includes/WatchedItemStore.php

   1 <?php
   2
   3 use Wikimedia\Assert\Assert;
   4
   5 /**
   6  * Storage layer class for WatchedItems.
   7  * Database interaction.
   8  *
   9  * @author Addshore
  10  *
  11  * @since 1.27
  12  */
  13 class WatchedItemStore {
  14
  15         /**
  16          * @var LoadBalancer
  17          */
  18         private $loadBalancer;
  19
  20         /**
  21          * @var HashBagOStuff
  22          */
  23         private $cache;
  24
  25         /**
  26          * @var array[] Looks like $cacheIndex[Namespace ID][Target DB Key][User Id] => 'key'
  27          * The index is needed so that on mass changes all relevant items can be un-cached.
  28          * For example: Clearing a users watchlist of all items or updating notification timestamps
  29          *              for all users watching a single target.
  30          */
  31         private $cacheIndex = [];
  32
  33         /**
  34          * @var callable|null
  35          */
  36         private $deferredUpdatesAddCallableUpdateCallback;
  37
  38         /**
  39          * @var callable|null
  40          */
  41         private $revisionGetTimestampFromIdCallback;
  42
  43         /**
  44          * @var self|null
  45          */
  46         private static $instance;
  47
  48         public function __construct( LoadBalancer $loadBalancer, HashBagOStuff $cache ) {
  49                 $this->loadBalancer = $loadBalancer;
  50                 $this->cache = $cache;
  51                 $this->deferredUpdatesAddCallableUpdateCallback = [ 'DeferredUpdates', 'addCallableUpdate' ];
  52                 $this->revisionGetTimestampFromIdCallback = [ 'Revision', 'getTimestampFromId' ];
  53         }
  54
  55         /**
  56          * Overrides the DeferredUpdates::addCallableUpdate callback
  57          * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
  58          *
  59          * @param callable $callback
  60          * @see DeferredUpdates::addCallableUpdate for callback signiture
  61          *
  62          * @throws MWException
  63          */
  64         public function overrideDeferredUpdatesAddCallableUpdateCallback( $callback ) {
  65                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
  66                         throw new MWException(
  67                                 'Cannot override DeferredUpdates::addCallableUpdate callback in operation.'
  68                         );
  69                 }
  70                 Assert::parameterType( 'callable', $callback, '$callback' );
  71                 $this->deferredUpdatesAddCallableUpdateCallback = $callback;
  72         }
  73
  74         /**
  75          * Overrides the Revision::getTimestampFromId callback
  76          * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
  77          *
  78          * @param callable $callback
  79          * @see Revision::getTimestampFromId for callback signiture
  80          *
  81          * @throws MWException
  82          */
  83         public function overrideRevisionGetTimestampFromIdCallback( $callback ) {
  84                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
  85                         throw new MWException(
  86                                 'Cannot override Revision::getTimestampFromId callback in operation.'
  87                         );
  88                 }
  89                 Assert::parameterType( 'callable', $callback, '$callback' );
  90                 $this->revisionGetTimestampFromIdCallback = $callback;
  91         }
  92
  93         /**
  94          * Overrides the default instance of this class
  95          * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
  96          *
  97          * @param WatchedItemStore $store
  98          *
  99          * @throws MWException
 100          */
 101         public static function overrideDefaultInstance( WatchedItemStore $store ) {
 102                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 103                         throw new MWException(
 104                                 'Cannot override ' . __CLASS__ . 'default instance in operation.'
