includes/MessageCache.php

   1 <?php
   2 /**
   3  *
   4  * @package MediaWiki
   5  * @subpackage Cache
   6  */
   7
   8 /**
   9  *
  10  */
  11 define( 'MSG_LOAD_TIMEOUT', 60);
  12 define( 'MSG_LOCK_TIMEOUT', 10);
  13 define( 'MSG_WAIT_TIMEOUT', 10);
  14
  15 /**
  16  * Message cache
  17  * Performs various useful MediaWiki namespace-related functions
  18  *
  19  * @package MediaWiki
  20  */
  21 class MessageCache {
  22         var $mCache, $mUseCache, $mDisable, $mExpiry;
  23         var $mMemcKey, $mKeys, $mParserOptions, $mParser;
  24         var $mExtensionMessages = array();
  25         var $mInitialised = false;
  26         var $mDeferred = true;
  27
  28         function __construct( &$memCached, $useDB, $expiry, $memcPrefix) {
  29                 wfProfileIn( __METHOD__ );
  30
  31                 $this->mUseCache = !is_null( $memCached );
  32                 $this->mMemc = &$memCached;
  33                 $this->mDisable = !$useDB;
  34                 $this->mExpiry = $expiry;
  35                 $this->mDisableTransform = false;
  36                 $this->mMemcKey = $memcPrefix.':messages';
  37                 $this->mKeys = false; # initialised on demand
  38                 $this->mInitialised = true;
  39                 $this->mParser = null;
  40
  41                 # When we first get asked for a message,
  42                 # then we'll fill up the cache. If we
  43                 # can return a cache hit, this saves
  44                 # some extra milliseconds
  45                 $this->mDeferred = true;
  46
  47                 wfProfileOut( __METHOD__ );
  48         }
  49
  50         function getParserOptions() {
  51                 if ( !$this->mParserOptions ) {
  52                         $this->mParserOptions = new ParserOptions;
  53                 }
  54                 return $this->mParserOptions;
  55         }
  56
  57         /**
  58          * Try to load the cache from a local file
  59          */
  60         function loadFromLocal( $hash ) {
  61                 global $wgLocalMessageCache;
  62
  63                 $this->mCache = false;
  64                 if ( $wgLocalMessageCache === false ) {
  65                         return;
  66                 }
  67
  68                 $filename = "$wgLocalMessageCache/messages-" . wfWikiID();
  69
  70                 wfSuppressWarnings();
  71                 $file = fopen( $filename, 'r' );
  72                 wfRestoreWarnings();
  73                 if ( !$file ) {
  74                         return;
  75                 }
  76
  77                 // Check to see if the file has the hash specified
  78                 $localHash = fread( $file, 32 );
  79                 if ( $hash == $localHash ) {
  80                         // All good, get the rest of it
  81                         $serialized = fread( $file, 10000000 );
  82                         $this->mCache = unserialize( $serialized );
  83                 }
  84                 fclose( $file );
  85         }
  86
  87         /**
  88          * Save the cache to a local file
  89          */
  90         function saveToLocal( $serialized, $hash ) {
  91                 global $wgLocalMessageCache;
  92
  93                 if ( $wgLocalMessageCache === false ) {
  94                         return;
  95                 }
  96
  97                 $filename = "$wgLocalMessageCache/messages-" . wfWikiID();
  98                 $oldUmask = umask( 0 );
  99                 wfMkdirParents( $wgLocalMessageCache, 0777 );
 100                 umask( $oldUmask );
 101
 102                 $file = fopen( $filename, 'w' );
 103                 if ( !$file ) {
 104                         wfDebug( "Unable to open local cache file for writing\n" );
 105                         return;
 106                 }
 107
 108                 fwrite( $file, $hash . $serialized );
 109                 fclose( $file );
 110                 @chmod( $filename, 0666 );
 111         }
 112
 113         function loadFromScript( $hash ) {
 114                 global $wgLocalMessageCache;
 115                 if ( $wgLocalMessageCache === false ) {
 116                         return;
 117                 }
 118
 119                 $filename = "$wgLocalMessageCache/messages-" . wfWikiID();
 120
 121                 wfSuppressWarnings();
 122                 $file = fopen( $filename, 'r' );
 123                 wfRestoreWarnings();
 124                 if ( !$file ) {
 125                         return;
 126                 }
 127                 $localHash=substr(fread($file,40),8);
 128                 fclose($file);
 129                 if ($hash!=$localHash) {
 130                         return;
 131                 }
 132                 require("$wgLocalMessageCache/messages-" . wfWikiID());
 133         }
 134
 135         function saveToScript($array, $hash) {
 136                 global $wgLocalMessageCache;
 137                 if ( $wgLocalMessageCache === false ) {
