includes/MessageCache.php

   1 <?php
   2 /**
   3  *
   4  * @package MediaWiki
   5  * @subpackage Cache
   6  */
   7
   8 /** */
   9 require_once( 'Revision.php' );
  10
  11 /**
  12  *
  13  */
  14 define( 'MSG_LOAD_TIMEOUT', 60);
  15 define( 'MSG_LOCK_TIMEOUT', 10);
  16 define( 'MSG_WAIT_TIMEOUT', 10);
  17
  18 /**
  19  * Message cache
  20  * Performs various useful MediaWiki namespace-related functions
  21  *
  22  * @package MediaWiki
  23  */
  24 class MessageCache {
  25         var $mCache, $mUseCache, $mDisable, $mExpiry;
  26         var $mMemcKey, $mKeys, $mParserOptions, $mParser;
  27         var $mExtensionMessages = array();
  28         var $mInitialised = false;
  29         var $mDeferred = true;
  30
  31         function initialise( &$memCached, $useDB, $expiry, $memcPrefix) {
  32                 $fname = 'MessageCache::initialise';
  33                 wfProfileIn( $fname );
  34
  35                 $this->mUseCache = !is_null( $memCached );
  36                 $this->mMemc = &$memCached;
  37                 $this->mDisable = !$useDB;
  38                 $this->mExpiry = $expiry;
  39                 $this->mDisableTransform = false;
  40                 $this->mMemcKey = $memcPrefix.':messages';
  41                 $this->mKeys = false; # initialised on demand
  42                 $this->mInitialised = true;
  43
  44                 wfProfileIn( $fname.'-parseropt' );
  45                 $this->mParserOptions = ParserOptions::newFromUser( $u=NULL );
  46                 wfProfileOut( $fname.'-parseropt' );
  47                 wfProfileIn( $fname.'-parser' );
  48                 $this->mParser = new Parser;
  49                 wfProfileOut( $fname.'-parser' );
  50
  51                 # When we first get asked for a message,
  52                 # then we'll fill up the cache. If we
  53                 # can return a cache hit, this saves
  54                 # some extra milliseconds
  55                 $this->mDeferred = true;
  56
  57                 wfProfileOut( $fname );
  58         }
  59
  60         /**
  61          * Try to load the cache from a local file
  62          */
  63         function loadFromLocal( $hash ) {
  64                 global $wgLocalMessageCache, $wgDBname;
  65
  66                 $this->mCache = false;
  67                 if ( $wgLocalMessageCache === false ) {
  68                         return;
  69                 }
  70
  71                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
  72
  73                 wfSuppressWarnings();
  74                 $file = fopen( $filename, 'r' );
  75                 wfRestoreWarnings();
  76                 if ( !$file ) {
  77                         return;
  78                 }
  79
  80                 // Check to see if the file has the hash specified
  81                 $localHash = fread( $file, 32 );
  82                 if ( $hash == $localHash ) {
  83                         // All good, get the rest of it
  84                         $serialized = fread( $file, 1000000 );
  85                         $this->mCache = unserialize( $serialized );
  86                 }
  87                 fclose( $file );
  88         }
  89
  90         /**
  91          * Save the cache to a local file
  92          */
  93         function saveToLocal( $serialized, $hash ) {
  94                 global $wgLocalMessageCache, $wgDBname;
  95
  96                 if ( $wgLocalMessageCache === false ) {
  97                         return;
  98                 }
  99
 100                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
 101                 $oldUmask = umask( 0 );
 102                 wfMkdirParents( $wgLocalMessageCache, 0777 );
 103                 umask( $oldUmask );
 104
 105                 $file = fopen( $filename, 'w' );
 106                 if ( !$file ) {
 107                         wfDebug( "Unable to open local cache file for writing\n" );
 108                         return;
 109                 }
 110
 111                 fwrite( $file, $hash . $serialized );
 112                 fclose( $file );
 113                 @chmod( $filename, 0666 );
 114         }
 115
 116
 117         /**
 118          * Loads messages either from memcached or the database, if not disabled
 119          * On error, quietly switches to a fallback mode
 120          * Returns false for a reportable error, true otherwise
 121          */
 122         function load() {
 123                 global $wgLocalMessageCache;
 124
 125                 if ( $this->mDisable ) {
 126                         static $shownDisabled = false;
 127                         if ( !$shownDisabled ) {
 128                                 wfDebug( "MessageCache::load(): disabled\n" );
 129                                 $shownDisabled = true;
 130                         }
 131                         return true;
 132                 }
 133                 $fname = 'MessageCache::load';
 134                 wfProfileIn( $fname );
 135                 $success = true;
 136
 137                 if ( $this->mUseCache ) {
 138                         $this->mCache = false;
 139
 140                         # Try local cache
 141                         wfProfileIn( $fname.'-fromlocal' );
 142                         $hash = $this->mMemc->get( "{$this->mMemcKey}-hash" );