 105                         );
 106                 }
 107                 self::$instance = $store;
 108         }
 109
 110         /**
 111          * @return self
 112          */
 113         public static function getDefaultInstance() {
 114                 if ( !self::$instance ) {
 115                         self::$instance = new self(
 116                                 wfGetLB(),
 117                                 new HashBagOStuff( [ 'maxKeys' => 100 ] )
 118                         );
 119                 }
 120                 return self::$instance;
 121         }
 122
 123         private function getCacheKey( User $user, LinkTarget $target ) {
 124                 return $this->cache->makeKey(
 125                         (string)$target->getNamespace(),
 126                         $target->getDBkey(),
 127                         (string)$user->getId()
 128                 );
 129         }
 130
 131         private function cache( WatchedItem $item ) {
 132                 $user = $item->getUser();
 133                 $target = $item->getLinkTarget();
 134                 $key = $this->getCacheKey( $user, $target );
 135                 $this->cache->set( $key, $item );
 136                 $this->cacheIndex[$target->getNamespace()][$target->getDBkey()][$user->getId()] = $key;
 137         }
 138
 139         private function uncache( User $user, LinkTarget $target ) {
 140                 $this->cache->delete( $this->getCacheKey( $user, $target ) );
 141                 unset( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()][$user->getId()] );
 142         }
 143
 144         private function uncacheLinkTarget( LinkTarget $target ) {
 145                 if ( !isset( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()] ) ) {
 146                         return;
 147                 }
 148                 foreach ( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()] as $key ) {
 149                         $this->cache->delete( $key );
 150                 }
 151         }
 152
 153         /**
 154          * @param User $user
 155          * @param LinkTarget $target
 156          *
 157          * @return WatchedItem|null
 158          */
 159         private function getCached( User $user, LinkTarget $target ) {
 160                 return $this->cache->get( $this->getCacheKey( $user, $target ) );
 161         }
 162
 163         /**
 164          * Return an array of conditions to select or update the appropriate database
 165          * row.
 166          *
 167          * @param User $user
 168          * @param LinkTarget $target
 169          *
 170          * @return array
 171          */
 172         private function dbCond( User $user, LinkTarget $target ) {
 173                 return [
 174                         'wl_user' => $user->getId(),
 175                         'wl_namespace' => $target->getNamespace(),
 176                         'wl_title' => $target->getDBkey(),
 177                 ];
 178         }
 179
 180         /**
 181          * Get an item (may be cached)
 182          *
 183          * @param User $user
 184          * @param LinkTarget $target
 185          *
 186          * @return WatchedItem|false
 187          */
 188         public function getWatchedItem( User $user, LinkTarget $target ) {
 189                 $cached = $this->getCached( $user, $target );
 190                 if ( $cached ) {
 191                         return $cached;
 192                 }
 193                 return $this->loadWatchedItem( $user, $target );
 194         }
 195
 196         /**
 197          * Loads an item from the db
 198          *
 199          * @param User $user
 200          * @param LinkTarget $target
 201          *
 202          * @return WatchedItem|false
 203          */
 204         public function loadWatchedItem( User $user, LinkTarget $target ) {
 205                 // Only loggedin user can have a watchlist
 206                 if ( $user->isAnon() ) {
 207                         return false;
 208                 }
 209
 210                 $dbr = $this->loadBalancer->getConnection( DB_SLAVE, [ 'watchlist' ] );
 211                 $row = $dbr->selectRow(
 212                         'watchlist',
 213                         'wl_notificationtimestamp',
 214                         $this->dbCond( $user, $target ),
 215                         __METHOD__
 216                 );
 217                 $this->loadBalancer->reuseConnection( $dbr );
 218
 219                 if ( !$row ) {
 220                         return false;
 221                 }
 222
 223                 $item = new WatchedItem(
 224                         $user,
 225                         $target,
 226                         $row->wl_notificationtimestamp
 227                 );
 228                 $this->cache( $item );
 229
 230                 return $item;
 231         }
 232
 233         /**
 234          * Must be called separately for Subject & Talk namespaces
 235          *
 236          * @param User $user
 237          * @param LinkTarget $target
 238          *
