includes/LocalisationCache.php

   1 <?php
   2
   3 define( 'MW_LC_VERSION', 2 );
   4
   5 /**
   6  * Class for caching the contents of localisation files, Messages*.php
   7  * and *.i18n.php.
   8  *
   9  * An instance of this class is available using Language::getLocalisationCache().
  10  *
  11  * The values retrieved from here are merged, containing items from extension
  12  * files, core messages files and the language fallback sequence (e.g. zh-cn ->
  13  * zh-hans -> en ). Some common errors are corrected, for example namespace
  14  * names with spaces instead of underscores, but heavyweight processing, such
  15  * as grammatical transformation, is done by the caller.
  16  */
  17 class LocalisationCache {
  18         /** Configuration associative array */
  19         var $conf;
  20
  21         /**
  22          * True if recaching should only be done on an explicit call to recache().
  23          * Setting this reduces the overhead of cache freshness checking, which
  24          * requires doing a stat() for every extension i18n file.
  25          */
  26         var $manualRecache = false;
  27
  28         /**
  29          * True to treat all files as expired until they are regenerated by this object.
  30          */
  31         var $forceRecache = false;
  32
  33         /**
  34          * The cache data. 3-d array, where the first key is the language code,
  35          * the second key is the item key e.g. 'messages', and the third key is
  36          * an item specific subkey index. Some items are not arrays and so for those
  37          * items, there are no subkeys.
  38          */
  39         var $data = array();
  40
  41         /**
  42          * The persistent store object. An instance of LCStore.
  43          *
  44          * @var LCStore
  45          */
  46         var $store;
  47
  48         /**
  49          * A 2-d associative array, code/key, where presence indicates that the item
  50          * is loaded. Value arbitrary.
  51          *
  52          * For split items, if set, this indicates that all of the subitems have been
  53          * loaded.
  54          */
  55         var $loadedItems = array();
  56
  57         /**
  58          * A 3-d associative array, code/key/subkey, where presence indicates that
  59          * the subitem is loaded. Only used for the split items, i.e. messages.
  60          */
  61         var $loadedSubitems = array();
  62
  63         /**
  64          * An array where presence of a key indicates that that language has been
  65          * initialised. Initialisation includes checking for cache expiry and doing
  66          * any necessary updates.
  67          */
  68         var $initialisedLangs = array();
  69
  70         /**
  71          * An array mapping non-existent pseudo-languages to fallback languages. This
  72          * is filled by initShallowFallback() when data is requested from a language
  73          * that lacks a Messages*.php file.
  74          */
  75         var $shallowFallbacks = array();
  76
  77         /**
  78          * An array where the keys are codes that have been recached by this instance.
  79          */
  80         var $recachedLangs = array();
  81
  82         /**
  83          * All item keys
  84          */
  85         static public $allKeys = array(
  86                 'fallback', 'namespaceNames', 'bookstoreList',
  87                 'magicWords', 'messages', 'rtl', 'capitalizeAllNouns', 'digitTransformTable',
  88                 'separatorTransformTable', 'fallback8bitEncoding', 'linkPrefixExtension',
  89                 'linkTrail', 'namespaceAliases',
  90                 'dateFormats', 'datePreferences', 'datePreferenceMigrationMap',
  91                 'defaultDateFormat', 'extraUserToggles', 'specialPageAliases',
  92                 'imageFiles', 'preloadedMessages', 'namespaceGenderAliases',
  93                 'digitGroupingPattern'
  94         );
  95
  96         /**
  97          * Keys for items which consist of associative arrays, which may be merged
  98          * by a fallback sequence.
  99          */
 100         static public $mergeableMapKeys = array( 'messages', 'namespaceNames',
 101                 'dateFormats', 'imageFiles', 'preloadedMessages',
 102         );
 103
 104         /**
 105          * Keys for items which are a numbered array.
 106          */
 107         static public $mergeableListKeys = array( 'extraUserToggles' );
 108
 109         /**
 110          * Keys for items which contain an array of arrays of equivalent aliases
 111          * for each subitem. The aliases may be merged by a fallback sequence.
 112          */
 113         static public $mergeableAliasListKeys = array( 'specialPageAliases' );
 114
 115         /**
 116          * Keys for items which contain an associative array, and may be merged if
 117          * the primary value contains the special array key "inherit". That array
 118          * key is removed after the first merge.
 119          */
 120         static public $optionalMergeKeys = array( 'bookstoreList' );
 121
 122         /**
 123          * Keys for items that are formatted like $magicWords
 124          */
 125         static public $magicWordKeys = array( 'magicWords' );
 126
 127         /**
 128          * Keys for items where the subitems are stored in the backend separately.
 129          */
 130         static public $splitKeys = array( 'messages' );
 131
 132         /**
 133          * Keys which are loaded automatically by initLanguage()
 134          */
 135         static public $preloadedKeys = array( 'dateFormats', 'namespaceNames' );
 136
 137         var $mergeableKeys = null;
 138
 139         /**
 140          * Constructor.
