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