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 use Cdb\Exception as CdbException;
  24 use Cdb\Reader as CdbReader;
  25 use Cdb\Writer as CdbWriter;
  26 /**
  27  * Class for caching the contents of localisation files, Messages*.php
  28  * and *.i18n.php.
  29  *
  30  * An instance of this class is available using Language::getLocalisationCache().
  31  *
  32  * The values retrieved from here are merged, containing items from extension
  33  * files, core messages files and the language fallback sequence (e.g. zh-cn ->
  34  * zh-hans -> en ). Some common errors are corrected, for example namespace
  35  * names with spaces instead of underscores, but heavyweight processing, such
  36  * as grammatical transformation, is done by the caller.
  37  */
  38 class LocalisationCache {
  39         const VERSION = 2;
  40
  41         /** Configuration associative array */
  42         private $conf;
  43
  44         /**
  45          * True if recaching should only be done on an explicit call to recache().
  46          * Setting this reduces the overhead of cache freshness checking, which
  47          * requires doing a stat() for every extension i18n file.
  48          */
  49         private $manualRecache = false;
  50
  51         /**
  52          * True to treat all files as expired until they are regenerated by this object.
  53          */
  54         private $forceRecache = false;
  55
  56         /**
  57          * The cache data. 3-d array, where the first key is the language code,
  58          * the second key is the item key e.g. 'messages', and the third key is
  59          * an item specific subkey index. Some items are not arrays and so for those
  60          * items, there are no subkeys.
  61          */
  62         protected $data = array();
  63
  64         /**
  65          * The persistent store object. An instance of LCStore.
  66          *
  67          * @var LCStore
  68          */
  69         private $store;
  70
  71         /**
  72          * A 2-d associative array, code/key, where presence indicates that the item
  73          * is loaded. Value arbitrary.
  74          *
  75          * For split items, if set, this indicates that all of the subitems have been
  76          * loaded.
  77          */
  78         private $loadedItems = array();
  79
  80         /**
  81          * A 3-d associative array, code/key/subkey, where presence indicates that
  82          * the subitem is loaded. Only used for the split items, i.e. messages.
  83          */
  84         private $loadedSubitems = array();
  85
  86         /**
  87          * An array where presence of a key indicates that that language has been
  88          * initialised. Initialisation includes checking for cache expiry and doing
  89          * any necessary updates.
  90          */
  91         private $initialisedLangs = array();
  92
  93         /**
  94          * An array mapping non-existent pseudo-languages to fallback languages. This
  95          * is filled by initShallowFallback() when data is requested from a language
  96          * that lacks a Messages*.php file.
  97          */
  98         private $shallowFallbacks = array();
  99
 100         /**
 101          * An array where the keys are codes that have been recached by this instance.
 102          */
 103         private $recachedLangs = array();
 104
 105         /**
 106          * All item keys
 107          */
 108         static public $allKeys = array(
 109                 'fallback', 'namespaceNames', 'bookstoreList',
 110                 'magicWords', 'messages', 'rtl', 'capitalizeAllNouns', 'digitTransformTable',
 111                 'separatorTransformTable', 'fallback8bitEncoding', 'linkPrefixExtension',
 112                 'linkTrail', 'linkPrefixCharset', 'namespaceAliases',
 113                 'dateFormats', 'datePreferences', 'datePreferenceMigrationMap',
 114                 'defaultDateFormat', 'extraUserToggles', 'specialPageAliases',
 115                 'imageFiles', 'preloadedMessages', 'namespaceGenderAliases',
 116                 'digitGroupingPattern', 'pluralRules', 'pluralRuleTypes', 'compiledPluralRules',
 117         );
 118
 119         /**
 120          * Keys for items which consist of associative arrays, which may be merged
 121          * by a fallback sequence.
 122          */
 123         static public $mergeableMapKeys = array( 'messages', 'namespaceNames',
 124                 'dateFormats', 'imageFiles', 'preloadedMessages'
 125         );
 126
 127         /**
 128          * Keys for items which are a numbered array.
