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          * Data added by extensions using the deprecated $wgMessageCache->addMessages()
  82          * interface.
  83          */
  84         var $legacyData = array();
  85
  86         /**
  87          * All item keys
  88          */
  89         static public $allKeys = array(
  90                 'fallback', 'namespaceNames', 'mathNames', 'bookstoreList',
  91                 'magicWords', 'messages', 'rtl', 'capitalizeAllNouns', 'digitTransformTable',
  92                 'separatorTransformTable', 'fallback8bitEncoding', 'linkPrefixExtension',
  93                 'defaultUserOptionOverrides', 'linkTrail', 'namespaceAliases',
  94                 'dateFormats', 'datePreferences', 'datePreferenceMigrationMap',
  95                 'defaultDateFormat', 'extraUserToggles', 'specialPageAliases',
  96                 'imageFiles', 'preloadedMessages',
  97         );
  98
  99         /**
 100          * Keys for items which consist of associative arrays, which may be merged
 101          * by a fallback sequence.
 102          */
 103         static public $mergeableMapKeys = array( 'messages', 'namespaceNames', 'mathNames',
 104                 'dateFormats', 'defaultUserOptionOverrides', 'magicWords', 'imageFiles',
 105                 'preloadedMessages',
 106         );
 107
 108         /**
 109          * Keys for items which are a numbered array.
 110          */
 111         static public $mergeableListKeys = array( 'extraUserToggles' );
 112
 113         /**
 114          * Keys for items which contain an array of arrays of equivalent aliases
 115          * for each subitem. The aliases may be merged by a fallback sequence.
 116          */
 117         static public $mergeableAliasListKeys = array( 'specialPageAliases' );
 118
 119         /**
 120          * Keys for items which contain an associative array, and may be merged if
 121          * the primary value contains the special array key "inherit". That array
 122          * key is removed after the first merge.
 123          */
 124         static public $optionalMergeKeys = array( 'bookstoreList' );
 125
 126         /**
 127          * Keys for items where the subitems are stored in the backend separately.
 128          */
 129         static public $splitKeys = array( 'messages' );
 130
 131         /**
 132          * Keys which are loaded automatically by initLanguage()
 133          */
 134         static public $preloadedKeys = array( 'dateFormats', 'namespaceNames',
 135                 'defaultUserOptionOverrides' );
 136
 137         /**
 138          * Constructor.
 139          * For constructor parameters, see the documentation in DefaultSettings.php
 140          * for $wgLocalisationCacheConf.
 141          */
 142         function __construct( $conf ) {
 143                 global $wgCacheDirectory;
 144
 145                 $this->conf = $conf;
 146                 $storeConf = array();
 147                 if ( !empty( $conf['storeClass'] ) ) {
 148                         $storeClass = $conf['storeClass'];
 149                 } else {
 150                         switch ( $conf['store'] ) {
 151                                 case 'files':
 152                                 case 'file':
 153                                         $storeClass = 'LCStore_CDB';
 154                                         break;
 155                                 case 'db':
 156                                         $storeClass = 'LCStore_DB';
 157                                         break;
 158                                 case 'detect':
 159                                         $storeClass = $wgCacheDirectory ? 'LCStore_CDB' : 'LCStore_DB';
 160                                         break;
 161                                 default:
 162                                         throw new MWException(
 163                                                 'Please set $wgLocalisationCacheConf[\'store\'] to something sensible.' );
 164                         }
 165                 }
 166
 167                 wfDebug( get_class( $this ) . ": using store $storeClass\n" );
 168                 if ( !empty( $conf['storeDirectory'] ) ) {
 169                         $storeConf['directory'] = $conf['storeDirectory'];
 170                 }
 171
 172                 $this->store = new $storeClass( $storeConf );
 173                 foreach ( array( 'manualRecache', 'forceRecache' ) as $var ) {
 174                         if ( isset( $conf[$var] ) ) {
 175                                 $this->$var = $conf[$var];
 176                         }
 177                 }
 178         }
 179
 180         /**
 181          * Returns true if the given key is mergeable, that is, if it is an associative
 182          * array which can be merged through a fallback sequence.
