includes/cache/MessageCache.php

   1 <?php
   2 /**
   3  * @file
   4  * @ingroup Cache
   5  */
   6
   7 /**
   8  *
   9  */
  10 define( 'MSG_LOAD_TIMEOUT', 60 );
  11 define( 'MSG_LOCK_TIMEOUT', 10 );
  12 define( 'MSG_WAIT_TIMEOUT', 10 );
  13 define( 'MSG_CACHE_VERSION', 1 );
  14
  15 /**
  16  * Message cache
  17  * Performs various MediaWiki namespace-related functions
  18  * @ingroup Cache
  19  */
  20 class MessageCache {
  21         /**
  22          * Process local cache of loaded messages that are defined in
  23          * MediaWiki namespace. First array level is a language code,
  24          * second level is message key and the values are either message
  25          * content prefixed with space, or !NONEXISTENT for negative
  26          * caching.
  27          */
  28         protected $mCache;
  29
  30         // Should  mean that database cannot be used, but check
  31         protected $mDisable;
  32
  33         /// Lifetime for cache, used by object caching
  34         protected $mExpiry;
  35
  36         /**
  37          * Message cache has it's own parser which it uses to transform
  38          * messages.
  39          */
  40         protected $mParserOptions, $mParser;
  41
  42         /// Variable for tracking which variables are already loaded
  43         protected $mLoadedLanguages = array();
  44
  45         /**
  46          * Used for automatic detection of most used messages.
  47          */
  48         protected $mRequestedMessages = array();
  49
  50         /**
  51          * How long the message request counts are stored. Longer period gives
  52          * better sample, but also takes longer to adapt changes. The counts
  53          * are aggregrated per day, regardless of the value of this variable.
  54          */
  55         protected static $mAdaptiveDataAge = 604800; // Is 7*24*3600
  56
  57         /**
  58          * Filter the tail of less used messages that are requested more seldom
  59          * than this factor times the number of request of most requested message.
  60          * These messages are not loaded in the default set, but are still cached
  61          * individually on demand with the normal cache expiry time.
  62          */
  63         protected static $mAdaptiveInclusionThreshold = 0.05;
  64
  65         /**
  66          * Singleton instance
  67          *
  68          * @var MessageCache
  69          */
  70         private static $instance;
  71
  72         /**
  73          * @var bool
  74          */
  75         protected $mInParser = false;
  76
  77         /**
  78          * Get the signleton instance of this class
  79          *
  80          * @since 1.18
  81          * @return MessageCache object
  82          */
  83         public static function singleton() {
  84                 if ( is_null( self::$instance ) ) {
  85                         global $wgUseDatabaseMessages, $wgMsgCacheExpiry;
  86                         self::$instance = new self( wfGetMessageCacheStorage(), $wgUseDatabaseMessages, $wgMsgCacheExpiry );
  87                 }
  88                 return self::$instance;
  89         }
  90
  91         /**
  92          * Destroy the singleton instance
  93          *
  94          * @since 1.18
  95          */
  96         public static function destroyInstance() {
  97                 self::$instance = null;
  98         }
  99
 100         function __construct( $memCached, $useDB, $expiry ) {
 101                 if ( !$memCached ) {
 102                         $memCached = wfGetCache( CACHE_NONE );
 103                 }
 104
 105                 $this->mMemc = $memCached;
 106                 $this->mDisable = !$useDB;
 107                 $this->mExpiry = $expiry;
 108         }
 109
 110         /**
 111          * ParserOptions is lazy initialised.
 112          *
 113          * @return ParserOptions
 114          */
 115         function getParserOptions() {
 116                 if ( !$this->mParserOptions ) {
 117                         $this->mParserOptions = new ParserOptions;
 118                 }
 119                 return $this->mParserOptions;
 120         }
 121
 122         /**
 123          * Try to load the cache from a local file.
 124          * Actual format of the file depends on the $wgLocalMessageCacheSerialized
 125          * setting.
 126          *
 127          * @param $hash String: the hash of contents, to check validity.
 128          * @param $code Mixed: Optional language code, see documenation of load().
 129          * @return false on failure.
