ) {
1062                         $k = wfMemcKey( 'l10n', $this->currentLang, 'k', $key );
1063                         $this->keys[$k] = true;
1064                         $this->cache->set( $k, $value );
1065                 }
1066         }
1067 }
1068
1069 /**
1070  * LCStore implementation which uses the standard DB functions to store data.
1071  * This will work on any MediaWiki installation.
1072  */
1073 class LCStoreDB implements LCStore {
1074         private $currentLang;
1075         private $writesDone = false;
1076
1077         /**
1078          * @var DatabaseBase
1079          */
1080         private $dbw;
1081         private $batch;
1082         private $readOnly = false;
1083
1084         public function get( $code, $key ) {
1085                 if ( $this->writesDone ) {
1086                         $db = wfGetDB( DB_MASTER );
1087                 } else {
1088                         $db = wfGetDB( DB_SLAVE );
1089                 }
1090                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1091                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1092                 if ( $row ) {
1093                         return unserialize( $row->lc_value );
1094                 } else {
1095                         return null;
1096                 }
1097         }
1098
1099         public function startWrite( $code ) {
1100                 if ( $this->readOnly ) {
1101                         return;
1102                 }
1103
1104                 if ( !$code ) {
1105                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1106                 }
1107
1108                 $this->dbw = wfGetDB( DB_MASTER );
1109                 try {
1110                         $this->dbw->begin( __METHOD__ );
1111                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
1112                 } catch ( DBQueryError $e ) {
1113                         if ( $this->dbw->wasReadOnlyError() ) {
1114                                 $this->readOnly = true;
1115                                 $this->dbw->rollback( __METHOD__ );
1116
1117                                 return;
1118                         } else {
1119                                 throw $e;
1120                         }
1121                 }
1122
1123                 $this->currentLang = $code;
1124                 $this->batch = array();
1125         }
1126
1127         public function finishWrite() {
1128                 if ( $this->readOnly ) {
1129                         return;
1130                 }
1131
1132                 if ( $this->batch ) {
1133                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1134                 }
1135
1136                 $this->dbw->commit( __METHOD__ );
1137                 $this->currentLang = null;
1138                 $this->dbw = null;
1139                 $this->batch = array();
1140                 $this->writesDone = true;
1141         }
1142
1143         public function set( $key, $value ) {
1144                 if ( $this->readOnly ) {
1145                         return;
1146                 }
1147
1148                 if ( is_null( $this->currentLang ) ) {
1149                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1150                 }
1151
1152                 $this->batch[] = array(
1153                         'lc_lang' => $this->currentLang,
1154                         'lc_key' => $key,
1155                         'lc_value' => serialize( $value ) );
1156
1157                 if ( count( $this->batch ) >= 100 ) {
1158                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1159                         $this->batch = array();
1160                 }
1161         }
1162 }
1163
1164 /**
1165  * LCStore implementation which stores data as a collection of CDB files in the
1166  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1167  * will throw an exception.
1168  *
1169  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1170  * the directory is on a local filesystem and there is ample kernel cache
1171  * space. The performance advantage is greater when the DBA extension is
1172  * available than it is with the PHP port.
1173  *
1174  * See Cdb.php and http://cr.yp.to/cdb.html
1175  */
1176 class LCStoreCDB implements LCStore {
1177         private $readers;
1178         private $writer;
1179         private $currentLang;
1180         private $directory;
1181
1182         function __construct( $conf = array() ) {
1183                 global $wgCacheDirectory;
1184
1185                 if ( isset( $conf['directory'] ) ) {
1186                         $this->directory = $conf['directory'];
1187                 } else {
1188                         $this->directory = $wgCacheDirectory;
1189                 }
1190         }
1191
1192         public function get( $code, $key ) {
1193                 if ( !isset( $this->readers[$code] ) ) {
1194                         $fileName = $this->getFileName( $code );
1195
1196                         if ( !file_exists( $fileName ) ) {
1197                                 $this->readers[$code] = false;
1198                         } else {
1199                                 $this->readers[$code] = CdbReader::open( $fileName );
1200                         }
1201                 }
1202
1203                 if ( !$this->readers[$code] ) {
1204                         return null;
1205                 } else {
1206                         $value = $this->readers[$code]->get( $key );
1207
1208                         if ( $value === false ) {
1209                                 return null;
1210                         }
1211
1212                         return unserialize( $value );
1213                 }
1214         }
1215
1216         public function startWrite( $code ) {
1217                 if ( !file_exists( $this->directory ) ) {
1218                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1219                                 throw new MWException( "Unable to create the localisation store " .