 183          */
 184         public function isMergeableKey( $key ) {
 185                 if ( !isset( $this->mergeableKeys ) ) {
 186                         $this->mergeableKeys = array_flip( array_merge(
 187                                 self::$mergeableMapKeys,
 188                                 self::$mergeableListKeys,
 189                                 self::$mergeableAliasListKeys,
 190                                 self::$optionalMergeKeys
 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( $this->legacyData[$code][$key][$subkey] ) ) {
 219                         return $this->legacyData[$code][$key][$subkey];
 220                 }
 221                 if ( !isset( $this->loadedSubitems[$code][$key][$subkey] )
 222                         && !isset( $this->loadedItems[$code][$key] ) )
 223                 {
 224                         wfProfileIn( __METHOD__.'-load' );
 225                         $this->loadSubitem( $code, $key, $subkey );
 226                         wfProfileOut( __METHOD__.'-load' );
 227                 }
 228                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 229                         return $this->data[$code][$key][$subkey];
 230                 } else {
 231                         return null;
 232                 }
 233         }
 234
 235         /**
 236          * Get the list of subitem keys for a given item.
 237          *
 238          * This is faster than array_keys($lc->getItem(...)) for the items listed in
 239          * self::$splitKeys.
 240          *
 241          * Will return null if the item is not found, or false if the item is not an
 242          * array.
 243          */
 244         public function getSubitemList( $code, $key ) {
 245                 if ( in_array( $key, self::$splitKeys ) ) {
 246                         return $this->getSubitem( $code, 'list', $key );
 247                 } else {
 248                         $item = $this->getItem( $code, $key );
 249                         if ( is_array( $item ) ) {
 250                                 return array_keys( $item );
 251                         } else {
 252                                 return false;
 253                         }
 254                 }
 255         }
 256
 257         /**
 258          * Load an item into the cache.
 259          */
 260         protected function loadItem( $code, $key ) {
 261                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 262                         $this->initLanguage( $code );
 263                 }
 264                 // Check to see if initLanguage() loaded it for us
 265                 if ( isset( $this->loadedItems[$code][$key] ) ) {
 266                         return;
 267                 }
 268                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 269                         $this->loadItem( $this->shallowFallbacks[$code], $key );
 270                         return;
 271                 }
 272                 if ( in_array( $key, self::$splitKeys ) ) {
 273                         $subkeyList = $this->getSubitem( $code, 'list', $key );
 274                         foreach ( $subkeyList as $subkey ) {
 275                                 if ( isset( $this->data[$code][$key][$subkey] ) ) {
 276                                         continue;
 277                                 }
 278                                 $this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
 279                         }
 280                 } else {
 281                         $this->data[$code][$key] = $this->store->get( $code, $key );
 282                 }
 283                 $this->loadedItems[$code][$key] = true;
 284         }
 285
 286         /**
 287          * Load a subitem into the cache
 288          */
 289         protected function loadSubitem( $code, $key, $subkey ) {
 290                 if ( !in_array( $key, self::$splitKeys ) ) {
 291                         $this->loadItem( $code, $key );
 292                         return;
 293                 }
 294                 if ( !isset( $this->initialisedLangs[$code] ) ) {
 295                         $this->initLanguage( $code );
 296                 }
 297                 // Check to see if initLanguage() loaded it for us
 298                 if ( isset( $this->loadedItems[$code][$key] )
 299                         || isset( $this->loadedSubitems[$code][$key][$subkey] ) )
 300                 {
 301                         return;
 302                 }
 303                 if ( isset( $this->shallowFallbacks[$code] ) ) {
 304                         $this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
 305                         return;
 306                 }
 307                 $value = $this->store->get( $code, "$key:$subkey" );
 308                 $this->data[$code][$key][$subkey] = $value;
 309                 $this->loadedSubitems[$code][$key][$subkey] = true;
 310         }
 311
 312         /**
 313          * Returns true if the cache identified by $code is missing or expired.
