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 $mDeferred = true;
  27
  28         function initialise( &$memCached, $useDB, $expiry, $memcPrefix) {
  29                 $fname = 'MessageCache::initialise';
  30                 wfProfileIn( $fname );
  31
  32                 $this->mUseCache = !is_null( $memCached );
  33                 $this->mMemc = &$memCached;
  34                 $this->mDisable = !$useDB;
  35                 $this->mExpiry = $expiry;
  36                 $this->mDisableTransform = false;
  37                 $this->mMemcKey = $memcPrefix.':messages';
  38                 $this->mKeys = false; # initialised on demand
  39                 $this->mInitialised = true;
  40
  41                 wfProfileIn( $fname.'-parseropt' );
  42                 $this->mParserOptions = ParserOptions::newFromUser( $u=NULL );
  43                 wfProfileOut( $fname.'-parseropt' );
  44                 wfProfileIn( $fname.'-parser' );
  45                 $this->mParser = new Parser;
  46                 wfProfileOut( $fname.'-parser' );
  47
  48                 # When we first get asked for a message,
  49                 # then we'll fill up the cache. If we
  50                 # can return a cache hit, this saves
  51                 # some extra milliseconds
  52                 $this->mDeferred = true;
  53
  54                 wfProfileOut( $fname );
  55         }
  56
  57         /**
  58          * Try to load the cache from a local file
  59          */
  60         function loadFromLocal( $hash ) {
  61                 global $wgLocalMessageCache, $wgDBname;
  62
  63                 $this->mCache = false;
  64                 if ( $wgLocalMessageCache === false ) {
  65                         return;
  66                 }
  67
  68                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
  69
  70                 wfSuppressWarnings();
  71                 $file = fopen( $filename, 'r' );
  72                 wfRestoreWarnings();
  73                 if ( !$file ) {
  74                         return;
  75                 }
  76
  77                 // Check to see if the file has the hash specified
  78                 $localHash = fread( $file, 32 );
  79                 if ( $hash == $localHash ) {
  80                         // All good, get the rest of it
  81                         $serialized = fread( $file, 1000000 );
  82                         $this->mCache = unserialize( $serialized );
  83                 }
  84                 fclose( $file );
  85         }
  86
  87         /**
  88          * Save the cache to a local file
  89          */
  90         function saveToLocal( $serialized, $hash ) {
  91                 global $wgLocalMessageCache, $wgDBname;
  92
  93                 if ( $wgLocalMessageCache === false ) {
  94                         return;
  95                 }
  96
  97                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
  98                 $oldUmask = umask( 0 );
  99                 wfMkdirParents( $wgLocalMessageCache, 0777 );
 100                 umask( $oldUmask );
 101
 102                 $file = fopen( $filename, 'w' );
 103                 if ( !$file ) {
 104                         wfDebug( "Unable to open local cache file for writing\n" );
 105                         return;
 106                 }
 107
 108                 fwrite( $file, $hash . $serialized );
 109                 fclose( $file );
 110                 @chmod( $filename, 0666 );
 111         }
 112
 113         function loadFromScript( $hash ) {
 114                 global $wgLocalMessageCache, $wgDBname;
 115                 if ( $wgLocalMessageCache === false ) {
 116                         return;
 117                 }
 118
 119                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
 120
 121                 wfSuppressWarnings();
 122                 $file = fopen( $filename, 'r' );
 123                 wfRestoreWarnings();
 124                 if ( !$file ) {
 125                         return;
 126                 }
 127                 $localHash=substr(fread($file,40),8);
 128                 fclose($file);
 129                 if ($hash!=$localHash) {
 130                         return;
 131                 }
 132                 require("$wgLocalMessageCache/messages-$wgDBname");
 133         }
 134
 135         function saveToScript($array, $hash) {
 136                 global $wgLocalMessageCache, $wgDBname;
 137                 if ( $wgLocalMessageCache === false ) {
 138                         return;
 139                 }
 140
 141                 $filename = "$wgLocalMessageCache/messages-$wgDBname";
 142                 $oldUmask = umask( 0 );
 143                 wfMkdirParents( $wgLocalMessageCache, 0777 );
 144                 umask( $oldUmask );
 145                 $file = fopen( $filename.'.tmp', 'w');
 146                 fwrite($file,"<?php\n//$hash\n\n \$this->mCache = array(");
 147
 148                 foreach ($array as $key => $message) {
 149                         fwrite($file, "'". $this->escapeForScript($key).
