includes/WatchedItemStore.php

   1 <?php
   2
   3 use Liuggio\StatsdClient\Factory\StatsdDataFactoryInterface;
   4 use MediaWiki\Linker\LinkTarget;
   5 use Wikimedia\Assert\Assert;
   6 use Wikimedia\ScopedCallback;
   7
   8 /**
   9  * Storage layer class for WatchedItems.
  10  * Database interaction.
  11  *
  12  * @author Addshore
  13  *
  14  * @since 1.27
  15  */
  16 class WatchedItemStore implements StatsdAwareInterface {
  17
  18         const SORT_DESC = 'DESC';
  19         const SORT_ASC = 'ASC';
  20
  21         /**
  22          * @var LoadBalancer
  23          */
  24         private $loadBalancer;
  25
  26         /**
  27          * @var HashBagOStuff
  28          */
  29         private $cache;
  30
  31         /**
  32          * @var array[] Looks like $cacheIndex[Namespace ID][Target DB Key][User Id] => 'key'
  33          * The index is needed so that on mass changes all relevant items can be un-cached.
  34          * For example: Clearing a users watchlist of all items or updating notification timestamps
  35          *              for all users watching a single target.
  36          */
  37         private $cacheIndex = [];
  38
  39         /**
  40          * @var callable|null
  41          */
  42         private $deferredUpdatesAddCallableUpdateCallback;
  43
  44         /**
  45          * @var callable|null
  46          */
  47         private $revisionGetTimestampFromIdCallback;
  48
  49         /**
  50          * @var StatsdDataFactoryInterface
  51          */
  52         private $stats;
  53
  54         /**
  55          * @param LoadBalancer $loadBalancer
  56          * @param HashBagOStuff $cache
  57          */
  58         public function __construct(
  59                 LoadBalancer $loadBalancer,
  60                 HashBagOStuff $cache
  61         ) {
  62                 $this->loadBalancer = $loadBalancer;
  63                 $this->cache = $cache;
  64                 $this->stats = new NullStatsdDataFactory();
  65                 $this->deferredUpdatesAddCallableUpdateCallback = [ 'DeferredUpdates', 'addCallableUpdate' ];
  66                 $this->revisionGetTimestampFromIdCallback = [ 'Revision', 'getTimestampFromId' ];
  67         }
  68
  69         public function setStatsdDataFactory( StatsdDataFactoryInterface $stats ) {
  70                 $this->stats = $stats;
  71         }
  72
  73         /**
  74          * Overrides the DeferredUpdates::addCallableUpdate callback
  75          * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
  76          *
  77          * @param callable $callback
  78          *
  79          * @see DeferredUpdates::addCallableUpdate for callback signiture
  80          *
  81          * @return ScopedCallback to reset the overridden value
  82          * @throws MWException
  83          */
  84         public function overrideDeferredUpdatesAddCallableUpdateCallback( callable $callback ) {
  85                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
  86                         throw new MWException(
  87                                 'Cannot override DeferredUpdates::addCallableUpdate callback in operation.'
  88                         );
  89                 }
  90                 $previousValue = $this->deferredUpdatesAddCallableUpdateCallback;
  91                 $this->deferredUpdatesAddCallableUpdateCallback = $callback;
  92                 return new ScopedCallback( function() use ( $previousValue ) {
  93                         $this->deferredUpdatesAddCallableUpdateCallback = $previousValue;
  94                 } );
  95         }
  96
  97         /**
  98          * Overrides the Revision::getTimestampFromId callback
  99          * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
 100          *
 101          * @param callable $callback
 102          * @see Revision::getTimestampFromId for callback signiture
 103          *
 104          * @return ScopedCallback to reset the overridden value
 105          * @throws MWException
 106          */
 107         public function overrideRevisionGetTimestampFromIdCallback( callable $callback ) {
 108                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 109                         throw new MWException(
 110                                 'Cannot override Revision::getTimestampFromId callback in operation.'