 141          * For constructor parameters, see the documentation in DefaultSettings.php
 142          * for $wgLocalisationCacheConf.
 143          *
 144          * @param $conf Array
 145          */
 146         function __construct( $conf ) {
 147                 global $wgCacheDirectory;
 148
 149                 $this->conf = $conf;
 150                 $storeConf = array();
 151                 if ( !empty( $conf['storeClass'] ) ) {
 152                         $storeClass = $conf['storeClass'];
 153                 } else {
 154                         switch ( $conf['store'] ) {
 155                                 case 'files':
 156                                 case 'file':
 157                                         $storeClass = 'LCStore_CDB';
 158                                         break;
 159                                 case 'db':
 160                                         $storeClass = 'LCStore_DB';
 161                                         break;
 162                                 case 'accel':
 163                                         $storeClass = 'LCStore_Accel';
 164                                         break;
 165                                 case 'detect':
 166                                         try {
 167                                                 $c = wfGetCache( CACHE_ACCEL );
 168                                                 $storeClass = 'LCStore_Accel';
 169                                         } catch( Exception $c ) {
 170                                                 $storeClass = $wgCacheDirectory ? 'LCStore_CDB' : 'LCStore_DB';
 171                                         }
 172                                         break;
 173                                 default:
 174                                         throw new MWException(
 175                                                 'Please set $wgLocalisationCacheConf[\'store\'] to something sensible.' );
 176                         }
 177                 }
 178
 179                 wfDebug( get_class( $this ) . ": using store $storeClass\n" );
 180                 if ( !empty( $conf['storeDirectory'] ) ) {
 181                         $storeConf['directory'] = $conf['storeDirectory'];
 182                 }
 183
 184                 $this->store = new $storeClass( $storeConf );
 185                 foreach ( array( 'manualRecache', 'forceRecache' ) as $var ) {
 186                         if ( isset( $conf[$var] ) ) {
 187                                 $this->$var = $conf[$var];
 188                         }
 189                 }
 190         }
 191
 192         /**
 193          * Returns true if the given key is mergeable, that is, if it is an associative
 194          * array which can be merged through a fallback sequence.
 195          * @param $key
 196          * @return bool
 197          */
 198         public function isMergeableKey( $key ) {
 199                 if ( $this->mergeableKeys === null ) {
 200                         $this->mergeableKeys = array_flip( array_merge(
 201                                 self::$mergeableMapKeys,
 202                                 self::$mergeableListKeys,
 203                                 self::$mergeableAliasListKeys,
 204                                 self::$optionalMergeKeys,
 205                                 self::$magicWordKeys
 206                         ) );
 207                 }
 208                 return isset( $this->mergeableKeys[$key] );
 209         }
 210
 211         /**
 212          * Get a cache item.
 213          *
 214          * Warning: this may be slow for split items (messages), since it will
 215          * need to fetch all of the subitems from the cache individually.
 216          * @param $code
 217          * @param $key
 218          * @return mixed
 219          */
 220         public function getItem( $code, $key ) {
 221                 if ( !isset( $this->loadedItems[$code][$key] ) ) {
 222                         wfProfileIn( __METHOD__.'-load' );
 223                         $this->loadItem( $code, $key );
 224                         wfProfileOut( __METHOD__.'-load' );
 225                 }
 226
 227                 if ( $key === 'fallback' && isset( $this->shallowFallbacks[$code] ) ) {
 228                         return $this->shallowFallbacks[$code];
 229                 }
 230
 231                 return $this->data[$code][$key];
 232         }
 233
 234         /**
 235          * Get a subitem, for instance a single message for a given language.
 236          * @param $code
 237          * @param $key
 238          * @param $subkey
 239          * @return null
 240          */
 241         public function getSubitem( $code, $key, $subkey ) {
 242                 if ( !isset( $this->loadedSubitems[$code][$key][$subkey] ) &&
 243                          !isset( $this->loadedItems[$code][$key] ) ) {
 244                         wfProfileIn( __METHOD__.'-load' );
 245                         $this->loadSubitem( $code, $key, $subkey );
 246                         wfProfileOut( __METHOD__.'-load' );
 247                 }
 248
 249                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 250                         return $this->data[$code][$key][$subkey];
 251                 } else {
 252                         return null;
 253                 }
 254         }
 255
 256         /**
 257          * Get the list of subitem keys for a given item.
 258          *
 259          * This is faster than array_keys($lc->getItem(...)) for the items listed in
 260          * self::$splitKeys.
 261          *
 262          * Will return null if the item is not found, or false if the item is not an
 263          * array.
 264          * @param $code
 265          * @param $key
 266          * @return bool|null|string
 267          */
 268         public function getSubitemList( $code, $key ) {
 269                 if ( in_array( $key, self::$splitKeys ) ) {
 270                         return $this->getSubitem( $code, 'list', $key );
 271                 } else {
 272                         $item = $this->getItem( $code, $key );
 273                         if ( is_array( $item ) ) {
 274                                 return array_keys( $item );
 275                         } else {
 276                                 return false;
 277                         }
 278                 }
 279         }
 280
 281         /**
 282          * Load an item into the cache.