 150                                 "' => '" . $this->escapeForScript($message).
 151                                 "',\n");
 152                 }
 153                 fwrite($file,");\n?>");
 154                 fclose($file);
 155                 rename($filename.'.tmp',$filename);
 156         }
 157
 158         function escapeForScript($string) {
 159                 $string = str_replace( '\\', '\\\\', $string );
 160                 $string = str_replace( '\'', '\\\'', $string );
 161                 return $string;
 162         }
 163
 164         /**
 165          * Loads messages either from memcached or the database, if not disabled
 166          * On error, quietly switches to a fallback mode
 167          * Returns false for a reportable error, true otherwise
 168          */
 169         function load() {
 170                 global $wgLocalMessageCache, $wgLocalMessageCacheSerialized;
 171
 172                 if ( $this->mDisable ) {
 173                         static $shownDisabled = false;
 174                         if ( !$shownDisabled ) {
 175                                 wfDebug( "MessageCache::load(): disabled\n" );
 176                                 $shownDisabled = true;
 177                         }
 178                         return true;
 179                 }
 180                 $fname = 'MessageCache::load';
 181                 wfProfileIn( $fname );
 182                 $success = true;
 183
 184                 if ( $this->mUseCache ) {
 185                         $this->mCache = false;
 186
 187                         # Try local cache
 188                         wfProfileIn( $fname.'-fromlocal' );
 189                         $hash = $this->mMemc->get( "{$this->mMemcKey}-hash" );
 190                         if ( $hash ) {
 191                                 if ($wgLocalMessageCacheSerialized) {
 192                                         $this->loadFromLocal( $hash );
 193                                 } else {
 194                                         $this->loadFromScript( $hash );
 195                                 }
 196                         }
 197                         wfProfileOut( $fname.'-fromlocal' );
 198
 199                         # Try memcached
 200                         if ( !$this->mCache ) {
 201                                 wfProfileIn( $fname.'-fromcache' );
 202                                 $this->mCache = $this->mMemc->get( $this->mMemcKey );
 203
 204                                 # Save to local cache
 205                                 if ( $wgLocalMessageCache !== false ) {
 206                                         $serialized = serialize( $this->mCache );
 207                                         if ( !$hash ) {
 208                                                 $hash = md5( $serialized );
 209                                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 210                                         }
 211                                         if ($wgLocalMessageCacheSerialized) {
 212                                                 $this->saveToLocal( $serialized,$hash );
 213                                         } else {
 214                                                 $this->saveToScript( $this->mCache, $hash );
 215                                         }
 216                                 }
 217                                 wfProfileOut( $fname.'-fromcache' );
 218                         }
 219
 220
 221                         # If there's nothing in memcached, load all the messages from the database
 222                         if ( !$this->mCache ) {
 223                                 wfDebug( "MessageCache::load(): loading all messages\n" );
 224                                 $this->lock();
 225                                 # Other threads don't need to load the messages if another thread is doing it.
