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