 111                         );
 112                 }
 113                 $previousValue = $this->revisionGetTimestampFromIdCallback;
 114                 $this->revisionGetTimestampFromIdCallback = $callback;
 115                 return new ScopedCallback( function() use ( $previousValue ) {
 116                         $this->revisionGetTimestampFromIdCallback = $previousValue;
 117                 } );
 118         }
 119
 120         private function getCacheKey( User $user, LinkTarget $target ) {
 121                 return $this->cache->makeKey(
 122                         (string)$target->getNamespace(),
 123                         $target->getDBkey(),
 124                         (string)$user->getId()
 125                 );
 126         }
 127
 128         private function cache( WatchedItem $item ) {
 129                 $user = $item->getUser();
 130                 $target = $item->getLinkTarget();
 131                 $key = $this->getCacheKey( $user, $target );
 132                 $this->cache->set( $key, $item );
 133                 $this->cacheIndex[$target->getNamespace()][$target->getDBkey()][$user->getId()] = $key;
 134                 $this->stats->increment( 'WatchedItemStore.cache' );
 135         }
 136
 137         private function uncache( User $user, LinkTarget $target ) {
 138                 $this->cache->delete( $this->getCacheKey( $user, $target ) );
 139                 unset( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()][$user->getId()] );
 140                 $this->stats->increment( 'WatchedItemStore.uncache' );
 141         }
 142
 143         private function uncacheLinkTarget( LinkTarget $target ) {
 144                 $this->stats->increment( 'WatchedItemStore.uncacheLinkTarget' );
 145                 if ( !isset( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()] ) ) {
 146                         return;
 147                 }
 148                 foreach ( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()] as $key ) {
 149                         $this->stats->increment( 'WatchedItemStore.uncacheLinkTarget.items' );
 150                         $this->cache->delete( $key );
 151                 }
 152         }
 153
 154         private function uncacheUser( User $user ) {
 155                 $this->stats->increment( 'WatchedItemStore.uncacheUser' );
 156                 foreach ( $this->cacheIndex as $ns => $dbKeyArray ) {
 157                         foreach ( $dbKeyArray as $dbKey => $userArray ) {
 158                                 if ( isset( $userArray[$user->getId()] ) ) {
 159                                         $this->stats->increment( 'WatchedItemStore.uncacheUser.items' );
 160                                         $this->cache->delete( $userArray[$user->getId()] );
 161                                 }
 162                         }
 163                 }
 164         }
 165
 166         /**
 167          * @param User $user
 168          * @param LinkTarget $target
 169          *
 170          * @return WatchedItem|false
 171          */
 172         private function getCached( User $user, LinkTarget $target ) {
 173                 return $this->cache->get( $this->getCacheKey( $user, $target ) );
 174         }
 175
 176         /**
 177          * Return an array of conditions to select or update the appropriate database
 178          * row.
 179          *
 180          * @param User $user
 181          * @param LinkTarget $target
 182          *
 183          * @return array
 184          */
 185         private function dbCond( User $user, LinkTarget $target ) {
 186                 return [
 187                         'wl_user' => $user->getId(),
 188                         'wl_namespace' => $target->getNamespace(),
 189                         'wl_title' => $target->getDBkey(),
 190                 ];
 191         }
 192
 193         /**
 194          * @param int $dbIndex DB_MASTER or DB_REPLICA
 195          *
 196          * @return IDatabase
 197          * @throws MWException
 198          */
 199         private function getConnectionRef( $dbIndex ) {
 200                 return $this->loadBalancer->getConnectionRef( $dbIndex, [ 'watchlist' ] );
 201         }
 202
 203         /**
 204          * Count the number of individual items that are watched by the user.
 205          * If a subject and corresponding talk page are watched this will return 2.
 206          *
 207          * @param User $user
 208          *
 209          * @return int
 210          */
 211         public function countWatchedItems( User $user ) {
 212                 $dbr = $this->getConnectionRef( DB_REPLICA );
 213                 $return = (int)$dbr->selectField(
 214                         'watchlist',
 215                         'COUNT(*)',
 216                         [
 217                                 'wl_user' => $user->getId()
 218                         ],
 219                         __METHOD__
 220                 );
 221
 222                 return $return;
 223         }
 224
 225         /**
 226          * @param LinkTarget $target
 227          *
 228          * @return int
 229          */
 230         public function countWatchers( LinkTarget $target ) {
 231                 $dbr = $this->getConnectionRef( DB_REPLICA );
 232                 $return = (int)$dbr->selectField(
 233                         'watchlist',
 234                         'COUNT(*)',
 235                         [
 236                                 'wl_namespace' => $target->getNamespace(),
 237                                 'wl_title' => $target->getDBkey(),
 238                         ],
 239                         __METHOD__
 240                 );
 241
 242                 return $return;
 243         }
 244
 245         /**
 246          * Number of page watchers who also visited a "recent" edit
 247          *
 248          * @param LinkTarget $target
 249          * @param mixed $threshold timestamp accepted by wfTimestamp
 250          *
 251          * @return int
 252          * @throws DBUnexpectedError
 253          * @throws MWException
 254          */
 255         public function countVisitingWatchers( LinkTarget $target, $threshold ) {
 256                 $dbr = $this->getConnectionRef( DB_REPLICA );
 257                 $visitingWatchers = (int)$dbr->selectField(
 258                         'watchlist',
 259                         'COUNT(*)',
 260                         [
 261                                 'wl_namespace' => $target->getNamespace(),
 262                                 'wl_title' => $target->getDBkey(),
 263                                 'wl_notificationtimestamp >= ' .
