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
  40                 wfProfileIn( __METHOD__.'-parseropt' );
  41                 $this->mParserOptions = new ParserOptions( $u=NULL );
  42                 wfProfileOut( __METHOD__.'-parseropt' );
  43                 $this->mParser = null;
  44
  45                 # When we first get asked for a message,
  46                 # then we'll fill up the cache. If we
  47                 # can return a cache hit, this saves
  48                 # some extra milliseconds
  49                 $this->mDeferred = true;
  50
  51                 wfProfileOut( __METHOD__ );
  52         }
  53
  54         /**
  55          * Try to load the cache from a local file
  56          */
  57         function loadFromLocal( $hash ) {
  58                 global $wgLocalMessageCache, $wgDBname;
  59
  60                 $this->mCache = false;
  61                 if ( $wgLocalMessageCache === false ) {
  62                         return;
  63                 }
  64
  65                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
  66
  67                 wfSuppressWarnings();
  68                 $file = fopen( $filename, 'r' );
  69                 wfRestoreWarnings();
  70                 if ( !$file ) {
  71                         return;
  72                 }
  73
  74                 // Check to see if the file has the hash specified
  75                 $localHash = fread( $file, 32 );
  76                 if ( $hash == $localHash ) {
  77                         // All good, get the rest of it
  78                         $serialized = fread( $file, 1000000 );
  79                         $this->mCache = unserialize( $serialized );
  80                 }
  81                 fclose( $file );
  82         }
  83
  84         /**
  85          * Save the cache to a local file
  86          */
  87         function saveToLocal( $serialized, $hash ) {
  88                 global $wgLocalMessageCache, $wgDBname;
  89
  90                 if ( $wgLocalMessageCache === false ) {
  91                         return;
  92                 }
  93
  94                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
  95                 $oldUmask = umask( 0 );
  96                 wfMkdirParents( $wgLocalMessageCache, 0777 );
  97                 umask( $oldUmask );
  98
  99                 $file = fopen( $filename, 'w' );
 100                 if ( !$file ) {
 101                         wfDebug( "Unable to open local cache file for writing\n" );
 102                         return;
 103                 }
 104
 105                 fwrite( $file, $hash . $serialized );
 106                 fclose( $file );
 107                 @chmod( $filename, 0666 );
 108         }
 109
 110         function loadFromScript( $hash ) {
 111                 global $wgLocalMessageCache, $wgDBname;
 112                 if ( $wgLocalMessageCache === false ) {
 113                         return;
 114                 }
 115
 116                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
 117
 118                 wfSuppressWarnings();
 119                 $file = fopen( $filename, 'r' );
 120                 wfRestoreWarnings();
 121                 if ( !$file ) {
 122                         return;
 123                 }
 124                 $localHash=substr(fread($file,40),8);
 125                 fclose($file);
 126                 if ($hash!=$localHash) {
 127                         return;
 128                 }
 129                 require("$wgLocalMessageCache/messages-$wgDBname");
 130         }
 131
 132         function saveToScript($array, $hash) {
 133                 global $wgLocalMessageCache, $wgDBname;
 134                 if ( $wgLocalMessageCache === false ) {
 135                         return;
 136                 }
 137
 138                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
 139                 $oldUmask = umask( 0 );
 140                 wfMkdirParents( $wgLocalMessageCache, 0777 );
 141                 umask( $oldUmask );
 142                 $file = fopen( $filename.'.tmp', 'w');
 143                 fwrite($file,"<?php\n//$hash\n\n \$this->mCache = array(");
 144
 145                 foreach ($array as $key => $message) {
 146                         fwrite($file, "'". $this->escapeForScript($key).
 147                                 "' => '" . $this->escapeForScript($message).
