From 121636900cd5c8400dda8aa7fc1c48dd3a6571f4 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Wed, 10 Jul 2019 14:32:08 -0700
Subject: [PATCH] objectcache: remove inheritence from CachedBagOStuff

Change-Id: I24e5b6a95d74730c1679bdc7b7b394adcb6bd794
---
 includes/libs/objectcache/CachedBagOStuff.php | 73 ++++++++++---------
 includes/libs/objectcache/HashBagOStuff.php   |  2 +-
 2 files changed, 40 insertions(+), 35 deletions(-)

diff --git a/includes/libs/objectcache/CachedBagOStuff.php b/includes/libs/objectcache/CachedBagOStuff.php
index e193497c7f..50ee1e3fdf 100644
--- a/includes/libs/objectcache/CachedBagOStuff.php
+++ b/includes/libs/objectcache/CachedBagOStuff.php
@@ -32,62 +32,61 @@
  *   up going to the HashBagOStuff used for the in-memory cache).
  *
  * @ingroup Cache
- * @TODO: Make this class use composition instead of calling super
  */
-class CachedBagOStuff extends HashBagOStuff {
+class CachedBagOStuff extends BagOStuff {
 	/** @var BagOStuff */
 	protected $backend;
+	/** @var HashBagOStuff */
+	protected $procCache;
 
 	/**
 	 * @param BagOStuff $backend Permanent backend to use
 	 * @param array $params Parameters for HashBagOStuff
 	 */
-	function __construct( BagOStuff $backend, $params = [] ) {
+	public function __construct( BagOStuff $backend, $params = [] ) {
 		unset( $params['reportDupes'] ); // useless here
 
 		parent::__construct( $params );
 
 		$this->backend = $backend;
+		$this->procCache = new HashBagOStuff( $params );
 		$this->attrMap = $backend->attrMap;
 	}
 
-	public function get( $key, $flags = 0 ) {
-		$ret = parent::get( $key, $flags );
-		if ( $ret === false && !$this->hasKey( $key ) ) {
+	protected function doGet( $key, $flags = 0, &$casToken = null ) {
+		$ret = $this->procCache->get( $key, $flags );
+		if ( $ret === false && !$this->procCache->hasKey( $key ) ) {
 			$ret = $this->backend->get( $key, $flags );
-			$this->set( $key, $ret, 0, self::WRITE_CACHE_ONLY );
+			$this->set( $key, $ret, self::TTL_INDEFINITE, self::WRITE_CACHE_ONLY );
 		}
+
 		return $ret;
 	}
 
-	public function set( $key, $value, $exptime = 0, $flags = 0 ) {
-		parent::set( $key, $value, $exptime, $flags );
-		if ( !( $flags & self::WRITE_CACHE_ONLY ) ) {
-			$this->backend->set( $key, $value, $exptime, $flags & ~self::WRITE_CACHE_ONLY );
+	protected function doSet( $key, $value, $exptime = 0, $flags = 0 ) {
+		$this->procCache->set( $key, $value, $exptime, $flags );
+		if ( ( $flags & self::WRITE_CACHE_ONLY ) != self::WRITE_CACHE_ONLY ) {
+			$this->backend->set( $key, $value, $exptime, $flags );
 		}
+
 		return true;
 	}
 
-	public function delete( $key, $flags = 0 ) {
-		parent::delete( $key, $flags );
-		if ( !( $flags & self::WRITE_CACHE_ONLY ) ) {
-			$this->backend->delete( $key );
+	protected function doDelete( $key, $flags = 0 ) {
+		$this->procCache->delete( $key, $flags );
+		if ( ( $flags & self::WRITE_CACHE_ONLY ) != self::WRITE_CACHE_ONLY ) {
+			$this->backend->delete( $key, $flags );
 		}
 
 		return true;
 	}
 
-	public function setDebug( $bool ) {
-		parent::setDebug( $bool );
-		$this->backend->setDebug( $bool );
-	}
-
 	public function deleteObjectsExpiringBefore(
 		$timestamp,
 		callable $progressCallback = null,
 		$limit = INF
 	) {
-		parent::deleteObjectsExpiringBefore( $timestamp, $progressCallback, $limit );
+		$this->procCache->deleteObjectsExpiringBefore( $timestamp, $progressCallback, $limit );
 
 		return $this->backend->deleteObjectsExpiringBefore(
 			$timestamp,
@@ -96,18 +95,6 @@ class CachedBagOStuff extends HashBagOStuff {
 		);
 	}
 
-	public function makeKeyInternal( $keyspace, $args ) {
-		return $this->backend->makeKeyInternal( ...func_get_args() );
-	}
-
-	public function makeKey( $class, $component = null ) {
-		return $this->backend->makeKey( ...func_get_args() );
-	}
-
-	public function makeGlobalKey( $class, $component = null ) {
-		return $this->backend->makeGlobalKey( ...func_get_args() );
-	}
-
 	// These just call the backend (tested elsewhere)
 	// @codeCoverageIgnoreStart
 
@@ -121,7 +108,8 @@ class CachedBagOStuff extends HashBagOStuff {
 
 	public function incr( $key, $value = 1 ) {
 		$n = $this->backend->incr( $key, $value );
-		parent::delete( $key );
+
+		$this->procCache->delete( $key );
 
 		return $n;
 	}
@@ -134,6 +122,23 @@ class CachedBagOStuff extends HashBagOStuff {
 		return $this->backend->unlock( $key );
 	}
 
+	public function makeKeyInternal( $keyspace, $args ) {
+		return $this->backend->makeKeyInternal( ...func_get_args() );
+	}
+
+	public function makeKey( $class, $component = null ) {
+		return $this->backend->makeKey( ...func_get_args() );
+	}
+
+	public function makeGlobalKey( $class, $component = null ) {
+		return $this->backend->makeGlobalKey( ...func_get_args() );
+	}
+
+	public function setDebug( $bool ) {
+		parent::setDebug( $bool );
+		$this->backend->setDebug( $bool );
+	}
+
 	public function getLastError() {
 		return $this->backend->getLastError();
 	}
diff --git a/includes/libs/objectcache/HashBagOStuff.php b/includes/libs/objectcache/HashBagOStuff.php
index 016bdfe36e..c74bb6e087 100644
--- a/includes/libs/objectcache/HashBagOStuff.php
+++ b/includes/libs/objectcache/HashBagOStuff.php
@@ -149,7 +149,7 @@ class HashBagOStuff extends BagOStuff {
 	 * @return bool
 	 * @since 1.27
 	 */
-	protected function hasKey( $key ) {
+	public function hasKey( $key ) {
 		return isset( $this->bag[$key] );
 	}
 }
-- 
2.20.1