 138                         return;
 139                 }
 140
 141                 $filename = "$wgLocalMessageCache/messages-" . wfWikiID();
 142                 $oldUmask = umask( 0 );
 143                 wfMkdirParents( $wgLocalMessageCache, 0777 );
 144                 umask( $oldUmask );
 145                 $file = fopen( $filename.'.tmp', 'w');
 146                 fwrite($file,"<?php\n//$hash\n\n \$this->mCache = array(");
 147
 148                 foreach ($array as $key => $message) {
 149                         fwrite($file, "'". $this->escapeForScript($key).
 150                                 "' => '" . $this->escapeForScript($message).
 151                                 "',\n");
 152                 }
 153                 fwrite($file,");\n?>");
 154                 fclose($file);
 155                 rename($filename.'.tmp',$filename);
 156         }
 157
 158         function escapeForScript($string) {
 159                 $string = str_replace( '\\', '\\\\', $string );
 160                 $string = str_replace( '\'', '\\\'', $string );
 161                 return $string;
 162         }
 163
 164         /**
 165          * Loads messages either from memcached or the database, if not disabled
 166          * On error, quietly switches to a fallback mode
 167          * Returns false for a reportable error, true otherwise
 168          */
 169         function load() {
 170                 global $wgLocalMessageCache, $wgLocalMessageCacheSerialized;
 171
 172                 if ( $this->mDisable ) {
 173                         static $shownDisabled = false;
 174                         if ( !$shownDisabled ) {
 175                                 wfDebug( "MessageCache::load(): disabled\n" );
 176                                 $shownDisabled = true;
 177                         }
 178                         return true;
 179                 }
 180                 $fname = 'MessageCache::load';
 181                 wfProfileIn( $fname );
 182                 $success = true;
 183
 184                 if ( $this->mUseCache ) {
 185                         $this->mCache = false;
 186
 187                         # Try local cache
 188                         wfProfileIn( $fname.'-fromlocal' );
 189                         $hash = $this->mMemc->get( "{$this->mMemcKey}-hash" );
 190                         if ( $hash ) {
 191                                 if ($wgLocalMessageCacheSerialized) {
 192                                         $this->loadFromLocal( $hash );
 193                                 } else {
 194                                         $this->loadFromScript( $hash );
 195                                 }
 196                                 if ( $this->mCache ) {
 197                                         wfDebug( "MessageCache::load(): got from local cache\n" );
 198                                 }
 199                         }
 200                         wfProfileOut( $fname.'-fromlocal' );
 201
 202                         # Try memcached
 203                         if ( !$this->mCache ) {
 204                                 wfProfileIn( $fname.'-fromcache' );
 205                                 $this->mCache = $this->mMemc->get( $this->mMemcKey );
 206                                 if ( $this->mCache ) {
 207                                         wfDebug( "MessageCache::load(): got from global cache\n" );
 208                                         # Save to local cache
 209                                         if ( $wgLocalMessageCache !== false ) {
 210                                                 $serialized = serialize( $this->mCache );
 211                                                 if ( !$hash ) {
 212                                                         $hash = md5( $serialized );
 213                                                         $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 214                                                 }
 215                                                 if ($wgLocalMessageCacheSerialized) {
 216                                                         $this->saveToLocal( $serialized,$hash );
 217                                                 } else {
 218                                                         $this->saveToScript( $this->mCache, $hash );
 219                                                 }
 220                                         }
 221                                 }
 222                                 wfProfileOut( $fname.'-fromcache' );
 223                         }
 224
 225
 226                         # If there's nothing in memcached, load all the messages from the database
 227                         if ( !$this->mCache ) {
 228                                 wfDebug( "MessageCache::load(): loading all messages\n" );
 229                                 $this->lock();
 230                                 # Other threads don't need to load the messages if another thread is doing it.
