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