 283          * @param $code
 284          * @param $key
 285          */
 286         protected function loadItem( $code, $key ) {
 287                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 288                         $this->initLanguage( $code );
 289                 }
 290
 291                 // Check to see if initLanguage() loaded it for us
 292                 if ( isset( $this->loadedItems[$code][$key] ) ) {
 293                         return;
 294                 }
 295
 296                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 297                         $this->loadItem( $this->shallowFallbacks[$code], $key );
 298                         return;
 299                 }
 300
 301                 if ( in_array( $key, self::$splitKeys ) ) {
 302                         $subkeyList = $this->getSubitem( $code, 'list', $key );
 303                         foreach ( $subkeyList as $subkey ) {
 304                                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 305                                         continue;
 306                                 }
 307                                 $this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
 308                         }
 309                 } else {
 310                         $this->data[$code][$key] = $this->store->get( $code, $key );
 311                 }
 312
 313                 $this->loadedItems[$code][$key] = true;
 314         }
 315
 316         /**
 317          * Load a subitem into the cache
 318          * @param $code
 319          * @param $key
 320          * @param $subkey
 321          * @return
 322          */
 323         protected function loadSubitem( $code, $key, $subkey ) {
 324                 if ( !in_array( $key, self::$splitKeys ) ) {
 325                         $this->loadItem( $code, $key );
 326                         return;
 327                 }
 328
 329                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 330                         $this->initLanguage( $code );
 331                 }
 332
 333                 // Check to see if initLanguage() loaded it for us
 334                 if ( isset( $this->loadedItems[$code][$key] ) ||
 335                          isset( $this->loadedSubitems[$code][$key][$subkey] ) ) {
 336                         return;
 337                 }
 338
 339                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 340                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 341                         return;
 342                 }
 343
 344                 $value = $this->store->get( $code, "$key:$subkey" );
 345                 $this->data[$code][$key][$subkey] = $value;
 346                 $this->loadedSubitems[$code][$key][$subkey] = true;
 347         }
 348
 349         /**
 350          * Returns true if the cache identified by $code is missing or expired.
 351          */
 352         public function isExpired( $code ) {
 353                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 354                         wfDebug( __METHOD__."($code): forced reload\n" );
 355                         return true;
 356                 }
 357
 358                 $deps = $this->store->get( $code, 'deps' );
 359                 $keys = $this->store->get( $code, 'list', 'messages' );
 360                 $preload = $this->store->get( $code, 'preload' );
 361                 // Different keys may expire separately, at least in LCStore_Accel
 362                 if ( $deps === null || $keys === null || $preload === null ) {
 363                         wfDebug( __METHOD__."($code): cache missing, need to make one\n" );
 364                         return true;
 365                 }
 366
 367                 foreach ( $deps as $dep ) {
 368                         // Because we're unserializing stuff from cache, we
 369                         // could receive objects of classes that don't exist
 370                         // anymore (e.g. uninstalled extensions)
 371                         // When this happens, always expire the cache
 372                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 373                                 wfDebug( __METHOD__."($code): cache for $code expired due to " .
 374                                         get_class( $dep ) . "\n" );
 375                                 return true;
 376                         }
 377                 }
 378
 379                 return false;
 380         }
 381
 382         /**
 383          * Initialise a language in this object. Rebuild the cache if necessary.
 384          * @param $code
 385          */
 386         protected function initLanguage( $code ) {
 387                 if ( isset( $this->initialisedLangs[$code] ) ) {
 388                         return;
 389                 }
 390
 391                 $this->initialisedLangs[$code] = true;
 392
 393                 # If the code is of the wrong form for a Messages*.php file, do a shallow fallback
 394                 if ( !Language::isValidBuiltInCode( $code ) ) {
 395                         $this->initShallowFallback( $code, 'en' );
 396                         return;
 397                 }
 398
 399                 # Recache the data if necessary
 400                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 401                         if ( file_exists( Language::getMessagesFileName( $code ) ) ) {
 402                                 $this->recache( $code );
 403                         } elseif ( $code === 'en' ) {
 404                                 throw new MWException( 'MessagesEn.php is missing.' );
 405                         } else {
 406                                 $this->initShallowFallback( $code, 'en' );
 407                         }
 408                         return;
 409                 }
 410
 411                 # Preload some stuff
 412                 $preload = $this->getItem( $code, 'preload' );
 413                 if ( $preload === null ) {
 414                         if ( $this->manualRecache ) {
 415                                 // No Messages*.php file. Do shallow fallback to en.
 416                                 if ( $code === 'en' ) {
 417                                         throw new MWException( 'No localisation cache found for English. ' .