 231                                 $success = $this->mMemc->add( $this->mMemcKey.'-status', "loading", MSG_LOAD_TIMEOUT );
 232                                 if ( $success ) {
 233                                         wfProfileIn( $fname.'-load' );
 234                                         $this->loadFromDB();
 235                                         wfProfileOut( $fname.'-load' );
 236
 237                                         # Save in memcached
 238                                         # Keep trying if it fails, this is kind of important
 239                                         wfProfileIn( $fname.'-save' );
 240                                         for ($i=0; $i<20 &&
 241                                                    !$this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 242                                              $i++ ) {
 243                                                 usleep(mt_rand(500000,1500000));
 244                                         }
 245
 246                                         # Save to local cache
 247                                         if ( $wgLocalMessageCache !== false ) {
 248                                                 $serialized = serialize( $this->mCache );
 249                                                 $hash = md5( $serialized );
 250                                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 251                                                 if ($wgLocalMessageCacheSerialized) {
 252                                                         $this->saveToLocal( $serialized,$hash );
 253                                                 } else {
 254                                                         $this->saveToScript( $this->mCache, $hash );
 255                                                 }
 256                                         }
 257
 258                                         wfProfileOut( $fname.'-save' );
 259                                         if ( $i == 20 ) {
 260                                                 $this->mMemc->set( $this->mMemcKey.'-status', 'error', 60*5 );
 261                                                 wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
 262                                         }
 263                                 }
 264                                 $this->unlock();
 265                         }
 266
 267                         if ( !is_array( $this->mCache ) ) {
 268                                 wfDebug( "MessageCache::load(): individual message mode\n" );
 269                                 # If it is 'loading' or 'error', switch to individual message mode, otherwise disable
 270                                 # Causing too much DB load, disabling -- TS
 271                                 $this->mDisable = true;
 272                                 /*
 273                                 if ( $this->mCache == "loading" ) {
 274                                         $this->mUseCache = false;
 275                                 } elseif ( $this->mCache == "error" ) {
 276                                         $this->mUseCache = false;
 277                                         $success = false;
 278                                 } else {
 279                                         $this->mDisable = true;
 280                                         $success = false;
 281                                 }*/
 282                                 $this->mCache = false;
 283                         }
 284                 }
 285                 wfProfileOut( $fname );
 286                 $this->mDeferred = false;
 287                 return $success;
 288         }
 289
 290         /**
 291          * Loads all or main part of cacheable messages from the database
 292          */
 293         function loadFromDB() {
 294                 global $wgLang;
 295
 296                 $fname = 'MessageCache::loadFromDB';
 297                 $dbr =& wfGetDB( DB_SLAVE );
 298                 if ( !$dbr ) {
 299                         throw new MWException( 'Invalid database object' );
 300                 }
 301                 $res = $dbr->select( array( 'page', 'revision', 'text' ),
 302                         array( 'page_title', 'old_text', 'old_flags' ),
 303                         'page_is_redirect=0 AND page_namespace='.NS_MEDIAWIKI.' AND page_latest=rev_id AND rev_text_id=old_id',
 304                         $fname
 305                 );
 306
 307                 $this->mCache = array();
 308                 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
 309                         $this->mCache[$row->page_title] = Revision::getRevisionText( $row );
 310                 }
 311
 312                 # Negative caching
 313                 # Go through the language array and the extension array and make a note of
