includes/WatchedItemStore.php

   1 <?php
   2
   3 use Liuggio\StatsdClient\Factory\StatsdDataFactoryInterface;
   4 use MediaWiki\Linker\LinkTarget;
   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( callable $callback ) {
  84                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
  85                         throw new MWException(
  86                                 'Cannot override DeferredUpdates::addCallableUpdate callback in operation.'
  87                         );
  88                 }
  89                 $previousValue = $this->deferredUpdatesAddCallableUpdateCallback;
  90                 $this->deferredUpdatesAddCallableUpdateCallback = $callback;
  91                 return new ScopedCallback( function() use ( $previousValue ) {
  92                         $this->deferredUpdatesAddCallableUpdateCallback = $previousValue;
  93                 } );
  94         }
  95
  96         /**
  97          * Overrides the Revision::getTimestampFromId callback
  98          * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
  99          *
 100          * @param callable $callback
 101          * @see Revision::getTimestampFromId for callback signiture
 102          *
 103          * @return ScopedCallback to reset the overridden value
 104          * @throws MWException
 105          */
 106         public function overrideRevisionGetTimestampFromIdCallback( callable $callback ) {
 107                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 108                         throw new MWException(
 109                                 'Cannot override Revision::getTimestampFromId callback in operation.'
 110                         );
 111                 }
 112                 $previousValue = $this->revisionGetTimestampFromIdCallback;
 113                 $this->revisionGetTimestampFromIdCallback = $callback;
 114                 return new ScopedCallback( function() use ( $previousValue ) {
 115                         $this->revisionGetTimestampFromIdCallback = $previousValue;
 116                 } );
 117         }
 118
 119         private function getCacheKey( User $user, LinkTarget $target ) {
 120                 return $this->cache->makeKey(
 121                         (string)$target->getNamespace(),
 122                         $target->getDBkey(),
 123                         (string)$user->getId()
 124                 );
 125         }
 126
 127         private function cache( WatchedItem $item ) {
 128                 $user = $item->getUser();
 129                 $target = $item->getLinkTarget();
 130                 $key = $this->getCacheKey( $user, $target );
 131                 $this->cache->set( $key, $item );
 132                 $this->cacheIndex[$target->getNamespace()][$target->getDBkey()][$user->getId()] = $key;
 133                 $this->stats->increment( 'WatchedItemStore.cache' );
 134         }
 135
 136         private function uncache( User $user, LinkTarget $target ) {
 137                 $this->cache->delete( $this->getCacheKey( $user, $target ) );
 138                 unset( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()][$user->getId()] );
 139                 $this->stats->increment( 'WatchedItemStore.uncache' );
 140         }
 141
 142         private function uncacheLinkTarget( LinkTarget $target ) {
 143                 $this->stats->increment( 'WatchedItemStore.uncacheLinkTarget' );
 144                 if ( !isset( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()] ) ) {
 145                         return;
 146                 }
 147                 foreach ( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()] as $key ) {
 148                         $this->stats->increment( 'WatchedItemStore.uncacheLinkTarget.items' );
 149                         $this->cache->delete( $key );
 150                 }
 151         }
 152
 153         private function uncacheUser( User $user ) {
 154                 $this->stats->increment( 'WatchedItemStore.uncacheUser' );
 155                 foreach ( $this->cacheIndex as $ns => $dbKeyArray ) {
 156                         foreach ( $dbKeyArray as $dbKey => $userArray ) {
 157                                 if ( isset( $userArray[$user->getId()] ) ) {
 158                                         $this->stats->increment( 'WatchedItemStore.uncacheUser.items' );
 159                                         $this->cache->delete( $userArray[$user->getId()] );
 160                                 }
 161                         }
 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                         $timestamps[$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 $user The user to set the timestamp for
 679          * @param string $timestamp Set the update timestamp to this value
 680          * @param LinkTarget[] $targets List of targets to update. Default to all targets
 681          *
 682          * @return bool success
 683          */
 684         public function setNotificationTimestampsForUser( User $user, $timestamp, array $targets = [] ) {
 685                 // Only loggedin user can have a watchlist
 686                 if ( $user->isAnon() ) {
 687                         return false;
 688                 }
 689
 690                 $dbw = $this->getConnection( DB_MASTER );
 691
 692                 $conds = [ 'wl_user' => $user->getId() ];
 693                 if ( $targets ) {
 694                         $batch = new LinkBatch( $targets );
 695                         $conds[] = $batch->constructSet( 'wl', $dbw );
 696                 }
 697
 698                 $success = $dbw->update(
 699                         'watchlist',
 700                         [ 'wl_notificationtimestamp' => $dbw->timestamp( $timestamp ) ],
 701                         $conds,
 702                         __METHOD__
 703                 );
 704
 705                 $this->reuseConnection( $dbw );
 706
 707                 $this->uncacheUser( $user );
 708
 709                 return $success;
 710         }
 711
 712         /**
 713          * @param User $editor The editor that triggered the update. Their notification
 714          *  timestamp will not be updated(they have already seen it)
 715          * @param LinkTarget $target The target to update timestamps for
 716          * @param string $timestamp Set the update timestamp to this value
 717          *
 718          * @return int[] Array of user IDs the timestamp has been updated for
