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                 'defaultUserOptionOverrides', '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', 'defaultUserOptionOverrides', 'imageFiles',
  99                 'preloadedMessages',
 100         );
 101
 102         /**
 103          * Keys for items which are a numbered array.
 104          */
 105         static public $mergeableListKeys = array( 'extraUserToggles' );
 106
 107         /**
 108          * Keys for items which contain an array of arrays of equivalent aliases
 109          * for each subitem. The aliases may be merged by a fallback sequence.
 110          */
 111         static public $mergeableAliasListKeys = array( 'specialPageAliases' );
 112
 113         /**
 114          * Keys for items which contain an associative array, and may be merged if
 115          * the primary value contains the special array key "inherit". That array
 116          * key is removed after the first merge.
 117          */
 118         static public $optionalMergeKeys = array( 'bookstoreList' );
 119
 120         /**
 121          * Keys for items that are formatted like $magicWords
 122          */
 123         static public $magicWordKeys = array( 'magicWords' );
 124
 125         /**
 126          * Keys for items where the subitems are stored in the backend separately.
 127          */
 128         static public $splitKeys = array( 'messages' );
 129
 130         /**
 131          * Keys which are loaded automatically by initLanguage()
 132          */
 133         static public $preloadedKeys = array( 'dateFormats', 'namespaceNames',
 134                 'defaultUserOptionOverrides' );
 135
 136         /**
 137          * Constructor.
 138          * For constructor parameters, see the documentation in DefaultSettings.php
 139          * for $wgLocalisationCacheConf.
 140          *
 141          * @param $conf Array
 142          */
 143         function __construct( $conf ) {
 144                 global $wgCacheDirectory;
 145
 146                 $this->conf = $conf;
 147                 $storeConf = array();
 148                 if ( !empty( $conf['storeClass'] ) ) {
 149                         $storeClass = $conf['storeClass'];
 150                 } else {
 151                         switch ( $conf['store'] ) {
 152                                 case 'files':
 153                                 case 'file':
 154                                         $storeClass = 'LCStore_CDB';
 155                                         break;
 156                                 case 'db':
 157                                         $storeClass = 'LCStore_DB';
 158                                         break;
 159                                 case 'detect':
 160                                         $storeClass = $wgCacheDirectory ? 'LCStore_CDB' : 'LCStore_DB';
 161                                         break;
 162                                 default:
 163                                         throw new MWException(
 164                                                 'Please set $wgLocalisationCacheConf[\'store\'] to something sensible.' );
 165                         }
 166                 }
 167
 168                 wfDebug( get_class( $this ) . ": using store $storeClass\n" );
 169                 if ( !empty( $conf['storeDirectory'] ) ) {
 170                         $storeConf['directory'] = $conf['storeDirectory'];
 171                 }
 172
 173                 $this->store = new $storeClass( $storeConf );
 174                 foreach ( array( 'manualRecache', 'forceRecache' ) as $var ) {
 175                         if ( isset( $conf[$var] ) ) {
 176                                 $this->$var = $conf[$var];
 177                         }
 178                 }
 179         }
 180
 181         /**
 182          * Returns true if the given key is mergeable, that is, if it is an associative
 183          * array which can be merged through a fallback sequence.
 184          */
 185         public function isMergeableKey( $key ) {
 186                 if ( !isset( $this->mergeableKeys ) ) {
 187                         $this->mergeableKeys = array_flip( array_merge(
 188                                 self::$mergeableMapKeys,
 189                                 self::$mergeableListKeys,
 190                                 self::$mergeableAliasListKeys,
 191                                 self::$optionalMergeKeys,
 192                                 self::$magicWordKeys
 193                         ) );
 194                 }
 195                 return isset( $this->mergeableKeys[$key] );
 196         }
 197
 198         /**
 199          * Get a cache item.
 200          *
 201          * Warning: this may be slow for split items (messages), since it will
 202          * need to fetch all of the subitems from the cache individually.
