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', 'mathNames', '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', 'mathNames',
  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         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                 # Recache the data if necessary
 347                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 348                         if ( file_exists( Language::getMessagesFileName( $code ) ) ) {
 349                                 $this->recache( $code );
 350                         } elseif ( $code === 'en' ) {
 351                                 throw new MWException( 'MessagesEn.php is missing.' );
 352                         } else {
 353                                 $this->initShallowFallback( $code, 'en' );
 354                         }
 355                         return;
 356                 }
 357
 358                 # Preload some stuff
 359                 $preload = $this->getItem( $code, 'preload' );
 360                 if ( $preload === null ) {
 361                         if ( $this->manualRecache ) {
 362                                 // No Messages*.php file. Do shallow fallback to en.
 363                                 if ( $code === 'en' ) {
 364                                         throw new MWException( 'No localisation cache found for English. ' .
 365                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 366                                 }
 367                                 $this->initShallowFallback( $code, 'en' );
 368                                 return;
 369                         } else {
 370                                 throw new MWException( 'Invalid or missing localisation cache.' );
 371                         }
 372                 }
 373                 $this->data[$code] = $preload;
 374                 foreach ( $preload as $key => $item ) {
 375                         if ( in_array( $key, self::$splitKeys ) ) {
 376                                 foreach ( $item as $subkey => $subitem ) {
 377                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 378                                 }
 379                         } else {
 380                                 $this->loadedItems[$code][$key] = true;
 381                         }
 382                 }
 383         }
 384
 385         /**
 386          * Create a fallback from one language to another, without creating a
 387          * complete persistent cache.
 388          */
 389         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 390                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 391                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 392                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 393                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 394         }
 395
 396         /**
 397          * Read a PHP file containing localisation data.
 398          */
 399         protected function readPHPFile( $_fileName, $_fileType ) {
 400                 // Disable APC caching
 401                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 402                 include( $_fileName );
 403                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 404
 405                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 406                         $data = compact( self::$allKeys );
 407                 } elseif ( $_fileType == 'aliases' ) {
 408                         $data = compact( 'aliases' );
 409                 } else {
 410                         throw new MWException( __METHOD__.": Invalid file type: $_fileType" );
 411                 }
 412                 return $data;
 413         }
 414
 415         /**
 416          * Merge two localisation values, a primary and a fallback, overwriting the
 417          * primary value in place.
 418          */
 419         protected function mergeItem( $key, &$value, $fallbackValue ) {
 420                 if ( !is_null( $value ) ) {
 421                         if ( !is_null( $fallbackValue ) ) {
 422                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 423                                         $value = $value + $fallbackValue;
 424                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 425                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 426                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 427                                         $value = array_merge_recursive( $value, $fallbackValue );
 428                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 429                                         if ( !empty( $value['inherit'] ) )  {
 430                                                 $value = array_merge( $fallbackValue, $value );
 431                                         }
 432                                         if ( isset( $value['inherit'] ) ) {
 433                                                 unset( $value['inherit'] );
 434                                         }
 435                                 } elseif ( in_array( $key, self::$magicWordKeys ) ) {
 436                                         $this->mergeMagicWords( $value, $fallbackValue );
 437                                 }
 438                         }
 439                 } else {
 440                         $value = $fallbackValue;
 441                 }
 442         }
 443
 444         protected function mergeMagicWords( &$value, $fallbackValue ) {
 445                 foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
 446                         if ( !isset( $value[$magicName] ) ) {
 447                                 $value[$magicName] = $fallbackInfo;
 448                         } else {
 449                                 $oldSynonyms = array_slice( $fallbackInfo, 1 );
 450                                 $newSynonyms = array_slice( $value[$magicName], 1 );
 451                                 $synonyms = array_unique( array_merge( $oldSynonyms, $newSynonyms ) );
 452                                 $value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
 453                         }
 454                 }
 455         }
 456
 457         /**
 458          * Given an array mapping language code to localisation value, such as is
 459          * found in extension *.i18n.php files, iterate through a fallback sequence
 460          * to merge the given data with an existing primary value.