 264                                 $dbr->addQuotes( $dbr->timestamp( $threshold ) ) .
 265                                 ' OR wl_notificationtimestamp IS NULL'
 266                         ],
 267                         __METHOD__
 268                 );
 269
 270                 return $visitingWatchers;
 271         }
 272
 273         /**
 274          * @param LinkTarget[] $targets
 275          * @param array $options Allowed keys:
 276          *        'minimumWatchers' => int
 277          *
 278          * @return array multi dimensional like $return[$namespaceId][$titleString] = int $watchers
 279          *         All targets will be present in the result. 0 either means no watchers or the number
 280          *         of watchers was below the minimumWatchers option if passed.
 281          */
 282         public function countWatchersMultiple( array $targets, array $options = [] ) {
 283                 $dbOptions = [ 'GROUP BY' => [ 'wl_namespace', 'wl_title' ] ];
 284
 285                 $dbr = $this->getConnectionRef( DB_REPLICA );
 286
 287                 if ( array_key_exists( 'minimumWatchers', $options ) ) {
 288                         $dbOptions['HAVING'] = 'COUNT(*) >= ' . (int)$options['minimumWatchers'];
 289                 }
 290
 291                 $lb = new LinkBatch( $targets );
 292                 $res = $dbr->select(
 293                         'watchlist',
 294                         [ 'wl_title', 'wl_namespace', 'watchers' => 'COUNT(*)' ],
 295                         [ $lb->constructSet( 'wl', $dbr ) ],
 296                         __METHOD__,
 297                         $dbOptions
 298                 );
 299
 300                 $watchCounts = [];
 301                 foreach ( $targets as $linkTarget ) {
 302                         $watchCounts[$linkTarget->getNamespace()][$linkTarget->getDBkey()] = 0;
 303                 }
 304
 305                 foreach ( $res as $row ) {
 306                         $watchCounts[$row->wl_namespace][$row->wl_title] = (int)$row->watchers;
 307                 }
 308
 309                 return $watchCounts;
 310         }
 311
 312         /**
 313          * Number of watchers of each page who have visited recent edits to that page
 314          *
 315          * @param array $targetsWithVisitThresholds array of pairs (LinkTarget $target, mixed $threshold),
 316          *        $threshold is:
 317          *        - a timestamp of the recent edit if $target exists (format accepted by wfTimestamp)
 318          *        - null if $target doesn't exist
 319          * @param int|null $minimumWatchers
 320          * @return array multi-dimensional like $return[$namespaceId][$titleString] = $watchers,
 321          *         where $watchers is an int:
 322          *         - if the page exists, number of users watching who have visited the page recently
 323          *         - if the page doesn't exist, number of users that have the page on their watchlist
 324          *         - 0 means there are no visiting watchers or their number is below the minimumWatchers
 325          *         option (if passed).
 326          */
 327         public function countVisitingWatchersMultiple(
 328                 array $targetsWithVisitThresholds,
 329                 $minimumWatchers = null
 330         ) {
 331                 $dbr = $this->getConnectionRef( DB_REPLICA );
 332
 333                 $conds = $this->getVisitingWatchersCondition( $dbr, $targetsWithVisitThresholds );
 334
 335                 $dbOptions = [ 'GROUP BY' => [ 'wl_namespace', 'wl_title' ] ];
 336                 if ( $minimumWatchers !== null ) {
 337                         $dbOptions['HAVING'] = 'COUNT(*) >= ' . (int)$minimumWatchers;
 338                 }
 339                 $res = $dbr->select(
 340                         'watchlist',
 341                         [ 'wl_namespace', 'wl_title', 'watchers' => 'COUNT(*)' ],
 342                         $conds,
 343                         __METHOD__,
 344                         $dbOptions
 345                 );
 346
 347                 $watcherCounts = [];
 348                 foreach ( $targetsWithVisitThresholds as list( $target ) ) {
 349                         /* @var LinkTarget $target */
 350                         $watcherCounts[$target->getNamespace()][$target->getDBkey()] = 0;
 351                 }
 352
 353                 foreach ( $res as $row ) {
 354                         $watcherCounts[$row->wl_namespace][$row->wl_title] = (int)$row->watchers;
 355                 }
 356
 357                 return $watcherCounts;
 358         }
 359
 360         /**
 361          * Generates condition for the query used in a batch count visiting watchers.