 130          */
 131         function loadFromLocal( $hash, $code ) {
 132                 global $wgCacheDirectory, $wgLocalMessageCacheSerialized;
 133
 134                 $filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
 135
 136                 # Check file existence
 137                 wfSuppressWarnings();
 138                 $file = fopen( $filename, 'r' );
 139                 wfRestoreWarnings();
 140                 if ( !$file ) {
 141                         return false; // No cache file
 142                 }
 143
 144                 if ( $wgLocalMessageCacheSerialized ) {
 145                         // Check to see if the file has the hash specified
 146                         $localHash = fread( $file, 32 );
 147                         if ( $hash === $localHash ) {
 148                                 // All good, get the rest of it
 149                                 $serialized = '';
 150                                 while ( !feof( $file ) ) {
 151                                         $serialized .= fread( $file, 100000 );
 152                                 }
 153                                 fclose( $file );
 154                                 return $this->setCache( unserialize( $serialized ), $code );
 155                         } else {
 156                                 fclose( $file );
 157                                 return false; // Wrong hash
 158                         }
 159                 } else {
 160                         $localHash = substr( fread( $file, 40 ), 8 );
 161                         fclose( $file );
 162                         if ( $hash != $localHash ) {
 163                                 return false; // Wrong hash
 164                         }
 165
 166                         # Require overwrites the member variable or just shadows it?
 167                         require( $filename );
 168                         return $this->setCache( $this->mCache, $code );
 169                 }
 170         }
 171
 172         /**
 173          * Save the cache to a local file.
 174          */
 175         function saveToLocal( $serialized, $hash, $code ) {
 176                 global $wgCacheDirectory;
 177
 178                 $filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
 179                 wfMkdirParents( $wgCacheDirectory, null, __METHOD__ ); // might fail
 180
 181                 wfSuppressWarnings();
 182                 $file = fopen( $filename, 'w' );
 183                 wfRestoreWarnings();
 184
 185                 if ( !$file ) {
 186                         wfDebug( "Unable to open local cache file for writing\n" );
 187                         return;
 188                 }
 189
 190                 fwrite( $file, $hash . $serialized );
 191                 fclose( $file );
 192                 wfSuppressWarnings();
 193                 chmod( $filename, 0666 );
 194                 wfRestoreWarnings();
 195         }
 196
 197         function saveToScript( $array, $hash, $code ) {
 198                 global $wgCacheDirectory;
 199
 200                 $filename = "$wgCacheDirectory/messages-" . wfWikiID() . "-$code";
 201                 $tempFilename = $filename . '.tmp';
 202                 wfMkdirParents( $wgCacheDirectory, null, __METHOD__ ); // might fail
 203
 204                 wfSuppressWarnings();
 205                 $file = fopen( $tempFilename, 'w' );
 206                 wfRestoreWarnings();
 207
 208                 if ( !$file ) {
 209                         wfDebug( "Unable to open local cache file for writing\n" );
 210                         return;
 211                 }
 212
 213                 fwrite( $file, "<?php\n//$hash\n\n \$this->mCache = array(" );
 214
 215                 foreach ( $array as $key => $message ) {
 216                         $key = $this->escapeForScript( $key );
 217                         $message = $this->escapeForScript( $message );
 218                         fwrite( $file, "'$key' => '$message',\n" );
 219                 }
 220
 221                 fwrite( $file, ");\n?>" );
 222                 fclose( $file);
 223                 rename( $tempFilename, $filename );
 224         }
 225
 226         function escapeForScript( $string ) {
 227                 $string = str_replace( '\\', '\\\\', $string );
 228                 $string = str_replace( '\'', '\\\'', $string );
 229                 return $string;
 230         }
 231
 232         /**
 233          * Set the cache to $cache, if it is valid. Otherwise set the cache to false.
 234          *
 235          * @return bool
 236          */
 237         function setCache( $cache, $code ) {
 238                 if ( isset( $cache['VERSION'] ) && $cache['VERSION'] == MSG_CACHE_VERSION ) {
 239                         $this->mCache[$code] = $cache;
 240                         return true;
 241                 } else {
 242                         return false;
 243                 }
 244         }
 245
 246         /**
 247          * Loads messages from caches or from database in this order:
 248          * (1) local message cache (if $wgUseLocalMessageCache is enabled)
 249          * (2) memcached
 250          * (3) from the database.
 251          *
 252          * When succesfully loading from (2) or (3), all higher level caches are
 253          * updated for the newest version.
 254          *
 255          * Nothing is loaded if member variable mDisable is true, either manually
 256          * set by calling code or if message loading fails (is this possible?).
 257          *
 258          * Returns true if cache is already populated or it was succesfully populated,
 259          * or false if populating empty cache fails. Also returns true if MessageCache
 260          * is disabled.
 261          *
 262          * @param $code String: language to which load messages
 263          */
 264         function load( $code = false ) {
 265                 global $wgUseLocalMessageCache;
 266
 267                 if( !is_string( $code ) ) {
 268                         # This isn't really nice, so at least make a note about it and try to
 269                         # fall back
 270                         wfDebug( __METHOD__ . " called without providing a language code\n" );
 271                         $code = 'en';
 272                 }
 273
 274                 # Don't do double loading...
