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 array $conf
 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                 wfDebugLog( 'caches', get_class( $this ) . ": using store $storeClass" );
 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 string $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 string $code
 254          * @param string $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 string $code
 274          * @param string $key
 275          * @param string $subkey
 276          * @return mixed|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 string $code
 303          * @param string $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 string $code
 322          * @param string $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 string $code
 358          * @param string $key
 359          * @param string $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 string $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 ( Language::isSupportedLanguage( $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 string $primaryCode
 494          * @param string $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 string $_fileName
 506          * @param string $_fileType
 507          * @throws MWException
 508          * @return array
 509          */
 510         protected function readPHPFile( $_fileName, $_fileType ) {
 511                 wfProfileIn( __METHOD__ );
 512                 // Disable APC caching
 513                 wfSuppressWarnings();
 514                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 515                 wfRestoreWarnings();
 516
 517                 include $_fileName;
 518
 519                 wfSuppressWarnings();
 520                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 521                 wfRestoreWarnings();
 522
 523                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 524                         $data = compact( self::$allKeys );
 525                 } elseif ( $_fileType == 'aliases' ) {
 526                         $data = compact( 'aliases' );
 527                 } else {
 528                         wfProfileOut( __METHOD__ );
 529                         throw new MWException( __METHOD__ . ": Invalid file type: $_fileType" );
 530                 }
 531                 wfProfileOut( __METHOD__ );
 532
 533                 return $data;
 534         }
 535
 536         /**
 537          * Read a JSON file containing localisation messages.
 538          * @param string $fileName Name of file to read
 539          * @throws MWException If there is a syntax error in the JSON file
 540          * @return array Array with a 'messages' key, or empty array if the file doesn't exist
 541          */
 542         public function readJSONFile( $fileName ) {
 543                 wfProfileIn( __METHOD__ );
 544
 545                 if ( !is_readable( $fileName ) ) {
 546                         wfProfileOut( __METHOD__ );
 547
 548                         return array();
 549                 }
 550
 551                 $json = file_get_contents( $fileName );
 552                 if ( $json === false ) {
 553                         wfProfileOut( __METHOD__ );
 554
 555                         return array();
 556                 }
 557
 558                 $data = FormatJson::decode( $json, true );
 559                 if ( $data === null ) {
 560                         wfProfileOut( __METHOD__ );
 561
 562                         throw new MWException( __METHOD__ . ": Invalid JSON file: $fileName" );
 563                 }
 564
 565                 // Remove keys starting with '@', they're reserved for metadata and non-message data
 566                 foreach ( $data as $key => $unused ) {
 567                         if ( $key === '' || $key[0] === '@' ) {
 568                                 unset( $data[$key] );
 569                         }
 570                 }
 571
 572                 wfProfileOut( __METHOD__ );
 573
 574                 // The JSON format only supports messages, none of the other variables, so wrap the data
 575                 return array( 'messages' => $data );
 576         }
 577
 578         /**
 579          * Get the compiled plural rules for a given language from the XML files.
 580          * @since 1.20
 581          * @param string $code
 582          * @return array|null
 583          */
 584         public function getCompiledPluralRules( $code ) {
 585                 $rules = $this->getPluralRules( $code );
 586                 if ( $rules === null ) {
 587                         return null;
 588                 }
 589                 try {
 590                         $compiledRules = CLDRPluralRuleEvaluator::compile( $rules );
 591                 } catch ( CLDRPluralRuleError $e ) {
 592                         wfDebugLog( 'l10n', $e->getMessage() );
 593
 594                         return array();
 595                 }
 596
 597                 return $compiledRules;
 598         }
 599
 600         /**
 601          * Get the plural rules for a given language from the XML files.
 602          * Cached.
 603          * @since 1.20
 604          * @param string $code
 605          * @return array|null
 606          */
 607         public function getPluralRules( $code ) {
 608                 if ( $this->pluralRules === null ) {
 609                         $this->loadPluralFiles();
 610                 }
 611                 if ( !isset( $this->pluralRules[$code] ) ) {
 612                         return null;
 613                 } else {
 614                         return $this->pluralRules[$code];
 615                 }
 616         }
 617
 618         /**
 619          * Get the plural rule types for a given language from the XML files.