 226                                 $success = $this->mMemc->add( $this->mMemcKey.'-status', "loading", MSG_LOAD_TIMEOUT );
 227                                 if ( $success ) {
 228                                         wfProfileIn( $fname.'-load' );
 229                                         $this->loadFromDB();
 230                                         wfProfileOut( $fname.'-load' );
 231
 232                                         # Save in memcached
 233                                         # Keep trying if it fails, this is kind of important
 234                                         wfProfileIn( $fname.'-save' );
 235                                         for ($i=0; $i<20 &&
 236                                                    !$this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 237                                              $i++ ) {
 238                                                 usleep(mt_rand(500000,1500000));
 239                                         }
 240
 241                                         # Save to local cache
 242                                         if ( $wgLocalMessageCache !== false ) {
 243                                                 $serialized = serialize( $this->mCache );
 244                                                 $hash = md5( $serialized );
 245                                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 246                                                 if ($wgLocalMessageCacheSerialized) {
 247                                                         $this->saveToLocal( $serialized,$hash );
 248                                                 } else {
 249                                                         $this->saveToScript( $this->mCache, $hash );
 250                                                 }
 251                                         }
 252
 253                                         wfProfileOut( $fname.'-save' );
 254                                         if ( $i == 20 ) {
 255                                                 $this->mMemc->set( $this->mMemcKey.'-status', 'error', 60*5 );
 256                                                 wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
 257                                         }
 258                                 }
 259                                 $this->unlock();
 260                         }
 261
 262                         if ( !is_array( $this->mCache ) ) {
 263                                 wfDebug( "MessageCache::load(): individual message mode\n" );
 264                                 # If it is 'loading' or 'error', switch to individual message mode, otherwise disable
 265                                 # Causing too much DB load, disabling -- TS
 266                                 $this->mDisable = true;
 267                                 /*
 268                                 if ( $this->mCache == "loading" ) {
 269                                         $this->mUseCache = false;
 270                                 } elseif ( $this->mCache == "error" ) {
 271                                         $this->mUseCache = false;
 272                                         $success = false;
 273                                 } else {
 274                                         $this->mDisable = true;
 275                                         $success = false;
 276                                 }*/
 277                                 $this->mCache = false;
 278                         }
 279                 }
 280                 wfProfileOut( $fname );
 281                 $this->mDeferred = false;
 282                 return $success;
 283         }
 284
 285         /**
 286          * Loads all or main part of cacheable messages from the database
 287          */
 288         function loadFromDB() {
 289                 global $wgAllMessagesEn, $wgLang;
 290
 291                 $fname = 'MessageCache::loadFromDB';
 292                 $dbr =& wfGetDB( DB_SLAVE );
 293                 if ( !$dbr ) {
 294                         throw new MWException( 'Invalid database object' );
 295                 }
 296                 $conditions = array( 'page_is_redirect' => 0,
 297                                         'page_namespace' => NS_MEDIAWIKI);
 298                 $res = $dbr->select( array( 'page', 'revision', 'text' ),
 299                         array( 'page_title', 'old_text', 'old_flags' ),
 300                         'page_is_redirect=0 AND page_namespace='.NS_MEDIAWIKI.' AND page_latest=rev_id AND rev_text_id=old_id',
 301                         $fname
 302                 );
 303
 304                 $this->mCache = array();
 305                 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
 306                         $this->mCache[$row->page_title] = Revision::getRevisionText( $row );
 307                 }
 308
 309                 # Negative caching
 310                 # Go through the language array and the extension array and make a note of
 311                 # any keys missing from the cache
 312                 foreach ( $wgAllMessagesEn as $key => $value ) {
 313                         $uckey = $wgLang->ucfirst( $key );
 314                         if ( !array_key_exists( $uckey, $this->mCache ) ) {
 315                                 $this->mCache[$uckey] = false;
 316                         }
 317                 }
 318                 foreach ( $this->mExtensionMessages as $key => $value ) {
 319                         $uckey = $wgLang->ucfirst( $key );
 320                         if ( !array_key_exists( $uckey, $this->mCache ) ) {
 321                                 $this->mCache[$uckey] = false;