 314                 # any keys missing from the cache
 315                 $allMessages = Language::getMessagesFor( 'en' );
 316                 foreach ( $allMessages as $key => $unused ) {
 317                         $uckey = $wgLang->ucfirst( $key );
 318                         if ( !array_key_exists( $uckey, $this->mCache ) ) {
 319                                 $this->mCache[$uckey] = false;
 320                         }
 321                 }
 322
 323                 # Make sure all extension messages are available
 324                 MessageCache::loadAllMessages();
 325
 326                 # Add them to the cache
 327                 foreach ( $this->mExtensionMessages as $key => $unused ) {
 328                         $uckey = $wgLang->ucfirst( $key );
 329                         if ( !array_key_exists( $uckey, $this->mCache ) &&
 330                          ( isset( $this->mExtensionMessages[$key][$wgLang->getCode()] ) || isset( $this->mExtensionMessages[$key]['en'] ) )  ) {
 331                                 $this->mCache[$uckey] = false;
 332                         }
 333                 }
 334
 335                 $dbr->freeResult( $res );
 336         }
 337
 338         /**
 339          * Not really needed anymore
 340          */
 341         function getKeys() {
 342                 global $wgContLang;
 343                 if ( !$this->mKeys ) {
 344                         $this->mKeys = array();
 345                         $allMessages = Language::getMessagesFor( 'en' );
 346                         foreach ( $allMessages as $key => $unused ) {
 347                                 $title = $wgContLang->ucfirst( $key );
 348                                 array_push( $this->mKeys, $title );
 349                         }
 350                 }
 351                 return $this->mKeys;
 352         }
 353
 354         /**
 355          * @deprecated
 356          */
 357         function isCacheable( $key ) {
 358                 return true;
 359         }
 360
 361         function replace( $title, $text ) {
 362                 global $wgLocalMessageCache, $wgLocalMessageCacheSerialized, $parserMemc;
 363
 364                 $this->lock();
 365                 $this->load();
 366                 $parserMemc->delete(wfMemcKey('sidebar'));
 367                 if ( is_array( $this->mCache ) ) {
 368                         $this->mCache[$title] = $text;
 369                         $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 370
 371                         # Save to local cache
 372                         if ( $wgLocalMessageCache !== false ) {
 373                                 $serialized = serialize( $this->mCache );
 374                                 $hash = md5( $serialized );
 375                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 376                                 if ($wgLocalMessageCacheSerialized) {
 377                                         $this->saveToLocal( $serialized,$hash );
 378                                 } else {
 379                                         $this->saveToScript( $this->mCache, $hash );
 380                                 }
 381                         }
 382
 383
 384                 }
 385                 $this->unlock();
 386         }
 387
 388         /**
 389          * Returns success
 390          * Represents a write lock on the messages key
 391          */
 392         function lock() {
 393                 if ( !$this->mUseCache ) {
 394                         return true;
 395                 }
 396
 397                 $lockKey = $this->mMemcKey . 'lock';
 398                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 399                         sleep(1);
 400                 }
 401
 402                 return $i >= MSG_WAIT_TIMEOUT;
 403         }
 404
 405         function unlock() {
 406                 if ( !$this->mUseCache ) {
 407                         return;
 408                 }
 409
 410                 $lockKey = $this->mMemcKey . 'lock';
 411                 $this->mMemc->delete( $lockKey );
 412         }
 413
 414         function get( $key, $useDB = true, $forcontent = true, $isfullkey = false ) {
 415                 global $wgContLanguageCode, $wgContLang, $wgLang;
 416                 if( $forcontent ) {
 417                         $lang =& $wgContLang;
 418                 } else {
 419                         $lang =& $wgLang;
 420                 }
 421                 $langcode = $lang->getCode();
 422                 # If uninitialised, someone is trying to call this halfway through Setup.php
 423                 if( !$this->mInitialised ) {
 424                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 425                 }
 426                 # If cache initialization was deferred, start it now.