 203          */
 204         public function getItem( $code, $key ) {
 205                 if ( !isset( $this->loadedItems[$code][$key] ) ) {
 206                         wfProfileIn( __METHOD__.'-load' );
 207                         $this->loadItem( $code, $key );
 208                         wfProfileOut( __METHOD__.'-load' );
 209                 }
 210                 if ( $key === 'fallback' && isset( $this->shallowFallbacks[$code] ) ) {
 211                         return $this->shallowFallbacks[$code];
 212                 }
 213                 return $this->data[$code][$key];
 214         }
 215
 216         /**
 217          * Get a subitem, for instance a single message for a given language.
 218          */
 219         public function getSubitem( $code, $key, $subkey ) {
 220                 if ( !isset( $this->loadedSubitems[$code][$key][$subkey] )
 221                         && !isset( $this->loadedItems[$code][$key] ) )
 222                 {
 223                         wfProfileIn( __METHOD__.'-load' );
 224                         $this->loadSubitem( $code, $key, $subkey );
 225                         wfProfileOut( __METHOD__.'-load' );
 226                 }
 227                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 228                         return $this->data[$code][$key][$subkey];
 229                 } else {
 230                         return null;
 231                 }
 232         }
 233
 234         /**
 235          * Get the list of subitem keys for a given item.
 236          *
 237          * This is faster than array_keys($lc->getItem(...)) for the items listed in
 238          * self::$splitKeys.
 239          *
 240          * Will return null if the item is not found, or false if the item is not an
 241          * array.
 242          */
 243         public function getSubitemList( $code, $key ) {
 244                 if ( in_array( $key, self::$splitKeys ) ) {
 245                         return $this->getSubitem( $code, 'list', $key );
 246                 } else {
 247                         $item = $this->getItem( $code, $key );
 248                         if ( is_array( $item ) ) {
 249                                 return array_keys( $item );
 250                         } else {
 251                                 return false;
 252                         }
 253                 }
 254         }
 255
 256         /**
 257          * Load an item into the cache.
 258          */
 259         protected function loadItem( $code, $key ) {
 260                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 261                         $this->initLanguage( $code );
 262                 }
 263                 // Check to see if initLanguage() loaded it for us
 264                 if ( isset( $this->loadedItems[$code][$key] ) ) {
 265                         return;
 266                 }
 267                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 268                         $this->loadItem( $this->shallowFallbacks[$code], $key );
 269                         return;
 270                 }
 271                 if ( in_array( $key, self::$splitKeys ) ) {
 272                         $subkeyList = $this->getSubitem( $code, 'list', $key );
 273                         foreach ( $subkeyList as $subkey ) {
 274                                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 275                                         continue;
 276                                 }
 277                                 $this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
 278                         }
 279                 } else {
 280                         $this->data[$code][$key] = $this->store->get( $code, $key );
 281                 }
 282                 $this->loadedItems[$code][$key] = true;
 283         }
 284
 285         /**
 286          * Load a subitem into the cache
 287          */
 288         protected function loadSubitem( $code, $key, $subkey ) {
 289                 if ( !in_array( $key, self::$splitKeys ) ) {
 290                         $this->loadItem( $code, $key );
 291                         return;
 292                 }
 293                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 294                         $this->initLanguage( $code );
 295                 }
 296                 // Check to see if initLanguage() loaded it for us
 297                 if ( isset( $this->loadedItems[$code][$key] )
 298                         || isset( $this->loadedSubitems[$code][$key][$subkey] ) )
 299                 {
 300                         return;
 301                 }
 302                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 303                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 304                         return;
 305                 }
 306                 $value = $this->store->get( $code, "$key:$subkey" );
 307                 $this->data[$code][$key][$subkey] = $value;
 308                 $this->loadedSubitems[$code][$key][$subkey] = true;
 309         }
 310
 311         /**
 312          * Returns true if the cache identified by $code is missing or expired.