 275                 if ( isset( $this->mLoadedLanguages[$code] ) ) {
 276                         return true;
 277                 }
 278
 279                 # 8 lines of code just to say (once) that message cache is disabled
 280                 if ( $this->mDisable ) {
 281                         static $shownDisabled = false;
 282                         if ( !$shownDisabled ) {
 283                                 wfDebug( __METHOD__ . ": disabled\n" );
 284                                 $shownDisabled = true;
 285                         }
 286                         return true;
 287                 }
 288
 289                 # Loading code starts
 290                 wfProfileIn( __METHOD__ );
 291                 $success = false; # Keep track of success
 292                 $where = array(); # Debug info, delayed to avoid spamming debug log too much
 293                 $cacheKey = wfMemcKey( 'messages', $code ); # Key in memc for messages
 294
 295                 # (1) local cache
 296                 # Hash of the contents is stored in memcache, to detect if local cache goes
 297                 # out of date (due to update in other thread?)
 298                 if ( $wgUseLocalMessageCache ) {
 299                         wfProfileIn( __METHOD__ . '-fromlocal' );
 300
 301                         $hash = $this->mMemc->get( wfMemcKey( 'messages', $code, 'hash' ) );
 302                         if ( $hash ) {
 303                                 $success = $this->loadFromLocal( $hash, $code );
 304                                 if ( $success ) $where[] = 'got from local cache';
 305                         }
 306                         wfProfileOut( __METHOD__ . '-fromlocal' );
 307                 }
 308
 309                 # (2) memcache
 310                 # Fails if nothing in cache, or in the wrong version.
 311                 if ( !$success ) {
 312                         wfProfileIn( __METHOD__ . '-fromcache' );
 313                         $cache = $this->mMemc->get( $cacheKey );
 314                         $success = $this->setCache( $cache, $code );
 315                         if ( $success ) {
 316                                 $where[] = 'got from global cache';
 317                                 $this->saveToCaches( $cache, false, $code );
 318                         }
 319                         wfProfileOut( __METHOD__ . '-fromcache' );
 320                 }
 321
 322                 # (3)
 323                 # Nothing in caches... so we need create one and store it in caches
 324                 if ( !$success ) {
 325                         $where[] = 'cache is empty';
 326                         $where[] = 'loading from database';
 327
 328                         $this->lock( $cacheKey );
 329
 330                         # Limit the concurrency of loadFromDB to a single process
 331                         # This prevents the site from going down when the cache expires
 332                         $statusKey = wfMemcKey( 'messages', $code, 'status' );
 333                         $success = $this->mMemc->add( $statusKey, 'loading', MSG_LOAD_TIMEOUT );
 334                         if ( $success ) {
 335                                 $cache = $this->loadFromDB( $code );
 336                                 $success = $this->setCache( $cache, $code );
 337                         }
 338                         if ( $success ) {
 339                                 $success = $this->saveToCaches( $cache, true, $code );
 340                                 if ( $success ) {
 341                                         $this->mMemc->delete( $statusKey );
 342                                 } else {
 343                                         $this->mMemc->set( $statusKey, 'error', 60 * 5 );
 344                                         wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
 345                                 }
 346                         }
 347                         $this->unlock($cacheKey);
 348                 }
 349
 350                 if ( !$success ) {
 351                         # Bad luck... this should not happen
 352                         $where[] = 'loading FAILED - cache is disabled';
 353                         $info = implode( ', ', $where );
 354                         wfDebug( __METHOD__ . ": Loading $code... $info\n" );
 355                         $this->mDisable = true;
 356                         $this->mCache = false;
 357                 } else {
 358                         # All good, just record the success
 359                         $info = implode( ', ', $where );
 360                         wfDebug( __METHOD__ . ": Loading $code... $info\n" );
 361                         $this->mLoadedLanguages[$code] = true;
 362                 }
 363                 wfProfileOut( __METHOD__ );
 364                 return $success;
 365         }
 366
 367         /**
 368          * Loads cacheable messages from the database. Messages bigger than
 369          * $wgMaxMsgCacheEntrySize are assigned a special value, and are loaded
 370          * on-demand from the database later.
 371          *
 372          * @param $code String: language code.
 373          * @return Array: loaded messages for storing in caches.