 418                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 419                                 }
 420                                 $this->initShallowFallback( $code, 'en' );
 421                                 return;
 422                         } else {
 423                                 throw new MWException( 'Invalid or missing localisation cache.' );
 424                         }
 425                 }
 426                 $this->data[$code] = $preload;
 427                 foreach ( $preload as $key => $item ) {
 428                         if ( in_array( $key, self::$splitKeys ) ) {
 429                                 foreach ( $item as $subkey => $subitem ) {
 430                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 431                                 }
 432                         } else {
 433                                 $this->loadedItems[$code][$key] = true;
 434                         }
 435                 }
 436         }
 437
 438         /**
 439          * Create a fallback from one language to another, without creating a
 440          * complete persistent cache.
 441          * @param $primaryCode
 442          * @param $fallbackCode
 443          */
 444         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 445                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 446                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 447                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 448                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 449         }
 450
 451         /**
 452          * Read a PHP file containing localisation data.
 453          * @param $_fileName
 454          * @param $_fileType
 455          * @return array
 456          */
 457         protected function readPHPFile( $_fileName, $_fileType ) {
 458                 // Disable APC caching
 459                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 460                 include( $_fileName );
 461                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 462
 463                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 464                         $data = compact( self::$allKeys );
 465                 } elseif ( $_fileType == 'aliases' ) {
 466                         $data = compact( 'aliases' );
 467                 } else {
 468                         throw new MWException( __METHOD__.": Invalid file type: $_fileType" );
 469                 }
 470
 471                 return $data;
 472         }
 473
 474         /**
 475          * Merge two localisation values, a primary and a fallback, overwriting the
 476          * primary value in place.
 477          * @param $key
 478          * @param $value
 479          * @param $fallbackValue
 480          */
 481         protected function mergeItem( $key, &$value, $fallbackValue ) {
 482                 if ( !is_null( $value ) ) {
 483                         if ( !is_null( $fallbackValue ) ) {
 484                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 485                                         $value = $value + $fallbackValue;
 486                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 487                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 488                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 489                                         $value = array_merge_recursive( $value, $fallbackValue );
 490                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 491                                         if ( !empty( $value['inherit'] ) )  {
 492                                                 $value = array_merge( $fallbackValue, $value );
 493                                         }
 494
 495                                         if ( isset( $value['inherit'] ) ) {
 496                                                 unset( $value['inherit'] );
 497                                         }
 498                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 499                                         $this->mergeMagicWords( $value, $fallbackValue );
 500                                 }
 501                         }
 502                 } else {
 503                         $value = $fallbackValue;
 504                 }
 505         }
 506
 507         /**
 508          * @param $value
 509          * @param $fallbackValue
 510          */
 511         protected function mergeMagicWords( &$value, $fallbackValue ) {
 512                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 513                         if ( !isset( $value[$magicName] ) ) {
 514                                 $value[$magicName] = $fallbackInfo;
 515                         } else {
 516                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 517                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 518                                 $synonyms = array_values( array_unique( array_merge(
 519                                         $newSynonyms, $oldSynonyms ) ) );
 520                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 521                         }
 522                 }
 523         }
 524
 525         /**
 526          * Given an array mapping language code to localisation value, such as is
 527          * found in extension *.i18n.php files, iterate through a fallback sequence
 528          * to merge the given data with an existing primary value.
 529          *
 530          * Returns true if any data from the extension array was used, false
 531          * otherwise.
 532          * @param $codeSequence
 533          * @param $key
 534          * @param $value
 535          * @param $fallbackValue
 536          * @return bool
 537          */
 538         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 539                 $used = false;
 540                 foreach ( $codeSequence as $code ) {
 541                         if ( isset( $fallbackValue[$code] ) ) {
 542                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 543                                 $used = true;
 544                         }
 545                 }
 546
 547                 return $used;
 548         }
 549
 550         /**
 551          * Load localisation data for a given language for both core and extensions
 552          * and save it to the persistent cache store and the process cache
 553          * @param $code
 554          */
 555         public function recache( $code ) {
 556                 global $wgExtensionMessagesFiles, $wgExtensionAliasesFiles;
 557                 wfProfileIn( __METHOD__ );
 558
 559                 if ( !$code ) {
 560                         throw new MWException( "Invalid language code requested" );
 561                 }
 562                 $this->recachedLangs[$code] = true;
 563
 564                 # Initial values
 565                 $initialData = array_combine(
 566                         self::$allKeys,
 567                         array_fill( 0, count( self::$allKeys ), null ) );
 568                 $coreData = $initialData;
 569                 $deps = array();
 570
 571                 # Load the primary localisation from the source file
 572                 $fileName = Language::getMessagesFileName( $code );
 573                 if ( !file_exists( $fileName ) ) {