 461          *
 462          * Returns true if any data from the extension array was used, false
 463          * otherwise.
 464          */
 465         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 466                 $used = false;
 467                 foreach ( $codeSequence as $code ) {
 468                         if ( isset( $fallbackValue[$code] ) ) {
 469                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 470                                 $used = true;
 471                         }
 472                 }
 473                 return $used;
 474         }
 475
 476         /**
 477          * Load localisation data for a given language for both core and extensions
 478          * and save it to the persistent cache store and the process cache
 479          */
 480         public function recache( $code ) {
 481                 static $recursionGuard = array();
 482                 global $wgExtensionMessagesFiles, $wgExtensionAliasesFiles;
 483                 wfProfileIn( __METHOD__ );
 484
 485                 if ( !$code ) {
 486                         throw new MWException( "Invalid language code requested" );
 487                 }
 488                 $this->recachedLangs[$code] = true;
 489
 490                 # Initial values
 491                 $initialData = array_combine(
 492                         self::$allKeys,
 493                         array_fill( 0, count( self::$allKeys ), null ) );
 494                 $coreData = $initialData;
 495                 $deps = array();
 496
 497                 # Load the primary localisation from the source file
 498                 $fileName = Language::getMessagesFileName( $code );
 499                 if ( !file_exists( $fileName ) ) {
 500                         wfDebug( __METHOD__.": no localisation file for $code, using fallback to en\n" );
 501                         $coreData['fallback'] = 'en';
 502                 } else {
 503                         $deps[] = new FileDependency( $fileName );
 504                         $data = $this->readPHPFile( $fileName, 'core' );
 505                         wfDebug( __METHOD__.": got localisation for $code from source\n" );
 506
 507                         # Merge primary localisation
 508                         foreach ( $data as $key => $value ) {
 509                                 $this->mergeItem( $key, $coreData[$key], $value );
 510                         }
 511                 }
 512
 513                 # Fill in the fallback if it's not there already
 514                 if ( is_null( $coreData['fallback'] ) ) {
 515                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 516                 }
 517
 518                 if ( $coreData['fallback'] !== false ) {
 519                         # Guard against circular references
 520                         if ( isset( $recursionGuard[$code] ) ) {
 521                                 throw new MWException( "Error: Circular fallback reference in language code $code" );
 522                         }
 523                         $recursionGuard[$code] = true;
 524
 525                         # Load the fallback localisation item by item and merge it
 526                         $deps = array_merge( $deps, $this->getItem( $coreData['fallback'], 'deps' ) );
 527                         foreach ( self::$allKeys as $key ) {
 528                                 if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 529                                         $fallbackValue = $this->getItem( $coreData['fallback'], $key );
 530                                         $this->mergeItem( $key, $coreData[$key], $fallbackValue );
 531                                 }
 532                         }
 533                         $fallbackSequence = $this->getItem( $coreData['fallback'], 'fallbackSequence' );
 534                         array_unshift( $fallbackSequence, $coreData['fallback'] );
 535                         $coreData['fallbackSequence'] = $fallbackSequence;
 536                         unset( $recursionGuard[$code] );
 537                 } else {
 538                         $coreData['fallbackSequence'] = array();
 539                 }
 540                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 541
 542                 # Load the extension localisations
 543                 # This is done after the core because we know the fallback sequence now.
 544                 # But it has a higher precedence for merging so that we can support things
 545                 # like site-specific message overrides.