 129          */
 130         static public $mergeableListKeys = array( 'extraUserToggles' );
 131
 132         /**
 133          * Keys for items which contain an array of arrays of equivalent aliases
 134          * for each subitem. The aliases may be merged by a fallback sequence.
 135          */
 136         static public $mergeableAliasListKeys = array( 'specialPageAliases' );
 137
 138         /**
 139          * Keys for items which contain an associative array, and may be merged if
 140          * the primary value contains the special array key "inherit". That array
 141          * key is removed after the first merge.
 142          */
 143         static public $optionalMergeKeys = array( 'bookstoreList' );
 144
 145         /**
 146          * Keys for items that are formatted like $magicWords
 147          */
 148         static public $magicWordKeys = array( 'magicWords' );
 149
 150         /**
 151          * Keys for items where the subitems are stored in the backend separately.
 152          */
 153         static public $splitKeys = array( 'messages' );
 154
 155         /**
 156          * Keys which are loaded automatically by initLanguage()
 157          */
 158         static public $preloadedKeys = array( 'dateFormats', 'namespaceNames' );
 159
 160         /**
 161          * Associative array of cached plural rules. The key is the language code,
 162          * the value is an array of plural rules for that language.
 163          */
 164         private $pluralRules = null;
 165
 166         /**
 167          * Associative array of cached plural rule types. The key is the language
 168          * code, the value is an array of plural rule types for that language. For
 169          * example, $pluralRuleTypes['ar'] = ['zero', 'one', 'two', 'few', 'many'].
 170          * The index for each rule type matches the index for the rule in
 171          * $pluralRules, thus allowing correlation between the two. The reason we
 172          * don't just use the type names as the keys in $pluralRules is because
 173          * Language::convertPlural applies the rules based on numeric order (or
 174          * explicit numeric parameter), not based on the name of the rule type. For
 175          * example, {{plural:count|wordform1|wordform2|wordform3}}, rather than
 176          * {{plural:count|one=wordform1|two=wordform2|many=wordform3}}.
 177          */
 178         private $pluralRuleTypes = null;
 179
 180         private $mergeableKeys = null;
 181
 182         /**
 183          * Constructor.
 184          * For constructor parameters, see the documentation in DefaultSettings.php
 185          * for $wgLocalisationCacheConf.
 186          *
 187          * @param array $conf
 188          * @throws MWException
 189          */
 190         function __construct( $conf ) {
 191                 global $wgCacheDirectory;
 192
 193                 $this->conf = $conf;
 194                 $storeConf = array();
 195                 if ( !empty( $conf['storeClass'] ) ) {
 196                         $storeClass = $conf['storeClass'];
 197                 } else {
 198                         switch ( $conf['store'] ) {
 199                                 case 'files':
 200                                 case 'file':
 201                                         $storeClass = 'LCStoreCDB';
 202                                         break;
 203                                 case 'db':
 204                                         $storeClass = 'LCStoreDB';
 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 for some stores
 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          * @return array
 690          */
 691         protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
 692                 global $IP;
 693                 wfProfileIn( __METHOD__ );
 694
 695                 // This reads in the PHP i18n file with non-messages l10n data
 696                 $fileName = Language::getMessagesFileName( $code );
 697                 if ( !file_exists( $fileName ) ) {
 698                         $data = array();
 699                 } else {
 700                         $deps[] = new FileDependency( $fileName );
 701                         $data = $this->readPHPFile( $fileName, 'core' );
 702                 }
 703
 704                 # Load CLDR plural rules for JavaScript
 705                 $data['pluralRules'] = $this->getPluralRules( $code );
 706                 # And for PHP
 707                 $data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
 708                 # Load plural rule types
 709                 $data['pluralRuleTypes'] = $this->getPluralRuleTypes( $code );
 710
 711                 $deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
 712                 $deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
 713
 714                 wfProfileOut( __METHOD__ );
 715
 716                 return $data;
 717         }
 718
 719         /**
 720          * Merge two localisation values, a primary and a fallback, overwriting the
 721          * primary value in place.