 574                         wfDebug( __METHOD__.": no localisation file for $code, using fallback to en\n" );
 575                         $coreData['fallback'] = 'en';
 576                 } else {
 577                         $deps[] = new FileDependency( $fileName );
 578                         $data = $this->readPHPFile( $fileName, 'core' );
 579                         wfDebug( __METHOD__.": got localisation for $code from source\n" );
 580
 581                         # Merge primary localisation
 582                         foreach ( $data as $key => $value ) {
 583                                 $this->mergeItem( $key, $coreData[$key], $value );
 584                         }
 585
 586                 }
 587
 588                 # Fill in the fallback if it's not there already
 589                 if ( is_null( $coreData['fallback'] ) ) {
 590                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 591                 }
 592
 593                 if ( $coreData['fallback'] === false ) {
 594                         $coreData['fallbackSequence'] = array();
 595                 } else {
 596                         $coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
 597                         $len = count( $coreData['fallbackSequence'] );
 598
 599                         # Ensure that the sequence ends at en
 600                         if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
 601                                 $coreData['fallbackSequence'][] = 'en';
 602                         }
 603
 604                         # Load the fallback localisation item by item and merge it
 605                         foreach ( $coreData['fallbackSequence'] as $fbCode ) {
 606                                 # Load the secondary localisation from the source file to
 607                                 # avoid infinite cycles on cyclic fallbacks
 608                                 $fbFilename = Language::getMessagesFileName( $fbCode );
 609
 610                                 if ( !file_exists( $fbFilename ) ) {
 611                                         continue;
 612                                 }
 613
 614                                 $deps[] = new FileDependency( $fbFilename );
 615                                 $fbData = $this->readPHPFile( $fbFilename, 'core' );
 616
 617                                 foreach ( self::$allKeys as $key ) {
 618                                         if ( !isset( $fbData[$key] ) ) {
 619                                                 continue;
 620                                         }
 621
 622                                         if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 623                                                 $this->mergeItem( $key, $coreData[$key], $fbData[$key] );
 624                                         }
 625                                 }
 626                         }
 627                 }
 628
 629                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 630
 631                 # Load the extension localisations
 632                 # This is done after the core because we know the fallback sequence now.
 633                 # But it has a higher precedence for merging so that we can support things
 634                 # like site-specific message overrides.
 635                 $allData = $initialData;
 636                 foreach ( $wgExtensionMessagesFiles as $fileName ) {
 637                         $data = $this->readPHPFile( $fileName, 'extension' );
 638                         $used = false;
 639
 640                         foreach ( $data as $key => $item ) {
 641                                 if( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 642                                         $used = true;
 643                                 }
 644                         }
 645
 646                         if ( $used ) {
 647                                 $deps[] = new FileDependency( $fileName );
 648                         }
 649                 }
 650
 651                 # Load deprecated $wgExtensionAliasesFiles
 652                 foreach ( $wgExtensionAliasesFiles as $fileName ) {
 653                         $data = $this->readPHPFile( $fileName, 'aliases' );
 654
 655                         if ( !isset( $data['aliases'] ) ) {
 656                                 continue;
 657                         }
 658
 659                         $used = $this->mergeExtensionItem( $codeSequence, 'specialPageAliases',
 660                                 $allData['specialPageAliases'], $data['aliases'] );
 661
 662                         if ( $used ) {
 663                                 $deps[] = new FileDependency( $fileName );
 664                         }
 665                 }
 666
 667                 # Merge core data into extension data
 668                 foreach ( $coreData as $key => $item ) {
 669                         $this->mergeItem( $key, $allData[$key], $item );
 670                 }
 671
 672                 # Add cache dependencies for any referenced globals
 673                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 674                 $deps['wgExtensionAliasesFiles'] = new GlobalDependency( 'wgExtensionAliasesFiles' );
 675                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 676
 677                 # Add dependencies to the cache entry
 678                 $allData['deps'] = $deps;
 679
 680                 # Replace spaces with underscores in namespace names
 681                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 682
 683                 # And do the same for special page aliases. $page is an array.
 684                 foreach ( $allData['specialPageAliases'] as &$page ) {
 685                         $page = str_replace( ' ', '_', $page );
 686                 }
 687                 # Decouple the reference to prevent accidental damage
 688                 unset($page);
 689
 690                 # Set the list keys
 691                 $allData['list'] = array();
 692                 foreach ( self::$splitKeys as $key ) {
 693                         $allData['list'][$key] = array_keys( $allData[$key] );
 694                 }
 695
 696                 # Run hooks
 697                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData ) );
 698
 699                 if ( is_null( $allData['namespaceNames'] ) ) {
 700                         throw new MWException( __METHOD__.': Localisation data failed sanity check! ' .
 701                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 702                 }
 703
 704                 # Set the preload key
 705                 $allData['preload'] = $this->buildPreload( $allData );
 706
 707                 # Save to the process cache and register the items loaded
 708                 $this->data[$code] = $allData;
 709                 foreach ( $allData as $key => $item ) {
 710                         $this->loadedItems[$code][$key] = true;
 711                 }
 712
 713                 # Write data to the persistant store
 714                 $this->saveLangInStore( $code, $data );
 715
 716                 wfProfileOut( __METHOD__ );
 717         }
 718
 719         /**
 720          * Helper for recache() this is not mean to be called outside of recache()
 721          * When the localisation store is null (LCStore_Null), method does nothing.