 546                 $allData = $initialData;
 547                 foreach ( $wgExtensionMessagesFiles as $fileName ) {
 548                         $data = $this->readPHPFile( $fileName, 'extension' );
 549                         $used = false;
 550                         foreach ( $data as $key => $item ) {
 551                                 if( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 552                                         $used = true;
 553                                 }
 554                         }
 555                         if ( $used ) {
 556                                 $deps[] = new FileDependency( $fileName );
 557                         }
 558                 }
 559
 560                 # Load deprecated $wgExtensionAliasesFiles
 561                 foreach ( $wgExtensionAliasesFiles as $fileName ) {
 562                         $data = $this->readPHPFile( $fileName, 'aliases' );
 563                         if ( !isset( $data['aliases'] ) ) {
 564                                 continue;
 565                         }
 566                         $used = $this->mergeExtensionItem( $codeSequence, 'specialPageAliases',
 567                                 $allData['specialPageAliases'], $data['aliases'] );
 568                         if ( $used ) {
 569                                 $deps[] = new FileDependency( $fileName );
 570                         }
 571                 }
 572
 573                 # Merge core data into extension data
 574                 foreach ( $coreData as $key => $item ) {
 575                         $this->mergeItem( $key, $allData[$key], $item );
 576                 }
 577
 578                 # Add cache dependencies for any referenced globals
 579                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 580                 $deps['wgExtensionAliasesFiles'] = new GlobalDependency( 'wgExtensionAliasesFiles' );
 581                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 582
 583                 # Add dependencies to the cache entry
 584                 $allData['deps'] = $deps;
 585
 586                 # Replace spaces with underscores in namespace names
 587                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 588
 589                 # And do the same for special page aliases. $page is an array.
 590                 foreach ( $allData['specialPageAliases'] as &$page ) {
 591                         $page = str_replace( ' ', '_', $page );
 592                 }
 593                 # Decouple the reference to prevent accidental damage
 594                 unset($page);
 595
 596                 # Fix broken defaultUserOptionOverrides
 597                 if ( !is_array( $allData['defaultUserOptionOverrides'] ) ) {
 598                         $allData['defaultUserOptionOverrides'] = array();
 599                 }
 600
 601                 # Set the list keys
 602                 $allData['list'] = array();
 603                 foreach ( self::$splitKeys as $key ) {
 604                         $allData['list'][$key] = array_keys( $allData[$key] );
 605                 }
 606
 607                 # Run hooks
 608                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData ) );
 609
 610                 if ( is_null( $allData['defaultUserOptionOverrides'] ) ) {
 611                         throw new MWException( __METHOD__.': Localisation data failed sanity check! ' .
 612                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 613                 }
 614
 615                 # Set the preload key
 616                 $allData['preload'] = $this->buildPreload( $allData );
 617
 618                 # Save to the process cache and register the items loaded
 619                 $this->data[$code] = $allData;
 620                 foreach ( $allData as $key => $item ) {
 621                         $this->loadedItems[$code][$key] = true;
 622                 }
 623
 624                 # Save to the persistent cache
 625                 $this->store->startWrite( $code );
 626                 foreach ( $allData as $key => $value ) {
 627                         if ( in_array( $key, self::$splitKeys ) ) {
 628                                 foreach ( $value as $subkey => $subvalue ) {
 629                                         $this->store->set( "$key:$subkey", $subvalue );
 630                                 }
 631                         } else {
 632                                 $this->store->set( $key, $value );
 633                         }
 634                 }
 635                 $this->store->finishWrite();
 636
 637                 # Clear out the MessageBlobStore
 638                 # HACK: If using a null (i.e. disabled) storage backend, we
 639                 # can't write to the MessageBlobStore either
 640                 if ( !$this->store instanceof LCStore_Null ) {
 641                         MessageBlobStore::clear();
 642                 }
 643
 644                 wfProfileOut( __METHOD__ );
 645         }
 646
 647         /**
 648          * Build the preload item from the given pre-cache data.
 649          *
 650          * The preload item will be loaded automatically, improving performance
 651          * for the commonly-requested items it contains.