 722          * @param string $key
 723          * @param mixed $value
 724          * @param mixed $fallbackValue
 725          */
 726         protected function mergeItem( $key, &$value, $fallbackValue ) {
 727                 if ( !is_null( $value ) ) {
 728                         if ( !is_null( $fallbackValue ) ) {
 729                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 730                                         $value = $value + $fallbackValue;
 731                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 732                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 733                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 734                                         $value = array_merge_recursive( $value, $fallbackValue );
 735                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 736                                         if ( !empty( $value['inherit'] ) ) {
 737                                                 $value = array_merge( $fallbackValue, $value );
 738                                         }
 739
 740                                         if ( isset( $value['inherit'] ) ) {
 741                                                 unset( $value['inherit'] );
 742                                         }
 743                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 744                                         $this->mergeMagicWords( $value, $fallbackValue );
 745                                 }
 746                         }
 747                 } else {
 748                         $value = $fallbackValue;
 749                 }
 750         }
 751
 752         /**
 753          * @param mixed $value
 754          * @param mixed $fallbackValue
 755          */
 756         protected function mergeMagicWords( &$value, $fallbackValue ) {
 757                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 758                         if ( !isset( $value[$magicName] ) ) {
 759                                 $value[$magicName] = $fallbackInfo;
 760                         } else {
 761                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 762                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 763                                 $synonyms = array_values( array_unique( array_merge(
 764                                         $newSynonyms, $oldSynonyms ) ) );
 765                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 766                         }
 767                 }
 768         }
 769
 770         /**
 771          * Given an array mapping language code to localisation value, such as is
 772          * found in extension *.i18n.php files, iterate through a fallback sequence
 773          * to merge the given data with an existing primary value.
 774          *
 775          * Returns true if any data from the extension array was used, false
 776          * otherwise.
 777          * @param array $codeSequence
 778          * @param string $key
 779          * @param mixed $value
 780          * @param mixed $fallbackValue
 781          * @return bool
 782          */
 783         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 784                 $used = false;
 785                 foreach ( $codeSequence as $code ) {
 786                         if ( isset( $fallbackValue[$code] ) ) {
 787                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 788                                 $used = true;
 789                         }
 790                 }
 791
 792                 return $used;
 793         }
 794
 795         /**
 796          * Load localisation data for a given language for both core and extensions
 797          * and save it to the persistent cache store and the process cache
 798          * @param string $code
 799          * @throws MWException
 800          */
 801         public function recache( $code ) {
 802                 global $wgExtensionMessagesFiles, $wgMessagesDirs;
 803                 wfProfileIn( __METHOD__ );
 804
 805                 if ( !$code ) {
 806                         wfProfileOut( __METHOD__ );
 807                         throw new MWException( "Invalid language code requested" );
 808                 }
 809                 $this->recachedLangs[$code] = true;
 810
 811                 # Initial values
 812                 $initialData = array_combine(
 813                         self::$allKeys,
 814                         array_fill( 0, count( self::$allKeys ), null ) );
 815                 $coreData = $initialData;
 816                 $deps = array();
 817
 818                 # Load the primary localisation from the source file
 819                 $data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
 820                 if ( $data === false ) {
 821                         wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
 822                         $coreData['fallback'] = 'en';
 823                 } else {
 824                         wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
 825
 826                         # Merge primary localisation
 827                         foreach ( $data as $key => $value ) {
 828                                 $this->mergeItem( $key, $coreData[$key], $value );
 829                         }
 830                 }
 831
 832                 # Fill in the fallback if it's not there already
 833                 if ( is_null( $coreData['fallback'] ) ) {
 834                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 835                 }
 836                 if ( $coreData['fallback'] === false ) {
 837                         $coreData['fallbackSequence'] = array();
 838                 } else {
 839                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 840                         $len = count( $coreData['fallbackSequence'] );
 841
 842                         # Ensure that the sequence ends at en
 843                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 844                                 $coreData['fallbackSequence'][] = 'en';
 845                         }
 846                 }
 847
 848                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 849
 850                 wfProfileIn( __METHOD__ . '-fallbacks' );
 851
 852                 # Load non-JSON localisation data for extensions
 853                 $extensionData = array_combine(
 854                         $codeSequence,
 855                         array_fill( 0, count( $codeSequence ), $initialData ) );
 856                 foreach ( $wgExtensionMessagesFiles as $extension => $fileName ) {
 857                         if ( isset( $wgMessagesDirs[$extension] ) ) {
 858                                 # This extension has JSON message data; skip the PHP shim
 859                                 continue;
 860                         }
 861
 862                         $data = $this->readPHPFile( $fileName, 'extension' );
 863                         $used = false;
 864
 865                         foreach ( $data as $key => $item ) {
 866                                 foreach ( $codeSequence as $csCode ) {
 867                                         if ( isset( $item[$csCode] ) ) {
 868                                                 $this->mergeItem( $key, $extensionData[$csCode][$key], $item[$csCode] );
 869                                                 $used = true;
 870                                         }
 871                                 }
 872                         }
 873
 874                         if ( $used ) {
 875                                 $deps[] = new FileDependency( $fileName );
 876                         }
 877                 }
 878
 879                 # Load the localisation data for each fallback, then merge it into the full array
 880                 $allData = $initialData;
 881                 foreach ( $codeSequence as $csCode ) {
 882                         $csData = $initialData;
 883
 884                         # Load core messages and the extension localisations.
