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