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