 885                         foreach ( $wgMessagesDirs as $dirs ) {
 886                                 foreach ( (array)$dirs as $dir ) {
 887                                         $fileName = "$dir/$csCode.json";
 888                                         $data = $this->readJSONFile( $fileName );
 889
 890                                         foreach ( $data as $key => $item ) {
 891                                                 $this->mergeItem( $key, $csData[$key], $item );
 892                                         }
 893
 894                                         $deps[] = new FileDependency( $fileName );
 895                                 }
 896                         }
 897
 898                         # Merge non-JSON extension data
 899                         if ( isset( $extensionData[$csCode] ) ) {
 900                                 foreach ( $extensionData[$csCode] as $key => $item ) {
 901                                         $this->mergeItem( $key, $csData[$key], $item );
 902                                 }
 903                         }
 904
 905                         if ( $csCode === $code ) {
 906                                 # Merge core data into extension data
 907                                 foreach ( $coreData as $key => $item ) {
 908                                         $this->mergeItem( $key, $csData[$key], $item );
 909                                 }
 910                         } else {
 911                                 # Load the secondary localisation from the source file to
 912                                 # avoid infinite cycles on cyclic fallbacks
 913                                 $fbData = $this->readSourceFilesAndRegisterDeps( $csCode, $deps );
 914                                 if ( $fbData !== false ) {
 915                                         # Only merge the keys that make sense to merge
 916                                         foreach ( self::$allKeys as $key ) {
 917                                                 if ( !isset( $fbData[$key] ) ) {
 918                                                         continue;
 919                                                 }
 920
 921                                                 if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 922                                                         $this->mergeItem( $key, $csData[$key], $fbData[$key] );
 923                                                 }
 924                                         }
 925                                 }
 926                         }
 927
 928                         # Allow extensions an opportunity to adjust the data for this
 929                         # fallback
 930                         wfRunHooks( 'LocalisationCacheRecacheFallback', array( $this, $csCode, &$csData ) );
 931
 932                         # Merge the data for this fallback into the final array
 933                         if ( $csCode === $code ) {
 934                                 $allData = $csData;
 935                         } else {
 936                                 foreach ( self::$allKeys as $key ) {
 937                                         if ( !isset( $csData[$key] ) ) {
 938                                                 continue;
 939                                         }
 940
 941                                         if ( is_null( $allData[$key] ) || $this->isMergeableKey( $key ) ) {
 942                                                 $this->mergeItem( $key, $allData[$key], $csData[$key] );
 943                                         }
 944                                 }
 945                         }
 946                 }
 947
 948                 wfProfileOut( __METHOD__ . '-fallbacks' );
 949
 950                 # Add cache dependencies for any referenced globals
 951                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 952                 $deps['wgMessagesDirs'] = new GlobalDependency( 'wgMessagesDirs' );
 953                 $deps['version'] = new ConstantDependency( 'LocalisationCache::VERSION' );
 954
 955                 # Add dependencies to the cache entry
 956                 $allData['deps'] = $deps;
 957
 958                 # Replace spaces with underscores in namespace names
 959                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 960
 961                 # And do the same for special page aliases. $page is an array.