 313          */
 314         public function isExpired( $code ) {
 315                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 316                         wfDebug( __METHOD__."($code): forced reload\n" );
 317                         return true;
 318                 }
 319
 320                 $deps = $this->store->get( $code, 'deps' );
 321                 if ( $deps === null ) {
 322                         wfDebug( __METHOD__."($code): cache missing, need to make one\n" );
 323                         return true;
 324                 }
 325                 foreach ( $deps as $dep ) {
 326                         // Because we're unserializing stuff from cache, we
 327                         // could receive objects of classes that don't exist
 328                         // anymore (e.g. uninstalled extensions)
 329                         // When this happens, always expire the cache
 330                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 331                                 wfDebug( __METHOD__."($code): cache for $code expired due to " .
 332                                         get_class( $dep ) . "\n" );
 333                                 return true;
 334                         }
 335                 }
 336                 return false;
 337         }
 338
 339         /**
 340          * Initialise a language in this object. Rebuild the cache if necessary.
 341          */
 342         protected function initLanguage( $code ) {
 343                 if ( isset( $this->initialisedLangs[$code] ) ) {
 344                         return;
 345                 }
 346                 $this->initialisedLangs[$code] = true;
 347
 348                 # If the code is of the wrong form for a Messages*.php file, do a shallow fallback
 349                 if ( !Language::isValidBuiltInCode( $code ) ) {
 350                         $this->initShallowFallback( $code, 'en' );
 351                         return;
 352                 }
 353
 354                 # Recache the data if necessary
 355                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 356                         if ( file_exists( Language::getMessagesFileName( $code ) ) ) {
 357                                 $this->recache( $code );
 358                         } elseif ( $code === 'en' ) {
 359                                 throw new MWException( 'MessagesEn.php is missing.' );
 360                         } else {
 361                                 $this->initShallowFallback( $code, 'en' );
 362                         }
 363                         return;
 364                 }
 365
 366                 # Preload some stuff
 367                 $preload = $this->getItem( $code, 'preload' );
 368                 if ( $preload === null ) {
 369                         if ( $this->manualRecache ) {
 370                                 // No Messages*.php file. Do shallow fallback to en.
 371                                 if ( $code === 'en' ) {
 372                                         throw new MWException( 'No localisation cache found for English. ' .
 373                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 374                                 }
 375                                 $this->initShallowFallback( $code, 'en' );
 376                                 return;
 377                         } else {
 378                                 throw new MWException( 'Invalid or missing localisation cache.' );
 379                         }
 380                 }
 381                 $this->data[$code] = $preload;
 382                 foreach ( $preload as $key => $item ) {
 383                         if ( in_array( $key, self::$splitKeys ) ) {
 384                                 foreach ( $item as $subkey => $subitem ) {
 385                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 386                                 }
 387                         } else {
 388                                 $this->loadedItems[$code][$key] = true;
 389                         }
 390                 }
 391         }
 392
 393         /**
 394          * Create a fallback from one language to another, without creating a
 395          * complete persistent cache.
 396          */
 397         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 398                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 399                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 400                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 401                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 402         }
 403
 404         /**
 405          * Read a PHP file containing localisation data.
 406          */
 407         protected function readPHPFile( $_fileName, $_fileType ) {
 408                 // Disable APC caching
 409                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 410                 include( $_fileName );
 411                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 412
 413                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 414                         $data = compact( self::$allKeys );
 415                 } elseif ( $_fileType == 'aliases' ) {
 416                         $data = compact( 'aliases' );
 417                 } else {
 418                         throw new MWException( __METHOD__.": Invalid file type: $_fileType" );
 419                 }
 420                 return $data;
 421         }
 422
 423         /**
 424          * Merge two localisation values, a primary and a fallback, overwriting the
 425          * primary value in place.