 374          */
 375         function loadFromDB( $code ) {
 376                 wfProfileIn( __METHOD__ );
 377                 global $wgMaxMsgCacheEntrySize, $wgLanguageCode, $wgAdaptiveMessageCache;
 378                 $dbr = wfGetDB( DB_SLAVE );
 379                 $cache = array();
 380
 381                 # Common conditions
 382                 $conds = array(
 383                         'page_is_redirect' => 0,
 384                         'page_namespace' => NS_MEDIAWIKI,
 385                 );
 386
 387                 $mostused = array();
 388                 if ( $wgAdaptiveMessageCache ) {
 389                         $mostused = $this->getMostUsedMessages();
 390                         if ( $code !== $wgLanguageCode ) {
 391                                 foreach ( $mostused as $key => $value ) {
 392                                         $mostused[$key] = "$value/$code";
 393                                 }
 394                         }
 395                 }
 396
 397                 if ( count( $mostused ) ) {
 398                         $conds['page_title'] = $mostused;
 399                 } elseif ( $code !== $wgLanguageCode ) {
 400                         $conds[] = 'page_title' . $dbr->buildLike( $dbr->anyString(), "/$code" );
 401                 } else {
 402                         # Effectively disallows use of '/' character in NS_MEDIAWIKI for uses
 403                         # other than language code.
 404                         $conds[] = 'page_title NOT' . $dbr->buildLike( $dbr->anyString(), '/', $dbr->anyString() );
 405                 }
 406
 407                 # Conditions to fetch oversized pages to ignore them
 408                 $bigConds = $conds;
 409                 $bigConds[] = 'page_len > ' . intval( $wgMaxMsgCacheEntrySize );
 410
 411                 # Load titles for all oversized pages in the MediaWiki namespace
 412                 $res = $dbr->select( 'page', 'page_title', $bigConds, __METHOD__ . "($code)-big" );
 413                 foreach ( $res as $row ) {
 414                         $cache[$row->page_title] = '!TOO BIG';
 415                 }
 416
 417                 # Conditions to load the remaining pages with their contents
 418                 $smallConds = $conds;
 419                 $smallConds[] = 'page_latest=rev_id';
 420                 $smallConds[] = 'rev_text_id=old_id';
 421                 $smallConds[] = 'page_len <= ' . intval( $wgMaxMsgCacheEntrySize );
 422
 423                 $res = $dbr->select(
 424                         array( 'page', 'revision', 'text' ),
 425                         array( 'page_title', 'old_text', 'old_flags' ),
 426                         $smallConds,
 427                         __METHOD__ . "($code)-small"
 428                 );
 429
 430                 foreach ( $res as $row ) {
 431                         $text = Revision::getRevisionText( $row );
 432                         if( $text === false ) {
 433                                 // Failed to fetch data; possible ES errors?
 434                                 // Store a marker to fetch on-demand as a workaround...
 435                                 $entry = '!TOO BIG';
 436                                 wfDebugLog( 'MessageCache', __METHOD__ . ": failed to load message page text for {$row->page_title} ($code)" );
 437                         } else {
 438                                 $entry = ' ' . $text;
 439                         }
 440                         $cache[$row->page_title] = $entry;
 441                 }
 442
 443                 foreach ( $mostused as $key ) {
 444                         if ( !isset( $cache[$key] ) ) {
 445                                 $cache[$key] = '!NONEXISTENT';
 446                         }
 447                 }
 448
 449                 $cache['VERSION'] = MSG_CACHE_VERSION;
 450                 wfProfileOut( __METHOD__ );
 451                 return $cache;
 452         }
 453
 454         /**
 455          * Updates cache as necessary when message page is changed
 456          *
 457          * @param $title String: name of the page changed.
 458          * @param $text Mixed: new contents of the page.
 459          */
 460         public function replace( $title, $text ) {
 461                 global $wgMaxMsgCacheEntrySize;
 462                 wfProfileIn( __METHOD__ );
 463
 464                 if ( $this->mDisable ) {
 465                         wfProfileOut( __METHOD__ );
 466                         return;
 467                 }
 468
 469                 list( $msg, $code ) = $this->figureMessage( $title );
 470
 471                 $cacheKey = wfMemcKey( 'messages', $code );
 472                 $this->load( $code );
 473                 $this->lock( $cacheKey );
 474
 475                 $titleKey = wfMemcKey( 'messages', 'individual', $title );
 476
 477                 if ( $text === false ) {
 478                         # Article was deleted
 479                         $this->mCache[$code][$title] = '!NONEXISTENT';
 480                         $this->mMemc->delete( $titleKey );
 481                 } elseif ( strlen( $text ) > $wgMaxMsgCacheEntrySize ) {
 482                         # Check for size
 483                         $this->mCache[$code][$title] = '!TOO BIG';
 484                         $this->mMemc->set( $titleKey, ' ' . $text, $this->mExpiry );
 485                 } else {
 486                         $this->mCache[$code][$title] = ' ' . $text;
 487                         $this->mMemc->delete( $titleKey );
 488                 }
 489
 490                 # Update caches
 491                 $this->saveToCaches( $this->mCache[$code], true, $code );
 492                 $this->unlock( $cacheKey );
 493
 494                 // Also delete cached sidebar... just in case it is affected
 495                 $codes = array( $code );
 496                 if ( $code === 'en'  ) {
 497                         // Delete all sidebars, like for example on action=purge on the
 498                         // sidebar messages
 499                         $codes = array_keys( Language::getLanguageNames() );
 500                 }
 501
 502                 global $wgMemc;
 503                 foreach ( $codes as $code ) {
 504                         $sidebarKey = wfMemcKey( 'sidebar', $code );
 505                         $wgMemc->delete( $sidebarKey );
 506                 }
 507
 508                 // Update the message in the message blob store
 509                 global $wgContLang;
 510                 MessageBlobStore::updateMessage( $wgContLang->lcfirst( $msg ) );
 511
 512                 wfRunHooks( 'MessageCacheReplace', array( $title, $text ) );
 513
 514                 wfProfileOut( __METHOD__ );
 515         }
 516
 517         /**
 518          * Shortcut to update caches.