 962                 foreach ( $allData['specialPageAliases'] as &$page ) {
 963                         $page = str_replace( ' ', '_', $page );
 964                 }
 965                 # Decouple the reference to prevent accidental damage
 966                 unset( $page );
 967
 968                 # If there were no plural rules, return an empty array
 969                 if ( $allData['pluralRules'] === null ) {
 970                         $allData['pluralRules'] = array();
 971                 }
 972                 if ( $allData['compiledPluralRules'] === null ) {
 973                         $allData['compiledPluralRules'] = array();
 974                 }
 975                 # If there were no plural rule types, return an empty array
 976                 if ( $allData['pluralRuleTypes'] === null ) {
 977                         $allData['pluralRuleTypes'] = array();
 978                 }
 979
 980                 # Set the list keys
 981                 $allData['list'] = array();
 982                 foreach ( self::$splitKeys as $key ) {
 983                         $allData['list'][$key] = array_keys( $allData[$key] );
 984                 }
 985                 # Run hooks
 986                 $purgeBlobs = true;
 987                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData, &$purgeBlobs ) );
 988
 989                 if ( is_null( $allData['namespaceNames'] ) ) {
 990                         wfProfileOut( __METHOD__ );
 991                         throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
 992                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 993                 }
 994
 995                 # Set the preload key
 996                 $allData['preload'] = $this->buildPreload( $allData );
 997
 998                 # Save to the process cache and register the items loaded
 999                 $this->data[$code] = $allData;
1000                 foreach ( $allData as $key => $item ) {
1001                         $this->loadedItems[$code][$key] = true;
1002                 }
1003
1004                 # Save to the persistent cache
1005                 wfProfileIn( __METHOD__ . '-write' );
1006                 $this->store->startWrite( $code );
1007                 foreach ( $allData as $key => $value ) {
1008                         if ( in_array( $key, self::$splitKeys ) ) {
1009                                 foreach ( $value as $subkey => $subvalue ) {
1010                                         $this->store->set( "$key:$subkey", $subvalue );
1011                                 }
1012                         } else {
1013                                 $this->store->set( $key, $value );
1014                         }
1015                 }
1016                 $this->store->finishWrite();
1017                 wfProfileOut( __METHOD__ . '-write' );
1018
1019                 # Clear out the MessageBlobStore
1020                 # HACK: If using a null (i.e. disabled) storage backend, we
1021                 # can't write to the MessageBlobStore either
1022                 if ( $purgeBlobs && !$this->store instanceof LCStoreNull ) {
1023                         MessageBlobStore::getInstance()->clear();
1024                 }
1025
1026                 wfProfileOut( __METHOD__ );
1027         }
1028
1029         /**
1030          * Build the preload item from the given pre-cache data.
1031          *
1032          * The preload item will be loaded automatically, improving performance
1033          * for the commonly-requested items it contains.
1034          * @param array $data
1035          * @return array
1036          */
1037         protected function buildPreload( $data ) {
1038                 $preload = array( 'messages' => array() );
1039                 foreach ( self::$preloadedKeys as $key ) {
1040                         $preload[$key] = $data[$key];
1041                 }
1042
1043                 foreach ( $data['preloadedMessages'] as $subkey ) {
1044                         if ( isset( $data['messages'][$subkey] ) ) {
1045                                 $subitem = $data['messages'][$subkey];
1046                         } else {
1047                                 $subitem = null;
1048                         }
1049                         $preload['messages'][$subkey] = $subitem;
1050                 }
1051
1052                 return $preload;
1053         }
1054
1055         /**
1056          * Unload the data for a given language from the object cache.
1057          * Reduces memory usage.