 322                         }
 323                 }
 324
 325                 $dbr->freeResult( $res );
 326         }
 327
 328         /**
 329          * Not really needed anymore
 330          */
 331         function getKeys() {
 332                 global $wgAllMessagesEn, $wgContLang;
 333                 if ( !$this->mKeys ) {
 334                         $this->mKeys = array();
 335                         foreach ( $wgAllMessagesEn as $key => $value ) {
 336                                 $title = $wgContLang->ucfirst( $key );
 337                                 array_push( $this->mKeys, $title );
 338                         }
 339                 }
 340                 return $this->mKeys;
 341         }
 342
 343         /**
 344          * @deprecated
 345          */
 346         function isCacheable( $key ) {
 347                 return true;
 348         }
 349
 350         function replace( $title, $text ) {
 351                 global $wgLocalMessageCache, $wgLocalMessageCacheSerialized, $parserMemc, $wgDBname;
 352
 353                 $this->lock();
 354                 $this->load();
 355                 $parserMemc->delete("$wgDBname:sidebar");
 356                 if ( is_array( $this->mCache ) ) {
 357                         $this->mCache[$title] = $text;
 358                         $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 359
 360                         # Save to local cache
 361                         if ( $wgLocalMessageCache !== false ) {
 362                                 $serialized = serialize( $this->mCache );
 363                                 $hash = md5( $serialized );
 364                                 $this->mMemc->set( "{$this->mMemcKey}-hash", $hash, $this->mExpiry );
 365                                 if ($wgLocalMessageCacheSerialized) {
 366                                         $this->saveToLocal( $serialized,$hash );
 367                                 } else {
 368                                         $this->saveToScript( $this->mCache, $hash );
 369                                 }
 370                         }
 371
 372
 373                 }
 374                 $this->unlock();
 375         }
 376
 377         /**
 378          * Returns success
 379          * Represents a write lock on the messages key
 380          */
 381         function lock() {
 382                 if ( !$this->mUseCache ) {
 383                         return true;
 384                 }
 385
 386                 $lockKey = $this->mMemcKey . 'lock';
 387                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 388                         sleep(1);
 389                 }
 390
 391                 return $i >= MSG_WAIT_TIMEOUT;
 392         }
 393
 394         function unlock() {
 395                 if ( !$this->mUseCache ) {
 396                         return;
 397                 }
 398
 399                 $lockKey = $this->mMemcKey . 'lock';
 400                 $this->mMemc->delete( $lockKey );
 401         }
 402
 403         function get( $key, $useDB, $forcontent=true, $isfullkey = false ) {
 404                 global $wgContLanguageCode;
 405                 if( $forcontent ) {
 406                         global $wgContLang;
 407                         $lang =& $wgContLang;
 408                         $langcode = $wgContLanguageCode;
 409                 } else {
 410                         global $wgLang, $wgLanguageCode;
 411                         $lang =& $wgLang;
 412                         $langcode = $wgLanguageCode;
 413                 }
 414                 # If uninitialised, someone is trying to call this halfway through Setup.php
 415                 if( !$this->mInitialised ) {
 416                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 417                 }
 418                 # If cache initialization was deferred, start it now.
 419                 if( $this->mDeferred && !$this->mDisable && $useDB ) {
 420                         $this->load();
 421                 }
 422
 423                 $message = false;
 424                 if( !$this->mDisable && $useDB ) {
 425                         $title = $lang->ucfirst( $key );
 426                         if(!$isfullkey && ($langcode != $wgContLanguageCode) ) {
 427                                 $title .= '/' . $langcode;
 428                         }
 429                         $message = $this->getFromCache( $title );
 430                 }
 431                 # Try the extension array
 432                 if( $message === false && array_key_exists( $key, $this->mExtensionMessages ) ) {
 433                         $message = $this->mExtensionMessages[$key];
 434                 }
 435
 436                 # Try the array in the language object
 437                 if( $message === false ) {
 438                         wfSuppressWarnings();
 439                         $message = $lang->getMessage( $key );
 440                         wfRestoreWarnings();
 441                         if ( is_null( $message ) ) {
 442                                 $message = false;
 443                         }
 444                 }
 445
 446                 # Try the English array
 447                 if( $message === false && $langcode != 'en' ) {
 448                         wfSuppressWarnings();
 449                         $message = Language::getMessage( $key );
 450                         wfRestoreWarnings();
 451                         if ( is_null( $message ) ) {
 452                                 $message = false;
 453                         }
 454                 }
 455
 456                 # Is this a custom message? Try the default language in the db...