 362          *
 363          * @param IDatabase $db
 364          * @param array $targetsWithVisitThresholds array of pairs (LinkTarget, last visit threshold)
 365          * @return string
 366          */
 367         private function getVisitingWatchersCondition(
 368                 IDatabase $db,
 369                 array $targetsWithVisitThresholds
 370         ) {
 371                 $missingTargets = [];
 372                 $namespaceConds = [];
 373                 foreach ( $targetsWithVisitThresholds as list( $target, $threshold ) ) {
 374                         if ( $threshold === null ) {
 375                                 $missingTargets[] = $target;
 376                                 continue;
 377                         }
 378                         /* @var LinkTarget $target */
 379                         $namespaceConds[$target->getNamespace()][] = $db->makeList( [
 380                                 'wl_title = ' . $db->addQuotes( $target->getDBkey() ),
 381                                 $db->makeList( [
 382                                         'wl_notificationtimestamp >= ' . $db->addQuotes( $db->timestamp( $threshold ) ),
 383                                         'wl_notificationtimestamp IS NULL'
 384                                 ], LIST_OR )
 385                         ], LIST_AND );
 386                 }
 387
 388                 $conds = [];
 389                 foreach ( $namespaceConds as $namespace => $pageConds ) {
 390                         $conds[] = $db->makeList( [
 391                                 'wl_namespace = ' . $namespace,
 392                                 '(' . $db->makeList( $pageConds, LIST_OR ) . ')'
 393                         ], LIST_AND );
 394                 }
 395
 396                 if ( $missingTargets ) {
 397                         $lb = new LinkBatch( $missingTargets );
 398                         $conds[] = $lb->constructSet( 'wl', $db );
 399                 }
 400
 401                 return $db->makeList( $conds, LIST_OR );
 402         }
 403
 404         /**
 405          * Get an item (may be cached)
 406          *
 407          * @param User $user
 408          * @param LinkTarget $target
 409          *
 410          * @return WatchedItem|false
 411          */
 412         public function getWatchedItem( User $user, LinkTarget $target ) {
 413                 if ( $user->isAnon() ) {
 414                         return false;
 415                 }
 416
 417                 $cached = $this->getCached( $user, $target );
 418                 if ( $cached ) {
 419                         $this->stats->increment( 'WatchedItemStore.getWatchedItem.cached' );
 420                         return $cached;
 421                 }
 422                 $this->stats->increment( 'WatchedItemStore.getWatchedItem.load' );
 423                 return $this->loadWatchedItem( $user, $target );
 424         }
 425
 426         /**
 427          * Loads an item from the db
 428          *
 429          * @param User $user
 430          * @param LinkTarget $target
 431          *
 432          * @return WatchedItem|false
 433          */
 434         public function loadWatchedItem( User $user, LinkTarget $target ) {
 435                 // Only loggedin user can have a watchlist
 436                 if ( $user->isAnon() ) {
 437                         return false;
 438                 }
 439
 440                 $dbr = $this->getConnectionRef( DB_REPLICA );
 441                 $row = $dbr->selectRow(
 442                         'watchlist',
 443                         'wl_notificationtimestamp',
 444                         $this->dbCond( $user, $target ),
 445                         __METHOD__
 446                 );
 447
 448                 if ( !$row ) {
 449                         return false;
 450                 }
 451
 452                 $item = new WatchedItem(
 453                         $user,
 454                         $target,
 455                         $row->wl_notificationtimestamp
 456                 );
 457                 $this->cache( $item );
 458
 459                 return $item;
 460         }
 461
 462         /**
 463          * @param User $user
 464          * @param array $options Allowed keys:
 465          *        'forWrite' => bool defaults to false
 466          *        'sort' => string optional sorting by namespace ID and title
 467          *                     one of the self::SORT_* constants
 468          *
 469          * @return WatchedItem[]
 470          */
 471         public function getWatchedItemsForUser( User $user, array $options = [] ) {
 472                 $options += [ 'forWrite' => false ];
 473
 474                 $dbOptions = [];
 475                 if ( array_key_exists( 'sort', $options ) ) {
 476                         Assert::parameter(
 477                                 ( in_array( $options['sort'], [ self::SORT_ASC, self::SORT_DESC ] ) ),
 478                                 '$options[\'sort\']',
 479                                 'must be SORT_ASC or SORT_DESC'
 480                         );
 481                         $dbOptions['ORDER BY'] = [
 482                                 "wl_namespace {$options['sort']}",
 483                                 "wl_title {$options['sort']}"
 484                         ];
 485                 }
 486                 $db = $this->getConnectionRef( $options['forWrite'] ? DB_MASTER : DB_REPLICA );
 487
 488                 $res = $db->select(
 489                         'watchlist',
 490                         [ 'wl_namespace', 'wl_title', 'wl_notificationtimestamp' ],
 491                         [ 'wl_user' => $user->getId() ],
 492                         __METHOD__,
 493                         $dbOptions
 494                 );
 495
 496                 $watchedItems = [];
 497                 foreach ( $res as $row ) {
 498                         // @todo: Should we add these to the process cache?