1058          * @param string $code
1059          */
1060         public function unload( $code ) {
1061                 unset( $this->data[$code] );
1062                 unset( $this->loadedItems[$code] );
1063                 unset( $this->loadedSubitems[$code] );
1064                 unset( $this->initialisedLangs[$code] );
1065                 unset( $this->shallowFallbacks[$code] );
1066
1067                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
1068                         if ( $fbCode === $code ) {
1069                                 $this->unload( $shallowCode );
1070                         }
1071                 }
1072         }
1073
1074         /**
1075          * Unload all data
1076          */
1077         public function unloadAll() {
1078                 foreach ( $this->initialisedLangs as $lang => $unused ) {
1079                         $this->unload( $lang );
1080                 }
1081         }
1082
1083         /**
1084          * Disable the storage backend
1085          */
1086         public function disableBackend() {
1087                 $this->store = new LCStoreNull;
1088                 $this->manualRecache = false;
1089         }
1090 }
1091
1092 /**
1093  * Interface for the persistence layer of LocalisationCache.
1094  *
1095  * The persistence layer is two-level hierarchical cache. The first level
1096  * is the language, the second level is the item or subitem.
1097  *
1098  * Since the data for a whole language is rebuilt in one operation, it needs
1099  * to have a fast and atomic method for deleting or replacing all of the
1100  * current data for a given language. The interface reflects this bulk update
1101  * operation. Callers writing to the cache must first call startWrite(), then
1102  * will call set() a couple of thousand times, then will call finishWrite()
1103  * to commit the operation. When finishWrite() is called, the cache is
1104  * expected to delete all data previously stored for that language.
1105  *
1106  * The values stored are PHP variables suitable for serialize(). Implementations
1107  * of LCStore are responsible for serializing and unserializing.
1108  */
1109 interface LCStore {
1110         /**
1111          * Get a value.
1112          * @param string $code Language code
1113          * @param string $key Cache key
1114          */
1115         function get( $code, $key );
1116
1117         /**
1118          * Start a write transaction.
1119          * @param string $code Language code
1120          */
1121         function startWrite( $code );
1122
1123         /**
1124          * Finish a write transaction.
1125          */
1126         function finishWrite();
1127
1128         /**
1129          * Set a key to a given value. startWrite() must be called before this
1130          * is called, and finishWrite() must be called afterwards.
1131          * @param string $key
1132          * @param mixed $value
1133          */
1134         function set( $key, $value );
1135 }
1136
1137 /**
1138  * LCStore implementation which uses the standard DB functions to store data.
1139  * This will work on any MediaWiki installation.
1140  */
1141 class LCStoreDB implements LCStore {
1142         private $currentLang;
1143         private $writesDone = false;
1144
1145         /** @var DatabaseBase */
1146         private $dbw;
1147         /** @var array */
1148         private $batch = array();
1149
1150         private $readOnly = false;
1151
1152         public function get( $code, $key ) {
1153                 if ( $this->writesDone ) {
1154                         $db = wfGetDB( DB_MASTER );
1155                 } else {
1156                         $db = wfGetDB( DB_SLAVE );
1157                 }
1158                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
1159                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
1160                 if ( $row ) {
1161                         return unserialize( $db->decodeBlob( $row->lc_value ) );
1162                 } else {
1163                         return null;
1164                 }
1165         }
1166
1167         public function startWrite( $code ) {
1168                 if ( $this->readOnly ) {
1169                         return;
1170                 } elseif ( !$code ) {
1171                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1172                 }
1173
1174                 $this->dbw = wfGetDB( DB_MASTER );
1175
1176                 $this->currentLang = $code;
1177                 $this->batch = array();
1178         }
1179
1180         public function finishWrite() {
1181                 if ( $this->readOnly ) {
1182                         return;
1183                 } elseif ( is_null( $this->currentLang ) ) {
1184                         throw new MWException( __CLASS__ . ': must call startWrite() before finishWrite()' );
1185                 }
1186
1187                 $this->dbw->begin( __METHOD__ );
1188                 try {
1189                         $this->dbw->delete( 'l10n_cache',
1190                                 array( 'lc_lang' => $this->currentLang ), __METHOD__ );
1191                         foreach ( array_chunk( $this->batch, 500 ) as $rows ) {
1192                                 $this->dbw->insert( 'l10n_cache', $rows, __METHOD__ );
1193                         }
1194                         $this->writesDone = true;
1195                 } catch ( DBQueryError $e ) {
1196                         if ( $this->dbw->wasReadOnlyError() ) {
1197                                 $this->readOnly = true; // just avoid site down time
1198                         } else {
1199                                 throw $e;
1200                         }
1201                 }
1202                 $this->dbw->commit( __METHOD__ );
1203
1204                 $this->currentLang = null;
1205                 $this->batch = array();
1206         }
1207
1208         public function set( $key, $value ) {
1209                 if ( $this->readOnly ) {
1210                         return;
1211                 } elseif ( is_null( $this->currentLang ) ) {
1212                         throw new MWException( __CLASS__ . ': must call startWrite() before set()' );
1213                 }
1214
1215                 $this->batch[] = array(
1216                         'lc_lang' => $this->currentLang,
1217                         'lc_key' => $key,
1218                         'lc_value' => $this->dbw->encodeBlob( serialize( $value ) ) );
1219         }
1220 }
1221
1222 /**
1223  * LCStore implementation which stores data as a collection of CDB files in the
1224  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1225  * will throw an exception.