 426          */
 427         protected function mergeItem( $key, &$value, $fallbackValue ) {
 428                 if ( !is_null( $value ) ) {
 429                         if ( !is_null( $fallbackValue ) ) {
 430                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 431                                         $value = $value + $fallbackValue;
 432                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 433                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 434                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 435                                         $value = array_merge_recursive( $value, $fallbackValue );
 436                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 437                                         if ( !empty( $value['inherit'] ) )  {
 438                                                 $value = array_merge( $fallbackValue, $value );
 439                                         }
 440                                         if ( isset( $value['inherit'] ) ) {
 441                                                 unset( $value['inherit'] );
 442                                         }
 443                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 444                                         $this->mergeMagicWords( $value, $fallbackValue );
 445                                 }
 446                         }
 447                 } else {
 448                         $value = $fallbackValue;
 449                 }
 450         }
 451
 452         protected function mergeMagicWords( &$value, $fallbackValue ) {
 453                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 454                         if ( !isset( $value[$magicName] ) ) {
 455                                 $value[$magicName] = $fallbackInfo;
 456                         } else {
 457                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 458                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 459                                 $synonyms = array_values( array_unique( array_merge(
 460                                         $newSynonyms, $oldSynonyms ) ) );
 461                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 462                         }
 463                 }
 464         }
 465
 466         /**
 467          * Given an array mapping language code to localisation value, such as is
 468          * found in extension *.i18n.php files, iterate through a fallback sequence
 469          * to merge the given data with an existing primary value.
 470          *
 471          * Returns true if any data from the extension array was used, false
 472          * otherwise.
 473          */
 474         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 475                 $used = false;
 476                 foreach ( $codeSequence as $code ) {
 477                         if ( isset( $fallbackValue[$code] ) ) {
 478                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 479                                 $used = true;
 480                         }
 481                 }
 482                 return $used;
 483         }
 484
 485         /**
 486          * Load localisation data for a given language for both core and extensions
 487          * and save it to the persistent cache store and the process cache
 488          */
 489         public function recache( $code ) {
 490                 static $recursionGuard = array();
 491                 global $wgExtensionMessagesFiles, $wgExtensionAliasesFiles;
 492                 wfProfileIn( __METHOD__ );
 493
 494                 if ( !$code ) {
 495                         throw new MWException( "Invalid language code requested" );
 496                 }
 497                 $this->recachedLangs[$code] = true;
 498
 499                 # Initial values
 500                 $initialData = array_combine(
 501                         self::$allKeys,
 502                         array_fill( 0, count( self::$allKeys ), null ) );
 503                 $coreData = $initialData;
 504                 $deps = array();
 505
 506                 # Load the primary localisation from the source file
 507                 $fileName = Language::getMessagesFileName( $code );
 508                 if ( !file_exists( $fileName ) ) {
 509                         wfDebug( __METHOD__.": no localisation file for $code, using fallback to en\n" );
 510                         $coreData['fallback'] = 'en';
 511                 } else {
 512                         $deps[] = new FileDependency( $fileName );
 513                         $data = $this->readPHPFile( $fileName, 'core' );
 514                         wfDebug( __METHOD__.": got localisation for $code from source\n" );
 515
 516                         # Merge primary localisation
 517                         foreach ( $data as $key => $value ) {
 518                                 $this->mergeItem( $key, $coreData[$key], $value );
 519                         }
 520                 }
 521
 522                 # Fill in the fallback if it's not there already
 523                 if ( is_null( $coreData['fallback'] ) ) {
 524                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 525                 }
 526
 527                 if ( $coreData['fallback'] !== false ) {
 528                         # Guard against circular references
 529                         if ( isset( $recursionGuard[$code] ) ) {
 530                                 throw new MWException( "Error: Circular fallback reference in language code $code" );
 531                         }
 532                         $recursionGuard[$code] = true;
 533
 534                         # Load the fallback localisation item by item and merge it
 535                         $deps = array_merge( $deps, $this->getItem( $coreData['fallback'], 'deps' ) );
 536                         foreach ( self::$allKeys as $key ) {
 537                                 if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 538                                         $fallbackValue = $this->getItem( $coreData['fallback'], $key );
 539                                         $this->mergeItem( $key, $coreData[$key], $fallbackValue );
 540                                 }
 541                         }
 542                         $fallbackSequence = $this->getItem( $coreData['fallback'], 'fallbackSequence' );
 543                         array_unshift( $fallbackSequence, $coreData['fallback'] );
 544                         $coreData['fallbackSequence'] = $fallbackSequence;
 545                         unset( $recursionGuard[$code] );
 546                 } else {
 547                         $coreData['fallbackSequence'] = array();
 548                 }
 549                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 550
 551                 # Load the extension localisations
 552                 # This is done after the core because we know the fallback sequence now.