 314          */
 315         public function isExpired( $code ) {
 316                 if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
 317                         wfDebug( __METHOD__."($code): forced reload\n" );
 318                         return true;
 319                 }
 320
 321                 $deps = $this->store->get( $code, 'deps' );
 322                 if ( $deps === null ) {
 323                         wfDebug( __METHOD__."($code): cache missing, need to make one\n" );
 324                         return true;
 325                 }
 326                 foreach ( $deps as $dep ) {
 327                         // Because we're unserializing stuff from cache, we
 328                         // could receive objects of classes that don't exist
 329                         // anymore (e.g. uninstalled extensions)
 330                         // When this happens, always expire the cache
 331                         if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
 332                                 wfDebug( __METHOD__."($code): cache for $code expired due to " .
 333                                         get_class( $dep ) . "\n" );
 334                                 return true;
 335                         }
 336                 }
 337                 return false;
 338         }
 339
 340         /**
 341          * Initialise a language in this object. Rebuild the cache if necessary.
 342          */
 343         protected function initLanguage( $code ) {
 344                 if ( isset( $this->initialisedLangs[$code] ) ) {
 345                         return;
 346                 }
 347                 $this->initialisedLangs[$code] = true;
 348
 349                 # Recache the data if necessary
 350                 if ( !$this->manualRecache && $this->isExpired( $code ) ) {
 351                         if ( file_exists( Language::getMessagesFileName( $code ) ) ) {
 352                                 $this->recache( $code );
 353                         } elseif ( $code === 'en' ) {
 354                                 throw new MWException( 'MessagesEn.php is missing.' );
 355                         } else {
 356                                 $this->initShallowFallback( $code, 'en' );
 357                         }
 358                         return;
 359                 }
 360
 361                 # Preload some stuff
 362                 $preload = $this->getItem( $code, 'preload' );
 363                 if ( $preload === null ) {
 364                         if ( $this->manualRecache ) {
 365                                 // No Messages*.php file. Do shallow fallback to en.
 366                                 if ( $code === 'en' ) {
 367                                         throw new MWException( 'No localisation cache found for English. ' .
 368                                                 'Please run maintenance/rebuildLocalisationCache.php.' );
 369                                 }
 370                                 $this->initShallowFallback( $code, 'en' );
 371                                 return;
 372                         } else {
 373                                 throw new MWException( 'Invalid or missing localisation cache.' );
 374                         }
 375                 }
 376                 $this->data[$code] = $preload;
 377                 foreach ( $preload as $key => $item ) {
 378                         if ( in_array( $key, self::$splitKeys ) ) {
 379                                 foreach ( $item as $subkey => $subitem ) {
 380                                         $this->loadedSubitems[$code][$key][$subkey] = true;
 381                                 }
 382                         } else {
 383                                 $this->loadedItems[$code][$key] = true;
 384                         }
 385                 }
 386         }
 387
 388         /**
 389          * Create a fallback from one language to another, without creating a
 390          * complete persistent cache.
 391          */
 392         public function initShallowFallback( $primaryCode, $fallbackCode ) {
 393                 $this->data[$primaryCode] =& $this->data[$fallbackCode];
 394                 $this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
 395                 $this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
 396                 $this->shallowFallbacks[$primaryCode] = $fallbackCode;
 397         }
 398
 399         /**
 400          * Read a PHP file containing localisation data.
 401          */
 402         protected function readPHPFile( $_fileName, $_fileType ) {
 403                 // Disable APC caching
 404                 $_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
 405                 include( $_fileName );
 406                 ini_set( 'apc.cache_by_default', $_apcEnabled );
 407
 408                 if ( $_fileType == 'core' || $_fileType == 'extension' ) {
 409                         $data = compact( self::$allKeys );
 410                 } elseif ( $_fileType == 'aliases' ) {
 411                         $data = compact( 'aliases' );
 412                 } else {
 413                         throw new MWException( __METHOD__.": Invalid file type: $_fileType" );
 414                 }
 415                 return $data;
 416         }
 417
 418         /**
 419          * Merge two localisation values, a primary and a fallback, overwriting the
 420          * primary value in place.