 519          *
 520          * @param $cache Array: cached messages with a version.
 521          * @param $memc Bool: Wether to update or not memcache.
 522          * @param $code String: Language code.
 523          * @return False on somekind of error.
 524          */
 525         protected function saveToCaches( $cache, $memc = true, $code = false ) {
 526                 wfProfileIn( __METHOD__ );
 527                 global $wgUseLocalMessageCache, $wgLocalMessageCacheSerialized;
 528
 529                 $cacheKey = wfMemcKey( 'messages', $code );
 530
 531                 if ( $memc ) {
 532                         $success = $this->mMemc->set( $cacheKey, $cache, $this->mExpiry );
 533                 } else {
 534                         $success = true;
 535                 }
 536
 537                 # Save to local cache
 538                 if ( $wgUseLocalMessageCache ) {
 539                         $serialized = serialize( $cache );
 540                         $hash = md5( $serialized );
 541                         $this->mMemc->set( wfMemcKey( 'messages', $code, 'hash' ), $hash, $this->mExpiry );
 542                         if ($wgLocalMessageCacheSerialized) {
 543                                 $this->saveToLocal( $serialized, $hash, $code );
 544                         } else {
 545                                 $this->saveToScript( $cache, $hash, $code );
 546                         }
 547                 }
 548
 549                 wfProfileOut( __METHOD__ );
 550                 return $success;
 551         }
 552
 553         /**
 554          * Represents a write lock on the messages key
 555          *
 556          * @param $key string
 557          *
 558          * @return Boolean: success
 559          */
 560         function lock( $key ) {
 561                 $lockKey = $key . ':lock';
 562                 for ( $i = 0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 563                         sleep( 1 );
 564                 }
 565
 566                 return $i >= MSG_WAIT_TIMEOUT;
 567         }
 568
 569         function unlock( $key ) {
 570                 $lockKey = $key . ':lock';
 571                 $this->mMemc->delete( $lockKey );
 572         }
 573
 574         /**
 575          * Get a message from either the content language or the user language.
 576          *
 577          * @param $key String: the message cache key
 578          * @param $useDB Boolean: get the message from the DB, false to use only
 579          *               the localisation
 580          * @param $langcode String: code of the language to get the message for, if
 581          *                  it is a valid code create a language for that language,
 582          *                  if it is a string but not a valid code then make a basic
 583          *                  language object, if it is a false boolean then use the
 584          *                  current users language (as a fallback for the old
 585          *                  parameter functionality), or if it is a true boolean
 586          *                  then use the wikis content language (also as a
 587          *                  fallback).
 588          * @param $isFullKey Boolean: specifies whether $key is a two part key
 589          *                   "msg/lang".
 590          *
 591          * @return string|false
 592          */
 593         function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {
 594                 global $wgLanguageCode, $wgContLang;
 595
 596                 if ( is_int( $key ) ) {
 597                         // "Non-string key given" exception sometimes happens for numerical strings that become ints somewhere on their way here
 598                         $key = strval( $key );
 599                 }
 600
 601                 if ( !is_string( $key ) ) {
 602                         throw new MWException( 'Non-string key given' );
 603                 }
 604
 605                 if ( strval( $key ) === '' ) {
 606                         # Shortcut: the empty key is always missing
 607                         return false;
 608                 }
 609
 610                 $lang = wfGetLangObj( $langcode );
 611                 if ( !$lang ) {
 612                         throw new MWException( "Bad lang code $langcode given" );
 613                 }
 614
 615                 $langcode = $lang->getCode();
 616
 617                 $message = false;
 618
 619                 # Normalise title-case input (with some inlining)
 620                 $lckey = str_replace( ' ', '_', $key );
 621                 if ( ord( $key ) < 128 ) {
 622                         $lckey[0] = strtolower( $lckey[0] );
 623                         $uckey = ucfirst( $lckey );
 624                 } else {
 625                         $lckey = $wgContLang->lcfirst( $lckey );
 626                         $uckey = $wgContLang->ucfirst( $lckey );
 627                 }
 628
 629                 /**
 630                  * Record each message request, but only once per request.