 553                 # But it has a higher precedence for merging so that we can support things
 554                 # like site-specific message overrides.
 555                 $allData = $initialData;
 556                 foreach ( $wgExtensionMessagesFiles as $fileName ) {
 557                         $data = $this->readPHPFile( $fileName, 'extension' );
 558                         $used = false;
 559                         foreach ( $data as $key => $item ) {
 560                                 if( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 561                                         $used = true;
 562                                 }
 563                         }
 564                         if ( $used ) {
 565                                 $deps[] = new FileDependency( $fileName );
 566                         }
 567                 }
 568
 569                 # Load deprecated $wgExtensionAliasesFiles
 570                 foreach ( $wgExtensionAliasesFiles as $fileName ) {
 571                         $data = $this->readPHPFile( $fileName, 'aliases' );
 572                         if ( !isset( $data['aliases'] ) ) {
 573                                 continue;
 574                         }
 575                         $used = $this->mergeExtensionItem( $codeSequence, 'specialPageAliases',
 576                                 $allData['specialPageAliases'], $data['aliases'] );
 577                         if ( $used ) {
 578                                 $deps[] = new FileDependency( $fileName );
 579                         }
 580                 }
 581
 582                 # Merge core data into extension data
 583                 foreach ( $coreData as $key => $item ) {
 584                         $this->mergeItem( $key, $allData[$key], $item );
 585                 }
 586
 587                 # Add cache dependencies for any referenced globals
 588                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 589                 $deps['wgExtensionAliasesFiles'] = new GlobalDependency( 'wgExtensionAliasesFiles' );
 590                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 591
 592                 # Add dependencies to the cache entry
 593                 $allData['deps'] = $deps;
 594
 595                 # Replace spaces with underscores in namespace names
 596                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 597
 598                 # And do the same for special page aliases. $page is an array.
 599                 foreach ( $allData['specialPageAliases'] as &$page ) {
 600                         $page = str_replace( ' ', '_', $page );
 601                 }
 602                 # Decouple the reference to prevent accidental damage
 603                 unset($page);
 604
 605                 # Fix broken defaultUserOptionOverrides
 606                 if ( !is_array( $allData['defaultUserOptionOverrides'] ) ) {
 607                         $allData['defaultUserOptionOverrides'] = array();
 608                 }
 609
 610                 # Set the list keys
 611                 $allData['list'] = array();
 612                 foreach ( self::$splitKeys as $key ) {
 613                         $allData['list'][$key] = array_keys( $allData[$key] );
 614                 }
 615
 616                 # Run hooks
 617                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData ) );
 618
 619                 if ( is_null( $allData['defaultUserOptionOverrides'] ) ) {
 620                         throw new MWException( __METHOD__.': Localisation data failed sanity check! ' .
 621                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 622                 }
 623
 624                 # Set the preload key
 625                 $allData['preload'] = $this->buildPreload( $allData );
 626
 627                 # Save to the process cache and register the items loaded
 628                 $this->data[$code] = $allData;
 629                 foreach ( $allData as $key => $item ) {
 630                         $this->loadedItems[$code][$key] = true;
 631                 }
 632
 633                 # Save to the persistent cache
 634                 $this->store->startWrite( $code );
 635                 foreach ( $allData as $key => $value ) {
 636                         if ( in_array( $key, self::$splitKeys ) ) {
 637                                 foreach ( $value as $subkey => $subvalue ) {
 638                                         $this->store->set( "$key:$subkey", $subvalue );
 639                                 }
 640                         } else {
 641                                 $this->store->set( $key, $value );
 642                         }
 643                 }
 644                 $this->store->finishWrite();
 645
 646                 # Clear out the MessageBlobStore
 647                 # HACK: If using a null (i.e. disabled) storage backend, we
 648                 # can't write to the MessageBlobStore either
 649                 if ( !$this->store instanceof LCStore_Null ) {
 650                         MessageBlobStore::clear();
 651                 }
 652
 653                 wfProfileOut( __METHOD__ );
 654         }
 655
 656         /**
 657          * Build the preload item from the given pre-cache data.