 421          */
 422         protected function mergeItem( $key, &$value, $fallbackValue ) {
 423                 if ( !is_null( $value ) ) {
 424                         if ( !is_null( $fallbackValue ) ) {
 425                                 if ( in_array( $key, self::$mergeableMapKeys ) ) {
 426                                         $value = $value + $fallbackValue;
 427                                 } elseif ( in_array( $key, self::$mergeableListKeys ) ) {
 428                                         $value = array_unique( array_merge( $fallbackValue, $value ) );
 429                                 } elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
 430                                         $value = array_merge_recursive( $value, $fallbackValue );
 431                                 } elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
 432                                         if ( !empty( $value['inherit'] ) )  {
 433                                                 $value = array_merge( $fallbackValue, $value );
 434                                         }
 435                                         if ( isset( $value['inherit'] ) ) {
 436                                                 unset( $value['inherit'] );
 437                                         }
 438                                 }
 439                         }
 440                 } else {
 441                         $value = $fallbackValue;
 442                 }
 443         }
 444
 445         /**
 446          * Given an array mapping language code to localisation value, such as is
 447          * found in extension *.i18n.php files, iterate through a fallback sequence
 448          * to merge the given data with an existing primary value.
 449          *
 450          * Returns true if any data from the extension array was used, false
 451          * otherwise.
 452          */
 453         protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
 454                 $used = false;
 455                 foreach ( $codeSequence as $code ) {
 456                         if ( isset( $fallbackValue[$code] ) ) {
 457                                 $this->mergeItem( $key, $value, $fallbackValue[$code] );
 458                                 $used = true;
 459                         }
 460                 }
 461                 return $used;
 462         }
 463
 464         /**
 465          * Load localisation data for a given language for both core and extensions
 466          * and save it to the persistent cache store and the process cache
 467          */
 468         public function recache( $code ) {
 469                 static $recursionGuard = array();
 470                 global $wgExtensionMessagesFiles, $wgExtensionAliasesFiles;
 471                 wfProfileIn( __METHOD__ );
 472
 473                 if ( !$code ) {
 474                         throw new MWException( "Invalid language code requested" );
 475                 }
 476                 $this->recachedLangs[$code] = true;
 477
 478                 # Initial values
 479                 $initialData = array_combine(
 480                         self::$allKeys,
 481                         array_fill( 0, count( self::$allKeys ), null ) );
 482                 $coreData = $initialData;
 483                 $deps = array();
 484
 485                 # Load the primary localisation from the source file
 486                 $fileName = Language::getMessagesFileName( $code );
 487                 if ( !file_exists( $fileName ) ) {
 488                         wfDebug( __METHOD__.": no localisation file for $code, using fallback to en\n" );
 489                         $coreData['fallback'] = 'en';
 490                 } else {
 491                         $deps[] = new FileDependency( $fileName );
 492                         $data = $this->readPHPFile( $fileName, 'core' );
 493                         wfDebug( __METHOD__.": got localisation for $code from source\n" );
 494
 495                         # Merge primary localisation
 496                         foreach ( $data as $key => $value ) {
 497                                 $this->mergeItem( $key, $coreData[$key], $value );
 498                         }
 499                 }
 500
 501                 # Fill in the fallback if it's not there already
 502                 if ( is_null( $coreData['fallback'] ) ) {
 503                         $coreData['fallback'] = $code === 'en' ? false : 'en';
 504                 }
 505
 506                 if ( $coreData['fallback'] !== false ) {
 507                         # Guard against circular references
 508                         if ( isset( $recursionGuard[$code] ) ) {
 509                                 throw new MWException( "Error: Circular fallback reference in language code $code" );
 510                         }
 511                         $recursionGuard[$code] = true;
 512
 513                         # Load the fallback localisation item by item and merge it
 514                         $deps = array_merge( $deps, $this->getItem( $coreData['fallback'], 'deps' ) );
 515                         foreach ( self::$allKeys as $key ) {
 516                                 if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
 517                                         $fallbackValue = $this->getItem( $coreData['fallback'], $key );
 518                                         $this->mergeItem( $key, $coreData[$key], $fallbackValue );
 519                                 }
 520                         }
 521                         $fallbackSequence = $this->getItem( $coreData['fallback'], 'fallbackSequence' );
 522                         array_unshift( $fallbackSequence, $coreData['fallback'] );
 523                         $coreData['fallbackSequence'] = $fallbackSequence;
 524                         unset( $recursionGuard[$code] );
 525                 } else {
 526                         $coreData['fallbackSequence'] = array();
 527                 }
 528                 $codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
 529
 530                 # Load the extension localisations
 531                 # This is done after the core because we know the fallback sequence now.