 239          * @return bool
 240          */
 241         public function isWatched( User $user, LinkTarget $target ) {
 242                 return (bool)$this->getWatchedItem( $user, $target );
 243         }
 244
 245         /**
 246          * Must be called separately for Subject & Talk namespaces
 247          *
 248          * @param User $user
 249          * @param LinkTarget $target
 250          */
 251         public function addWatch( User $user, LinkTarget $target ) {
 252                 $this->addWatchBatch( [ [ $user, $target ] ] );
 253         }
 254
 255         /**
 256          * @param array[] $userTargetCombinations array of arrays containing [0] => User [1] => LinkTarget
 257          *
 258          * @return bool success
 259          */
 260         public function addWatchBatch( array $userTargetCombinations ) {
 261                 if ( $this->loadBalancer->getReadOnlyReason() !== false ) {
 262                         return false;
 263                 }
 264
 265                 $rows = [];
 266                 foreach ( $userTargetCombinations as list( $user, $target ) ) {
 267                         /**
 268                          * @var User $user
 269                          * @var LinkTarget $target
 270                          */
 271
 272                         // Only loggedin user can have a watchlist
 273                         if ( $user->isAnon() ) {
 274                                 continue;
 275                         }
 276                         $rows[] = [
 277                                 'wl_user' => $user->getId(),
 278                                 'wl_namespace' => $target->getNamespace(),
 279                                 'wl_title' => $target->getDBkey(),
 280                                 'wl_notificationtimestamp' => null,
 281                         ];
 282                         $this->uncache( $user, $target );
 283                 }
 284
 285                 if ( !$rows ) {
 286                         return false;
 287                 }
 288
 289                 $dbw = $this->loadBalancer->getConnection( DB_MASTER, [ 'watchlist' ] );
 290                 foreach ( array_chunk( $rows, 100 ) as $toInsert ) {
 291                         // Use INSERT IGNORE to avoid overwriting the notification timestamp
 292                         // if there's already an entry for this page
 293                         $dbw->insert( 'watchlist', $toInsert, __METHOD__, 'IGNORE' );
 294                 }
 295                 $this->loadBalancer->reuseConnection( $dbw );
 296
 297                 return true;
 298         }
 299
 300         /**
 301          * Removes the an entry for the User watching the LinkTarget
 302          * Must be called separately for Subject & Talk namespaces
 303          *
 304          * @param User $user
 305          * @param LinkTarget $target
 306          *
 307          * @return bool success
 308          * @throws DBUnexpectedError
 309          * @throws MWException
 310          */
 311         public function removeWatch( User $user, LinkTarget $target ) {
 312                 // Only logged in user can have a watchlist
 313                 if ( $this->loadBalancer->getReadOnlyReason() !== false || $user->isAnon() ) {
 314                         return false;
 315                 }
 316
 317                 $this->uncache( $user, $target );
 318
 319                 $dbw = $this->loadBalancer->getConnection( DB_MASTER, [ 'watchlist' ] );
 320                 $dbw->delete( 'watchlist',
 321                         [
 322                                 'wl_user' => $user->getId(),
 323                                 'wl_namespace' => $target->getNamespace(),
 324                                 'wl_title' => $target->getDBkey(),
 325                         ], __METHOD__
 326                 );
 327                 $success = (bool)$dbw->affectedRows();
 328                 $this->loadBalancer->reuseConnection( $dbw );
 329
 330                 return $success;
 331         }
 332
 333         /**
 334          * @param User $editor The editor that triggered the update. Their notification
 335          *  timestamp will not be updated(they have already seen it)
 336          * @param LinkTarget $target The target to update timestamps for
 337          * @param string $timestamp Set the update timestamp to this value
 338          *
 339          * @return int[] Array of user IDs the timestamp has been updated for
 340          */
 341         public function updateNotificationTimestamp( User $editor, LinkTarget $target, $timestamp ) {
 342                 $dbw = $this->loadBalancer->getConnection( DB_MASTER, [ 'watchlist' ] );
 343                 $res = $dbw->select( [ 'watchlist' ],
 344                         [ 'wl_user' ],
 345                         [
 346                                 'wl_user != ' . intval( $editor->getId() ),
 347                                 'wl_namespace' => $target->getNamespace(),
 348                                 'wl_title' => $target->getDBkey(),
 349                                 'wl_notificationtimestamp IS NULL',