 499                         $watchedItems[] = new WatchedItem(
 500                                 $user,
 501                                 new TitleValue( (int)$row->wl_namespace, $row->wl_title ),
 502                                 $row->wl_notificationtimestamp
 503                         );
 504                 }
 505
 506                 return $watchedItems;
 507         }
 508
 509         /**
 510          * Must be called separately for Subject & Talk namespaces
 511          *
 512          * @param User $user
 513          * @param LinkTarget $target
 514          *
 515          * @return bool
 516          */
 517         public function isWatched( User $user, LinkTarget $target ) {
 518                 return (bool)$this->getWatchedItem( $user, $target );
 519         }
 520
 521         /**
 522          * @param User $user
 523          * @param LinkTarget[] $targets
 524          *
 525          * @return array multi-dimensional like $return[$namespaceId][$titleString] = $timestamp,
 526          *         where $timestamp is:
 527          *         - string|null value of wl_notificationtimestamp,
 528          *         - false if $target is not watched by $user.
 529          */
 530         public function getNotificationTimestampsBatch( User $user, array $targets ) {
 531                 $timestamps = [];
 532                 foreach ( $targets as $target ) {
 533                         $timestamps[$target->getNamespace()][$target->getDBkey()] = false;
 534                 }
 535
 536                 if ( $user->isAnon() ) {
 537                         return $timestamps;
 538                 }
 539
 540                 $targetsToLoad = [];
 541                 foreach ( $targets as $target ) {
 542                         $cachedItem = $this->getCached( $user, $target );
 543                         if ( $cachedItem ) {
 544                                 $timestamps[$target->getNamespace()][$target->getDBkey()] =
 545                                         $cachedItem->getNotificationTimestamp();
 546                         } else {
 547                                 $targetsToLoad[] = $target;
 548                         }
 549                 }
 550
 551                 if ( !$targetsToLoad ) {
 552                         return $timestamps;
 553                 }
 554
 555                 $dbr = $this->getConnectionRef( DB_REPLICA );
 556
 557                 $lb = new LinkBatch( $targetsToLoad );
 558                 $res = $dbr->select(
 559                         'watchlist',
 560                         [ 'wl_namespace', 'wl_title', 'wl_notificationtimestamp' ],
 561                         [
 562                                 $lb->constructSet( 'wl', $dbr ),
 563                                 'wl_user' => $user->getId(),
 564                         ],
 565                         __METHOD__
 566                 );
 567
 568                 foreach ( $res as $row ) {
 569                         $timestamps[$row->wl_namespace][$row->wl_title] = $row->wl_notificationtimestamp;
 570                 }
 571
 572                 return $timestamps;
 573         }
 574
 575         /**
 576          * Must be called separately for Subject & Talk namespaces
 577          *
 578          * @param User $user
 579          * @param LinkTarget $target
 580          */
 581         public function addWatch( User $user, LinkTarget $target ) {
 582                 $this->addWatchBatchForUser( $user, [ $target ] );
 583         }
 584
 585         /**
 586          * @param User $user
 587          * @param LinkTarget[] $targets
 588          *
 589          * @return bool success
 590          */
 591         public function addWatchBatchForUser( User $user, array $targets ) {
 592                 if ( $this->loadBalancer->getReadOnlyReason() !== false ) {
 593                         return false;
 594                 }
 595                 // Only loggedin user can have a watchlist
 596                 if ( $user->isAnon() ) {
 597                         return false;
 598                 }
 599
 600                 if ( !$targets ) {
 601                         return true;
 602                 }
 603
 604                 $rows = [];
 605                 $items = [];
 606                 foreach ( $targets as $target ) {
 607                         $rows[] = [
 608                                 'wl_user' => $user->getId(),
 609                                 'wl_namespace' => $target->getNamespace(),
 610                                 'wl_title' => $target->getDBkey(),
 611                                 'wl_notificationtimestamp' => null,
 612                         ];
 613                         $items[] = new WatchedItem(
 614                                 $user,
 615                                 $target,
 616                                 null
 617                         );
 618                         $this->uncache( $user, $target );
 619                 }
 620
 621                 $dbw = $this->getConnectionRef( DB_MASTER );
 622                 foreach ( array_chunk( $rows, 100 ) as $toInsert ) {
 623                         // Use INSERT IGNORE to avoid overwriting the notification timestamp
 624                         // if there's already an entry for this page
 625                         $dbw->insert( 'watchlist', $toInsert, __METHOD__, 'IGNORE' );
 626                 }
 627                 // Update process cache to ensure skin doesn't claim that the current
 628                 // page is unwatched in the response of action=watch itself (T28292).
