includes/LocalisationCache.php

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