 719          */
 720         public function updateNotificationTimestamp( User $editor, LinkTarget $target, $timestamp ) {
 721                 $dbw = $this->getConnection( DB_MASTER );
 722                 $res = $dbw->select( [ 'watchlist' ],
 723                         [ 'wl_user' ],
 724                         [
 725                                 'wl_user != ' . intval( $editor->getId() ),
 726                                 'wl_namespace' => $target->getNamespace(),
 727                                 'wl_title' => $target->getDBkey(),
 728                                 'wl_notificationtimestamp IS NULL',
 729                         ], __METHOD__
 730                 );
 731
 732                 $watchers = [];
 733                 foreach ( $res as $row ) {
 734                         $watchers[] = intval( $row->wl_user );
 735                 }
 736
 737                 if ( $watchers ) {
 738                         // Update wl_notificationtimestamp for all watching users except the editor
 739                         $fname = __METHOD__;
 740                         $dbw->onTransactionIdle(
 741                                 function () use ( $dbw, $timestamp, $watchers, $target, $fname ) {
 742                                         global $wgUpdateRowsPerQuery;
 743
 744                                         $watchersChunks = array_chunk( $watchers, $wgUpdateRowsPerQuery );
 745                                         foreach ( $watchersChunks as $watchersChunk ) {
 746                                                 $dbw->update( 'watchlist',
 747                                                         [ /* SET */
 748                                                                 'wl_notificationtimestamp' => $dbw->timestamp( $timestamp )
 749                                                         ], [ /* WHERE - TODO Use wl_id T130067 */
 750                                                                 'wl_user' => $watchersChunk,
 751                                                                 'wl_namespace' => $target->getNamespace(),
 752                                                                 'wl_title' => $target->getDBkey(),
 753                                                         ], $fname
 754                                                 );
 755                                                 if ( count( $watchersChunks ) > 1 ) {
 756                                                         $dbw->commit( __METHOD__, 'flush' );
 757                                                         wfGetLBFactory()->waitForReplication( [ 'wiki' => $dbw->getWikiID() ] );
 758                                                 }
 759                                         }
 760                                         $this->uncacheLinkTarget( $target );
 761                                 }
 762                         );
 763                 }
 764
 765                 $this->reuseConnection( $dbw );
 766
 767                 return $watchers;
 768         }
 769
 770         /**
 771          * Reset the notification timestamp of this entry
 772          *
 773          * @param User $user
 774          * @param Title $title
 775          * @param string $force Whether to force the write query to be executed even if the
 776          *    page is not watched or the notification timestamp is already NULL.
 777          *    'force' in order to force
 778          * @param int $oldid The revision id being viewed. If not given or 0, latest revision is assumed.
 779          *
 780          * @return bool success
 781          */
 782         public function resetNotificationTimestamp( User $user, Title $title, $force = '', $oldid = 0 ) {
 783                 // Only loggedin user can have a watchlist
 784                 if ( $this->loadBalancer->getReadOnlyReason() !== false || $user->isAnon() ) {
 785                         return false;
 786                 }
 787
 788                 $item = null;
 789                 if ( $force != 'force' ) {
 790                         $item = $this->loadWatchedItem( $user, $title );
 791                         if ( !$item || $item->getNotificationTimestamp() === null ) {
 792                                 return false;
 793                         }
 794                 }
 795
 796                 // If the page is watched by the user (or may be watched), update the timestamp
 797                 $job = new ActivityUpdateJob(
 798                         $title,
 799                         [
 800                                 'type'      => 'updateWatchlistNotification',
 801                                 'userid'    => $user->getId(),
 802                                 'notifTime' => $this->getNotificationTimestamp( $user, $title, $item, $force, $oldid ),
 803                                 'curTime'   => time()
 804                         ]
 805                 );
 806
 807                 // Try to run this post-send
 808                 // Calls DeferredUpdates::addCallableUpdate in normal operation
 809                 call_user_func(
 810                         $this->deferredUpdatesAddCallableUpdateCallback,
 811                         function() use ( $job ) {
 812                                 $job->run();
 813                         }
 814                 );
 815
 816                 $this->uncache( $user, $title );
 817
 818                 return true;
 819         }
 820
 821         private function getNotificationTimestamp( User $user, Title $title, $item, $force, $oldid ) {
 822                 if ( !$oldid ) {
 823                         // No oldid given, assuming latest revision; clear the timestamp.
 824                         return null;
 825                 }
 826
 827                 if ( !$title->getNextRevisionID( $oldid ) ) {
 828                         // Oldid given and is the latest revision for this title; clear the timestamp.
 829                         return null;
 830                 }
 831
 832                 if ( $item === null ) {
 833                         $item = $this->loadWatchedItem( $user, $title );
 834                 }
 835
 836                 if ( !$item ) {
 837                         // This can only happen if $force is enabled.
 838                         return null;
 839                 }
 840
 841                 // Oldid given and isn't the latest; update the timestamp.