 532                 # But it has a higher precedence for merging so that we can support things
 533                 # like site-specific message overrides.
 534                 $allData = $initialData;
 535                 foreach ( $wgExtensionMessagesFiles as $fileName ) {
 536                         $data = $this->readPHPFile( $fileName, 'extension' );
 537                         $used = false;
 538                         foreach ( $data as $key => $item ) {
 539                                 if( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
 540                                         $used = true;
 541                                 }
 542                         }
 543                         if ( $used ) {
 544                                 $deps[] = new FileDependency( $fileName );
 545                         }
 546                 }
 547
 548                 # Load deprecated $wgExtensionAliasesFiles
 549                 foreach ( $wgExtensionAliasesFiles as $fileName ) {
 550                         $data = $this->readPHPFile( $fileName, 'aliases' );
 551                         if ( !isset( $data['aliases'] ) ) {
 552                                 continue;
 553                         }
 554                         $used = $this->mergeExtensionItem( $codeSequence, 'specialPageAliases',
 555                                 $allData['specialPageAliases'], $data['aliases'] );
 556                         if ( $used ) {
 557                                 $deps[] = new FileDependency( $fileName );
 558                         }
 559                 }
 560
 561                 # Merge core data into extension data
 562                 foreach ( $coreData as $key => $item ) {
 563                         $this->mergeItem( $key, $allData[$key], $item );
 564                 }
 565
 566                 # Add cache dependencies for any referenced globals
 567                 $deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
 568                 $deps['wgExtensionAliasesFiles'] = new GlobalDependency( 'wgExtensionAliasesFiles' );
 569                 $deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
 570
 571                 # Add dependencies to the cache entry
 572                 $allData['deps'] = $deps;
 573
 574                 # Replace spaces with underscores in namespace names
 575                 $allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
 576
 577                 # And do the same for special page aliases. $page is an array.
 578                 foreach ( $allData['specialPageAliases'] as &$page ) {
 579                         $page = str_replace( ' ', '_', $page );
 580                 }
 581                 # Decouple the reference to prevent accidental damage
 582                 unset($page);
 583
 584                 # Fix broken defaultUserOptionOverrides
 585                 if ( !is_array( $allData['defaultUserOptionOverrides'] ) ) {
 586                         $allData['defaultUserOptionOverrides'] = array();
 587                 }
 588
 589                 # Set the list keys
 590                 $allData['list'] = array();
 591                 foreach ( self::$splitKeys as $key ) {
 592                         $allData['list'][$key] = array_keys( $allData[$key] );
 593                 }
 594
 595                 # Run hooks
 596                 wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData ) );
 597
 598                 if ( is_null( $allData['defaultUserOptionOverrides'] ) ) {
 599                         throw new MWException( __METHOD__.': Localisation data failed sanity check! ' .
 600                                 'Check that your languages/messages/MessagesEn.php file is intact.' );
 601                 }
 602
 603                 # Set the preload key
 604                 $allData['preload'] = $this->buildPreload( $allData );
 605
 606                 # Save to the process cache and register the items loaded
 607                 $this->data[$code] = $allData;
 608                 foreach ( $allData as $key => $item ) {
 609                         $this->loadedItems[$code][$key] = true;
 610                 }
 611
 612                 # Save to the persistent cache
 613                 $this->store->startWrite( $code );
 614                 foreach ( $allData as $key => $value ) {
 615                         if ( in_array( $key, self::$splitKeys ) ) {
 616                                 foreach ( $value as $subkey => $subvalue ) {
 617                                         $this->store->set( "$key:$subkey", $subvalue );
 618                                 }
 619                         } else {
 620                                 $this->store->set( $key, $value );
 621                         }
 622                 }
 623                 $this->store->finishWrite();
 624
 625                 # Clear out the MessageBlobStore
 626                 # HACK: If using a null (i.e. disabled) storage backend, we
 627                 # can't write to the MessageBlobStore either
 628                 if ( !$this->store instanceof LCStore_Null ) {
 629                         MessageBlobStore::clear();
 630                 }
 631
 632                 wfProfileOut( __METHOD__ );
 633         }
 634
 635         /**
 636          * Build the preload item from the given pre-cache data.
