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