 722          *
 723          * @param $code String: language code to save data for
 724          * @param $data Array: language data forged by recache()
 725          */
 726         protected function saveLangInStore( $code, $data ) {
 727                 wfProfileIn( __METHOD__ );
 728
 729                 if( $this->store instanceof LCStore_Null ) {
 730                         # No point in saving data to /dev/null
 731                         wfProfileOut( __METHOD__ );
 732                         return;
 733                 }
 734
 735                 # Save to the persistent cache
 736                 $this->store->startWrite( $code );
 737                 foreach ( $data as $key => $value ) {
 738                         if ( in_array( $key, self::$splitKeys ) ) {
 739                                 foreach ( $value as $subkey => $subvalue ) {
 740                                         $this->store->set( "$key:$subkey", $subvalue );
 741                                 }
 742                         } else {
 743                                 $this->store->set( $key, $value );
 744                         }
 745                 }
 746                 $this->store->finishWrite();
 747
 748                 # Clear out the MessageBlobStore
 749                 MessageBlobStore::clear();
 750
 751                 wfProfileOut( __METHOD__ );
 752         }
 753
 754         /**
 755          * Build the preload item from the given pre-cache data.
 756          *
 757          * The preload item will be loaded automatically, improving performance
 758          * for the commonly-requested items it contains.
 759          * @param $data
 760          * @return array
 761          */
 762         protected function buildPreload( $data ) {
 763                 $preload = array( 'messages' => array() );
 764                 foreach ( self::$preloadedKeys as $key ) {
 765                         $preload[$key] = $data[$key];
 766                 }
 767
 768                 foreach ( $data['preloadedMessages'] as $subkey ) {
 769                         if ( isset( $data['messages'][$subkey] ) ) {
 770                                 $subitem = $data['messages'][$subkey];
 771                         } else {
 772                                 $subitem = null;
 773                         }
 774                         $preload['messages'][$subkey] = $subitem;
 775                 }
 776
 777                 return $preload;
 778         }
 779
 780         /**
 781          * Unload the data for a given language from the object cache.
 782          * Reduces memory usage.
 783          * @param $code
 784          */
 785         public function unload( $code ) {
 786                 unset( $this->data[$code] );
 787                 unset( $this->loadedItems[$code] );
 788                 unset( $this->loadedSubitems[$code] );
 789                 unset( $this->initialisedLangs[$code] );
 790
 791                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
 792                         if ( $fbCode === $code ) {
 793                                 $this->unload( $shallowCode );
 794                         }
 795                 }
 796         }
 797
 798         /**
 799          * Unload all data
 800          */
 801         public function unloadAll() {
 802                 foreach ( $this->initialisedLangs as $lang => $unused ) {
 803                         $this->unload( $lang );
 804                 }
 805         }
 806
 807         /**
 808          * Disable the storage backend
 809          */
 810         public function disableBackend() {
 811                 $this->store = new LCStore_Null;
 812                 $this->manualRecache = false;
 813         }
 814 }
 815
 816 /**
 817  * Interface for the persistence layer of LocalisationCache.
 818  *
 819  * The persistence layer is two-level hierarchical cache. The first level
 820  * is the language, the second level is the item or subitem.
 821  *
 822  * Since the data for a whole language is rebuilt in one operation, it needs
 823  * to have a fast and atomic method for deleting or replacing all of the
 824  * current data for a given language. The interface reflects this bulk update
 825  * operation. Callers writing to the cache must first call startWrite(), then
 826  * will call set() a couple of thousand times, then will call finishWrite()
 827  * to commit the operation. When finishWrite() is called, the cache is
 828  * expected to delete all data previously stored for that language.
 829  *
 830  * The values stored are PHP variables suitable for serialize(). Implementations
 831  * of LCStore are responsible for serializing and unserializing.
 832  */
 833 interface LCStore {
 834         /**
 835          * Get a value.
 836          * @param $code Language code
 837          * @param $key Cache key
 838          */
 839         function get( $code, $key );
 840
 841         /**
 842          * Start a write transaction.
 843          * @param $code Language code
 844          */
 845         function startWrite( $code );
 846
 847         /**
 848          * Finish a write transaction.
 849          */
 850         function finishWrite();
 851
 852         /**
 853          * Set a key to a given value. startWrite() must be called before this
 854          * is called, and finishWrite() must be called afterwards.
 855          * @param $key
 856          * @param $value
 857          */
 858         function set( $key, $value );
 859 }
 860
 861 /**
 862  * LCStore implementation which uses PHP accelerator to store data.
 863  * This will work if one of XCache, eAccelerator, or APC cacher is configured.