 620          * Cached.
 621          * @since 1.22
 622          * @param string $code
 623          * @return array|null
 624          */
 625         public function getPluralRuleTypes( $code ) {
 626                 if ( $this->pluralRuleTypes === null ) {
 627                         $this->loadPluralFiles();
 628                 }
 629                 if ( !isset( $this->pluralRuleTypes[$code] ) ) {
 630                         return null;
 631                 } else {
 632                         return $this->pluralRuleTypes[$code];
 633                 }
 634         }
 635
 636         /**
 637          * Load the plural XML files.
 638          */
 639         protected function loadPluralFiles() {
 640                 global $IP;
 641                 $cldrPlural = "$IP/languages/data/plurals.xml";
 642                 $mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
 643                 // Load CLDR plural rules
 644                 $this->loadPluralFile( $cldrPlural );
 645                 if ( file_exists( $mwPlural ) ) {
 646                         // Override or extend
 647                         $this->loadPluralFile( $mwPlural );
 648                 }
 649         }
 650
 651         /**
 652          * Load a plural XML file with the given filename, compile the relevant
 653          * rules, and save the compiled rules in a process-local cache.
 654          *
 655          * @param string $fileName
 656          */
 657         protected function loadPluralFile( $fileName ) {
 658                 $doc = new DOMDocument;
 659                 $doc->load( $fileName );
 660                 $rulesets = $doc->getElementsByTagName( "pluralRules" );
 661                 foreach ( $rulesets as $ruleset ) {
 662                         $codes = $ruleset->getAttribute( 'locales' );
 663                         $rules = array();
 664                         $ruleTypes = array();
 665                         $ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
 666                         foreach ( $ruleElements as $elt ) {
 667                                 $ruleType = $elt->getAttribute( 'count' );
 668                                 if ( $ruleType === 'other' ) {
 669                                         // Don't record "other" rules, which have an empty condition
 670                                         continue;
 671                                 }
 672                                 $rules[] = $elt->nodeValue;
 673                                 $ruleTypes[] = $ruleType;
 674                         }
 675                         foreach ( explode( ' ', $codes ) as $code ) {
 676                                 $this->pluralRules[$code] = $rules;
 677                                 $this->pluralRuleTypes[$code] = $ruleTypes;
 678                         }
 679                 }
 680         }
 681
 682         /**
 683          * Read the data from the source files for a given language, and register
 684          * the relevant dependencies in the $deps array. If the localisation
 685          * exists, the data array is returned, otherwise false is returned.
 686          *
 687          * @param string $code
 688          * @param array $deps
 689          */
 690         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 691                 global $IP;
 692                 wfProfileIn( __METHOD__ );
 693
 694                 // This reads in the PHP i18n file with non-messages l10n data
 695                 $fileName = Language::getMessagesFileName( $code );
 696                 if ( !file_exists( $fileName ) ) {
 697                         $data = array();
 698                 } else {
 699                         $deps[] = new FileDependency( $fileName );
 700                         $data = $this->readPHPFile( $fileName, 'core' );
 701                 }
 702
 703                 # Load CLDR plural rules for JavaScript
 704                 $data['pluralRules'] = $this->getPluralRules( $code );
 705                 # And for PHP
 706                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 707                 # Load plural rule types
 708                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 709
 710                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 711                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 712
 713                 wfProfileOut( __METHOD__ );
 714
 715                 return $data;
 716         }
 717
 718         /**
 719          * Merge two localisation values, a primary and a fallback, overwriting the
 720          * primary value in place.