 631                  * This information is not used unless $wgAdaptiveMessageCache
 632                  * is enabled.
 633                  */
 634                 $this->mRequestedMessages[$uckey] = true;
 635
 636                 # Try the MediaWiki namespace
 637                 if( !$this->mDisable && $useDB ) {
 638                         $title = $uckey;
 639                         if( !$isFullKey && ( $langcode != $wgLanguageCode ) ) {
 640                                 $title .= '/' . $langcode;
 641                         }
 642                         $message = $this->getMsgFromNamespace( $title, $langcode );
 643                 }
 644
 645                 # Try the array in the language object
 646                 if ( $message === false ) {
 647                         $message = $lang->getMessage( $lckey );
 648                         if ( is_null( $message ) ) {
 649                                 $message = false;
 650                         }
 651                 }
 652
 653                 # Try the array of another language
 654                 if( $message === false ) {
 655                         $parts = explode( '/', $lckey );
 656                         # We may get calls for things that are http-urls from sidebar
 657                         # Let's not load nonexistent languages for those
 658                         # They usually have more than one slash.
 659                         if ( count( $parts ) == 2 && $parts[1] !== '' ) {
 660                                 $message = Language::getMessageFor( $parts[0], $parts[1] );
 661                                 if ( is_null( $message ) ) {
 662                                         $message = false;
 663                                 }
 664                         }
 665                 }
 666
 667                 # Is this a custom message? Try the default language in the db...
 668                 if( ( $message === false || $message === '-' ) &&
 669                         !$this->mDisable && $useDB &&
 670                         !$isFullKey && ( $langcode != $wgLanguageCode ) ) {
 671                         $message = $this->getMsgFromNamespace( $uckey, $wgLanguageCode );
 672                 }
 673
 674                 # Final fallback
 675                 if( $message === false ) {
 676                         return false;
 677                 }
 678
 679                 # Fix whitespace
 680                 $message = strtr( $message,
 681                         array(
 682                                 # Fix for trailing whitespace, removed by textarea
 683                                 '&#32;' => ' ',
 684                                 # Fix for NBSP, converted to space by firefox
 685                                 '&nbsp;' => "\xc2\xa0",
 686                                 '&#160;' => "\xc2\xa0",
 687                         ) );
 688
 689                 return $message;
 690         }
 691
 692         /**
 693          * Get a message from the MediaWiki namespace, with caching. The key must
 694          * first be converted to two-part lang/msg form if necessary.
 695          *
 696          * @param $title String: Message cache key with initial uppercase letter.
 697          * @param $code String: code denoting the language to try.
 698          *
 699          * @return string|false
 700          */
 701         function getMsgFromNamespace( $title, $code ) {
 702                 global $wgAdaptiveMessageCache;
 703
 704                 $this->load( $code );
 705                 if ( isset( $this->mCache[$code][$title] ) ) {
 706                         $entry = $this->mCache[$code][$title];
 707                         if ( substr( $entry, 0, 1 ) === ' ' ) {
 708                                 return substr( $entry, 1 );
 709                         } elseif ( $entry === '!NONEXISTENT' ) {
 710                                 return false;
 711                         } elseif( $entry === '!TOO BIG' ) {
 712                                 // Fall through and try invididual message cache below
 713                         }
 714                 } else {
 715                         // XXX: This is not cached in process cache, should it?
 716                         $message = false;
 717                         wfRunHooks( 'MessagesPreLoad', array( $title, &$message ) );
 718                         if ( $message !== false ) {
 719                                 return $message;
 720                         }
 721
 722                         /**
 723                          * If message cache is in normal mode, it is guaranteed
 724                          * (except bugs) that there is always entry (or placeholder)
 725                          * in the cache if message exists. Thus we can do minor
 726                          * performance improvement and return false early.
 727                          */
 728                         if ( !$wgAdaptiveMessageCache ) {
 729                                 return false;
 730                         }
 731                 }
 732
 733                 # Try the individual message cache
 734                 $titleKey = wfMemcKey( 'messages', 'individual', $title );
 735                 $entry = $this->mMemc->get( $titleKey );
 736                 if ( $entry ) {
 737                         if ( substr( $entry, 0, 1 ) === ' ' ) {
 738                                 $this->mCache[$code][$title] = $entry;
 739                                 return substr( $entry, 1 );
 740                         } elseif ( $entry === '!NONEXISTENT' ) {
 741                                 $this->mCache[$code][$title] = '!NONEXISTENT';
 742                                 return false;
 743                         } else {
 744                                 # Corrupt/obsolete entry, delete it
 745                                 $this->mMemc->delete( $titleKey );
 746                         }
 747                 }
 748
 749                 # Try loading it from the database
 750                 $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
 751                 if ( $revision ) {
 752                         $message = $revision->getText();
 753                         if ($message === false) {
 754                                 // A possibly temporary loading failure.
