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         private
  26                 $mCache,
  27                 $mDeferred = true,
  28                 $mDisable,
  29                 $mExpiry,
  30                 $mExtensionMessages = array(),
  31                 $mInitialised = false,
  32                 $mKeys,
  33                 $mMemcKey,
  34                 $mParser,
  35                 $mParserOptions,
  36                 $mUseCache ;
  37
  38         function initialise( &$memCached, $useDB, $expiry, $memcPrefix) {
  39                 $fname = 'MessageCache::initialise';
  40                 wfProfileIn( $fname );
  41
  42                 $this->mUseCache = !is_null( $memCached );
  43                 $this->mMemc = &$memCached;
  44                 $this->mDisable = !$useDB;
  45                 $this->mExpiry = $expiry;
  46                 $this->mDisableTransform = false;
  47                 $this->mMemcKey = $memcPrefix.':messages';
  48                 $this->mKeys = false; # initialised on demand
  49                 $this->mInitialised = true;
  50
  51                 wfProfileIn( $fname.'-parseropt' );
  52                 $this->mParserOptions = ParserOptions::newFromUser( $u=NULL );
  53                 wfProfileOut( $fname.'-parseropt' );
  54                 wfProfileIn( $fname.'-parser' );
  55                 $this->mParser = new Parser;
  56                 wfProfileOut( $fname.'-parser' );
  57
  58                 # When we first get asked for a message,
  59                 # then we'll fill up the cache. If we
  60                 # can return a cache hit, this saves
  61                 # some extra milliseconds
  62                 $this->mDeferred = true;
  63
  64                 wfProfileOut( $fname );
  65         }
  66
  67         /**
  68          * Try to load the cache from a local file
  69          */
  70         function loadFromLocal( $hash ) {
  71                 global $wgLocalMessageCache, $wgDBname;
  72
  73                 $this->mCache = false;
  74                 if ( $wgLocalMessageCache === false ) {
  75                         return;
  76                 }
  77
  78                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
  79
  80                 wfSuppressWarnings();
  81                 $file = fopen( $filename, 'r' );
  82                 wfRestoreWarnings();
  83                 if ( !$file ) {
  84                         return;
  85                 }
  86
  87                 // Check to see if the file has the hash specified
  88                 $localHash = fread( $file, 32 );
  89                 if ( $hash == $localHash ) {
  90                         // All good, get the rest of it
  91                         $serialized = fread( $file, 1000000 );
  92                         $this->mCache = unserialize( $serialized );
  93                 }
  94                 fclose( $file );
  95         }
  96
  97         /**
  98          * Save the cache to a local file
  99          */
 100         function saveToLocal( $serialized, $hash ) {
 101                 global $wgLocalMessageCache, $wgDBname;
 102
 103                 if ( $wgLocalMessageCache === false ) {
 104                         return;
 105                 }
 106
 107                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
 108                 $oldUmask = umask( 0 );
 109                 wfMkdirParents( $wgLocalMessageCache, 0777 );
 110                 umask( $oldUmask );
 111
 112                 $file = fopen( $filename, 'w' );
 113                 if ( !$file ) {
 114                         wfDebug( "Unable to open local cache file for writing\n" );
 115                         return;
 116                 }
 117
 118                 fwrite( $file, $hash . $serialized );
 119                 fclose( $file );
 120                 @chmod( $filename, 0666 );
 121         }
 122
 123
 124         /**
 125          * Loads messages either from memcached or the database, if not disabled
 126          * On error, quietly switches to a fallback mode
 127          * Returns false for a reportable error, true otherwise
 128          */
 129         function load() {
 130                 global $wgLocalMessageCache;
 131
 132                 if ( $this->mDisable ) {
 133                         static $shownDisabled = false;
 134                         if ( !$shownDisabled ) {
 135                                 wfDebug( "MessageCache::load(): disabled\n" );
 136                                 $shownDisabled = true;
 137                         }
 138                         return true;
 139                 }
 140                 $fname = 'MessageCache::load';
 141                 wfProfileIn( $fname );
 142                 $success = true;
 143
 144                 if ( $this->mUseCache ) {
 145                         $this->mCache = false;
 146
 147                         # Try local cache
 148                         wfProfileIn( $fname.'-fromlocal' );
 149                         $hash = $this->mMemc->get( "{$this->mMemcKey}-hash" );
 150                         if ( $hash ) {
 151                                 $this->loadFromLocal( $hash );
 152                         }
 153                         wfProfileOut( $fname.'-fromlocal' );
 154
 155                         # Try memcached
 156                         if ( !$this->mCache ) {
 157                                 wfProfileIn( $fname.'-fromcache' );
 158                                 $this->mCache = $this->mMemc->get( $this->mMemcKey );
 159
 160                                 # Save to local cache
 161                                 if ( $wgLocalMessageCache !== false ) {
 162                                         $serialized = serialize( $this->mCache );
 163                                         if ( !$hash ) {
 164                                                 $hash = md5( $serialized );
 165                                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 166                                         }
 167                                         $this->saveToLocal( $serialized, $hash );
 168                                 }
 169                                 wfProfileOut( $fname.'-fromcache' );
 170                         }
 171
 172
 173                         # If there's nothing in memcached, load all the messages from the database
 174                         if ( !$this->mCache ) {
 175                                 wfDebug( "MessageCache::load(): loading all messages\n" );
 176                                 $this->lock();
 177                                 # Other threads don't need to load the messages if another thread is doing it.