 721          * @param string $key
 722          * @param mixed $value
 723          * @param mixed $fallbackValue
 724          */
 725         protected function mergeItem( $key, &$value, $fallbackValue ) {
 726                 if ( !is_null( $value ) ) {
 727                         if ( !is_null( $fallbackValue ) ) {
 728                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 729                                         $value = $value + $fallbackValue;
 730                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 731                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 732                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 733                                         $value = array_merge_recursive( $value, $fallbackValue );
 734                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 735                                         if ( !empty( $value['inherit'] ) ) {
 736                                                 $value = array_merge( $fallbackValue, $value );
 737                                         }
 738
 739                                         if ( isset( $value['inherit'] ) ) {
 740                                                 unset( $value['inherit'] );
 741                                         }
 742                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 743                                         $this->mergeMagicWords( $value, $fallbackValue );
 744                                 }
 745                         }
 746                 } else {
 747                         $value = $fallbackValue;
 748                 }
 749         }
 750
 751         /**
 752          * @param mixed $value
 753          * @param mixed $fallbackValue
 754          */
 755         protected function mergeMagicWords( &$value, $fallbackValue ) {
 756                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 757                         if ( !isset( $value[$magicName] ) ) {
 758                                 $value[$magicName] = $fallbackInfo;
 759                         } else {
 760                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 761                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 762                                 $synonyms = array_values( array_unique( array_merge(
 763                                         $newSynonyms, $oldSynonyms ) ) );
 764                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 765                         }
 766                 }
 767         }
 768
 769         /**
 770          * Given an array mapping language code to localisation value, such as is
 771          * found in extension *.i18n.php files, iterate through a fallback sequence
 772          * to merge the given data with an existing primary value.
 773          *
 774          * Returns true if any data from the extension array was used, false
 775          * otherwise.
 776          * @param string $codeSequence
 777          * @param string $key
 778          * @param mixed $value
 779          * @param mixed $fallbackValue
 780          * @return bool
 781          */
 782         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 783                 $used = false;
 784                 foreach ( $codeSequence as $code ) {
 785                         if ( isset( $fallbackValue[$code] ) ) {
 786                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 787                                 $used = true;
 788                         }
 789                 }
 790
 791                 return $used;
 792         }
 793
 794         /**
 795          * Load localisation data for a given language for both core and extensions
 796          * and save it to the persistent cache store and the process cache
 797          * @param string $code
 798          * @throws MWException
 799          */
 800         public function recache( $code ) {
 801                 global $wgExtensionMessagesFiles, $wgMessagesDirs;
 802                 wfProfileIn( __METHOD__ );
 803
 804                 if ( !$code ) {
 805                         wfProfileOut( __METHOD__ );
 806                         throw new MWException( "Invalid language code requested" );
 807                 }
 808                 $this->recachedLangs[$code] = true;
 809
 810                 # Initial values
 811                 $initialData = array_combine(
 812                         self::$allKeys,
 813                         array_fill( 0, count( self::$allKeys ), null ) );
 814                 $coreData = $initialData;
 815                 $deps = array();
 816
 817                 # Load the primary localisation from the source file
 818                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 819                 if ( $data === false ) {
 820                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 821                         $coreData['fallback'] = 'en';
 822                 } else {
 823                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 824
 825                         # Merge primary localisation
 826                         foreach ( $data as $key => $value ) {
 827                                 $this->mergeItem( $key, $coreData[$key], $value );
 828                         }
 829                 }
 830
 831                 # Fill in the fallback if it's not there already
 832                 if ( is_null( $coreData['fallback'] ) ) {
 833                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 834                 }
 835                 if ( $coreData['fallback'] === false ) {
 836                         $coreData['fallbackSequence'] = array();
 837                 } else {
 838                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 839                         $len = count( $coreData['fallbackSequence'] );
 840
 841                         # Ensure that the sequence ends at en
 842                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 843                                 $coreData['fallbackSequence'][] = 'en';
 844                         }
 845
 846                         # Load the fallback localisation item by item and merge it
 847                         foreach ( $coreData['fallbackSequence'] as $fbCode ) {
 848                                 # Load the secondary localisation from the source file to
 849                                 # avoid infinite cycles on cyclic fallbacks
 850                                 $fbData = $this->readSourceFilesAndRegisterDeps( $fbCode, $deps );
 851                                 if ( $fbData === false ) {
 852                                         continue;
 853                                 }
 854
 855                                 foreach ( self::$allKeys as $key ) {
 856                                         if ( !isset( $fbData[$key] ) ) {
 857                                                 continue;
 858                                         }
 859
 860                                         if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 861                                                 $this->mergeItem( $key, $coreData[$key], $fbData[$key] );
 862                                         }
 863                                 }
 864                         }
 865                 }
 866
 867                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 868
 869                 # Load core messages and the extension localisations.