1226  *
1227  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1228  * the directory is on a local filesystem and there is ample kernel cache
1229  * space. The performance advantage is greater when the DBA extension is
1230  * available than it is with the PHP port.
1231  *
1232  * See Cdb.php and http://cr.yp.to/cdb.html
1233  */
1234 class LCStoreCDB implements LCStore {
1235         /** @var CdbReader[] */
1236         private $readers;
1237
1238         /** @var CdbWriter */
1239         private $writer;
1240
1241         /** @var string Current language code */
1242         private $currentLang;
1243
1244         /** @var bool|string Cache directory. False if not set */
1245         private $directory;
1246
1247         function __construct( $conf = array() ) {
1248                 global $wgCacheDirectory;
1249
1250                 if ( isset( $conf['directory'] ) ) {
1251                         $this->directory = $conf['directory'];
1252                 } else {
1253                         $this->directory = $wgCacheDirectory;
1254                 }
1255         }
1256
1257         public function get( $code, $key ) {
1258                 if ( !isset( $this->readers[$code] ) ) {
1259                         $fileName = $this->getFileName( $code );
1260
1261                         $this->readers[$code] = false;
1262                         if ( file_exists( $fileName ) ) {
1263                                 try {
1264                                         $this->readers[$code] = CdbReader::open( $fileName );
1265                                 } catch ( CdbException $e ) {
1266                                         wfDebug( __METHOD__ . ": unable to open cdb file for reading\n" );
1267                                 }
1268                         }
1269                 }
1270
1271                 if ( !$this->readers[$code] ) {
1272                         return null;
1273                 } else {
1274                         $value = false;
1275                         try {
1276                                 $value = $this->readers[$code]->get( $key );
1277                         } catch ( CdbException $e ) {
1278                                 wfDebug( __METHOD__ . ": CdbException caught, error message was "
1279                                         . $e->getMessage() . "\n" );
1280                         }
1281                         if ( $value === false ) {
1282                                 return null;
1283                         }
1284
1285                         return unserialize( $value );
1286                 }
1287         }
1288
1289         public function startWrite( $code ) {
1290                 if ( !file_exists( $this->directory ) ) {
1291                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1292                                 throw new MWException( "Unable to create the localisation store " .