 629                 // This would otherwise be re-queried from a slave by isWatched().
 630                 foreach ( $items as $item ) {
 631                         $this->cache( $item );
 632                 }
 633
 634                 return true;
 635         }
 636
 637         /**
 638          * Removes the an entry for the User watching the LinkTarget
 639          * Must be called separately for Subject & Talk namespaces
 640          *
 641          * @param User $user
 642          * @param LinkTarget $target
 643          *
 644          * @return bool success
 645          * @throws DBUnexpectedError
 646          * @throws MWException
 647          */
 648         public function removeWatch( User $user, LinkTarget $target ) {
 649                 // Only logged in user can have a watchlist
 650                 if ( $this->loadBalancer->getReadOnlyReason() !== false || $user->isAnon() ) {
 651                         return false;
 652                 }
 653
 654                 $this->uncache( $user, $target );
 655
 656                 $dbw = $this->getConnectionRef( DB_MASTER );
 657                 $dbw->delete( 'watchlist',
 658                         [
 659                                 'wl_user' => $user->getId(),
 660                                 'wl_namespace' => $target->getNamespace(),
 661                                 'wl_title' => $target->getDBkey(),
 662                         ], __METHOD__
 663                 );
 664                 $success = (bool)$dbw->affectedRows();
 665
 666                 return $success;
 667         }
 668
 669         /**
 670          * @param User $user The user to set the timestamp for
 671          * @param string|null $timestamp Set the update timestamp to this value
 672          * @param LinkTarget[] $targets List of targets to update. Default to all targets
 673          *
 674          * @return bool success
 675          */
 676         public function setNotificationTimestampsForUser( User $user, $timestamp, array $targets = [] ) {
 677                 // Only loggedin user can have a watchlist
 678                 if ( $user->isAnon() ) {
 679                         return false;
 680                 }
 681
 682                 $dbw = $this->getConnectionRef( DB_MASTER );
 683
 684                 $conds = [ 'wl_user' => $user->getId() ];
 685                 if ( $targets ) {
 686                         $batch = new LinkBatch( $targets );
 687                         $conds[] = $batch->constructSet( 'wl', $dbw );
 688                 }
 689
 690                 if ( $timestamp !== null ) {
 691                         $timestamp = $dbw->timestamp( $timestamp );
 692                 }
 693
 694                 $success = $dbw->update(
 695                         'watchlist',
 696                         [ 'wl_notificationtimestamp' => $timestamp ],
 697                         $conds,
 698                         __METHOD__
 699                 );
 700
 701                 $this->uncacheUser( $user );
 702
 703                 return $success;
 704         }
 705
 706         /**
 707          * @param User $editor The editor that triggered the update. Their notification
 708          *  timestamp will not be updated(they have already seen it)
 709          * @param LinkTarget $target The target to update timestamps for
 710          * @param string $timestamp Set the update timestamp to this value
 711          *
 712          * @return int[] Array of user IDs the timestamp has been updated for
 713          */
 714         public function updateNotificationTimestamp( User $editor, LinkTarget $target, $timestamp ) {
 715                 $dbw = $this->getConnectionRef( DB_MASTER );
 716                 $uids = $dbw->selectFieldValues(
 717                         'watchlist',
 718                         'wl_user',
 719                         [
 720                                 'wl_user != ' . intval( $editor->getId() ),
 721                                 'wl_namespace' => $target->getNamespace(),
 722                                 'wl_title' => $target->getDBkey(),
 723                                 'wl_notificationtimestamp IS NULL',
 724                         ],
 725                         __METHOD__
 726                 );
 727
 728                 $watchers = array_map( 'intval', $uids );
 729                 if ( $watchers ) {
 730                         // Update wl_notificationtimestamp for all watching users except the editor
 731                         $fname = __METHOD__;
 732                         DeferredUpdates::addCallableUpdate(
 733                                 function () use ( $timestamp, $watchers, $target, $fname ) {
 734                                         global $wgUpdateRowsPerQuery;
 735
 736                                         $dbw = $this->getConnectionRef( DB_MASTER );
 737                                         $factory = wfGetLBFactory();
 738                                         $ticket = $factory->getEmptyTransactionTicket( __METHOD__ );
 739
 740                                         $watchersChunks = array_chunk( $watchers, $wgUpdateRowsPerQuery );