 350                         ], __METHOD__
 351                 );
 352
 353                 $watchers = [];
 354                 foreach ( $res as $row ) {
 355                         $watchers[] = intval( $row->wl_user );
 356                 }
 357
 358                 if ( $watchers ) {
 359                         // Update wl_notificationtimestamp for all watching users except the editor
 360                         $fname = __METHOD__;
 361                         $dbw->onTransactionIdle(
 362                                 function () use ( $dbw, $timestamp, $watchers, $target, $fname ) {
 363                                         $dbw->update( 'watchlist',
 364                                                 [ /* SET */
 365                                                         'wl_notificationtimestamp' => $dbw->timestamp( $timestamp )
 366                                                 ], [ /* WHERE */
 367                                                         'wl_user' => $watchers,
 368                                                         'wl_namespace' => $target->getNamespace(),
 369                                                         'wl_title' => $target->getDBkey(),
 370                                                 ], $fname
 371                                         );
 372                                         $this->uncacheLinkTarget( $target );
 373                                 }
 374                         );
 375                 }
 376
 377                 $this->loadBalancer->reuseConnection( $dbw );
 378
 379                 return $watchers;
 380         }
 381
 382         /**
 383          * Reset the notification timestamp of this entry
 384          *
 385          * @param User $user
 386          * @param Title $title
 387          * @param string $force Whether to force the write query to be executed even if the
 388          *    page is not watched or the notification timestamp is already NULL.
 389          *    'force' in order to force
 390          * @param int $oldid The revision id being viewed. If not given or 0, latest revision is assumed.
 391          *
 392          * @return bool success
 393          */
 394         public function resetNotificationTimestamp( User $user, Title $title, $force = '', $oldid = 0 ) {
 395                 // Only loggedin user can have a watchlist
 396                 if ( $this->loadBalancer->getReadOnlyReason() !== false || $user->isAnon() ) {
 397                         return false;
 398                 }
 399
 400                 $item = null;
 401                 if ( $force != 'force' ) {
 402                         $item = $this->loadWatchedItem( $user, $title );
 403                         if ( !$item || $item->getNotificationTimestamp() === null ) {
 404                                 return false;
 405                         }
 406                 }
 407
 408                 // If the page is watched by the user (or may be watched), update the timestamp
 409                 $job = new ActivityUpdateJob(
 410                         $title,
 411                         [
 412                                 'type'      => 'updateWatchlistNotification',
 413                                 'userid'    => $user->getId(),
 414                                 'notifTime' => $this->getNotificationTimestamp( $user, $title, $item, $force, $oldid ),
 415                                 'curTime'   => time()
 416                         ]
 417                 );
 418
 419                 // Try to run this post-send
 420                 // Calls DeferredUpdates::addCallableUpdate in normal operation
 421                 call_user_func(
 422                         $this->deferredUpdatesAddCallableUpdateCallback,
 423                         function() use ( $job ) {
 424                                 $job->run();
 425                         }
 426                 );
 427
 428                 $this->uncache( $user, $title );
 429
 430                 return true;
 431         }
 432
 433         private function getNotificationTimestamp( User $user, Title $title, $item, $force, $oldid ) {
 434                 if ( !$oldid ) {
 435                         // No oldid given, assuming latest revision; clear the timestamp.
 436                         return null;
 437                 }
 438
 439                 if ( !$title->getNextRevisionID( $oldid ) ) {
 440                         // Oldid given and is the latest revision for this title; clear the timestamp.
 441                         return null;
 442                 }
 443
 444                 if ( $item === null ) {
 445                         $item = $this->loadWatchedItem( $user, $title );
 446                 }
 447
 448                 if ( !$item ) {
 449                         // This can only happen if $force is enabled.
 450                         return null;
 451                 }
 452
 453                 // Oldid given and isn't the latest; update the timestamp.
 454                 // This will result in no further notification emails being sent!