 148                                 "',\n");
 149                 }
 150                 fwrite($file,");\n?>");
 151                 fclose($file);
 152                 rename($filename.'.tmp',$filename);
 153         }
 154
 155         function escapeForScript($string) {
 156                 $string = str_replace( '\\', '\\\\', $string );
 157                 $string = str_replace( '\'', '\\\'', $string );
 158                 return $string;
 159         }
 160
 161         /**
 162          * Loads messages either from memcached or the database, if not disabled
 163          * On error, quietly switches to a fallback mode
 164          * Returns false for a reportable error, true otherwise
 165          */
 166         function load() {
 167                 global $wgLocalMessageCache, $wgLocalMessageCacheSerialized;
 168
 169                 if ( $this->mDisable ) {
 170                         static $shownDisabled = false;
 171                         if ( !$shownDisabled ) {
 172                                 wfDebug( "MessageCache::load(): disabled\n" );
 173                                 $shownDisabled = true;
 174                         }
 175                         return true;
 176                 }
 177                 $fname = 'MessageCache::load';
 178                 wfProfileIn( $fname );
 179                 $success = true;
 180
 181                 if ( $this->mUseCache ) {
 182                         $this->mCache = false;
 183
 184                         # Try local cache
 185                         wfProfileIn( $fname.'-fromlocal' );
 186                         $hash = $this->mMemc->get( "{$this->mMemcKey}-hash" );
 187                         if ( $hash ) {
 188                                 if ($wgLocalMessageCacheSerialized) {
 189                                         $this->loadFromLocal( $hash );
 190                                 } else {
 191                                         $this->loadFromScript( $hash );
 192                                 }
 193                         }
 194                         wfProfileOut( $fname.'-fromlocal' );
 195
 196                         # Try memcached
 197                         if ( !$this->mCache ) {
 198                                 wfProfileIn( $fname.'-fromcache' );
 199                                 $this->mCache = $this->mMemc->get( $this->mMemcKey );
 200
 201                                 # Save to local cache
 202                                 if ( $wgLocalMessageCache !== false ) {
 203                                         $serialized = serialize( $this->mCache );
 204                                         if ( !$hash ) {
 205                                                 $hash = md5( $serialized );
 206                                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 207                                         }
 208                                         if ($wgLocalMessageCacheSerialized) {
 209                                                 $this->saveToLocal( $serialized,$hash );
 210                                         } else {
 211                                                 $this->saveToScript( $this->mCache, $hash );
 212                                         }
 213                                 }
 214                                 wfProfileOut( $fname.'-fromcache' );
 215                         }
 216
 217
 218                         # If there's nothing in memcached, load all the messages from the database
 219                         if ( !$this->mCache ) {
 220                                 wfDebug( "MessageCache::load(): loading all messages\n" );
 221                                 $this->lock();
 222                                 # Other threads don't need to load the messages if another thread is doing it.
 223                                 $success = $this->mMemc->add( $this->mMemcKey.'-status', "loading", MSG_LOAD_TIMEOUT );
 224                                 if ( $success ) {
 225                                         wfProfileIn( $fname.'-load' );
 226                                         $this->loadFromDB();
 227                                         wfProfileOut( $fname.'-load' );
 228
 229                                         # Save in memcached
 230                                         # Keep trying if it fails, this is kind of important
 231                                         wfProfileIn( $fname.'-save' );
 232                                         for ($i=0; $i<20 &&
 233                                                    !$this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 234                                              $i++ ) {
 235                                                 usleep(mt_rand(500000,1500000));
 236                                         }
 237
 238                                         # Save to local cache
 239                                         if ( $wgLocalMessageCache !== false ) {
 240                                                 $serialized = serialize( $this->mCache );
 241                                                 $hash = md5( $serialized );
 242                                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 243                                                 if ($wgLocalMessageCacheSerialized) {
