includes/WatchedItemStore.php

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