 864  * (See ObjectCache.php)
 865  */
 866 class LCStore_Accel implements LCStore {
 867         var $currentLang;
 868         var $keys;
 869
 870         public function __construct() {
 871                 $this->cache = wfGetCache( CACHE_ACCEL );
 872         }
 873
 874         public function get( $code, $key ) {
 875                 $k = wfMemcKey( 'l10n', $code, 'k', $key );
 876                 $r = $this->cache->get( $k );
 877                 return $r === false ? null : $r;
 878         }
 879
 880         public function startWrite( $code ) {
 881                 $k = wfMemcKey( 'l10n', $code, 'l' );
 882                 $keys = $this->cache->get( $k );
 883                 if ( $keys ) {
 884                         foreach ( $keys as $k ) {
 885                                 $this->cache->delete( $k );
 886                         }
 887                 }
 888                 $this->currentLang = $code;
 889                 $this->keys = array();
 890         }
 891
 892         public function finishWrite() {
 893                 if ( $this->currentLang ) {
 894                         $k = wfMemcKey( 'l10n', $this->currentLang, 'l' );
 895                         $this->cache->set( $k, array_keys( $this->keys ) );
 896                 }
 897                 $this->currentLang = null;
 898                 $this->keys = array();
 899         }
 900
 901         public function set( $key, $value ) {
 902                 if ( $this->currentLang ) {
 903                         $k = wfMemcKey( 'l10n', $this->currentLang, 'k', $key );
 904                         $this->keys[$k] = true;
 905                         $this->cache->set( $k, $value );
 906                 }
 907         }
 908 }
 909
 910 /**
 911  * LCStore implementation which uses the standard DB functions to store data.
 912  * This will work on any MediaWiki installation.
 913  */
 914 class LCStore_DB implements LCStore {
 915         var $currentLang;
 916         var $writesDone = false;
 917
 918         /**
 919          * @var DatabaseBase
 920          */
 921         var $dbw;
 922         var $batch;
 923         var $readOnly = false;
 924
 925         public function get( $code, $key ) {
 926                 if ( $this->writesDone ) {
 927                         $db = wfGetDB( DB_MASTER );
 928                 } else {
 929                         $db = wfGetDB( DB_SLAVE );
 930                 }
 931                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
 932                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
 933                 if ( $row ) {
 934                         return unserialize( $row->lc_value );
 935                 } else {
 936                         return null;
 937                 }
 938         }
 939
 940         public function startWrite( $code ) {
 941                 if ( $this->readOnly ) {
 942                         return;
 943                 }
 944
 945                 if ( !$code ) {
 946                         throw new MWException( __METHOD__.": Invalid language \"$code\"" );
 947                 }
 948
 949                 $this->dbw = wfGetDB( DB_MASTER );
 950                 try {
 951                         $this->dbw->begin();
 952                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
 953                 } catch ( DBQueryError $e ) {
 954                         if ( $this->dbw->wasReadOnlyError() ) {
 955                                 $this->readOnly = true;
 956                                 $this->dbw->rollback();
 957                                 $this->dbw->ignoreErrors( false );
 958                                 return;
 959                         } else {
 960                                 throw $e;
 961                         }
 962                 }
 963
 964                 $this->currentLang = $code;
 965                 $this->batch = array();
 966         }
 967
 968         public function finishWrite() {
 969                 if ( $this->readOnly ) {
 970                         return;
 971                 }
 972
 973                 if ( $this->batch ) {
 974                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
 975                 }
 976
 977                 $this->dbw->commit();
 978                 $this->currentLang = null;
 979                 $this->dbw = null;
 980                 $this->batch = array();
 981                 $this->writesDone = true;
 982         }
 983
 984         public function set( $key, $value ) {
 985                 if ( $this->readOnly ) {
 986                         return;
 987                 }
 988
 989                 if ( is_null( $this->currentLang ) ) {
 990                         throw new MWException( __CLASS__.': must call startWrite() before calling set()' );
 991                 }
 992
 993                 $this->batch[] = array(
 994                         'lc_lang' => $this->currentLang,
 995                         'lc_key' => $key,
 996                         'lc_value' => serialize( $value ) );
 997
 998                 if ( count( $this->batch ) >= 100 ) {
 999                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
1000                         $this->batch = array();
1001                 }
1002         }
1003 }
1004
1005 /**
1006  * LCStore implementation which stores data as a collection of CDB files in the
1007  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
1008  * will throw an exception.
1009  *
1010  * Profiling indicates that on Linux, this implementation outperforms MySQL if
1011  * the directory is on a local filesystem and there is ample kernel cache
1012  * space. The performance advantage is greater when the DBA extension is
1013  * available than it is with the PHP port.
1014  *
1015  * See Cdb.php and http://cr.yp.to/cdb.html
1016  */
1017 class LCStore_CDB implements LCStore {
1018         var $readers, $writer, $currentLang, $directory;
1019
1020         function __construct( $conf = array() ) {
1021                 global $wgCacheDirectory;
1022
1023                 if ( isset( $conf['directory'] ) ) {
1024                         $this->directory = $conf['directory'];
1025                 } else {
1026                         $this->directory = $wgCacheDirectory;
1027                 }
1028         }
1029
1030         public function get( $code, $key ) {
1031                 if ( !isset( $this->readers[$code] ) ) {
1032                         $fileName = $this->getFileName( $code );
1033
1034                         if ( !file_exists( $fileName ) ) {
1035                                 $this->readers[$code] = false;
1036                         } else {
1037                                 $this->readers[$code] = CdbReader::open( $fileName );
1038                         }
1039                 }
1040
1041                 if ( !$this->readers[$code] ) {
1042                         return null;
1043                 } else {
1044                         $value = $this->readers[$code]->get( $key );
1045
1046                         if ( $value === false ) {
1047                                 return null;
1048                         }
1049                         return unserialize( $value );
1050                 }
1051         }
1052
1053         public function startWrite( $code ) {
1054                 if ( !file_exists( $this->directory ) ) {
1055                         if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
1056                                 throw new MWException( "Unable to create the localisation store " .