 244                                                         $this->saveToLocal( $serialized,$hash );
 245                                                 } else {
 246                                                         $this->saveToScript( $this->mCache, $hash );
 247                                                 }
 248                                         }
 249
 250                                         wfProfileOut( $fname.'-save' );
 251                                         if ( $i == 20 ) {
 252                                                 $this->mMemc->set( $this->mMemcKey.'-status', 'error', 60*5 );
 253                                                 wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
 254                                         }
 255                                 }
 256                                 $this->unlock();
 257                         }
 258
 259                         if ( !is_array( $this->mCache ) ) {
 260                                 wfDebug( "MessageCache::load(): individual message mode\n" );
 261                                 # If it is 'loading' or 'error', switch to individual message mode, otherwise disable
 262                                 # Causing too much DB load, disabling -- TS
 263                                 $this->mDisable = true;
 264                                 /*
 265                                 if ( $this->mCache == "loading" ) {
 266                                         $this->mUseCache = false;
 267                                 } elseif ( $this->mCache == "error" ) {
 268                                         $this->mUseCache = false;
 269                                         $success = false;
 270                                 } else {
 271                                         $this->mDisable = true;
 272                                         $success = false;
 273                                 }*/
 274                                 $this->mCache = false;
 275                         }
 276                 }
 277                 wfProfileOut( $fname );
 278                 $this->mDeferred = false;
 279                 return $success;
 280         }
 281
 282         /**
 283          * Loads all or main part of cacheable messages from the database
 284          */
 285         function loadFromDB() {
 286                 global $wgAllMessagesEn, $wgLang;
 287
 288                 $fname = 'MessageCache::loadFromDB';
 289                 $dbr =& wfGetDB( DB_SLAVE );
 290                 if ( !$dbr ) {
 291                         throw new MWException( 'Invalid database object' );
 292                 }
 293                 $conditions = array( 'page_is_redirect' => 0,
 294                                         'page_namespace' => NS_MEDIAWIKI);
 295                 $res = $dbr->select( array( 'page', 'revision', 'text' ),
 296                         array( 'page_title', 'old_text', 'old_flags' ),
 297                         'page_is_redirect=0 AND page_namespace='.NS_MEDIAWIKI.' AND page_latest=rev_id AND rev_text_id=old_id',
 298                         $fname
 299                 );
 300
 301                 $this->mCache = array();
 302                 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
 303                         $this->mCache[$row->page_title] = Revision::getRevisionText( $row );
 304                 }
 305
 306                 # Negative caching
 307                 # Go through the language array and the extension array and make a note of
 308                 # any keys missing from the cache
 309                 foreach ( $wgAllMessagesEn as $key => $value ) {
 310                         $uckey = $wgLang->ucfirst( $key );
 311                         if ( !array_key_exists( $uckey, $this->mCache ) ) {
 312                                 $this->mCache[$uckey] = false;
 313                         }
 314                 }
 315
 316                 # Make sure all extension messages are available
 317                 wfLoadAllExtensions();
 318
 319                 # Add them to the cache
 320                 foreach ( $this->mExtensionMessages as $key => $value ) {
 321                         $uckey = $wgLang->ucfirst( $key );
 322                         if ( !array_key_exists( $uckey, $this->mCache ) &&
 323                          ( isset( $this->mExtensionMessages[$key][$wgLang->getCode()] ) || isset( $this->mExtensionMessages[$key]['en'] ) )  ) {
 324                                 $this->mCache[$uckey] = false;
 325                         }
 326                 }
 327
 328                 $dbr->freeResult( $res );
 329         }
 330
 331         /**
 332          * Not really needed anymore
 333          */
 334         function getKeys() {
 335                 global $wgAllMessagesEn, $wgContLang;
 336                 if ( !$this->mKeys ) {
 337                         $this->mKeys = array();
 338                         foreach ( $wgAllMessagesEn as $key => $value ) {
 339                                 $title = $wgContLang->ucfirst( $key );
 340                                 array_push( $this->mKeys, $title );
 341                         }
 342                 }
 343                 return $this->mKeys;