 870                 wfProfileIn( __METHOD__ . '-extensions' );
 871                 $allData = $initialData;
 872                 foreach ( $wgMessagesDirs as $dirs ) {
 873                         foreach ( (array)$dirs as $dir ) {
 874                                 foreach ( $codeSequence as $csCode ) {
 875                                         $fileName = "$dir/$csCode.json";
 876                                         $data = $this->readJSONFile( $fileName );
 877
 878                                         foreach ( $data as $key => $item ) {
 879                                                 $this->mergeItem( $key, $allData[$key], $item );
 880                                         }
 881
 882                                         $deps[] = new FileDependency( $fileName );
 883                                 }
 884                         }
 885                 }
 886
 887                 foreach ( $wgExtensionMessagesFiles as $extension => $fileName ) {
 888                         if ( isset( $wgMessagesDirs[$extension] ) ) {
 889                                 # Already loaded the JSON files for this extension; skip the PHP shim
 890                                 continue;
 891                         }
 892
 893                         $data = $this->readPHPFile( $fileName, 'extension' );
 894                         $used = false;
 895
 896                         foreach ( $data as $key => $item ) {
 897                                 if ( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 898                                         $used = true;
 899                                 }
 900                         }
 901
 902                         if ( $used ) {
 903                                 $deps[] = new FileDependency( $fileName );
 904                         }
 905                 }
 906
 907                 # Merge core data into extension data
 908                 foreach ( $coreData as $key => $item ) {
 909                         $this->mergeItem( $key, $allData[$key], $item );
 910                 }
 911                 wfProfileOut( __METHOD__ . '-extensions' );
 912
 913                 # Add cache dependencies for any referenced globals
 914                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 915                 $deps['wgMessagesDirs'] = new GlobalDependency( 'wgMessagesDirs' );
 916                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 917
 918                 # Add dependencies to the cache entry
 919                 $allData['deps'] = $deps;
 920
 921                 # Replace spaces with underscores in namespace names
 922                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 923
 924                 # And do the same for special page aliases. $page is an array.
 925                 foreach ( $allData['specialPageAliases'] as &$page ) {
 926                         $page = str_replace( ' ', '_', $page );
 927                 }
 928                 # Decouple the reference to prevent accidental damage
 929                 unset( $page );
 930
 931                 # If there were no plural rules, return an empty array
 932                 if ( $allData['pluralRules'] === null ) {
 933                         $allData['pluralRules'] = array();
 934                 }
 935                 if ( $allData['compiledPluralRules'] === null ) {
 936                         $allData['compiledPluralRules'] = array();
 937                 }
 938                 # If there were no plural rule types, return an empty array
 939                 if ( $allData['pluralRuleTypes'] === null ) {
 940                         $allData['pluralRuleTypes'] = array();
 941                 }
 942
 943                 # Set the list keys
 944                 $allData['list'] = array();
 945                 foreach ( self::$splitKeys as $key ) {
 946                         $allData['list'][$key] = array_keys( $allData[$key] );
 947                 }
 948                 # Run hooks
 949                 $purgeBlobs = true;
 950                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData, &$purgeBlobs ) );
 951
 952                 if ( is_null( $allData['namespaceNames'] ) ) {
 953                         wfProfileOut( __METHOD__ );
 954                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
 955                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 956                 }
 957
 958                 # Set the preload key
 959                 $allData['preload'] = $this->buildPreload( $allData );
 960
 961                 # Save to the process cache and register the items loaded
 962                 $this->data[$code] = $allData;
 963                 foreach ( $allData as $key => $item ) {
 964                         $this->loadedItems[$code][$key] = true;
 965                 }
 966
 967                 # Save to the persistent cache
 968                 wfProfileIn( __METHOD__ . '-write' );
 969                 $this->store->startWrite( $code );
 970                 foreach ( $allData as $key => $value ) {
 971                         if ( in_array( $key, self::$splitKeys ) ) {
 972                                 foreach ( $value as $subkey => $subvalue ) {
 973                                         $this->store->set( "$key:$subkey", $subvalue );
 974                                 }
 975                         } else {
 976                                 $this->store->set( $key, $value );
 977                         }
 978                 }
 979                 $this->store->finishWrite();
 980                 wfProfileOut( __METHOD__ . '-write' );
 981
 982                 # Clear out the MessageBlobStore
 983                 # HACK: If using a null (i.e. disabled) storage backend, we
 984                 # can't write to the MessageBlobStore either
 985                 if ( $purgeBlobs && !$this->store instanceof LCStoreNull ) {
 986                         MessageBlobStore::clear();
 987                 }
 988
 989                 wfProfileOut( __METHOD__ );
 990         }
 991
 992         /**
 993          * Build the preload item from the given pre-cache data.