 658          *
 659          * The preload item will be loaded automatically, improving performance
 660          * for the commonly-requested items it contains.
 661          */
 662         protected function buildPreload( $data ) {
 663                 $preload = array( 'messages' => array() );
 664                 foreach ( self::$preloadedKeys as $key ) {
 665                         $preload[$key] = $data[$key];
 666                 }
 667                 foreach ( $data['preloadedMessages'] as $subkey ) {
 668                         if ( isset( $data['messages'][$subkey] ) ) {
 669                                 $subitem = $data['messages'][$subkey];
 670                         } else {
 671                                 $subitem = null;
 672                         }
 673                         $preload['messages'][$subkey] = $subitem;
 674                 }
 675                 return $preload;
 676         }
 677
 678         /**
 679          * Unload the data for a given language from the object cache.
 680          * Reduces memory usage.
 681          */
 682         public function unload( $code ) {
 683                 unset( $this->data[$code] );
 684                 unset( $this->loadedItems[$code] );
 685                 unset( $this->loadedSubitems[$code] );
 686                 unset( $this->initialisedLangs[$code] );
 687                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
 688                         if ( $fbCode === $code ) {
 689                                 $this->unload( $shallowCode );
 690                         }
 691                 }
 692         }
 693
 694         /**
 695          * Unload all data
 696          */
 697         public function unloadAll() {
 698                 foreach ( $this->initialisedLangs as $lang => $unused ) {
 699                         $this->unload( $lang );
 700                 }
 701         }
 702
 703         /**
 704          * Disable the storage backend
 705          */
 706         public function disableBackend() {
 707                 $this->store = new LCStore_Null;
 708                 $this->manualRecache = false;
 709         }
 710 }
 711
 712 /**
 713  * Interface for the persistence layer of LocalisationCache.
 714  *
 715  * The persistence layer is two-level hierarchical cache. The first level
 716  * is the language, the second level is the item or subitem.
 717  *
 718  * Since the data for a whole language is rebuilt in one operation, it needs
 719  * to have a fast and atomic method for deleting or replacing all of the
 720  * current data for a given language. The interface reflects this bulk update
 721  * operation. Callers writing to the cache must first call startWrite(), then
 722  * will call set() a couple of thousand times, then will call finishWrite()
 723  * to commit the operation. When finishWrite() is called, the cache is
 724  * expected to delete all data previously stored for that language.
 725  *
 726  * The values stored are PHP variables suitable for serialize(). Implementations
 727  * of LCStore are responsible for serializing and unserializing.
 728  */
 729 interface LCStore {
 730         /**
 731          * Get a value.
 732          * @param $code Language code
 733          * @param $key Cache key
 734          */
 735         function get( $code, $key );
 736
 737         /**
 738          * Start a write transaction.
 739          * @param $code Language code
 740          */
 741         function startWrite( $code );
 742
 743         /**
 744          * Finish a write transaction.
 745          */
 746         function finishWrite();
 747
 748         /**
 749          * Set a key to a given value. startWrite() must be called before this
 750          * is called, and finishWrite() must be called afterwards.
 751          */
 752         function set( $key, $value );
 753
 754 }
 755
 756 /**
 757  * LCStore implementation which uses the standard DB functions to store data.
 758  * This will work on any MediaWiki installation.