 741                                         foreach ( $watchersChunks as $watchersChunk ) {
 742                                                 $dbw->update( 'watchlist',
 743                                                         [ /* SET */
 744                                                                 'wl_notificationtimestamp' => $dbw->timestamp( $timestamp )
 745                                                         ], [ /* WHERE - TODO Use wl_id T130067 */
 746                                                                 'wl_user' => $watchersChunk,
 747                                                                 'wl_namespace' => $target->getNamespace(),
 748                                                                 'wl_title' => $target->getDBkey(),
 749                                                         ], $fname
 750                                                 );
 751                                                 if ( count( $watchersChunks ) > 1 ) {
 752                                                         $factory->commitAndWaitForReplication(
 753                                                                 __METHOD__, $ticket, [ 'wiki' => $dbw->getWikiID() ]
 754                                                         );
 755                                                 }
 756                                         }
 757                                         $this->uncacheLinkTarget( $target );
 758                                 },
 759                                 DeferredUpdates::POSTSEND,
 760                                 $dbw
 761                         );
 762                 }
 763
 764                 return $watchers;
 765         }
 766
 767         /**
 768          * Reset the notification timestamp of this entry
 769          *
 770          * @param User $user
 771          * @param Title $title
 772          * @param string $force Whether to force the write query to be executed even if the
 773          *    page is not watched or the notification timestamp is already NULL.
 774          *    'force' in order to force
 775          * @param int $oldid The revision id being viewed. If not given or 0, latest revision is assumed.
 776          *
 777          * @return bool success
 778          */
 779         public function resetNotificationTimestamp( User $user, Title $title, $force = '', $oldid = 0 ) {
 780                 // Only loggedin user can have a watchlist
 781                 if ( $this->loadBalancer->getReadOnlyReason() !== false || $user->isAnon() ) {
 782                         return false;
 783                 }
 784
 785                 $item = null;
 786                 if ( $force != 'force' ) {
 787                         $item = $this->loadWatchedItem( $user, $title );
 788                         if ( !$item || $item->getNotificationTimestamp() === null ) {
 789                                 return false;
 790                         }
 791                 }
 792
 793                 // If the page is watched by the user (or may be watched), update the timestamp
 794                 $job = new ActivityUpdateJob(
 795                         $title,
 796                         [
 797                                 'type'      => 'updateWatchlistNotification',
 798                                 'userid'    => $user->getId(),
 799                                 'notifTime' => $this->getNotificationTimestamp( $user, $title, $item, $force, $oldid ),
 800                                 'curTime'   => time()
 801                         ]
 802                 );
 803
 804                 // Try to run this post-send
 805                 // Calls DeferredUpdates::addCallableUpdate in normal operation
 806                 call_user_func(
 807                         $this->deferredUpdatesAddCallableUpdateCallback,
 808                         function() use ( $job ) {
 809                                 $job->run();
 810                         }
 811                 );
 812
 813                 $this->uncache( $user, $title );
 814
 815                 return true;
 816         }
 817
 818         private function getNotificationTimestamp( User $user, Title $title, $item, $force, $oldid ) {
 819                 if ( !$oldid ) {
 820                         // No oldid given, assuming latest revision; clear the timestamp.
 821                         return null;
 822                 }
 823
 824                 if ( !$title->getNextRevisionID( $oldid ) ) {
 825                         // Oldid given and is the latest revision for this title; clear the timestamp.
 826                         return null;
 827                 }
 828
 829                 if ( $item === null ) {
 830                         $item = $this->loadWatchedItem( $user, $title );
 831                 }
 832
 833                 if ( !$item ) {
 834                         // This can only happen if $force is enabled.
 835                         return null;
 836                 }
 837
 838                 // Oldid given and isn't the latest; update the timestamp.
 839                 // This will result in no further notification emails being sent!