 994          *
 995          * The preload item will be loaded automatically, improving performance
 996          * for the commonly-requested items it contains.
 997          * @param array $data
 998          * @return array
 999          */
1000         protected function buildPreload( $data ) {
1001                 $preload = array( 'messages' => array() );
1002                 foreach ( self::$preloadedKeys as $key ) {
1003                         $preload[$key] = $data[$key];
1004                 }
1005
1006                 foreach ( $data['preloadedMessages'] as $subkey ) {
1007                         if ( isset( $data['messages'][$subkey] ) ) {
1008                                 $subitem = $data['messages'][$subkey];
1009                         } else {
1010                                 $subitem = null;
1011                         }
1012                         $preload['messages'][$subkey] = $subitem;
1013                 }
1014
1015                 return $preload;
1016         }
1017
1018         /**
1019          * Unload the data for a given language from the object cache.
1020          * Reduces memory usage.
1021          * @param string $code
1022          */
1023         public function unload( $code ) {
1024                 unset( $this->data[$code] );
1025                 unset( $this->loadedItems[$code] );
1026                 unset( $this->loadedSubitems[$code] );
1027                 unset( $this->initialisedLangs[$code] );
1028                 unset( $this->shallowFallbacks[$code] );
1029
1030                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
1031                         if ( $fbCode === $code ) {
1032                                 $this->unload( $shallowCode );
1033                         }
1034                 }
1035         }
1036
1037         /**
1038          * Unload all data
1039          */
1040         public function unloadAll() {
1041                 foreach ( $this->initialisedLangs as $lang => $unused ) {
1042                         $this->unload( $lang );
1043                 }
1044         }
1045
1046         /**
1047          * Disable the storage backend
1048          */
1049         public function disableBackend() {
1050                 $this->store = new LCStoreNull;
1051                 $this->manualRecache = false;
1052         }
1053 }
1054
1055 /**
1056  * Interface for the persistence layer of LocalisationCache.
1057  *
1058  * The persistence layer is two-level hierarchical cache. The first level
1059  * is the language, the second level is the item or subitem.
1060  *
1061  * Since the data for a whole language is rebuilt in one operation, it needs
1062  * to have a fast and atomic method for deleting or replacing all of the
1063  * current data for a given language. The interface reflects this bulk update
1064  * operation. Callers writing to the cache must first call startWrite(), then
1065  * will call set() a couple of thousand times, then will call finishWrite()
1066  * to commit the operation. When finishWrite() is called, the cache is
1067  * expected to delete all data previously stored for that language.
1068  *
1069  * The values stored are PHP variables suitable for serialize(). Implementations
1070  * of LCStore are responsible for serializing and unserializing.
1071  */
1072 interface LCStore {
1073         /**
1074          * Get a value.
1075          * @param string $code Language code
1076          * @param string $key Cache key
1077          */
1078         function get( $code, $key );
1079
1080         /**
1081          * Start a write transaction.
1082          * @param string $code Language code
1083          */
1084         function startWrite( $code );
1085
1086         /**
1087          * Finish a write transaction.
1088          */
1089         function finishWrite();
1090
1091         /**
1092          * Set a key to a given value. startWrite() must be called before this
1093          * is called, and finishWrite() must be called afterwards.
1094          * @param string $key
1095          * @param mixed $value
1096          */
1097         function set( $key, $value );
1098 }
1099
1100 /**
1101  * LCStore implementation which uses PHP accelerator to store data.