 178                                 $success = $this->mMemc->add( $this->mMemcKey.'-status', "loading", MSG_LOAD_TIMEOUT );
 179                                 if ( $success ) {
 180                                         wfProfileIn( $fname.'-load' );
 181                                         $this->loadFromDB();
 182                                         wfProfileOut( $fname.'-load' );
 183
 184                                         # Save in memcached
 185                                         # Keep trying if it fails, this is kind of important
 186                                         wfProfileIn( $fname.'-save' );
 187                                         for ($i=0; $i<20 &&
 188                                                    !$this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 189                                              $i++ ) {
 190                                                 usleep(mt_rand(500000,1500000));
 191                                         }
 192
 193                                         # Save to local cache
 194                                         if ( $wgLocalMessageCache !== false ) {
 195                                                 $serialized = serialize( $this->mCache );
 196                                                 $hash = md5( $serialized );
 197                                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 198                                                 $this->saveToLocal( $serialized, $hash );
 199                                         }
 200
 201                                         wfProfileOut( $fname.'-save' );
 202                                         if ( $i == 20 ) {
 203                                                 $this->mMemc->set( $this->mMemcKey.'-status', 'error', 60*5 );
 204                                                 wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
 205                                         }
 206                                 }
 207                                 $this->unlock();
 208                         }
 209
 210                         if ( !is_array( $this->mCache ) ) {
 211                                 wfDebug( "MessageCache::load(): individual message mode\n" );
 212                                 # If it is 'loading' or 'error', switch to individual message mode, otherwise disable
 213                                 # Causing too much DB load, disabling -- TS
 214                                 $this->mDisable = true;
 215                                 /*
 216                                 if ( $this->mCache == "loading" ) {
 217                                         $this->mUseCache = false;
 218                                 } elseif ( $this->mCache == "error" ) {
 219                                         $this->mUseCache = false;
 220                                         $success = false;
 221                                 } else {
 222                                         $this->mDisable = true;
 223                                         $success = false;
 224                                 }*/
 225                                 $this->mCache = false;
 226                         }
 227                 }
 228                 wfProfileOut( $fname );
 229                 $this->mDeferred = false;
 230                 return $success;
 231         }
 232
 233         /**
 234          * Loads all or main part of cacheable messages from the database
 235          */
 236         function loadFromDB() {
 237                 global $wgAllMessagesEn, $wgLang;
 238
 239                 $fname = 'MessageCache::loadFromDB';
 240                 $dbr =& wfGetDB( DB_SLAVE );
 241                 if ( !$dbr ) {
 242                         wfDebugDieBacktrace( 'Invalid database object' );
 243                 }
 244                 $conditions = array( 'page_is_redirect' => 0,
 245                                         'page_namespace' => NS_MEDIAWIKI);
 246                 $res = $dbr->select( array( 'page', 'revision', 'text' ),
 247                         array( 'page_title', 'old_text', 'old_flags' ),
 248                         'page_is_redirect=0 AND page_namespace='.NS_MEDIAWIKI.' AND page_latest=rev_id AND rev_text_id=old_id',
 249                         $fname
 250                 );
 251
 252                 $this->mCache = array();
 253                 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
 254                         $this->mCache[$row->page_title] = Revision::getRevisionText( $row );
 255                 }
 256
 257                 # Negative caching
 258                 # Go through the language array and the extension array and make a note of
 259                 # any keys missing from the cache
 260                 foreach ( $wgAllMessagesEn as $key => $value ) {
 261                         $uckey = $wgLang->ucfirst( $key );
 262                         if ( !array_key_exists( $uckey, $this->mCache ) ) {
 263                                 $this->mCache[$uckey] = false;
 264                         }
 265                 }
 266                 foreach ( $this->mExtensionMessages as $key => $value ) {
 267                         $uckey = $wgLang->ucfirst( $key );
 268                         if ( !array_key_exists( $uckey, $this->mCache ) ) {
 269                                 $this->mCache[$uckey] = false;