 457                 if( ($message === false || $message === '-' ) &&
 458                         !$this->mDisable && $useDB &&
 459                         !$isfullkey && ($langcode != $wgContLanguageCode) ) {
 460                         $message = $this->getFromCache( $lang->ucfirst( $key ) );
 461                 }
 462
 463                 # Final fallback
 464                 if( $message === false ) {
 465                         return '&lt;' . htmlspecialchars($key) . '&gt;';
 466                 }
 467
 468                 # Replace brace tags
 469                 $message = $this->transform( $message );
 470                 return $message;
 471         }
 472
 473         function getFromCache( $title ) {
 474                 $message = false;
 475
 476                 # Try the cache
 477                 if( $this->mUseCache && is_array( $this->mCache ) && array_key_exists( $title, $this->mCache ) ) {
 478                         return $this->mCache[$title];
 479                 }
 480
 481                 # Try individual message cache
 482                 if ( $this->mUseCache ) {
 483                         $message = $this->mMemc->get( $this->mMemcKey . ':' . $title );
 484                         if ( $message == '###NONEXISTENT###' ) {
 485                                 return false;
 486                         } elseif( !is_null( $message ) ) {
 487                                 $this->mCache[$title] = $message;
 488                                 return $message;
 489                         } else {
 490                                 $message = false;
 491                         }
 492                 }
 493
 494                 # Call message Hooks, in case they are defined
 495                 wfRunHooks('MessagesPreLoad',array($title,&$message));
 496
 497                 # If it wasn't in the cache, load each message from the DB individually
 498                 $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
 499                 if( $revision ) {
 500                         $message = $revision->getText();
 501                         if ($this->mUseCache) {
 502                                 $this->mCache[$title]=$message;
 503                                 /* individual messages may be often
 504                                    recached until proper purge code exists
 505                                 */
 506                                 $this->mMemc->set( $this->mMemcKey . ':' . $title, $message, 300 );
 507                         }
 508                 } else {
 509                         # Negative caching
 510                         # Use some special text instead of false, because false gets converted to '' somewhere
 511                         $this->mMemc->set( $this->mMemcKey . ':' . $title, '###NONEXISTENT###', $this->mExpiry );
 512                 }
 513
 514                 return $message;
 515         }
 516
 517         function transform( $message ) {
 518                 if( !$this->mDisableTransform ) {
 519                         if( strpos( $message, '{{' ) !== false ) {
 520                                 $message = $this->mParser->transformMsg( $message, $this->mParserOptions );
 521                         }
 522                 }
 523                 return $message;
 524         }
 525
 526         function disable() { $this->mDisable = true; }
 527         function enable() { $this->mDisable = false; }
 528         function disableTransform() { $this->mDisableTransform = true; }
 529         function enableTransform() { $this->mDisableTransform = false; }
 530         function setTransform( $x ) { $this->mDisableTransform = $x; }
 531         function getTransform() { return $this->mDisableTransform; }
 532
 533         /**
 534          * Add a message to the cache
 535          *
 536          * @param mixed $key
 537          * @param mixed $value
 538          */
 539         function addMessage( $key, $value ) {
 540                 $this->mExtensionMessages[$key] = $value;
 541         }
 542
 543         /**
 544          * Add an associative array of message to the cache
 545          *
 546          * @param array $messages An associative array of key => values to be added
 547          */
 548         function addMessages( $messages ) {
 549                 foreach ( $messages as $key => $value ) {
 550                         $this->addMessage( $key, $value );
 551                 }
 552         }
 553
 554         /**
 555          * Clear all stored messages. Mainly used after a mass rebuild.
 556          */
 557         function clear() {
 558                 if( $this->mUseCache ) {
 559                         $this->mMemc->delete( $this->mMemcKey );
 560                 }
 561         }
 562 }
 563 ?>