 840                 // Calls Revision::getTimestampFromId in normal operation
 841                 $notificationTimestamp = call_user_func(
 842                         $this->revisionGetTimestampFromIdCallback,
 843                         $title,
 844                         $oldid
 845                 );
 846
 847                 // We need to go one second to the future because of various strict comparisons
 848                 // throughout the codebase
 849                 $ts = new MWTimestamp( $notificationTimestamp );
 850                 $ts->timestamp->add( new DateInterval( 'PT1S' ) );
 851                 $notificationTimestamp = $ts->getTimestamp( TS_MW );
 852
 853                 if ( $notificationTimestamp < $item->getNotificationTimestamp() ) {
 854                         if ( $force != 'force' ) {
 855                                 return false;
 856                         } else {
 857                                 // This is a little silly…
 858                                 return $item->getNotificationTimestamp();
 859                         }
 860                 }
 861
 862                 return $notificationTimestamp;
 863         }
 864
 865         /**
 866          * @param User $user
 867          * @param int $unreadLimit
 868          *
 869          * @return int|bool The number of unread notifications
 870          *                  true if greater than or equal to $unreadLimit
 871          */
 872         public function countUnreadNotifications( User $user, $unreadLimit = null ) {
 873                 $queryOptions = [];
 874                 if ( $unreadLimit !== null ) {
 875                         $unreadLimit = (int)$unreadLimit;
 876                         $queryOptions['LIMIT'] = $unreadLimit;
 877                 }
 878
 879                 $dbr = $this->getConnectionRef( DB_REPLICA );
 880                 $rowCount = $dbr->selectRowCount(
 881                         'watchlist',
 882                         '1',
 883                         [
 884                                 'wl_user' => $user->getId(),
 885                                 'wl_notificationtimestamp IS NOT NULL',
 886                         ],
 887                         __METHOD__,
 888                         $queryOptions
 889                 );
 890
 891                 if ( !isset( $unreadLimit ) ) {
 892                         return $rowCount;
 893                 }
 894
 895                 if ( $rowCount >= $unreadLimit ) {
 896                         return true;
 897                 }
 898
 899                 return $rowCount;
 900         }
 901
 902         /**
 903          * Check if the given title already is watched by the user, and if so
 904          * add a watch for the new title.
 905          *
 906          * To be used for page renames and such.
 907          *
 908          * @param LinkTarget $oldTarget
 909          * @param LinkTarget $newTarget
 910          */
 911         public function duplicateAllAssociatedEntries( LinkTarget $oldTarget, LinkTarget $newTarget ) {
 912                 $oldTarget = Title::newFromLinkTarget( $oldTarget );
 913                 $newTarget = Title::newFromLinkTarget( $newTarget );
 914
 915                 $this->duplicateEntry( $oldTarget->getSubjectPage(), $newTarget->getSubjectPage() );
 916                 $this->duplicateEntry( $oldTarget->getTalkPage(), $newTarget->getTalkPage() );
 917         }
 918
 919         /**
 920          * Check if the given title already is watched by the user, and if so
 921          * add a watch for the new title.
 922          *
 923          * To be used for page renames and such.
 924          * This must be called separately for Subject and Talk pages
 925          *
 926          * @param LinkTarget $oldTarget
 927          * @param LinkTarget $newTarget
 928          */
 929         public function duplicateEntry( LinkTarget $oldTarget, LinkTarget $newTarget ) {
 930                 $dbw = $this->getConnectionRef( DB_MASTER );
 931
 932                 $result = $dbw->select(
 933                         'watchlist',
 934                         [ 'wl_user', 'wl_notificationtimestamp' ],
 935                         [
 936                                 'wl_namespace' => $oldTarget->getNamespace(),
 937                                 'wl_title' => $oldTarget->getDBkey(),
 938                         ],
 939                         __METHOD__,
 940                         [ 'FOR UPDATE' ]
 941                 );
 942
 943                 $newNamespace = $newTarget->getNamespace();
 944                 $newDBkey = $newTarget->getDBkey();
 945
 946                 # Construct array to replace into the watchlist
 947                 $values = [];
 948                 foreach ( $result as $row ) {
 949                         $values[] = [
 950                                 'wl_user' => $row->wl_user,
 951                                 'wl_namespace' => $newNamespace,
 952                                 'wl_title' => $newDBkey,
 953                                 'wl_notificationtimestamp' => $row->wl_notificationtimestamp,
 954                         ];
 955                 }
 956
 957                 if ( !empty( $values ) ) {
 958                         # Perform replace
 959                         # Note that multi-row replace is very efficient for MySQL but may be inefficient for
 960                         # some other DBMSes, mostly due to poor simulation by us
 961                         $dbw->replace(
 962                                 'watchlist',
 963                                 [ [ 'wl_user', 'wl_namespace', 'wl_title' ] ],
 964                                 $values,
 965                                 __METHOD__
 966                         );
 967                 }
 968         }
 969
 970 }