 427                 if( $this->mDeferred && !$this->mDisable && $useDB ) {
 428                         $this->load();
 429                 }
 430
 431                 $message = false;
 432                 if( !$this->mDisable && $useDB ) {
 433                         $title = $wgContLang->ucfirst( $key );
 434                         if(!$isfullkey && ($langcode != $wgContLanguageCode) ) {
 435                                 $title .= '/' . $langcode;
 436                         }
 437                         $message = $this->getFromCache( $title );
 438                 }
 439                 # Try the extension array
 440                 if( $message === false && array_key_exists( $key, $this->mExtensionMessages ) ) {
 441                         if ( isset( $this->mExtensionMessages[$key][$langcode] ) ) {
 442                                 $message = $this->mExtensionMessages[$key][$langcode];
 443                         } elseif ( isset( $this->mExtensionMessages[$key]['en'] ) ) {
 444                                 $message = $this->mExtensionMessages[$key]['en'];
 445                         }
 446                 }
 447
 448                 # Try the array in the language object
 449                 if( $message === false ) {
 450                         #wfDebug( "Trying language object for message $key\n" );
 451                         wfSuppressWarnings();
 452                         $message = $lang->getMessage( $key );
 453                         wfRestoreWarnings();
 454                         if ( is_null( $message ) ) {
 455                                 $message = false;
 456                         }
 457                 }
 458
 459                 # Try the array of another language
 460                 if( $message === false && strpos( $key, '/' ) ) {
 461                         $message = explode( '/', $key );
 462                         if ( $message[1] ) {
 463                                 wfSuppressWarnings();
 464                                 $message = Language::getMessageFor( $message[0], $message[1] );
 465                                 wfRestoreWarnings();
 466                                 if ( is_null( $message ) ) {
 467                                         $message = false;
 468                                 }
 469                         } else {
 470                                 $message = false;
 471                         }
 472                 }
 473
 474                 # Is this a custom message? Try the default language in the db...
 475                 if( ($message === false || $message === '-' ) &&
 476                         !$this->mDisable && $useDB &&
 477                         !$isfullkey && ($langcode != $wgContLanguageCode) ) {
 478                         $message = $this->getFromCache( $wgContLang->ucfirst( $key ) );
 479                 }
 480
 481                 # Final fallback
 482                 if( $message === false ) {
 483                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 484                 }
 485
 486                 # Replace brace tags
 487                 $message = $this->transform( $message );
 488                 return $message;
 489         }
 490
 491         function getFromCache( $title ) {
 492                 $message = false;
 493
 494                 # Try the cache
 495                 if( $this->mUseCache && is_array( $this->mCache ) && array_key_exists( $title, $this->mCache ) ) {
 496                         return $this->mCache[$title];
 497                 }
 498
 499                 # Try individual message cache
 500                 if ( $this->mUseCache ) {
 501                         $message = $this->mMemc->get( $this->mMemcKey . ':' . $title );
 502                         if ( $message == '###NONEXISTENT###' ) {
 503                                 $this->mCache[$title] = false;
 504                                 return false;
 505                         } elseif( !is_null( $message ) ) {
 506                                 $this->mCache[$title] = $message;
 507                                 return $message;
 508                         } else {
 509                                 $message = false;
 510                         }
 511                 }
 512
 513                 # Call message Hooks, in case they are defined
 514                 wfRunHooks('MessagesPreLoad',array($title,&$message));
 515
 516                 # If it wasn't in the cache, load each message from the DB individually
 517                 $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
 518                 if( $revision ) {
 519                         $message = $revision->getText();
 520                         if ($this->mUseCache) {
 521                                 $this->mCache[$title]=$message;
