From 8d984cebb252a074bafd8d01e21a1c831a0e5aea Mon Sep 17 00:00:00 2001
From: addshore <addshorewiki@gmail.com>
Date: Thu, 10 Mar 2016 13:07:35 +0000
Subject: [PATCH] Uncache things in
 WatchedItemStore::updateNotificationTimestamp

When the notification timestamp for a LinkTarget is
updated all items relating to that LinkTarget should
be uncached!..

This also switches this class from a BagOStuff to
a HashBagOStuff as this cache index is only maintained
per process..

Change-Id: I5dc58e018a6a4a15903abc1e0b326b4220abc75e
---
 includes/WatchedItemStore.php                 | 32 +++++++++++++++----
 .../WatchedItemStoreIntegrationTest.php       |  2 +-
 .../includes/WatchedItemStoreUnitTest.php     |  4 +--
 3 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/includes/WatchedItemStore.php b/includes/WatchedItemStore.php
index 1aed8e01f2..721901f2ce 100644
--- a/includes/WatchedItemStore.php
+++ b/includes/WatchedItemStore.php
@@ -18,10 +18,18 @@ class WatchedItemStore {
 	private $loadBalancer;
 
 	/**
-	 * @var BagOStuff
+	 * @var HashBagOStuff
 	 */
 	private $cache;
 
+	/**
+	 * @var array[] Looks like $cacheIndex[Namespace ID][Target DB Key][User Id] => 'key'
+	 * The index is needed so that on mass changes all relevant items can be un-cached.
+	 * For example: Clearing a users watchlist of all items or updating notification timestamps
+	 *              for all users watching a single target.
+	 */
+	private $cacheIndex = [];
+
 	/**
 	 * @var callable|null
 	 */
@@ -37,7 +45,7 @@ class WatchedItemStore {
 	 */
 	private static $instance;
 
-	public function __construct( LoadBalancer $loadBalancer, BagOStuff $cache ) {
+	public function __construct( LoadBalancer $loadBalancer, HashBagOStuff $cache ) {
 		$this->loadBalancer = $loadBalancer;
 		$this->cache = $cache;
 		$this->deferredUpdatesAddCallableUpdateCallback = [ 'DeferredUpdates', 'addCallableUpdate' ];
@@ -121,14 +129,25 @@ class WatchedItemStore {
 	}
 
 	private function cache( WatchedItem $item ) {
-		$this->cache->set(
-			$this->getCacheKey( $item->getUser(), $item->getLinkTarget() ),
-			$item
-		);
+		$user = $item->getUser();
+		$target = $item->getLinkTarget();
+		$key = $this->getCacheKey( $user, $target );
+		$this->cache->set( $key, $item );
+		$this->cacheIndex[$target->getNamespace()][$target->getDBkey()][$user->getId()] = $key;
 	}
 
 	private function uncache( User $user, LinkTarget $target ) {
 		$this->cache->delete( $this->getCacheKey( $user, $target ) );
+		unset( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()][$user->getId()] );
+	}
+
+	private function uncacheLinkTarget( LinkTarget $target ) {
+		if ( !isset( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()] ) ) {
+			return;
+		}
+		foreach ( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()] as $key ) {
+			$this->cache->delete( $key );
+		}
 	}
 
 	/**
@@ -350,6 +369,7 @@ class WatchedItemStore {
 							'wl_title' => $target->getDBkey(),
 						], $fname
 					);
+					$this->uncacheLinkTarget( $target );
 				}
 			);
 		}
diff --git a/tests/phpunit/includes/WatchedItemStoreIntegrationTest.php b/tests/phpunit/includes/WatchedItemStoreIntegrationTest.php
index 9341fb89b6..e2ab512b29 100644
--- a/tests/phpunit/includes/WatchedItemStoreIntegrationTest.php
+++ b/tests/phpunit/includes/WatchedItemStoreIntegrationTest.php
@@ -57,7 +57,7 @@ class WatchedItemStoreIntegrationTest extends MediaWikiTestCase {
 		);
 
 		$this->assertTrue( $store->resetNotificationTimestamp( $user, $title ) );
-		$this->assertNull( $store->loadWatchedItem( $user, $title )->getNotificationTimestamp() );
+		$this->assertNull( $store->getWatchedItem( $user, $title )->getNotificationTimestamp() );
 	}
 
 	public function testDuplicateAllAssociatedEntries() {
diff --git a/tests/phpunit/includes/WatchedItemStoreUnitTest.php b/tests/phpunit/includes/WatchedItemStoreUnitTest.php
index 709b4b419f..fdb25455ee 100644
--- a/tests/phpunit/includes/WatchedItemStoreUnitTest.php
+++ b/tests/phpunit/includes/WatchedItemStoreUnitTest.php
@@ -31,10 +31,10 @@ class WatchedItemStoreUnitTest extends PHPUnit_Framework_TestCase {
 	}
 
 	/**
-	 * @return PHPUnit_Framework_MockObject_MockObject|BagOStuff
+	 * @return PHPUnit_Framework_MockObject_MockObject|HashBagOStuff
 	 */
 	private function getMockCache() {
-		$mock = $this->getMockBuilder( BagOStuff::class )
+		$mock = $this->getMockBuilder( HashBagOStuff::class )
 			->disableOriginalConstructor()
 			->getMock();
 		$mock->expects( $this->any() )
-- 
2.20.1