 755                                 wfDebugLog( 'MessageCache', __METHOD__ . ": failed to load message page text for {$title->getDbKey()} ($code)" );
 756                         } else {
 757                                 $this->mCache[$code][$title] = ' ' . $message;
 758                                 $this->mMemc->set( $titleKey, ' ' . $message, $this->mExpiry );
 759                         }
 760                 } else {
 761                         $message = false;
 762                         $this->mCache[$code][$title] = '!NONEXISTENT';
 763                         $this->mMemc->set( $titleKey, '!NONEXISTENT', $this->mExpiry );
 764                 }
 765
 766                 return $message;
 767         }
 768
 769         /**
 770          * @param $message string
 771          * @param $interface bool
 772          * @param $language
 773          * @param $title Title
 774          * @return string
 775          */
 776         function transform( $message, $interface = false, $language = null, $title = null ) {
 777                 // Avoid creating parser if nothing to transform
 778                 if( strpos( $message, '{{' ) === false ) {
 779                         return $message;
 780                 }
 781
 782                 if ( $this->mInParser ) {
 783                         return $message;
 784                 }
 785
 786                 $parser = $this->getParser();
 787                 if ( $parser ) {
 788                         $popts = $this->getParserOptions();
 789                         $popts->setInterfaceMessage( $interface );
 790                         $popts->setTargetLanguage( $language );
 791
 792                         $userlang = $popts->setUserLang( $language );
 793                         $this->mInParser = true;
 794                         $message = $parser->transformMsg( $message, $popts, $title );
 795                         $this->mInParser = false;
 796                         $popts->setUserLang( $userlang );
 797                 }
 798                 return $message;
 799         }
 800
 801         /**
 802          * @return Parser
 803          */
 804         function getParser() {
 805                 global $wgParser, $wgParserConf;
 806                 if ( !$this->mParser && isset( $wgParser ) ) {
 807                         # Do some initialisation so that we don't have to do it twice
 808                         $wgParser->firstCallInit();
 809                         # Clone it and store it
 810                         $class = $wgParserConf['class'];
 811                         if ( $class == 'Parser_DiffTest' ) {
 812                                 # Uncloneable
 813                                 $this->mParser = new $class( $wgParserConf );
 814                         } else {
 815                                 $this->mParser = clone $wgParser;
 816                         }
 817                 }
 818                 return $this->mParser;
 819         }
 820
 821         /**
 822          * @param $text string
 823          * @param $title Title
 824          * @param $linestart bool
 825          * @param $interface bool
 826          * @param $language
 827          * @return ParserOutput
 828          */
 829         public function parse( $text, $title = null, $linestart = true, $interface = false, $language = null  ) {
 830                 if ( $this->mInParser ) {
 831                         return htmlspecialchars( $text );
 832                 }
 833
 834                 $parser = $this->getParser();
 835                 $popts = $this->getParserOptions();
 836
 837                 if ( $interface ) {
 838                         $popts->setInterfaceMessage( true );
 839                 }
 840                 if ( $language !== null ) {
 841                         $popts->setTargetLanguage( $language );
 842                 }
 843
 844                 wfProfileIn( __METHOD__ );
 845                 if ( !$title || !$title instanceof Title ) {
 846                         global $wgTitle;
 847                         $title = $wgTitle;
 848                 }
 849                 // Sometimes $wgTitle isn't set either...
 850                 if ( !$title ) {
 851                         # It's not uncommon having a null $wgTitle in scripts. See r80898
 852                         # Create a ghost title in such case
 853                         $title = Title::newFromText( 'Dwimmerlaik' );
 854                 }
 855
 856                 $this->mInParser = true;
 857                 $res = $parser->parse( $text, $title, $popts, $linestart );
 858                 $this->mInParser = false;
 859
 860                 wfProfileOut( __METHOD__ );
 861                 return $res;
 862         }
 863
 864         function disable() {
 865                 $this->mDisable = true;
 866         }
 867
 868         function enable() {
 869                 $this->mDisable = false;
 870         }
 871
 872         /**
 873          * Clear all stored messages. Mainly used after a mass rebuild.