1102  * This will work if one of XCache, WinCache or APC cacher is configured.
1103  * (See ObjectCache.php)
1104  */
1105 class LCStoreAccel implements LCStore {
1106         private $currentLang;
1107         private $keys;
1108
1109         public function __construct() {
1110                 $this->cache = wfGetCache( CACHE_ACCEL );
1111         }
1112
1113         public function get( $code, $key ) {
1114                 $k = wfMemcKey( 'l10n', $code, 'k', $key );
1115                 $r = $this->cache->get( $k );
1116
1117                 return $r === false ? null : $r;
1118         }
1119
1120         public function startWrite( $code ) {
1121                 $k = wfMemcKey( 'l10n', $code, 'l' );
1122                 $keys = $this->cache->get( $k );
1123                 if ( $keys ) {
1124                         foreach ( $keys as $k ) {
1125                                 $this->cache->delete( $k );
1126                         }
1127                 }
1128                 $this->currentLang = $code;
1129                 $this->keys = array();
1130         }
1131
1132         public function finishWrite() {
1133                 if ( $this->currentLang ) {
1134                         $k = wfMemcKey( 'l10n', $this->currentLang, 'l' );
1135                         $this->cache->set( $k, array_keys( $this->keys ) );
1136                 }
1137                 $this->currentLang = null;
1138                 $this->keys = array();
1139         }
1140
1141         public function set( $key, $value ) {
1142                 if ( $this->currentLang ) {
1143                         $k = wfMemcKey( 'l10n', $this->currentLang, 'k', $key );
1144                         $this->keys[$k] = true;
1145                         $this->cache->set( $k, $value );
1146                 }
1147         }
1148 }
1149
1150 /**
1151  * LCStore implementation which uses the standard DB functions to store data.
1152  * This will work on any MediaWiki installation.
1153  */
1154 class LCStoreDB implements LCStore {
1155         private $currentLang;
1156         private $writesDone = false;
1157
1158         /** @var DatabaseBase */
1159         private $dbw;
1160         /** @var array */
1161         private $batch = array();
1162
1163         private $readOnly = false;
1164
1165         public function get( $code, $key ) {
1166                 if ( $this->writesDone && $this->dbw ) {
1167                         $db = $this->dbw;
1168                 } else {
1169                         $db = wfGetDB( DB_SLAVE );
1170                 }
1171                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1172                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1173                 if ( $row ) {
1174                         return unserialize( $db->decodeBlob( $row->lc_value ) );
1175                 } else {
1176                         return null;
1177                 }
1178         }
1179
1180         public function startWrite( $code ) {
1181                 if ( $this->readOnly ) {
1182                         return;
1183                 } elseif ( !$code ) {
1184                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1185                 }
1186
1187                 // We must keep a separate connection to MySQL in order to avoid breaking
1188                 // main transactions. However, SQLite deadlocks when using two connections.
1189                 // @todo get this trick to work on PostgreSQL too
1190                 if ( wfGetDB( DB_MASTER )->getType() == 'mysql' ) {
1191                         $lb = wfGetLBFactory()->newMainLB();
1192                         $this->dbw = $lb->getConnection( DB_MASTER );
1193                         $this->dbw->clearFlag( DBO_TRX ); // auto-commit mode
1194                 } else {
1195                         $this->dbw = wfGetDB( DB_MASTER );
1196                 }
1197
1198                 $this->currentLang = $code;
1199                 $this->batch = array();
1200         }
1201
1202         public function finishWrite() {
1203                 if ( $this->readOnly ) {
1204                         return;
1205                 } elseif ( is_null( $this->currentLang ) ) {
1206                         throw new MWException( __CLASS__ . ': must call startWrite() before finishWrite()' );
1207                 }
1208
1209                 $this->dbw->begin( __METHOD__ );
1210                 try {
1211                         $this->dbw->delete( 'l10n_cache',
1212                                 array( 'lc_lang' => $this->currentLang ), __METHOD__ );
1213                         foreach ( array_chunk( $this->batch, 500 ) as $rows ) {
1214                                 $this->dbw->insert( 'l10n_cache', $rows, __METHOD__ );
1215                         }
1216                         $this->writesDone = true;
1217                 } catch ( DBQueryError $e ) {
1218                         if ( $this->dbw->wasReadOnlyError() ) {
1219                                 $this->readOnly = true; // just avoid site down time
1220                         } else {
1221                                 throw $e;
1222                         }
1223                 }
1224                 $this->dbw->commit( __METHOD__ );
1225
1226                 $this->currentLang = null;
1227                 $this->batch = array();
1228         }
1229
1230         public function set( $key, $value ) {
1231                 if ( $this->readOnly ) {
1232                         return;
1233                 } elseif ( is_null( $this->currentLang ) ) {
1234                         throw new MWException( __CLASS__ . ': must call startWrite() before set()' );
1235                 }
1236
1237                 $this->batch[] = array(
1238                         'lc_lang' => $this->currentLang,
1239                         'lc_key' => $key,
1240                         'lc_value' => $this->dbw->encodeBlob( serialize( $value ) ) );
1241         }
1242 }
1243
1244 /**
1245  * LCStore implementation which stores data as a collection of CDB files in the
1246  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1247  * will throw an exception.