 344         }
 345
 346         /**
 347          * @deprecated
 348          */
 349         function isCacheable( $key ) {
 350                 return true;
 351         }
 352
 353         function replace( $title, $text ) {
 354                 global $wgLocalMessageCache, $wgLocalMessageCacheSerialized, $parserMemc, $wgDBname;
 355
 356                 $this->lock();
 357                 $this->load();
 358                 $parserMemc->delete("$wgDBname:sidebar");
 359                 if ( is_array( $this->mCache ) ) {
 360                         $this->mCache[$title] = $text;
 361                         $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 362
 363                         # Save to local cache
 364                         if ( $wgLocalMessageCache !== false ) {
 365                                 $serialized = serialize( $this->mCache );
 366                                 $hash = md5( $serialized );
 367                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 368                                 if ($wgLocalMessageCacheSerialized) {
 369                                         $this->saveToLocal( $serialized,$hash );
 370                                 } else {
 371                                         $this->saveToScript( $this->mCache, $hash );
 372                                 }
 373                         }
 374
 375
 376                 }
 377                 $this->unlock();
 378         }
 379
 380         /**
 381          * Returns success
 382          * Represents a write lock on the messages key
 383          */
 384         function lock() {
 385                 if ( !$this->mUseCache ) {
 386                         return true;
 387                 }
 388
 389                 $lockKey = $this->mMemcKey . 'lock';
 390                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 391                         sleep(1);
 392                 }
 393
 394                 return $i >= MSG_WAIT_TIMEOUT;
 395         }
 396
 397         function unlock() {
 398                 if ( !$this->mUseCache ) {
 399                         return;
 400                 }
 401
 402                 $lockKey = $this->mMemcKey . 'lock';
 403                 $this->mMemc->delete( $lockKey );
 404         }
 405
 406         function get( $key, $useDB, $forcontent=true, $isfullkey = false ) {
 407                 global $wgContLanguageCode;
 408                 if( $forcontent ) {
 409                         global $wgContLang;
 410                         $lang =& $wgContLang;
 411                         $langcode = $wgContLanguageCode;
 412                 } else {
 413                         global $wgLang, $wgLanguageCode;
 414                         $lang =& $wgLang;
 415                         $langcode = $wgLanguageCode;
 416                 }
 417                 # If uninitialised, someone is trying to call this halfway through Setup.php
 418                 if( !$this->mInitialised ) {
 419                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 420                 }
 421                 # If cache initialization was deferred, start it now.
 422                 if( $this->mDeferred && !$this->mDisable && $useDB ) {
 423                         $this->load();
 424                 }
 425
 426                 $message = false;
 427                 if( !$this->mDisable && $useDB ) {
 428                         $title = $lang->ucfirst( $key );
 429                         if(!$isfullkey && ($langcode != $wgContLanguageCode) ) {
 430                                 $title .= '/' . $langcode;
 431                         }
 432                         $message = $this->getFromCache( $title );
 433                 }
 434                 # Try the extension array
 435                 if( $message === false && array_key_exists( $key, $this->mExtensionMessages ) ) {
 436                         if ( isset( $this->mExtensionMessages[$key][$langcode] ) ) {
 437                                 $message = $this->mExtensionMessages[$key][$langcode];
 438                         } elseif ( isset( $this->mExtensionMessages[$key]['en'] ) ) {
 439                                 $message = $this->mExtensionMessages[$key]['en'];
 440                         }
 441                 }
 442
 443                 # Try the array in the language object
 444                 if( $message === false ) {
 445                         wfSuppressWarnings();
 446                         $message = $lang->getMessage( $key );
 447                         wfRestoreWarnings();
 448                         if ( is_null( $message ) ) {
 449                                 $message = false;
 450                         }
 451                 }
 452
 453                 # Try the English array
 454                 if( $message === false && $langcode != 'en' ) {
 455                         wfSuppressWarnings();
 456                         $message = Language::getMessage( $key );
 457                         wfRestoreWarnings();
 458                         if ( is_null( $message ) ) {
 459                                 $message = false;
 460                         }
 461                 }
 462
 463                 # Is this a custom message? Try the default language in the db...