 652          */
 653         protected function buildPreload( $data ) {
 654                 $preload = array( 'messages' => array() );
 655                 foreach ( self::$preloadedKeys as $key ) {
 656                         $preload[$key] = $data[$key];
 657                 }
 658                 foreach ( $data['preloadedMessages'] as $subkey ) {
 659                         if ( isset( $data['messages'][$subkey] ) ) {
 660                                 $subitem = $data['messages'][$subkey];
 661                         } else {
 662                                 $subitem = null;
 663                         }
 664                         $preload['messages'][$subkey] = $subitem;
 665                 }
 666                 return $preload;
 667         }
 668
 669         /**
 670          * Unload the data for a given language from the object cache.
 671          * Reduces memory usage.
 672          */
 673         public function unload( $code ) {
 674                 unset( $this->data[$code] );
 675                 unset( $this->loadedItems[$code] );
 676                 unset( $this->loadedSubitems[$code] );
 677                 unset( $this->initialisedLangs[$code] );
 678                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
 679                         if ( $fbCode === $code ) {
 680                                 $this->unload( $shallowCode );
 681                         }
 682                 }
 683         }
 684
 685         /**
 686          * Unload all data
 687          */
 688         public function unloadAll() {
 689                 foreach ( $this->initialisedLangs as $lang => $unused ) {
 690                         $this->unload( $lang );
 691                 }
 692         }
 693
 694         /**
 695          * Disable the storage backend
 696          */
 697         public function disableBackend() {
 698                 $this->store = new LCStore_Null;
 699                 $this->manualRecache = false;
 700         }
 701 }
 702
 703 /**
 704  * Interface for the persistence layer of LocalisationCache.
 705  *
 706  * The persistence layer is two-level hierarchical cache. The first level
 707  * is the language, the second level is the item or subitem.
 708  *
 709  * Since the data for a whole language is rebuilt in one operation, it needs
 710  * to have a fast and atomic method for deleting or replacing all of the
 711  * current data for a given language. The interface reflects this bulk update
 712  * operation. Callers writing to the cache must first call startWrite(), then
 713  * will call set() a couple of thousand times, then will call finishWrite()
 714  * to commit the operation. When finishWrite() is called, the cache is
 715  * expected to delete all data previously stored for that language.
 716  *
 717  * The values stored are PHP variables suitable for serialize(). Implementations
 718  * of LCStore are responsible for serializing and unserializing.
 719  */
 720 interface LCStore {
 721         /**
 722          * Get a value.
 723          * @param $code Language code
 724          * @param $key Cache key
 725          */
 726         function get( $code, $key );
 727
 728         /**
 729          * Start a write transaction.
 730          * @param $code Language code
 731          */
 732         function startWrite( $code );
 733
 734         /**
 735          * Finish a write transaction.
 736          */
 737         function finishWrite();
 738
 739         /**
 740          * Set a key to a given value. startWrite() must be called before this
 741          * is called, and finishWrite() must be called afterwards.
 742          */
 743         function set( $key, $value );
 744
 745 }
 746
 747 /**
 748  * LCStore implementation which uses the standard DB functions to store data.
 749  * This will work on any MediaWiki installation.