 759  */
 760 class LCStore_DB implements LCStore {
 761         var $currentLang;
 762         var $writesDone = false;
 763         var $dbw, $batch;
 764         var $readOnly = false;
 765
 766         public function get( $code, $key ) {
 767                 if ( $this->writesDone ) {
 768                         $db = wfGetDB( DB_MASTER );
 769                 } else {
 770                         $db = wfGetDB( DB_SLAVE );
 771                 }
 772                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
 773                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
 774                 if ( $row ) {
 775                         return unserialize( $row->lc_value );
 776                 } else {
 777                         return null;
 778                 }
 779         }
 780
 781         public function startWrite( $code ) {
 782                 if ( $this->readOnly ) {
 783                         return;
 784                 }
 785                 if ( !$code ) {
 786                         throw new MWException( __METHOD__.": Invalid language \"$code\"" );
 787                 }
 788                 $this->dbw = wfGetDB( DB_MASTER );
 789                 try {
 790                         $this->dbw->begin();
 791                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
 792                 } catch ( DBQueryError $e ) {
 793                         if ( $this->dbw->wasReadOnlyError() ) {
 794                                 $this->readOnly = true;
 795                                 $this->dbw->rollback();
 796                                 $this->dbw->ignoreErrors( false );
 797                                 return;
 798                         } else {
 799                                 throw $e;
 800                         }
 801                 }
 802                 $this->currentLang = $code;
 803                 $this->batch = array();
 804         }
 805
 806         public function finishWrite() {
 807                 if ( $this->readOnly ) {
 808                         return;
 809                 }
 810                 if ( $this->batch ) {
 811                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
 812                 }
 813                 $this->dbw->commit();
 814                 $this->currentLang = null;
 815                 $this->dbw = null;
 816                 $this->batch = array();
 817                 $this->writesDone = true;
 818         }
 819
 820         public function set( $key, $value ) {
 821                 if ( $this->readOnly ) {
 822                         return;
 823                 }
 824                 if ( is_null( $this->currentLang ) ) {
 825                         throw new MWException( __CLASS__.': must call startWrite() before calling set()' );
 826                 }
 827                 $this->batch[] = array(
 828                         'lc_lang' => $this->currentLang,
 829                         'lc_key' => $key,
 830                         'lc_value' => serialize( $value ) );
 831                 if ( count( $this->batch ) >= 100 ) {
 832                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
 833                         $this->batch = array();
 834                 }
 835         }
 836 }
 837
 838 /**
 839  * LCStore implementation which stores data as a collection of CDB files in the
 840  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
 841  * will throw an exception.
 842  *
 843  * Profiling indicates that on Linux, this implementation outperforms MySQL if
 844  * the directory is on a local filesystem and there is ample kernel cache
 845  * space. The performance advantage is greater when the DBA extension is
 846  * available than it is with the PHP port.
 847  *
 848  * See Cdb.php and http://cr.yp.to/cdb.html
 849  */
 850 class LCStore_CDB implements LCStore {
 851         var $readers, $writer, $currentLang, $directory;
 852
 853         function __construct( $conf = array() ) {
 854                 global $wgCacheDirectory;
 855                 if ( isset( $conf['directory'] ) ) {
 856                         $this->directory = $conf['directory'];
 857                 } else {
 858                         $this->directory = $wgCacheDirectory;
 859                 }
 860         }
 861
 862         public function get( $code, $key ) {
 863                 if ( !isset( $this->readers[$code] ) ) {
 864                         $fileName = $this->getFileName( $code );
 865                         if ( !file_exists( $fileName ) ) {
 866                                 $this->readers[$code] = false;
 867                         } else {
 868                                 $this->readers[$code] = CdbReader::open( $fileName );
 869                         }
 870                 }
 871                 if ( !$this->readers[$code] ) {
 872                         return null;
 873                 } else {
 874                         $value = $this->readers[$code]->get( $key );
 875                         if ( $value === false ) {
 876                                 return null;
 877                         }
 878                         return unserialize( $value );
 879                 }
 880         }
 881
 882         public function startWrite( $code ) {
 883                 if ( !file_exists( $this->directory ) ) {
 884                         if ( !wfMkdirParents( $this->directory ) ) {
 885                                 throw new MWException( "Unable to create the localisation store " .