 637          *
 638          * The preload item will be loaded automatically, improving performance
 639          * for the commonly-requested items it contains.
 640          */
 641         protected function buildPreload( $data ) {
 642                 $preload = array( 'messages' => array() );
 643                 foreach ( self::$preloadedKeys as $key ) {
 644                         $preload[$key] = $data[$key];
 645                 }
 646                 foreach ( $data['preloadedMessages'] as $subkey ) {
 647                         if ( isset( $data['messages'][$subkey] ) ) {
 648                                 $subitem = $data['messages'][$subkey];
 649                         } else {
 650                                 $subitem = null;
 651                         }
 652                         $preload['messages'][$subkey] = $subitem;
 653                 }
 654                 return $preload;
 655         }
 656
 657         /**
 658          * Unload the data for a given language from the object cache.
 659          * Reduces memory usage.
 660          */
 661         public function unload( $code ) {
 662                 unset( $this->data[$code] );
 663                 unset( $this->loadedItems[$code] );
 664                 unset( $this->loadedSubitems[$code] );
 665                 unset( $this->initialisedLangs[$code] );
 666                 // We don't unload legacyData because there's no way to get it back
 667                 // again, it's not really a cache
 668                 foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
 669                         if ( $fbCode === $code ) {
 670                                 $this->unload( $shallowCode );
 671                         }
 672                 }
 673         }
 674
 675         /**
 676          * Unload all data
 677          */
 678         public function unloadAll() {
 679                 foreach ( $this->initialisedLangs as $lang => $unused ) {
 680                         $this->unload( $lang );
 681                 }
 682         }
 683
 684         /**
 685          * Add messages to the cache, from an extension that has not yet been
 686          * migrated to $wgExtensionMessages or the LocalisationCacheRecache hook.
 687          * Called by deprecated function $wgMessageCache->addMessages().
 688          */
 689         public function addLegacyMessages( $messages ) {
 690                 foreach ( $messages as $lang => $langMessages ) {
 691                         if ( isset( $this->legacyData[$lang]['messages'] ) ) {
 692                                 $this->legacyData[$lang]['messages'] =
 693                                         $langMessages + $this->legacyData[$lang]['messages'];
 694                         } else {
 695                                 $this->legacyData[$lang]['messages'] = $langMessages;
 696                         }
 697                 }
 698         }
 699
 700         /**
 701          * Disable the storage backend
 702          */
 703         public function disableBackend() {
 704                 $this->store = new LCStore_Null;
 705                 $this->manualRecache = false;
 706         }
 707 }
 708
 709 /**
 710  * Interface for the persistence layer of LocalisationCache.
 711  *
 712  * The persistence layer is two-level hierarchical cache. The first level
 713  * is the language, the second level is the item or subitem.
 714  *
 715  * Since the data for a whole language is rebuilt in one operation, it needs
 716  * to have a fast and atomic method for deleting or replacing all of the
 717  * current data for a given language. The interface reflects this bulk update
 718  * operation. Callers writing to the cache must first call startWrite(), then
 719  * will call set() a couple of thousand times, then will call finishWrite()
 720  * to commit the operation. When finishWrite() is called, the cache is
 721  * expected to delete all data previously stored for that language.
 722  *
 723  * The values stored are PHP variables suitable for serialize(). Implementations
 724  * of LCStore are responsible for serializing and unserializing.
 725  */
 726 interface LCStore {
 727         /**
 728          * Get a value.
 729          * @param $code Language code
 730          * @param $key Cache key
 731          */
 732         function get( $code, $key );
 733
 734         /**
 735          * Start a write transaction.
 736          * @param $code Language code
 737          */
 738         function startWrite( $code );
 739
 740         /**
 741          * Finish a write transaction.
 742          */
 743         function finishWrite();
 744
 745         /**
 746          * Set a key to a given value. startWrite() must be called before this
 747          * is called, and finishWrite() must be called afterwards.
 748          */
 749         function set( $key, $value );
 750
 751 }
 752
 753 /**
 754  * LCStore implementation which uses the standard DB functions to store data.
 755  * This will work on any MediaWiki installation.