 750  */
 751 class LCStore_DB implements LCStore {
 752         var $currentLang;
 753         var $writesDone = false;
 754         var $dbw, $batch;
 755         var $readOnly = false;
 756
 757         public function get( $code, $key ) {
 758                 if ( $this->writesDone ) {
 759                         $db = wfGetDB( DB_MASTER );
 760                 } else {
 761                         $db = wfGetDB( DB_SLAVE );
 762                 }
 763                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
 764                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
 765                 if ( $row ) {
 766                         return unserialize( $row->lc_value );
 767                 } else {
 768                         return null;
 769                 }
 770         }
 771
 772         public function startWrite( $code ) {
 773                 if ( $this->readOnly ) {
 774                         return;
 775                 }
 776                 if ( !$code ) {
 777                         throw new MWException( __METHOD__.": Invalid language \"$code\"" );
 778                 }
 779                 $this->dbw = wfGetDB( DB_MASTER );
 780                 try {
 781                         $this->dbw->begin();
 782                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
 783                 } catch ( DBQueryError $e ) {
 784                         if ( $this->dbw->wasReadOnlyError() ) {
 785                                 $this->readOnly = true;
 786                                 $this->dbw->rollback();
 787                                 $this->dbw->ignoreErrors( false );
 788                                 return;
 789                         } else {
 790                                 throw $e;
 791                         }
 792                 }
 793                 $this->currentLang = $code;
 794                 $this->batch = array();
 795         }
 796
 797         public function finishWrite() {
 798                 if ( $this->readOnly ) {
 799                         return;
 800                 }
 801                 if ( $this->batch ) {
 802                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
 803                 }
 804                 $this->dbw->commit();
 805                 $this->currentLang = null;
 806                 $this->dbw = null;
 807                 $this->batch = array();
 808                 $this->writesDone = true;
 809         }
 810
 811         public function set( $key, $value ) {
 812                 if ( $this->readOnly ) {
 813                         return;
 814                 }
 815                 if ( is_null( $this->currentLang ) ) {
 816                         throw new MWException( __CLASS__.': must call startWrite() before calling set()' );
 817                 }
 818                 $this->batch[] = array(
 819                         'lc_lang' => $this->currentLang,
 820                         'lc_key' => $key,
 821                         'lc_value' => serialize( $value ) );
 822                 if ( count( $this->batch ) >= 100 ) {
 823                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
 824                         $this->batch = array();
 825                 }
 826         }
 827 }
 828
 829 /**
 830  * LCStore implementation which stores data as a collection of CDB files in the
 831  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
 832  * will throw an exception.
 833  *
 834  * Profiling indicates that on Linux, this implementation outperforms MySQL if
 835  * the directory is on a local filesystem and there is ample kernel cache
 836  * space. The performance advantage is greater when the DBA extension is
 837  * available than it is with the PHP port.
 838  *
 839  * See Cdb.php and http://cr.yp.to/cdb.html
 840  */
 841 class LCStore_CDB implements LCStore {
 842         var $readers, $writer, $currentLang, $directory;
 843
 844         function __construct( $conf = array() ) {
 845                 global $wgCacheDirectory;
 846                 if ( isset( $conf['directory'] ) ) {
 847                         $this->directory = $conf['directory'];
 848                 } else {
 849                         $this->directory = $wgCacheDirectory;
 850                 }
 851         }
 852
 853         public function get( $code, $key ) {
 854                 if ( !isset( $this->readers[$code] ) ) {
 855                         $fileName = $this->getFileName( $code );
 856                         if ( !file_exists( $fileName ) ) {
 857                                 $this->readers[$code] = false;
 858                         } else {
 859                                 $this->readers[$code] = CdbReader::open( $fileName );
 860                         }
 861                 }
 862                 if ( !$this->readers[$code] ) {
 863                         return null;
 864                 } else {
 865                         $value = $this->readers[$code]->get( $key );
 866                         if ( $value === false ) {
 867                                 return null;
 868                         }
 869                         return unserialize( $value );
 870                 }
 871         }
 872
 873         public function startWrite( $code ) {
 874                 if ( !file_exists( $this->directory ) ) {
 875                         if ( !wfMkdirParents( $this->directory ) ) {
 876                                 throw new MWException( "Unable to create the localisation store " .