 464                 if( ($message === false || $message === '-' ) &&
 465                         !$this->mDisable && $useDB &&
 466                         !$isfullkey && ($langcode != $wgContLanguageCode) ) {
 467                         $message = $this->getFromCache( $lang->ucfirst( $key ) );
 468                 }
 469
 470                 # Final fallback
 471                 if( $message === false ) {
 472                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 473                 }
 474
 475                 # Replace brace tags
 476                 $message = $this->transform( $message );
 477                 return $message;
 478         }
 479
 480         function getFromCache( $title ) {
 481                 $message = false;
 482
 483                 # Try the cache
 484                 if( $this->mUseCache && is_array( $this->mCache ) && array_key_exists( $title, $this->mCache ) ) {
 485                         return $this->mCache[$title];
 486                 }
 487
 488                 # Try individual message cache
 489                 if ( $this->mUseCache ) {
 490                         $message = $this->mMemc->get( $this->mMemcKey . ':' . $title );
 491                         if ( $message == '###NONEXISTENT###' ) {
 492                                 return false;
 493                         } elseif( !is_null( $message ) ) {
 494                                 $this->mCache[$title] = $message;
 495                                 return $message;
 496                         } else {
 497                                 $message = false;
 498                         }
 499                 }
 500
 501                 # Call message Hooks, in case they are defined
 502                 wfRunHooks('MessagesPreLoad',array($title,&$message));
 503
 504                 # If it wasn't in the cache, load each message from the DB individually
 505                 $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
 506                 if( $revision ) {
 507                         $message = $revision->getText();
 508                         if ($this->mUseCache) {
 509                                 $this->mCache[$title]=$message;
 510                                 /* individual messages may be often
 511                                    recached until proper purge code exists
 512                                 */
 513                                 $this->mMemc->set( $this->mMemcKey . ':' . $title, $message, 300 );
 514                         }
 515                 } else {
 516                         # Negative caching
 517                         # Use some special text instead of false, because false gets converted to '' somewhere
 518                         $this->mMemc->set( $this->mMemcKey . ':' . $title, '###NONEXISTENT###', $this->mExpiry );
 519                 }
 520
 521                 return $message;
 522         }
 523
 524         function transform( $message ) {
 525                 global $wgParser;
 526                 if ( !$this->mParser && isset( $wgParser ) ) {
 527                         # Do some initialisation so that we don't have to do it twice
 528                         $wgParser->firstCallInit();
 529                         # Clone it and store it
 530                         $this->mParser = clone $wgParser;
 531                 }
 532                 if ( !$this->mDisableTransform && $this->mParser ) {
 533                         if( strpos( $message, '{{' ) !== false ) {
 534                                 $message = $this->mParser->transformMsg( $message, $this->mParserOptions );
 535                         }
 536                 }
 537                 return $message;
 538         }
 539
 540         function disable() { $this->mDisable = true; }
 541         function enable() { $this->mDisable = false; }
 542         function disableTransform() { $this->mDisableTransform = true; }
 543         function enableTransform() { $this->mDisableTransform = false; }
 544         function setTransform( $x ) { $this->mDisableTransform = $x; }
 545         function getTransform() { return $this->mDisableTransform; }
 546
 547         /**
 548          * Add a message to the cache
 549          *
 550          * @param mixed $key
 551          * @param mixed $value
 552          * @param string $lang The messages language, English by default
 553          */
 554         function addMessage( $key, $value, $lang = 'en' ) {
 555                 $this->mExtensionMessages[$key][$lang] = $value;
 556         }
 557
 558         /**
 559          * Add an associative array of message to the cache
 560          *
 561          * @param array $messages An associative array of key => values to be added
 562          * @param string $lang The messages language, English by default
 563          */
 564         function addMessages( $messages, $lang = 'en' ) {
 565                 wfProfileIn( __METHOD__ );
 566                 foreach ( $messages as $key => $value ) {
 567                         $this->addMessage( $key, $value, $lang );
 568                 }
 569                 wfProfileOut( __METHOD__ );
 570         }
 571
 572         /**
 573          * Clear all stored messages. Mainly used after a mass rebuild.
 574          */
 575         function clear() {
 576                 if( $this->mUseCache ) {
 577                         $this->mMemc->delete( $this->mMemcKey );
 578                 }
 579         }
 580 }
 581 ?>