 455                 // Calls Revision::getTimestampFromId in normal operation
 456                 $notificationTimestamp = call_user_func(
 457                         $this->revisionGetTimestampFromIdCallback,
 458                         $title,
 459                         $oldid
 460                 );
 461
 462                 // We need to go one second to the future because of various strict comparisons
 463                 // throughout the codebase
 464                 $ts = new MWTimestamp( $notificationTimestamp );
 465                 $ts->timestamp->add( new DateInterval( 'PT1S' ) );
 466                 $notificationTimestamp = $ts->getTimestamp( TS_MW );
 467
 468                 if ( $notificationTimestamp < $item->getNotificationTimestamp() ) {
 469                         if ( $force != 'force' ) {
 470                                 return false;
 471                         } else {
 472                                 // This is a little silly…
 473                                 return $item->getNotificationTimestamp();
 474                         }
 475                 }
 476
 477                 return $notificationTimestamp;
 478         }
 479
 480         /**
 481          * Check if the given title already is watched by the user, and if so
 482          * add a watch for the new title.
 483          *
 484          * To be used for page renames and such.
 485          *
 486          * @param LinkTarget $oldTarget
 487          * @param LinkTarget $newTarget
 488          */
 489         public function duplicateAllAssociatedEntries( LinkTarget $oldTarget, LinkTarget $newTarget ) {
 490                 if ( !$oldTarget instanceof Title ) {
 491                         $oldTarget = Title::newFromLinkTarget( $oldTarget );
 492                 }
 493                 if ( !$newTarget instanceof Title ) {
 494                         $newTarget = Title::newFromLinkTarget( $newTarget );
 495                 }
 496
 497                 $this->duplicateEntry( $oldTarget->getSubjectPage(), $newTarget->getSubjectPage() );
 498                 $this->duplicateEntry( $oldTarget->getTalkPage(), $newTarget->getTalkPage() );
 499         }
 500
 501         /**
 502          * Check if the given title already is watched by the user, and if so
 503          * add a watch for the new title.
 504          *
 505          * To be used for page renames and such.
 506          * This must be called separately for Subject and Talk pages
 507          *
 508          * @param LinkTarget $oldTarget
 509          * @param LinkTarget $newTarget
 510          */
 511         public function duplicateEntry( LinkTarget $oldTarget, LinkTarget $newTarget ) {
 512                 $dbw = $this->loadBalancer->getConnection( DB_MASTER, [ 'watchlist' ] );
 513
 514                 $result = $dbw->select(
 515                         'watchlist',
 516                         [ 'wl_user', 'wl_notificationtimestamp' ],
 517                         [
 518                                 'wl_namespace' => $oldTarget->getNamespace(),
 519                                 'wl_title' => $oldTarget->getDBkey(),
 520                         ],
 521                         __METHOD__,
 522                         [ 'FOR UPDATE' ]
 523                 );
 524
 525                 $newNamespace = $newTarget->getNamespace();
 526                 $newDBkey = $newTarget->getDBkey();
 527
 528                 # Construct array to replace into the watchlist
 529                 $values = [];
 530                 foreach ( $result as $row ) {
 531                         $values[] = [
 532                                 'wl_user' => $row->wl_user,
 533                                 'wl_namespace' => $newNamespace,
 534                                 'wl_title' => $newDBkey,
 535                                 'wl_notificationtimestamp' => $row->wl_notificationtimestamp,
 536                         ];
 537                 }
 538
 539                 if ( !empty( $values ) ) {
 540                         # Perform replace
 541                         # Note that multi-row replace is very efficient for MySQL but may be inefficient for
 542                         # some other DBMSes, mostly due to poor simulation by us
 543                         $dbw->replace(
 544                                 'watchlist',
 545                                 [ [ 'wl_user', 'wl_namespace', 'wl_title' ] ],
 546                                 $values,
 547                                 __METHOD__
 548                         );
 549                 }
 550
 551                 $this->loadBalancer->reuseConnection( $dbw );
 552         }
 553
 554 }