 270                         }
 271                 }
 272
 273                 $dbr->freeResult( $res );
 274         }
 275
 276         /**
 277          * Not really needed anymore
 278          */
 279         function getKeys() {
 280                 global $wgAllMessagesEn, $wgContLang;
 281                 if ( !$this->mKeys ) {
 282                         $this->mKeys = array();
 283                         foreach ( $wgAllMessagesEn as $key => $value ) {
 284                                 $title = $wgContLang->ucfirst( $key );
 285                                 array_push( $this->mKeys, $title );
 286                         }
 287                 }
 288                 return $this->mKeys;
 289         }
 290
 291         /**
 292          * @deprecated
 293          */
 294         function isCacheable( $key ) {
 295                 return true;
 296         }
 297
 298         function replace( $title, $text ) {
 299                 global $wgLocalMessageCache, $parserMemc, $wgDBname;
 300
 301                 $this->lock();
 302                 $this->load();
 303                 $parserMemc->delete("$wgDBname:sidebar");
 304                 if ( is_array( $this->mCache ) ) {
 305                         $this->mCache[$title] = $text;
 306                         $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 307
 308                         # Save to local cache
 309                         if ( $wgLocalMessageCache !== false ) {
 310                                 $serialized = serialize( $this->mCache );
 311                                 $hash = md5( $serialized );
 312                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 313                                 $this->saveToLocal( $serialized, $hash );
 314                         }
 315
 316
 317                 }
 318                 $this->unlock();
 319         }
 320
 321         /**
 322          * Returns success
 323          * Represents a write lock on the messages key
 324          */
 325         function lock() {
 326                 if ( !$this->mUseCache ) {
 327                         return true;
 328                 }
 329
 330                 $lockKey = $this->mMemcKey . 'lock';
 331                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 332                         sleep(1);
 333                 }
 334
 335                 return $i >= MSG_WAIT_TIMEOUT;
 336         }
 337
 338         function unlock() {
 339                 if ( !$this->mUseCache ) {
 340                         return;
 341                 }
 342
 343                 $lockKey = $this->mMemcKey . 'lock';
 344                 $this->mMemc->delete( $lockKey );
 345         }
 346
 347         function get( $key, $useDB, $forcontent=true, $isfullkey = false ) {
 348                 global $wgContLanguageCode;
 349                 if( $forcontent ) {
 350                         global $wgContLang;
 351                         $lang =& $wgContLang;
 352                         $langcode = $wgContLanguageCode;
 353                 } else {
 354                         global $wgLang, $wgLanguageCode;
 355                         $lang =& $wgLang;
 356                         $langcode = $wgLanguageCode;
 357                 }
 358                 # If uninitialised, someone is trying to call this halfway through Setup.php
 359                 if( !$this->mInitialised ) {
 360                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 361                 }
 362                 # If cache initialization was deferred, start it now.
 363                 if( $this->mDeferred && !$this->mDisable && $useDB ) {
 364                         $this->load();
 365                 }
 366
 367                 $message = false;
 368                 if( !$this->mDisable && $useDB ) {
 369                         $title = $lang->ucfirst( $key );
 370                         if(!$isfullkey && ($langcode != $wgContLanguageCode) ) {
 371                                 $title .= '/' . $langcode;
 372                         }
 373                         $message = $this->getFromCache( $title );
 374                 }
 375                 # Try the extension array
 376                 if( $message === false && array_key_exists( $key, $this->mExtensionMessages ) ) {
 377                         $message = $this->mExtensionMessages[$key];
 378                 }
 379
 380                 # Try the array in the language object
 381                 if( $message === false ) {
 382                         wfSuppressWarnings();
 383                         $message = $lang->getMessage( $key );
 384                         wfRestoreWarnings();
 385                         if ( is_null( $message ) ) {
 386                                 $message = false;
 387                         }
 388                 }
 389
 390                 # Try the English array
 391                 if( $message === false && $langcode != 'en' ) {
 392                         wfSuppressWarnings();
 393                         $message = Language::getMessage( $key );
 394                         wfRestoreWarnings();
 395                         if ( is_null( $message ) ) {
 396                                 $message = false;
 397                         }
 398                 }
 399
 400                 # Is this a custom message? Try the default language in the db...