1248  *
1249  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1250  * the directory is on a local filesystem and there is ample kernel cache
1251  * space. The performance advantage is greater when the DBA extension is
1252  * available than it is with the PHP port.
1253  *
1254  * See Cdb.php and http://cr.yp.to/cdb.html
1255  */
1256 class LCStoreCDB implements LCStore {
1257         /** @var CdbReader[] */
1258         private $readers;
1259
1260         /** @var CdbWriter */
1261         private $writer;
1262
1263         /** @var string Current language code */
1264         private $currentLang;
1265
1266         /** @var bool|string Cache directory. False if not set */
1267         private $directory;
1268
1269         function __construct( $conf = array() ) {
1270                 global $wgCacheDirectory;
1271
1272                 if ( isset( $conf['directory'] ) ) {
1273                         $this->directory = $conf['directory'];
1274                 } else {
1275                         $this->directory = $wgCacheDirectory;
1276                 }
1277         }
1278
1279         public function get( $code, $key ) {
1280                 if ( !isset( $this->readers[$code] ) ) {
1281                         $fileName = $this->getFileName( $code );
1282
1283                         $this->readers[$code] = false;
1284                         if ( file_exists( $fileName ) ) {
1285                                 try {
1286                                         $this->readers[$code] = CdbReader::open( $fileName );
1287                                 } catch ( CdbException $e ) {
1288                                         wfDebug( __METHOD__ . ": unable to open cdb file for reading\n" );
1289                                 }
1290                         }
1291                 }
1292
1293                 if ( !$this->readers[$code] ) {
1294                         return null;
1295                 } else {
1296                         $value = false;
1297                         try {
1298                                 $value = $this->readers[$code]->get( $key );
1299                         } catch ( CdbException $e ) {
1300                                 wfDebug( __METHOD__ . ": CdbException caught, error message was "
1301                                         . $e->getMessage() . "\n" );
1302                         }
1303                         if ( $value === false ) {
1304                                 return null;
1305                         }
1306
1307                         return unserialize( $value );
1308                 }
1309         }
1310
1311         public function startWrite( $code ) {
1312                 if ( !file_exists( $this->directory ) ) {
1313                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1314                                 throw new MWException( "Unable to create the localisation store " .