 143                         if ( $hash ) {
 144                                 $this->loadFromLocal( $hash );
 145                         }
 146                         wfProfileOut( $fname.'-fromlocal' );
 147
 148                         # Try memcached
 149                         if ( !$this->mCache ) {
 150                                 wfProfileIn( $fname.'-fromcache' );
 151                                 $this->mCache = $this->mMemc->get( $this->mMemcKey );
 152
 153                                 # Save to local cache
 154                                 if ( $wgLocalMessageCache !== false ) {
 155                                         $serialized = serialize( $this->mCache );
 156                                         if ( !$hash ) {
 157                                                 $hash = md5( $serialized );
 158                                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 159                                         }
 160                                         $this->saveToLocal( $serialized, $hash );
 161                                 }
 162                                 wfProfileOut( $fname.'-fromcache' );
 163                         }
 164
 165
 166                         # If there's nothing in memcached, load all the messages from the database
 167                         if ( !$this->mCache ) {
 168                                 wfDebug( "MessageCache::load(): loading all messages\n" );
 169                                 $this->lock();
 170                                 # Other threads don't need to load the messages if another thread is doing it.
 171                                 $success = $this->mMemc->add( $this->mMemcKey.'-status', "loading", MSG_LOAD_TIMEOUT );
 172                                 if ( $success ) {
 173                                         wfProfileIn( $fname.'-load' );
 174                                         $this->loadFromDB();
 175                                         wfProfileOut( $fname.'-load' );
 176
 177                                         # Save in memcached
 178                                         # Keep trying if it fails, this is kind of important
 179                                         wfProfileIn( $fname.'-save' );
 180                                         for ($i=0; $i<20 &&
 181                                                    !$this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 182                                              $i++ ) {
 183                                                 usleep(mt_rand(500000,1500000));
 184                                         }
 185
 186                                         # Save to local cache
 187                                         if ( $wgLocalMessageCache !== false ) {
 188                                                 $serialized = serialize( $this->mCache );
 189                                                 $hash = md5( $serialized );
 190                                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 191                                                 $this->saveToLocal( $serialized, $hash );
 192                                         }
 193
 194                                         wfProfileOut( $fname.'-save' );
 195                                         if ( $i == 20 ) {
 196                                                 $this->mMemc->set( $this->mMemcKey.'-status', 'error', 60*5 );
 197                                                 wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
 198                                         }
 199                                 }
 200                                 $this->unlock();
 201                         }
 202
 203                         if ( !is_array( $this->mCache ) ) {
 204                                 wfDebug( "MessageCache::load(): individual message mode\n" );
 205                                 # If it is 'loading' or 'error', switch to individual message mode, otherwise disable
 206                                 # Causing too much DB load, disabling -- TS
 207                                 $this->mDisable = true;
 208                                 /*
 209                                 if ( $this->mCache == "loading" ) {
 210                                         $this->mUseCache = false;
 211                                 } elseif ( $this->mCache == "error" ) {
 212                                         $this->mUseCache = false;
 213                                         $success = false;
 214                                 } else {
 215                                         $this->mDisable = true;
 216                                         $success = false;
 217                                 }*/
 218                                 $this->mCache = false;
 219                         }
 220                 }
 221                 wfProfileOut( $fname );
 222                 $this->mDeferred = false;
 223                 return $success;
 224         }
 225
 226         /**
 227          * Loads all or main part of cacheable messages from the database
 228          */
 229         function loadFromDB() {
 230                 global $wgAllMessagesEn, $wgLang;
 231
 232                 $fname = 'MessageCache::loadFromDB';