 874          */
 875         function clear() {
 876                 $langs = Language::getLanguageNames( false );
 877                 foreach ( array_keys($langs) as $code ) {
 878                         # Global cache
 879                         $this->mMemc->delete( wfMemcKey( 'messages', $code ) );
 880                         # Invalidate all local caches
 881                         $this->mMemc->delete( wfMemcKey( 'messages', $code, 'hash' ) );
 882                 }
 883                 $this->mLoadedLanguages = array();
 884         }
 885
 886         /**
 887          * @param $key
 888          * @return array
 889          */
 890         public function figureMessage( $key ) {
 891                 global $wgLanguageCode;
 892                 $pieces = explode( '/', $key );
 893                 if( count( $pieces ) < 2 ) {
 894                         return array( $key, $wgLanguageCode );
 895                 }
 896
 897                 $lang = array_pop( $pieces );
 898                 $validCodes = Language::getLanguageNames();
 899                 if( !array_key_exists( $lang, $validCodes ) ) {
 900                         return array( $key, $wgLanguageCode );
 901                 }
 902
 903                 $message = implode( '/', $pieces );
 904                 return array( $message, $lang );
 905         }
 906
 907         public static function logMessages() {
 908                 wfProfileIn( __METHOD__ );
 909                 global $wgAdaptiveMessageCache;
 910                 if ( !$wgAdaptiveMessageCache || !self::$instance instanceof MessageCache ) {
 911                         wfProfileOut( __METHOD__ );
 912                         return;
 913                 }
 914
 915                 $cachekey = wfMemckey( 'message-profiling' );
 916                 $cache = wfGetCache( CACHE_DB );
 917                 $data = $cache->get( $cachekey );
 918
 919                 if ( !$data ) {
 920                         $data = array();
 921                 }
 922
 923                 $age = self::$mAdaptiveDataAge;
 924                 $filterDate = substr( wfTimestamp( TS_MW, time() - $age ), 0, 8 );
 925                 foreach ( array_keys( $data ) as $key ) {
 926                         if ( $key < $filterDate ) {
 927                                 unset( $data[$key] );
 928                         }
 929                 }
 930
 931                 $index = substr( wfTimestampNow(), 0, 8 );
 932                 if ( !isset( $data[$index] ) ) {
 933                         $data[$index] = array();
 934                 }
 935
 936                 foreach ( self::$instance->mRequestedMessages as $message => $_ ) {
 937                         if ( !isset( $data[$index][$message] ) ) {
 938                                 $data[$index][$message] = 0;
 939                         }
 940                         $data[$index][$message]++;
 941                 }
 942
 943                 $cache->set( $cachekey, $data );
 944                 wfProfileOut( __METHOD__ );
 945         }
 946
 947         /**
 948          * @return array
 949          */
 950         public function getMostUsedMessages() {
 951                 wfProfileIn( __METHOD__ );
 952                 $cachekey = wfMemcKey( 'message-profiling' );
 953                 $cache = wfGetCache( CACHE_DB );
 954                 $data = $cache->get( $cachekey );
 955                 if ( !$data ) {
 956                         wfProfileOut( __METHOD__ );
 957                         return array();
 958                 }
 959
 960                 $list = array();
 961
 962                 foreach( $data as $messages ) {
 963                         foreach( $messages as $message => $count ) {
 964                                 $key = $message;
 965                                 if ( !isset( $list[$key] ) ) {
 966                                         $list[$key] = 0;
 967                                 }
 968                                 $list[$key] += $count;
 969                         }
 970                 }
 971
 972                 $max = max( $list );
 973                 foreach ( $list as $message => $count ) {
 974                         if ( $count < intval( $max * self::$mAdaptiveInclusionThreshold ) ) {
 975                                 unset( $list[$message] );
 976                         }
 977                 }
 978
 979                 wfProfileOut( __METHOD__ );
 980                 return array_keys( $list );
 981         }
 982
 983         /**
 984          * Get all message keys stored in the message cache for a given language.
 985          * If $code is the content language code, this will return all message keys
 986          * for which MediaWiki:msgkey exists. If $code is another language code, this
 987          * will ONLY return message keys for which MediaWiki:msgkey/$code exists.
 988          * @param $code string
 989          * @return array of message keys (strings)
 990          */
 991         public function getAllMessageKeys( $code ) {
 992                 global $wgContLang;
 993                 $this->load( $code );
 994                 if ( !isset( $this->mCache[$code] ) ) {
 995                         // Apparently load() failed
 996                         return null;
 997                 }
 998                 $cache = $this->mCache[$code]; // Copy the cache
 999                 unset( $cache['VERSION'] ); // Remove the VERSION key
1000                 $cache = array_diff( $cache, array( '!NONEXISTENT' ) ); // Remove any !NONEXISTENT keys
1001                 // Keys may appear with a capital first letter. lcfirst them.
1002                 return array_map( array( $wgContLang, 'lcfirst' ), array_keys( $cache ) );
1003         }
1004 }