 842                 // This will result in no further notification emails being sent!
 843                 // Calls Revision::getTimestampFromId in normal operation
 844                 $notificationTimestamp = call_user_func(
 845                         $this->revisionGetTimestampFromIdCallback,
 846                         $title,
 847                         $oldid
 848                 );
 849
 850                 // We need to go one second to the future because of various strict comparisons
 851                 // throughout the codebase
 852                 $ts = new MWTimestamp( $notificationTimestamp );
 853                 $ts->timestamp->add( new DateInterval( 'PT1S' ) );
 854                 $notificationTimestamp = $ts->getTimestamp( TS_MW );
 855
 856                 if ( $notificationTimestamp < $item->getNotificationTimestamp() ) {
 857                         if ( $force != 'force' ) {
 858                                 return false;
 859                         } else {
 860                                 // This is a little silly…
 861                                 return $item->getNotificationTimestamp();
 862                         }
 863                 }
 864
 865                 return $notificationTimestamp;
 866         }
 867
 868         /**
 869          * @param User $user
 870          * @param int $unreadLimit
 871          *
 872          * @return int|bool The number of unread notifications
 873          *                  true if greater than or equal to $unreadLimit
 874          */
 875         public function countUnreadNotifications( User $user, $unreadLimit = null ) {
 876                 $queryOptions = [];
 877                 if ( $unreadLimit !== null ) {
 878                         $unreadLimit = (int)$unreadLimit;
 879                         $queryOptions['LIMIT'] = $unreadLimit;
 880                 }
 881
 882                 $dbr = $this->getConnection( DB_SLAVE );
 883                 $rowCount = $dbr->selectRowCount(
 884                         'watchlist',
 885                         '1',
 886                         [
 887                                 'wl_user' => $user->getId(),
 888                                 'wl_notificationtimestamp IS NOT NULL',
 889                         ],
 890                         __METHOD__,
 891                         $queryOptions
 892                 );
 893                 $this->reuseConnection( $dbr );
 894
 895                 if ( !isset( $unreadLimit ) ) {
 896                         return $rowCount;
 897                 }
 898
 899                 if ( $rowCount >= $unreadLimit ) {
 900                         return true;
 901                 }
 902
 903                 return $rowCount;
 904         }
 905
 906         /**
 907          * Check if the given title already is watched by the user, and if so
 908          * add a watch for the new title.
 909          *
 910          * To be used for page renames and such.
 911          *
 912          * @param LinkTarget $oldTarget
 913          * @param LinkTarget $newTarget
 914          */
 915         public function duplicateAllAssociatedEntries( LinkTarget $oldTarget, LinkTarget $newTarget ) {
 916                 $oldTarget = Title::newFromLinkTarget( $oldTarget );
 917                 $newTarget = Title::newFromLinkTarget( $newTarget );
 918
 919                 $this->duplicateEntry( $oldTarget->getSubjectPage(), $newTarget->getSubjectPage() );
 920                 $this->duplicateEntry( $oldTarget->getTalkPage(), $newTarget->getTalkPage() );
 921         }
 922
 923         /**
 924          * Check if the given title already is watched by the user, and if so
 925          * add a watch for the new title.
 926          *
 927          * To be used for page renames and such.
 928          * This must be called separately for Subject and Talk pages
 929          *
 930          * @param LinkTarget $oldTarget
 931          * @param LinkTarget $newTarget
 932          */
 933         public function duplicateEntry( LinkTarget $oldTarget, LinkTarget $newTarget ) {
 934                 $dbw = $this->getConnection( DB_MASTER );
 935
 936                 $result = $dbw->select(
 937                         'watchlist',
 938                         [ 'wl_user', 'wl_notificationtimestamp' ],
 939                         [
 940                                 'wl_namespace' => $oldTarget->getNamespace(),
 941                                 'wl_title' => $oldTarget->getDBkey(),
 942                         ],
 943                         __METHOD__,
 944                         [ 'FOR UPDATE' ]
 945                 );
 946
 947                 $newNamespace = $newTarget->getNamespace();
 948                 $newDBkey = $newTarget->getDBkey();
 949
 950                 # Construct array to replace into the watchlist
 951                 $values = [];
 952                 foreach ( $result as $row ) {
 953                         $values[] = [
 954                                 'wl_user' => $row->wl_user,
 955                                 'wl_namespace' => $newNamespace,
 956                                 'wl_title' => $newDBkey,
 957                                 'wl_notificationtimestamp' => $row->wl_notificationtimestamp,
 958                         ];
 959                 }
 960
 961                 if ( !empty( $values ) ) {
 962                         # Perform replace
 963                         # Note that multi-row replace is very efficient for MySQL but may be inefficient for
 964                         # some other DBMSes, mostly due to poor simulation by us
 965                         $dbw->replace(
 966                                 'watchlist',
 967                                 [ [ 'wl_user', 'wl_namespace', 'wl_title' ] ],
 968                                 $values,
 969                                 __METHOD__
 970                         );
 971                 }
 972
 973                 $this->reuseConnection( $dbw );
 974         }
 975
 976 }