 233                 $dbr =& wfGetDB( DB_SLAVE );
 234                 if ( !$dbr ) {
 235                         wfDebugDieBacktrace( 'Invalid database object' );
 236                 }
 237                 $conditions = array( 'page_is_redirect' => 0,
 238                                         'page_namespace' => NS_MEDIAWIKI);
 239                 $res = $dbr->select( array( 'page', 'revision', 'text' ),
 240                         array( 'page_title', 'old_text', 'old_flags' ),
 241                         'page_is_redirect=0 AND page_namespace='.NS_MEDIAWIKI.' AND page_latest=rev_id AND rev_text_id=old_id',
 242                         $fname
 243                 );
 244
 245                 $this->mCache = array();
 246                 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
 247                         $this->mCache[$row->page_title] = Revision::getRevisionText( $row );
 248                 }
 249
 250                 # Negative caching
 251                 # Go through the language array and the extension array and make a note of
 252                 # any keys missing from the cache
 253                 foreach ( $wgAllMessagesEn as $key => $value ) {
 254                         $uckey = $wgLang->ucfirst( $key );
 255                         if ( !array_key_exists( $uckey, $this->mCache ) ) {
 256                                 $this->mCache[$uckey] = false;
 257                         }
 258                 }
 259                 foreach ( $this->mExtensionMessages as $key => $value ) {
 260                         $uckey = $wgLang->ucfirst( $key );
 261                         if ( !array_key_exists( $uckey, $this->mCache ) ) {
 262                                 $this->mCache[$uckey] = false;
 263                         }
 264                 }
 265
 266                 $dbr->freeResult( $res );
 267         }
 268
 269         /**
 270          * Not really needed anymore
 271          */
 272         function getKeys() {
 273                 global $wgAllMessagesEn, $wgContLang;
 274                 if ( !$this->mKeys ) {
 275                         $this->mKeys = array();
 276                         foreach ( $wgAllMessagesEn as $key => $value ) {
 277                                 $title = $wgContLang->ucfirst( $key );
 278                                 array_push( $this->mKeys, $title );
 279                         }
 280                 }
 281                 return $this->mKeys;
 282         }
 283
 284         /**
 285          * @deprecated
 286          */
 287         function isCacheable( $key ) {
 288                 return true;
 289         }
 290
 291         function replace( $title, $text ) {
 292                 global $wgLocalMessageCache, $parserMemc, $wgDBname;
 293
 294                 $this->lock();
 295                 $this->load();
 296                 $parserMemc->delete("$wgDBname:sidebar");
 297                 if ( is_array( $this->mCache ) ) {
 298                         $this->mCache[$title] = $text;
 299                         $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 300
 301                         # Save to local cache
 302                         if ( $wgLocalMessageCache !== false ) {
 303                                 $serialized = serialize( $this->mCache );
 304                                 $hash = md5( $serialized );
 305                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 306                                 $this->saveToLocal( $serialized, $hash );
 307                         }
 308
 309
 310                 }
 311                 $this->unlock();
 312         }
 313
 314         /**
 315          * Returns success
 316          * Represents a write lock on the messages key
 317          */
 318         function lock() {
 319                 if ( !$this->mUseCache ) {
 320                         return true;
 321                 }
 322
 323                 $lockKey = $this->mMemcKey . 'lock';
 324                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 325                         sleep(1);
 326                 }
 327
 328                 return $i >= MSG_WAIT_TIMEOUT;
 329         }
 330
 331         function unlock() {
 332                 if ( !$this->mUseCache ) {
 333                         return;
 334                 }
 335
 336                 $lockKey = $this->mMemcKey . 'lock';
 337                 $this->mMemc->delete( $lockKey );
 338         }
 339
 340         function get( $key, $useDB, $forcontent=true, $isfullkey = false ) {
 341                 global $wgContLanguageCode;
 342                 if( $forcontent ) {
 343                         global $wgContLang;
 344                         $lang =& $wgContLang;
 345                         $langcode = $wgContLanguageCode;
 346                 } else {
 347                         global $wgLang, $wgLanguageCode;
 348                         $lang =& $wgLang;
 349                         $langcode = $wgLanguageCode;
 350                 }
 351                 # If uninitialised, someone is trying to call this halfway through Setup.php
 352                 if( !$this->mInitialised ) {
 353                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 354                 }
 355                 # If cache initialization was deferred, start it now.