 401                 if( $message === false &&
 402                         !$this->mDisable && $useDB &&
 403                         !$isfullkey && ($langcode != $wgContLanguageCode) ) {
 404                         $message = $this->getFromCache( $lang->ucfirst( $key ) );
 405                 }
 406
 407                 # Final fallback
 408                 if( $message === false ) {
 409                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 410                 }
 411
 412                 # Replace brace tags
 413                 $message = $this->transform( $message );
 414                 return $message;
 415         }
 416
 417         function getFromCache( $title ) {
 418                 $message = false;
 419
 420                 # Try the cache
 421                 if( $this->mUseCache && is_array( $this->mCache ) && array_key_exists( $title, $this->mCache ) ) {
 422                         return $this->mCache[$title];
 423                 }
 424
 425                 # Try individual message cache
 426                 if ( $this->mUseCache ) {
 427                         $message = $this->mMemc->get( $this->mMemcKey . ':' . $title );
 428                         if ( $message == '###NONEXISTENT###' ) {
 429                                 return false;
 430                         } elseif( !is_null( $message ) ) {
 431                                 $this->mCache[$title] = $message;
 432                                 return $message;
 433                         } else {
 434                                 $message = false;
 435                         }
 436                 }
 437
 438                 # Call message Hooks, in case they are defined
 439                 wfRunHooks('MessagesPreLoad',array($title,&$message));
 440
 441                 # If it wasn't in the cache, load each message from the DB individually
 442                 $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
 443                 if( $revision ) {
 444                         $message = $revision->getText();
 445                         if ($this->mUseCache) {
 446                                 $this->mCache[$title]=$message;
 447                                 /* individual messages may be often
 448                                    recached until proper purge code exists
 449                                 */
 450                                 $this->mMemc->set( $this->mMemcKey . ':' . $title, $message, 300 );
 451                         }
 452                 } else {
 453                         # Negative caching
 454                         # Use some special text instead of false, because false gets converted to '' somewhere
 455                         $this->mMemc->set( $this->mMemcKey . ':' . $title, '###NONEXISTENT###', $this->mExpiry );
 456                 }
 457
 458                 return $message;
 459         }
 460
 461         function transform( $message ) {
 462                 if( !$this->mDisableTransform ) {
 463                         if( strpos( $message, '{{' ) !== false ) {
 464                                 $message = $this->mParser->transformMsg( $message, $this->mParserOptions );
 465                         }
 466                 }
 467                 return $message;
 468         }
 469
 470         function disable() { $this->mDisable = true; }
 471         function enable() { $this->mDisable = false; }
 472         function disableTransform() { $this->mDisableTransform = true; }
 473         function enableTransform() { $this->mDisableTransform = false; }
 474         function setTransform( $x ) { $this->mDisableTransform = $x; }
 475         function getTransform() { return $this->mDisableTransform; }
 476
 477         /**
 478          * Add a message to the cache
 479          *
 480          * @param mixed $key
 481          * @param mixed $value
 482          */
 483         function addMessage( $key, $value ) {
 484                 $this->mExtensionMessages[$key] = $value;
 485         }
 486
 487         /**
 488          * Add an associative array of message to the cache
 489          *
 490          * @param array $messages An associative array of key => values to be added
 491          */
 492         function addMessages( $messages ) {
 493                 foreach ( $messages as $key => $value ) {
 494                         $this->addMessage( $key, $value );
 495                 }
 496         }
 497
 498         /**
 499          * Clear all stored messages. Mainly used after a mass rebuild.
 500          */
 501         function clear() {
 502                 if( $this->mUseCache ) {
 503                         $this->mMemc->delete( $this->mMemcKey );
 504                 }
 505         }
 506 }
 507 ?>