From bcf563ef38b59b8d2e1e614887986543229c8624 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Tue, 5 Mar 2019 11:31:55 -0800
Subject: [PATCH] objectcache: add metrics for WAN cache deletes and check key
 touches/resets

Change-Id: I3dc707af53e480b27b7349aca53292f3bb26c45a
---
 includes/libs/objectcache/WANObjectCache.php  | 30 ++++++++++++-------
 .../libs/objectcache/WANObjectCacheTest.php   |  4 +--
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/includes/libs/objectcache/WANObjectCache.php b/includes/libs/objectcache/WANObjectCache.php
index bed7965149..9598b3ddfe 100644
--- a/includes/libs/objectcache/WANObjectCache.php
+++ b/includes/libs/objectcache/WANObjectCache.php
@@ -696,16 +696,17 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 * @return bool True if the item was purged or not found, false on failure
 	 */
 	final public function delete( $key, $ttl = self::HOLDOFF_TTL ) {
-		$key = self::VALUE_KEY_PREFIX . $key;
-
 		if ( $ttl <= 0 ) {
 			// Publish the purge to all datacenters
-			$ok = $this->relayDelete( $key );
+			$ok = $this->relayDelete( self::VALUE_KEY_PREFIX . $key );
 		} else {
 			// Publish the purge to all datacenters
-			$ok = $this->relayPurge( $key, $ttl, self::HOLDOFF_NONE );
+			$ok = $this->relayPurge( self::VALUE_KEY_PREFIX . $key, $ttl, self::HOLDOFF_NONE );
 		}
 
+		$kClass = $this->determineKeyClassForStats( $key );
+		$this->stats->increment( "wanobjectcache.$kClass.delete." . ( $ok ? 'ok' : 'error' ) );
+
 		return $ok;
 	}
 
@@ -860,7 +861,12 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 */
 	final public function touchCheckKey( $key, $holdoff = self::HOLDOFF_TTL ) {
 		// Publish the purge to all datacenters
-		return $this->relayPurge( self::TIME_KEY_PREFIX . $key, self::CHECK_KEY_TTL, $holdoff );
+		$ok = $this->relayPurge( self::TIME_KEY_PREFIX . $key, self::CHECK_KEY_TTL, $holdoff );
+
+		$kClass = $this->determineKeyClassForStats( $key );
+		$this->stats->increment( "wanobjectcache.$kClass.ck_touch." . ( $ok ? 'ok' : 'error' ) );
+
+		return $ok;
 	}
 
 	/**
@@ -892,7 +898,12 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 */
 	final public function resetCheckKey( $key ) {
 		// Publish the purge to all datacenters
-		return $this->relayDelete( self::TIME_KEY_PREFIX . $key );
+		$ok = $this->relayDelete( self::TIME_KEY_PREFIX . $key );
+
+		$kClass = $this->determineKeyClassForStats( $key );
+		$this->stats->increment( "wanobjectcache.$kClass.ck_reset." . ( $ok ? 'ok' : 'error' ) );
+
+		return $ok;
 	}
 
 	/**
@@ -1288,8 +1299,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 		$touchedCb = $opts['touchedCallback'] ?? null;
 		$initialTime = $this->getCurrentTime();
 
-		// Get a collection name to describe this class of key
-		$kClass = $this->determineKeyClass( $key );
+		$kClass = $this->determineKeyClassForStats( $key );
 
 		// Get the current key value
 		$curTTL = self::PASS_BY_REF;
@@ -2299,9 +2309,9 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 
 	/**
 	 * @param string $key String of the format <scope>:<class>[:<class or variable>]...
-	 * @return string
+	 * @return string A collection name to describe this class of key
 	 */
-	protected function determineKeyClass( $key ) {
+	protected function determineKeyClassForStats( $key ) {
 		$parts = explode( ':', $key );
 
 		return $parts[1] ?? $parts[0]; // sanity
diff --git a/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php b/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php
index 87c1d1edc6..017d745e49 100644
--- a/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php
+++ b/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php
@@ -1841,14 +1841,14 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 
 	/**
 	 * @dataProvider statsKeyProvider
-	 * @covers WANObjectCache::determineKeyClass
+	 * @covers WANObjectCache::determineKeyClassForStats
 	 */
 	public function testStatsKeyClass( $key, $class ) {
 		$wanCache = TestingAccessWrapper::newFromObject( new WANObjectCache( [
 			'cache' => new HashBagOStuff
 		] ) );
 
-		$this->assertEquals( $class, $wanCache->determineKeyClass( $key ) );
+		$this->assertEquals( $class, $wanCache->determineKeyClassForStats( $key ) );
 	}
 }
 
-- 
2.20.1