 756  */
 757 class LCStore_DB implements LCStore {
 758         var $currentLang;
 759         var $writesDone = false;
 760         var $dbw, $batch;
 761         var $readOnly = false;
 762
 763         public function get( $code, $key ) {
 764                 if ( $this->writesDone ) {
 765                         $db = wfGetDB( DB_MASTER );
 766                 } else {
 767                         $db = wfGetDB( DB_SLAVE );
 768                 }
 769                 $row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
 770                         array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
 771                 if ( $row ) {
 772                         return unserialize( $row->lc_value );
 773                 } else {
 774                         return null;
 775                 }
 776         }
 777
 778         public function startWrite( $code ) {
 779                 if ( $this->readOnly ) {
 780                         return;
 781                 }
 782                 if ( !$code ) {
 783                         throw new MWException( __METHOD__.": Invalid language \"$code\"" );
 784                 }
 785                 $this->dbw = wfGetDB( DB_MASTER );
 786                 try {
 787                         $this->dbw->begin();
 788                         $this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
 789                 } catch ( DBQueryError $e ) {
 790                         if ( $this->dbw->wasReadOnlyError() ) {
 791                                 $this->readOnly = true;
 792                                 $this->dbw->rollback();
 793                                 $this->dbw->ignoreErrors( false );
 794                                 return;
 795                         } else {
 796                                 throw $e;
 797                         }
 798                 }
 799                 $this->currentLang = $code;
 800                 $this->batch = array();
 801         }
 802
 803         public function finishWrite() {
 804                 if ( $this->readOnly ) {
 805                         return;
 806                 }
 807                 if ( $this->batch ) {
 808                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
 809                 }
 810                 $this->dbw->commit();
 811                 $this->currentLang = null;
 812                 $this->dbw = null;
 813                 $this->batch = array();
 814                 $this->writesDone = true;
 815         }
 816
 817         public function set( $key, $value ) {
 818                 if ( $this->readOnly ) {
 819                         return;
 820                 }
 821                 if ( is_null( $this->currentLang ) ) {
 822                         throw new MWException( __CLASS__.': must call startWrite() before calling set()' );
 823                 }
 824                 $this->batch[] = array(
 825                         'lc_lang' => $this->currentLang,
 826                         'lc_key' => $key,
 827                         'lc_value' => serialize( $value ) );
 828                 if ( count( $this->batch ) >= 100 ) {
 829                         $this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
 830                         $this->batch = array();
 831                 }
 832         }
 833 }
 834
 835 /**
 836  * LCStore implementation which stores data as a collection of CDB files in the
 837  * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
 838  * will throw an exception.
 839  *
 840  * Profiling indicates that on Linux, this implementation outperforms MySQL if
 841  * the directory is on a local filesystem and there is ample kernel cache
 842  * space. The performance advantage is greater when the DBA extension is
 843  * available than it is with the PHP port.
 844  *
 845  * See Cdb.php and http://cr.yp.to/cdb.html
 846  */
 847 class LCStore_CDB implements LCStore {
 848         var $readers, $writer, $currentLang, $directory;
 849
 850         function __construct( $conf = array() ) {
 851                 global $wgCacheDirectory;
 852                 if ( isset( $conf['directory'] ) ) {
 853                         $this->directory = $conf['directory'];
 854                 } else {
 855                         $this->directory = $wgCacheDirectory;
 856                 }
 857         }
 858
 859         public function get( $code, $key ) {
 860                 if ( !isset( $this->readers[$code] ) ) {
 861                         $fileName = $this->getFileName( $code );
 862                         if ( !file_exists( $fileName ) ) {
 863                                 $this->readers[$code] = false;
 864                         } else {
 865                                 $this->readers[$code] = CdbReader::open( $fileName );
 866                         }
 867                 }
 868                 if ( !$this->readers[$code] ) {
 869                         return null;
 870                 } else {
 871                         $value = $this->readers[$code]->get( $key );
 872                         if ( $value === false ) {
 873                                 return null;
 874                         }
 875                         return unserialize( $value );
 876                 }
 877         }
 878
 879         public function startWrite( $code ) {
 880                 if ( !file_exists( $this->directory ) ) {
 881                         if ( !wfMkdirParents( $this->directory ) ) {
 882                                 throw new MWException( "Unable to create the localisation store " .