1293                                         "directory \"{$this->directory}\"" );
1294                         }
1295                 }
1296
1297                 // Close reader to stop permission errors on write
1298                 if ( !empty( $this->readers[$code] ) ) {
1299                         $this->readers[$code]->close();
1300                 }
1301
1302                 try {
1303                         $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1304                 } catch ( CdbException $e ) {
1305                         throw new MWException( $e->getMessage() );
1306                 }
1307                 $this->currentLang = $code;
1308         }
1309
1310         public function finishWrite() {
1311                 // Close the writer
1312                 try {
1313                         $this->writer->close();
1314                 } catch ( CdbException $e ) {
1315                         throw new MWException( $e->getMessage() );
1316                 }
1317                 $this->writer = null;
1318                 unset( $this->readers[$this->currentLang] );
1319                 $this->currentLang = null;
1320         }
1321
1322         public function set( $key, $value ) {
1323                 if ( is_null( $this->writer ) ) {
1324                         throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
1325                 }
1326                 try {
1327                         $this->writer->set( $key, serialize( $value ) );
1328                 } catch ( CdbException $e ) {
1329                         throw new MWException( $e->getMessage() );
1330                 }
1331         }
1332
1333         protected function getFileName( $code ) {
1334                 if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
1335                         throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
1336                 }
1337
1338                 return "{$this->directory}/l10n_cache-$code.cdb";
1339         }
1340 }
1341
1342 /**
1343  * Null store backend, used to avoid DB errors during install
1344  */
1345 class LCStoreNull implements LCStore {
1346         public function get( $code, $key ) {
1347                 return null;
1348         }
1349
1350         public function startWrite( $code ) {
1351         }
1352
1353         public function finishWrite() {
1354         }
1355
1356         public function set( $key, $value ) {
1357         }
1358 }
1359
1360 /**
1361  * A localisation cache optimised for loading large amounts of data for many
1362  * languages. Used by rebuildLocalisationCache.php.
1363  */
1364 class LocalisationCacheBulkLoad extends LocalisationCache {
1365         /**
1366          * A cache of the contents of data files.
1367          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1368          */
1369         private $fileCache = array();
1370
1371         /**
1372          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1373          * to keep the most recently used language codes at the end of the array, and
1374          * the language codes that are ready to be deleted at the beginning.
1375          */
1376         private $mruLangs = array();
1377
1378         /**
1379          * Maximum number of languages that may be loaded into $this->data
1380          */
1381         private $maxLoadedLangs = 10;
1382
1383         /**
1384          * @param string $fileName
1385          * @param string $fileType
1386          * @return array|mixed
1387          */
1388         protected function readPHPFile( $fileName, $fileType ) {
1389                 $serialize = $fileType === 'core';
1390                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1391                         $data = parent::readPHPFile( $fileName, $fileType );
1392
1393                         if ( $serialize ) {
1394                                 $encData = serialize( $data );
1395                         } else {
1396                                 $encData = $data;
1397                         }
1398
1399                         $this->fileCache[$fileName][$fileType] = $encData;
1400
1401                         return $data;
1402                 } elseif ( $serialize ) {
1403                         return unserialize( $this->fileCache[$fileName][$fileType] );
1404                 } else {
1405                         return $this->fileCache[$fileName][$fileType];
1406                 }
1407         }
1408
1409         /**
1410          * @param string $code
1411          * @param string $key
1412          * @return mixed
1413          */
1414         public function getItem( $code, $key ) {
1415                 unset( $this->mruLangs[$code] );
1416                 $this->mruLangs[$code] = true;
1417
1418                 return parent::getItem( $code, $key );
1419         }
1420
1421         /**
1422          * @param string $code
1423          * @param string $key
1424          * @param string $subkey
1425          * @return mixed
1426          */
1427         public function getSubitem( $code, $key, $subkey ) {
1428                 unset( $this->mruLangs[$code] );
1429                 $this->mruLangs[$code] = true;
1430
1431                 return parent::getSubitem( $code, $key, $subkey );
1432         }
1433
1434         /**
1435          * @param string $code
1436          */
1437         public function recache( $code ) {
1438                 parent::recache( $code );
1439                 unset( $this->mruLangs[$code] );
1440                 $this->mruLangs[$code] = true;
1441                 $this->trimCache();
1442         }
1443
1444         /**
1445          * @param string $code
1446          */
1447         public function unload( $code ) {
1448                 unset( $this->mruLangs[$code] );
1449                 parent::unload( $code );
1450         }
1451
1452         /**
1453          * Unload cached languages until there are less than $this->maxLoadedLangs
1454          */
1455         protected function trimCache() {
1456                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1457                         reset( $this->mruLangs );
1458                         $code = key( $this->mruLangs );
1459                         wfDebug( __METHOD__ . ": unloading $code\n" );
1460                         $this->unload( $code );
1461                 }
1462         }
1463 }