1057                                         "directory \"{$this->directory}\"" );
1058                         }
1059                 }
1060
1061                 // Close reader to stop permission errors on write
1062                 if( !empty($this->readers[$code]) ) {
1063                         $this->readers[$code]->close();
1064                 }
1065
1066                 $this->writer = CdbWriter::open( $this->getFileName( $code ) );
1067                 $this->currentLang = $code;
1068         }
1069
1070         public function finishWrite() {
1071                 // Close the writer
1072                 $this->writer->close();
1073                 $this->writer = null;
1074                 unset( $this->readers[$this->currentLang] );
1075                 $this->currentLang = null;
1076         }
1077
1078         public function set( $key, $value ) {
1079                 if ( is_null( $this->writer ) ) {
1080                         throw new MWException( __CLASS__.': must call startWrite() before calling set()' );
1081                 }
1082                 $this->writer->set( $key, serialize( $value ) );
1083         }
1084
1085         protected function getFileName( $code ) {
1086                 if ( !$code || strpos( $code, '/' ) !== false ) {
1087                         throw new MWException( __METHOD__.": Invalid language \"$code\"" );
1088                 }
1089                 return "{$this->directory}/l10n_cache-$code.cdb";
1090         }
1091 }
1092
1093 /**
1094  * Null store backend, used to avoid DB errors during install
1095  */
1096 class LCStore_Null implements LCStore {
1097         public function get( $code, $key ) {
1098                 return null;
1099         }
1100
1101         public function startWrite( $code ) {}
1102         public function finishWrite() {}
1103         public function set( $key, $value ) {}
1104 }
1105
1106 /**
1107  * A localisation cache optimised for loading large amounts of data for many
1108  * languages. Used by rebuildLocalisationCache.php.
1109  */
1110 class LocalisationCache_BulkLoad extends LocalisationCache {
1111         /**
1112          * A cache of the contents of data files.
1113          * Core files are serialized to avoid using ~1GB of RAM during a recache.
1114          */
1115         var $fileCache = array();
1116
1117         /**
1118          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
1119          * to keep the most recently used language codes at the end of the array, and
1120          * the language codes that are ready to be deleted at the beginning.
1121          */
1122         var $mruLangs = array();
1123
1124         /**
1125          * Maximum number of languages that may be loaded into $this->data
1126          */
1127         var $maxLoadedLangs = 10;
1128
1129         /**
1130          * @param $fileName
1131          * @param $fileType
1132          * @return array|mixed
1133          */
1134         protected function readPHPFile( $fileName, $fileType ) {
1135                 $serialize = $fileType === 'core';
1136                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
1137                         $data = parent::readPHPFile( $fileName, $fileType );
1138
1139                         if ( $serialize ) {
1140                                 $encData = serialize( $data );
1141                         } else {
1142                                 $encData = $data;
1143                         }
1144
1145                         $this->fileCache[$fileName][$fileType] = $encData;
1146
1147                         return $data;
1148                 } elseif ( $serialize ) {
1149                         return unserialize( $this->fileCache[$fileName][$fileType] );
1150                 } else {
1151                         return $this->fileCache[$fileName][$fileType];
1152                 }
1153         }
1154
1155         /**
1156          * @param $code
1157          * @param $key
1158          * @return mixed
1159          */
1160         public function getItem( $code, $key ) {
1161                 unset( $this->mruLangs[$code] );
1162                 $this->mruLangs[$code] = true;
1163                 return parent::getItem( $code, $key );
1164         }
1165
1166         /**
1167          * @param $code
1168          * @param $key
1169          * @param $subkey
1170          * @return
1171          */
1172         public function getSubitem( $code, $key, $subkey ) {
1173                 unset( $this->mruLangs[$code] );
1174                 $this->mruLangs[$code] = true;
1175                 return parent::getSubitem( $code, $key, $subkey );
1176         }
1177
1178         /**
1179          * @param $code
1180          */
1181         public function recache( $code ) {
1182                 parent::recache( $code );
1183                 unset( $this->mruLangs[$code] );
1184                 $this->mruLangs[$code] = true;
1185                 $this->trimCache();
1186         }
1187
1188         /**
1189          * @param $code
1190          */
1191         public function unload( $code ) {
1192                 unset( $this->mruLangs[$code] );
1193                 parent::unload( $code );
1194         }
1195
1196         /**
1197          * Unload cached languages until there are less than $this->maxLoadedLangs
1198          */
1199         protected function trimCache() {
1200                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1201                         reset( $this->mruLangs );
1202                         $code = key( $this->mruLangs );
1203                         wfDebug( __METHOD__.": unloading $code\n" );
1204                         $this->unload( $code );
1205                 }
1206         }
1207 }