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