 886                                         "directory \"{$this->directory}\"" );
 887                         }
 888                 }
 889                 // Close reader to stop permission errors on write
 890                 if( !empty($this->readers[$code]) ) {
 891                         $this->readers[$code]->close();
 892                 }
 893                 $this->writer = CdbWriter::open( $this->getFileName( $code ) );
 894                 $this->currentLang = $code;
 895         }
 896
 897         public function finishWrite() {
 898                 // Close the writer
 899                 $this->writer->close();
 900                 $this->writer = null;
 901                 unset( $this->readers[$this->currentLang] );
 902                 $this->currentLang = null;
 903         }
 904
 905         public function set( $key, $value ) {
 906                 if ( is_null( $this->writer ) ) {
 907                         throw new MWException( __CLASS__.': must call startWrite() before calling set()' );
 908                 }
 909                 $this->writer->set( $key, serialize( $value ) );
 910         }
 911
 912         protected function getFileName( $code ) {
 913                 if ( !$code || strpos( $code, '/' ) !== false ) {
 914                         throw new MWException( __METHOD__.": Invalid language \"$code\"" );
 915                 }
 916                 return "{$this->directory}/l10n_cache-$code.cdb";
 917         }
 918 }
 919
 920 /**
 921  * Null store backend, used to avoid DB errors during install
 922  */
 923 class LCStore_Null implements LCStore {
 924         public function get( $code, $key ) {
 925                 return null;
 926         }
 927
 928         public function startWrite( $code ) {}
 929         public function finishWrite() {}
 930         public function set( $key, $value ) {}
 931 }
 932
 933 /**
 934  * A localisation cache optimised for loading large amounts of data for many
 935  * languages. Used by rebuildLocalisationCache.php.
 936  */
 937 class LocalisationCache_BulkLoad extends LocalisationCache {
 938         /**
 939          * A cache of the contents of data files.
 940          * Core files are serialized to avoid using ~1GB of RAM during a recache.
 941          */
 942         var $fileCache = array();
 943
 944         /**
 945          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
 946          * to keep the most recently used language codes at the end of the array, and
 947          * the language codes that are ready to be deleted at the beginning.
 948          */
 949         var $mruLangs = array();
 950
 951         /**
 952          * Maximum number of languages that may be loaded into $this->data
 953          */
 954         var $maxLoadedLangs = 10;
 955
 956         protected function readPHPFile( $fileName, $fileType ) {
 957                 $serialize = $fileType === 'core';
 958                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
 959                         $data = parent::readPHPFile( $fileName, $fileType );
 960                         if ( $serialize ) {
 961                                 $encData = serialize( $data );
 962                         } else {
 963                                 $encData = $data;
 964                         }
 965                         $this->fileCache[$fileName][$fileType] = $encData;
 966                         return $data;
 967                 } elseif ( $serialize ) {
 968                         return unserialize( $this->fileCache[$fileName][$fileType] );
 969                 } else {
 970                         return $this->fileCache[$fileName][$fileType];
 971                 }
 972         }
 973
 974         public function getItem( $code, $key ) {
 975                 unset( $this->mruLangs[$code] );
 976                 $this->mruLangs[$code] = true;
 977                 return parent::getItem( $code, $key );
 978         }
 979
 980         public function getSubitem( $code, $key, $subkey ) {
 981                 unset( $this->mruLangs[$code] );
 982                 $this->mruLangs[$code] = true;
 983                 return parent::getSubitem( $code, $key, $subkey );
 984         }
 985
 986         public function recache( $code ) {
 987                 parent::recache( $code );
 988                 unset( $this->mruLangs[$code] );
 989                 $this->mruLangs[$code] = true;
 990                 $this->trimCache();
 991         }
 992
 993         public function unload( $code ) {
 994                 unset( $this->mruLangs[$code] );
 995                 parent::unload( $code );
 996         }
 997
 998         /**
 999          * Unload cached languages until there are less than $this->maxLoadedLangs
1000          */
1001         protected function trimCache() {
1002                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1003                         reset( $this->mruLangs );
1004                         $code = key( $this->mruLangs );
1005                         wfDebug( __METHOD__.": unloading $code\n" );
1006                         $this->unload( $code );
1007                 }
1008         }
1009 }