includes/WatchedItemStore.php

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