 356                 if( $this->mDeferred && !$this->mDisable && $useDB ) {
 357                         $this->load();
 358                 }
 359
 360                 $message = false;
 361                 if( !$this->mDisable && $useDB ) {
 362                         $title = $lang->ucfirst( $key );
 363                         if(!$isfullkey && ($langcode != $wgContLanguageCode) ) {
 364                                 $title .= '/' . $langcode;
 365                         }
 366                         $message = $this->getFromCache( $title );
 367                 }
 368                 # Try the extension array
 369                 if( $message === false && array_key_exists( $key, $this->mExtensionMessages ) ) {
 370                         $message = $this->mExtensionMessages[$key];
 371                 }
 372
 373                 # Try the array in the language object
 374                 if( $message === false ) {
 375                         wfSuppressWarnings();
 376                         $message = $lang->getMessage( $key );
 377                         wfRestoreWarnings();
 378                         if ( is_null( $message ) ) {
 379                                 $message = false;
 380                         }
 381                 }
 382
 383                 # Try the English array
 384                 if( $message === false && $langcode != 'en' ) {
 385                         wfSuppressWarnings();
 386                         $message = Language::getMessage( $key );
 387                         wfRestoreWarnings();
 388                         if ( is_null( $message ) ) {
 389                                 $message = false;
 390                         }
 391                 }
 392
 393                 # Is this a custom message? Try the default language in the db...
 394                 if( $message === false &&
 395                         !$this->mDisable && $useDB &&
 396                         !$isfullkey && ($langcode != $wgContLanguageCode) ) {
 397                         $message = $this->getFromCache( $lang->ucfirst( $key ) );
 398                 }
 399
 400                 # Final fallback
 401                 if( $message === false ) {
 402                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 403                 }
 404
 405                 # Replace brace tags
 406                 $message = $this->transform( $message );
 407                 return $message;
 408         }
 409
 410         function getFromCache( $title ) {
 411                 $message = false;
 412
 413                 # Try the cache
 414                 if( $this->mUseCache && is_array( $this->mCache ) && array_key_exists( $title, $this->mCache ) ) {
 415                         return $this->mCache[$title];
 416                 }
 417
 418                 # Try individual message cache
 419                 if ( $this->mUseCache ) {
 420                         $message = $this->mMemc->get( $this->mMemcKey . ':' . $title );
 421                         if ( $message == '###NONEXISTENT###' ) {
 422                                 return false;
 423                         } elseif( !is_null( $message ) ) {
 424                                 $this->mCache[$title] = $message;
 425                                 return $message;
 426                         } else {
 427                                 $message = false;
 428                         }
 429                 }
 430
 431                 # Call message Hooks, in case they are defined
 432                 wfRunHooks('MessagesPreLoad',array($title,&$message));
 433
 434                 # If it wasn't in the cache, load each message from the DB individually
 435                 $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
 436                 if( $revision ) {
 437                         $message = $revision->getText();
 438                         if ($this->mUseCache) {
 439                                 $this->mCache[$title]=$message;
 440                                 /* individual messages may be often
 441                                    recached until proper purge code exists
 442                                 */
 443                                 $this->mMemc->set( $this->mMemcKey . ':' . $title, $message, 300 );
 444                         }
 445                 } else {
 446                         # Negative caching
 447                         # Use some special text instead of false, because false gets converted to '' somewhere
 448                         $this->mMemc->set( $this->mMemcKey . ':' . $title, '###NONEXISTENT###', $this->mExpiry );
 449                 }
 450
 451                 return $message;
 452         }
 453
 454         function transform( $message ) {
 455                 if( !$this->mDisableTransform ) {
 456                         if( strpos( $message, '{{' ) !== false ) {
 457                                 $message = $this->mParser->transformMsg( $message, $this->mParserOptions );
 458                         }
 459                 }
 460                 return $message;
 461         }
 462
 463         function disable() { $this->mDisable = true; }
 464         function enable() { $this->mDisable = false; }
 465         function disableTransform() { $this->mDisableTransform = true; }
 466         function enableTransform() { $this->mDisableTransform = false; }
 467         function setTransform( $x ) { $this->mDisableTransform = $x; }
 468         function getTransform() { return $this->mDisableTransform; }
 469
 470         /**
 471          * Add a message to the cache
 472          *
 473          * @param mixed $key
 474          * @param mixed $value
 475          */
 476         function addMessage( $key, $value ) {
 477                 $this->mExtensionMessages[$key] = $value;
 478         }
 479
 480         /**
 481          * Add an associative array of message to the cache
 482          *
 483          * @param array $messages An associative array of key => values to be added
 484          */
 485         function addMessages( $messages ) {
 486                 foreach ( $messages as $key => $value ) {
 487                         $this->addMessage( $key, $value );
 488                 }
 489         }
 490
 491         /**
 492          * Clear all stored messages. Mainly used after a mass rebuild.
 493          */
 494         function clear() {
 495                 if( $this->mUseCache ) {
 496                         $this->mMemc->delete( $this->mMemcKey );
 497                 }
 498         }
 499 }
 500 ?>