1315                                         "directory \"{$this->directory}\"" );
1316                         }
1317                 }
1318
1319                 // Close reader to stop permission errors on write
1320                 if ( !empty( $this->readers[$code] ) ) {
1321                         $this->readers[$code]->close();
1322                 }
1323
1324                 try {
1325                         $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1326                 } catch ( CdbException $e ) {
1327                         throw new MWException( $e->getMessage() );
1328                 }
1329                 $this->currentLang = $code;
1330         }
1331
1332         public function finishWrite() {
1333                 // Close the writer
1334                 try {
1335                         $this->writer->close();
1336                 } catch ( CdbException $e ) {
1337                         throw new MWException( $e->getMessage() );
1338                 }
1339                 $this->writer = null;
1340                 unset( $this->readers[$this->currentLang] );
1341                 $this->currentLang = null;
1342         }
1343
1344         public function set( $key, $value ) {
1345                 if ( is_null( $this->writer ) ) {
1346                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1347                 }
1348                 try {
1349                         $this->writer->set( $key, serialize( $value ) );
1350                 } catch ( CdbException $e ) {
1351                         throw new MWException( $e->getMessage() );
1352                 }
1353         }
1354
1355         protected function getFileName( $code ) {
1356                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1357                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1358                 }
1359
1360                 return "{$this->directory}/l10n_cache-$code.cdb";
1361         }
1362 }
1363
1364 /**
1365  * Null store backend, used to avoid DB errors during install
1366  */
1367 class LCStoreNull implements LCStore {
1368         public function get( $code, $key ) {
1369                 return null;
1370         }
1371
1372         public function startWrite( $code ) {
1373         }
1374
1375         public function finishWrite() {
1376         }
1377
1378         public function set( $key, $value ) {
1379         }
1380 }
1381
1382 /**
1383  * A localisation cache optimised for loading large amounts of data for many
1384  * languages. Used by rebuildLocalisationCache.php.
1385  */
1386 class LocalisationCacheBulkLoad extends LocalisationCache {
1387         /**
1388          * A cache of the contents of data files.
1389          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1390          */
1391         private $fileCache = array();
1392
1393         /**
1394          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1395          * to keep the most recently used language codes at the end of the array, and
1396          * the language codes that are ready to be deleted at the beginning.
1397          */
1398         private $mruLangs = array();
1399
1400         /**
1401          * Maximum number of languages that may be loaded into $this->data
1402          */
1403         private $maxLoadedLangs = 10;
1404
1405         /**
1406          * @param string $fileName
1407          * @param string $fileType
1408          * @return array|mixed
1409          */
1410         protected function readPHPFile( $fileName, $fileType ) {
1411                 $serialize = $fileType === 'core';
1412                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1413                         $data = parent::readPHPFile( $fileName, $fileType );
1414
1415                         if ( $serialize ) {
1416                                 $encData = serialize( $data );
1417                         } else {
1418                                 $encData = $data;
1419                         }
1420
1421                         $this->fileCache[$fileName][$fileType] = $encData;
1422
1423                         return $data;
1424                 } elseif ( $serialize ) {
1425                         return unserialize( $this->fileCache[$fileName][$fileType] );
1426                 } else {
1427                         return $this->fileCache[$fileName][$fileType];
1428                 }
1429         }
1430
1431         /**
1432          * @param string $code
1433          * @param string $key
1434          * @return mixed
1435          */
1436         public function getItem( $code, $key ) {
1437                 unset( $this->mruLangs[$code] );
1438                 $this->mruLangs[$code] = true;
1439
1440                 return parent::getItem( $code, $key );
1441         }
1442
1443         /**
1444          * @param string $code
1445          * @param string $key
1446          * @param string $subkey
1447          * @return mixed
1448          */
1449         public function getSubitem( $code, $key, $subkey ) {
1450                 unset( $this->mruLangs[$code] );
1451                 $this->mruLangs[$code] = true;
1452
1453                 return parent::getSubitem( $code, $key, $subkey );
1454         }
1455
1456         /**
1457          * @param string $code
1458          */
1459         public function recache( $code ) {
1460                 parent::recache( $code );
1461                 unset( $this->mruLangs[$code] );
1462                 $this->mruLangs[$code] = true;
1463                 $this->trimCache();
1464         }
1465
1466         /**
1467          * @param string $code
1468          */
1469         public function unload( $code ) {
1470                 unset( $this->mruLangs[$code] );
1471                 parent::unload( $code );
1472         }
1473
1474         /**
1475          * Unload cached languages until there are less than $this->maxLoadedLangs
1476          */
1477         protected function trimCache() {
1478                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1479                         reset( $this->mruLangs );
1480                         $code = key( $this->mruLangs );
1481                         wfDebug( __METHOD__ . ": unloading $code\n" );
1482                         $this->unload( $code );
1483                 }
1484         }
1485 }