 877                                         "directory \"{$this->directory}\"" );
 878                         }
 879                 }
 880                 // Close reader to stop permission errors on write
 881                 if( !empty($this->readers[$code]) ) {
 882                         $this->readers[$code]->close();
 883                 }
 884                 $this->writer = CdbWriter::open( $this->getFileName( $code ) );
 885                 $this->currentLang = $code;
 886         }
 887
 888         public function finishWrite() {
 889                 // Close the writer
 890                 $this->writer->close();
 891                 $this->writer = null;
 892                 unset( $this->readers[$this->currentLang] );
 893                 $this->currentLang = null;
 894         }
 895
 896         public function set( $key, $value ) {
 897                 if ( is_null( $this->writer ) ) {
 898                         throw new MWException( __CLASS__.': must call startWrite() before calling set()' );
 899                 }
 900                 $this->writer->set( $key, serialize( $value ) );
 901         }
 902
 903         protected function getFileName( $code ) {
 904                 if ( !$code || strpos( $code, '/' ) !== false ) {
 905                         throw new MWException( __METHOD__.": Invalid language \"$code\"" );
 906                 }
 907                 return "{$this->directory}/l10n_cache-$code.cdb";
 908         }
 909 }
 910
 911 /**
 912  * Null store backend, used to avoid DB errors during install
 913  */
 914 class LCStore_Null implements LCStore {
 915         public function get( $code, $key ) {
 916                 return null;
 917         }
 918
 919         public function startWrite( $code ) {}
 920         public function finishWrite() {}
 921         public function set( $key, $value ) {}
 922 }
 923
 924 /**
 925  * A localisation cache optimised for loading large amounts of data for many
 926  * languages. Used by rebuildLocalisationCache.php.
 927  */
 928 class LocalisationCache_BulkLoad extends LocalisationCache {
 929         /**
 930          * A cache of the contents of data files.
 931          * Core files are serialized to avoid using ~1GB of RAM during a recache.
 932          */
 933         var $fileCache = array();
 934
 935         /**
 936          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
 937          * to keep the most recently used language codes at the end of the array, and
 938          * the language codes that are ready to be deleted at the beginning.
 939          */
 940         var $mruLangs = array();
 941
 942         /**
 943          * Maximum number of languages that may be loaded into $this->data
 944          */
 945         var $maxLoadedLangs = 10;
 946
 947         protected function readPHPFile( $fileName, $fileType ) {
 948                 $serialize = $fileType === 'core';
 949                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
 950                         $data = parent::readPHPFile( $fileName, $fileType );
 951                         if ( $serialize ) {
 952                                 $encData = serialize( $data );
 953                         } else {
 954                                 $encData = $data;
 955                         }
 956                         $this->fileCache[$fileName][$fileType] = $encData;
 957                         return $data;
 958                 } elseif ( $serialize ) {
 959                         return unserialize( $this->fileCache[$fileName][$fileType] );
 960                 } else {
 961                         return $this->fileCache[$fileName][$fileType];
 962                 }
 963         }
 964
 965         public function getItem( $code, $key ) {
 966                 unset( $this->mruLangs[$code] );
 967                 $this->mruLangs[$code] = true;
 968                 return parent::getItem( $code, $key );
 969         }
 970
 971         public function getSubitem( $code, $key, $subkey ) {
 972                 unset( $this->mruLangs[$code] );
 973                 $this->mruLangs[$code] = true;
 974                 return parent::getSubitem( $code, $key, $subkey );
 975         }
 976
 977         public function recache( $code ) {
 978                 parent::recache( $code );
 979                 unset( $this->mruLangs[$code] );
 980                 $this->mruLangs[$code] = true;
 981                 $this->trimCache();
 982         }
 983
 984         public function unload( $code ) {
 985                 unset( $this->mruLangs[$code] );
 986                 parent::unload( $code );
 987         }
 988
 989         /**
 990          * Unload cached languages until there are less than $this->maxLoadedLangs
 991          */
 992         protected function trimCache() {
 993                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
 994                         reset( $this->mruLangs );
 995                         $code = key( $this->mruLangs );
 996                         wfDebug( __METHOD__.": unloading $code\n" );
 997                         $this->unload( $code );
 998                 }
 999         }
1000 }