1220                                         "directory \"{$this->directory}\"" );
1221                         }
1222                 }
1223
1224                 // Close reader to stop permission errors on write
1225                 if ( !empty( $this->readers[$code] ) ) {
1226                         $this->readers[$code]->close();
1227                 }
1228
1229                 $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1230                 $this->currentLang = $code;
1231         }
1232
1233         public function finishWrite() {
1234                 // Close the writer
1235                 $this->writer->close();
1236                 $this->writer = null;
1237                 unset( $this->readers[$this->currentLang] );
1238                 $this->currentLang = null;
1239         }
1240
1241         public function set( $key, $value ) {
1242                 if ( is_null( $this->writer ) ) {
1243                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1244                 }
1245                 $this->writer->set( $key, serialize( $value ) );
1246         }
1247
1248         protected function getFileName( $code ) {
1249                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1250                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1251                 }
1252
1253                 return "{$this->directory}/l10n_cache-$code.cdb";
1254         }
1255 }
1256
1257 /**
1258  * Null store backend, used to avoid DB errors during install
1259  */
1260 class LCStoreNull implements LCStore {
1261         public function get( $code, $key ) {
1262                 return null;
1263         }
1264
1265         public function startWrite( $code ) {
1266         }
1267
1268         public function finishWrite() {
1269         }
1270
1271         public function set( $key, $value ) {
1272         }
1273 }
1274
1275 /**
1276  * A localisation cache optimised for loading large amounts of data for many
1277  * languages. Used by rebuildLocalisationCache.php.
1278  */
1279 class LocalisationCacheBulkLoad extends LocalisationCache {
1280         /**
1281          * A cache of the contents of data files.
1282          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1283          */
1284         private $fileCache = array();
1285
1286         /**
1287          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1288          * to keep the most recently used language codes at the end of the array, and
1289          * the language codes that are ready to be deleted at the beginning.
1290          */
1291         private $mruLangs = array();
1292
1293         /**
1294          * Maximum number of languages that may be loaded into $this->data
1295          */
1296         private $maxLoadedLangs = 10;
1297
1298         /**
1299          * @param $fileName
1300          * @param $fileType
1301          * @return array|mixed
1302          */
1303         protected function readPHPFile( $fileName, $fileType ) {
1304                 $serialize = $fileType === 'core';
1305                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1306                         $data = parent::readPHPFile( $fileName, $fileType );
1307
1308                         if ( $serialize ) {
1309                                 $encData = serialize( $data );
1310                         } else {
1311                                 $encData = $data;
1312                         }
1313
1314                         $this->fileCache[$fileName][$fileType] = $encData;
1315
1316                         return $data;
1317                 } elseif ( $serialize ) {
1318                         return unserialize( $this->fileCache[$fileName][$fileType] );
1319                 } else {
1320                         return $this->fileCache[$fileName][$fileType];
1321                 }
1322         }
1323
1324         /**
1325          * @param $code
1326          * @param $key
1327          * @return mixed
1328          */
1329         public function getItem( $code, $key ) {
1330                 unset( $this->mruLangs[$code] );
1331                 $this->mruLangs[$code] = true;
1332
1333                 return parent::getItem( $code, $key );
1334         }
1335
1336         /**
1337          * @param $code
1338          * @param $key
1339          * @param $subkey
1340          * @return
1341          */
1342         public function getSubitem( $code, $key, $subkey ) {
1343                 unset( $this->mruLangs[$code] );
1344                 $this->mruLangs[$code] = true;
1345
1346                 return parent::getSubitem( $code, $key, $subkey );
1347         }
1348
1349         /**
1350          * @param $code
1351          */
1352         public function recache( $code ) {
1353                 parent::recache( $code );
1354                 unset( $this->mruLangs[$code] );
1355                 $this->mruLangs[$code] = true;
1356                 $this->trimCache();
1357         }
1358
1359         /**
1360          * @param $code
1361          */
1362         public function unload( $code ) {
1363                 unset( $this->mruLangs[$code] );
1364                 parent::unload( $code );
1365         }
1366
1367         /**
1368          * Unload cached languages until there are less than $this->maxLoadedLangs
1369          */
1370         protected function trimCache() {
1371                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1372                         reset( $this->mruLangs );
1373                         $code = key( $this->mruLangs );
1374                         wfDebug( __METHOD__ . ": unloading $code\n" );
1375                         $this->unload( $code );
1376                 }
1377         }
1378 }