 883                                         "directory \"{$this->directory}\"" );
 884                         }
 885                 }
 886                 // Close reader to stop permission errors on write
 887                 if( !empty($this->readers[$code]) ) {
 888                         $this->readers[$code]->close();
 889                 }
 890                 $this->writer = CdbWriter::open( $this->getFileName( $code ) );
 891                 $this->currentLang = $code;
 892         }
 893
 894         public function finishWrite() {
 895                 // Close the writer
 896                 $this->writer->close();
 897                 $this->writer = null;
 898                 unset( $this->readers[$this->currentLang] );
 899                 $this->currentLang = null;
 900         }
 901
 902         public function set( $key, $value ) {
 903                 if ( is_null( $this->writer ) ) {
 904                         throw new MWException( __CLASS__.': must call startWrite() before calling set()' );
 905                 }
 906                 $this->writer->set( $key, serialize( $value ) );
 907         }
 908
 909         protected function getFileName( $code ) {
 910                 if ( !$code || strpos( $code, '/' ) !== false ) {
 911                         throw new MWException( __METHOD__.": Invalid language \"$code\"" );
 912                 }
 913                 return "{$this->directory}/l10n_cache-$code.cdb";
 914         }
 915 }
 916
 917 /**
 918  * Null store backend, used to avoid DB errors during install
 919  */
 920 class LCStore_Null implements LCStore {
 921         public function get( $code, $key ) {
 922                 return null;
 923         }
 924
 925         public function startWrite( $code ) {}
 926         public function finishWrite() {}
 927         public function set( $key, $value ) {}
 928 }
 929
 930 /**
 931  * A localisation cache optimised for loading large amounts of data for many
 932  * languages. Used by rebuildLocalisationCache.php.
 933  */
 934 class LocalisationCache_BulkLoad extends LocalisationCache {
 935         /**
 936          * A cache of the contents of data files.
 937          * Core files are serialized to avoid using ~1GB of RAM during a recache.
 938          */
 939         var $fileCache = array();
 940
 941         /**
 942          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
 943          * to keep the most recently used language codes at the end of the array, and
 944          * the language codes that are ready to be deleted at the beginning.
 945          */
 946         var $mruLangs = array();
 947
 948         /**
 949          * Maximum number of languages that may be loaded into $this->data
 950          */
 951         var $maxLoadedLangs = 10;
 952
 953         protected function readPHPFile( $fileName, $fileType ) {
 954                 $serialize = $fileType === 'core';
 955                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
 956                         $data = parent::readPHPFile( $fileName, $fileType );
 957                         if ( $serialize ) {
 958                                 $encData = serialize( $data );
 959                         } else {
 960                                 $encData = $data;
 961                         }
 962                         $this->fileCache[$fileName][$fileType] = $encData;
 963                         return $data;
 964                 } elseif ( $serialize ) {
 965                         return unserialize( $this->fileCache[$fileName][$fileType] );
 966                 } else {
 967                         return $this->fileCache[$fileName][$fileType];
 968                 }
 969         }
 970
 971         public function getItem( $code, $key ) {
 972                 unset( $this->mruLangs[$code] );
 973                 $this->mruLangs[$code] = true;
 974                 return parent::getItem( $code, $key );
 975         }
 976
 977         public function getSubitem( $code, $key, $subkey ) {
 978                 unset( $this->mruLangs[$code] );
 979                 $this->mruLangs[$code] = true;
 980                 return parent::getSubitem( $code, $key, $subkey );
 981         }
 982
 983         public function recache( $code ) {
 984                 parent::recache( $code );
 985                 unset( $this->mruLangs[$code] );
 986                 $this->mruLangs[$code] = true;
 987                 $this->trimCache();
 988         }
 989
 990         public function unload( $code ) {
 991                 unset( $this->mruLangs[$code] );
 992                 parent::unload( $code );
 993         }
 994
 995         /**
 996          * Unload cached languages until there are less than $this->maxLoadedLangs
 997          */
 998         protected function trimCache() {
 999                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
1000                         reset( $this->mruLangs );
1001                         $code = key( $this->mruLangs );
1002                         wfDebug( __METHOD__.": unloading $code\n" );
1003                         $this->unload( $code );
1004                 }
1005         }
1006 }