 522                                 /* individual messages may be often
 523                                    recached until proper purge code exists
 524                                 */
 525                                 $this->mMemc->set( $this->mMemcKey . ':' . $title, $message, 300 );
 526                         }
 527                 } else {
 528                         # Negative caching
 529                         # Use some special text instead of false, because false gets converted to '' somewhere
 530                         $this->mMemc->set( $this->mMemcKey . ':' . $title, '###NONEXISTENT###', $this->mExpiry );
 531                         $this->mCache[$title] = false;
 532                 }
 533
 534                 return $message;
 535         }
 536
 537         function transform( $message ) {
 538                 global $wgParser;
 539                 if ( !$this->mParser && isset( $wgParser ) ) {
 540                         # Do some initialisation so that we don't have to do it twice
 541                         $wgParser->firstCallInit();
 542                         # Clone it and store it
 543                         $this->mParser = clone $wgParser;
 544                 }
 545                 if ( !$this->mDisableTransform && $this->mParser ) {
 546                         if( strpos( $message, '{{' ) !== false ) {
 547                                 $message = $this->mParser->transformMsg( $message, $this->getParserOptions() );
 548                         }
 549                 }
 550                 return $message;
 551         }
 552
 553         function disable() { $this->mDisable = true; }
 554         function enable() { $this->mDisable = false; }
 555         function disableTransform() { $this->mDisableTransform = true; }
 556         function enableTransform() { $this->mDisableTransform = false; }
 557         function setTransform( $x ) { $this->mDisableTransform = $x; }
 558         function getTransform() { return $this->mDisableTransform; }
 559
 560         /**
 561          * Add a message to the cache
 562          *
 563          * @param mixed $key
 564          * @param mixed $value
 565          * @param string $lang The messages language, English by default
 566          */
 567         function addMessage( $key, $value, $lang = 'en' ) {
 568                 $this->mExtensionMessages[$key][$lang] = $value;
 569         }
 570
 571         /**
 572          * Add an associative array of message to the cache
 573          *
 574          * @param array $messages An associative array of key => values to be added
 575          * @param string $lang The messages language, English by default
 576          */
 577         function addMessages( $messages, $lang = 'en' ) {
 578                 wfProfileIn( __METHOD__ );
 579                 foreach ( $messages as $key => $value ) {
 580                         $this->addMessage( $key, $value, $lang );
 581                 }
 582                 wfProfileOut( __METHOD__ );
 583         }
 584
 585         /**
 586          * Get the extension messages for a specific language
 587          *
 588          * @param string $lang The messages language, English by default
 589          */
 590         function getExtensionMessagesFor( $lang = 'en' ) {
 591                 wfProfileIn( __METHOD__ );
 592                 $messages = array();
 593                 foreach( $this->mExtensionMessages as $key => $message ) {
 594                         if ( isset( $message[$lang] ) ) {
 595                                 $messages[$key] = $message[$lang];
 596                         } elseif ( isset( $message['en'] ) ) {
 597                                 $messages[$key] = $message['en'];
 598                         }
 599                 }
 600                 wfProfileOut( __METHOD__ );
 601                 return $messages;
 602         }
 603
 604         /**
 605          * Clear all stored messages. Mainly used after a mass rebuild.
 606          */
 607         function clear() {
 608                 global $wgLocalMessageCache;
 609                 if( $this->mUseCache ) {
 610                         # Global cache
 611                         $this->mMemc->delete( $this->mMemcKey );
 612                         # Invalidate all local caches
 613                         $this->mMemc->delete( "{$this->mMemcKey}-hash" );
 614                 }
 615         }
 616
 617         static function loadAllMessages() {
 618                 # Some extensions will load their messages when you load their class file
 619                 wfLoadAllExtensions();
 620                 # Others will respond to this hook
 621                 wfRunHooks( 'LoadAllMessages' );
 622                 # Still others will respond to neither, they are EVIL. We sometimes need to know!
 623         }
 624 }
 625 ?>