From 3192278eb21d228411d2d8ffddca9a8c5f5ce8a3 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 28 Mar 2019 19:38:13 -0700
Subject: [PATCH] objectcache: remove messy inheritence from APCBagOStuff in
 APCUBagOStuff

Also make sure they always use PHP serialization to avoid CAS token problems
and bugs in the custom pecl extension serializers.

Change-Id: I43cef97ca4ac0f0cc21b65ba73d1887ed92e157f
---
 includes/libs/objectcache/APCBagOStuff.php  | 59 ++++-----------------
 includes/libs/objectcache/APCUBagOStuff.php | 30 +++++++----
 2 files changed, 30 insertions(+), 59 deletions(-)

diff --git a/includes/libs/objectcache/APCBagOStuff.php b/includes/libs/objectcache/APCBagOStuff.php
index 902cd6a0f8..9a5a433c66 100644
--- a/includes/libs/objectcache/APCBagOStuff.php
+++ b/includes/libs/objectcache/APCBagOStuff.php
@@ -24,53 +24,22 @@
 /**
  * This is a wrapper for APC's shared memory functions
  *
+ * Use PHP serialization to avoid bugs and easily create CAS tokens.
+ * APCu has a memory corruption bug when the serializer is set to 'default'.
+ * See T120267, and upstream bug reports:
+ *  - https://github.com/krakjoe/apcu/issues/38
+ *  - https://github.com/krakjoe/apcu/issues/35
+ *  - https://github.com/krakjoe/apcu/issues/111
+ *
  * @ingroup Cache
  */
 class APCBagOStuff extends BagOStuff {
-
-	/**
-	 * @var bool If true, trust the APC implementation to serialize and
-	 * deserialize objects correctly. If false, (de-)serialize in PHP.
-	 */
-	protected $nativeSerialize;
-
 	/**
 	 * @var string String to append to each APC key. This may be changed
 	 *  whenever the handling of values is changed, to prevent existing code
 	 *  from encountering older values which it cannot handle.
 	 */
-	const KEY_SUFFIX = ':2';
-
-	/**
-	 * Available parameters are:
-	 *   - nativeSerialize:     If true, pass objects to apc_store(), and trust it
-	 *                          to serialize them correctly. If false, serialize
-	 *                          all values in PHP.
-	 *
-	 * @param array $params
-	 */
-	public function __construct( array $params = [] ) {
-		parent::__construct( $params );
-
-		if ( isset( $params['nativeSerialize'] ) ) {
-			$this->nativeSerialize = $params['nativeSerialize'];
-		} elseif ( extension_loaded( 'apcu' ) && ini_get( 'apc.serializer' ) === 'default' ) {
-			// APCu has a memory corruption bug when the serializer is set to 'default'.
-			// See T120267, and upstream bug reports:
-			//  - https://github.com/krakjoe/apcu/issues/38
-			//  - https://github.com/krakjoe/apcu/issues/35
-			//  - https://github.com/krakjoe/apcu/issues/111
-			$this->logger->warning(
-				'The APCu extension is loaded and the apc.serializer INI setting ' .
-				'is set to "default". This can cause memory corruption! ' .
-				'You should change apc.serializer to "php" instead. ' .
-				'See <https://github.com/krakjoe/apcu/issues/38>.'
-			);
-			$this->nativeSerialize = false;
-		} else {
-			$this->nativeSerialize = true;
-		}
-	}
+	const KEY_SUFFIX = ':3';
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
 		$casToken = null;
@@ -117,18 +86,10 @@ class APCBagOStuff extends BagOStuff {
 	}
 
 	protected function serialize( $value ) {
-		if ( !$this->nativeSerialize && !$this->isInteger( $value ) ) {
-			$value = serialize( $value );
-		}
-		return $value;
+		return $this->isInteger( $value ) ? (int)$value : serialize( $value );
 	}
 
 	protected function unserialize( $value ) {
-		if ( is_string( $value ) && !$this->nativeSerialize ) {
-			$value = $this->isInteger( $value )
-				? intval( $value )
-				: unserialize( $value );
-		}
-		return $value;
+		return $this->isInteger( $value ) ? (int)$value : unserialize( $value );
 	}
 }
diff --git a/includes/libs/objectcache/APCUBagOStuff.php b/includes/libs/objectcache/APCUBagOStuff.php
index da6544b3d1..0483ee7ef2 100644
--- a/includes/libs/objectcache/APCUBagOStuff.php
+++ b/includes/libs/objectcache/APCUBagOStuff.php
@@ -24,20 +24,22 @@
 /**
  * This is a wrapper for APCU's shared memory functions
  *
+ * Use PHP serialization to avoid bugs and easily create CAS tokens.
+ * APCu has a memory corruption bug when the serializer is set to 'default'.
+ * See T120267, and upstream bug reports:
+ *  - https://github.com/krakjoe/apcu/issues/38
+ *  - https://github.com/krakjoe/apcu/issues/35
+ *  - https://github.com/krakjoe/apcu/issues/111
+ *
  * @ingroup Cache
  */
-class APCUBagOStuff extends APCBagOStuff {
+class APCUBagOStuff extends BagOStuff {
 	/**
-	 * Available parameters are:
-	 *   - nativeSerialize:     If true, pass objects to apcu_store(), and trust it
-	 *                          to serialize them correctly. If false, serialize
-	 *                          all values in PHP.
-	 *
-	 * @param array $params
+	 * @var string String to append to each APC key. This may be changed
+	 *  whenever the handling of values is changed, to prevent existing code
+	 *  from encountering older values which it cannot handle.
 	 */
-	public function __construct( array $params = [] ) {
-		parent::__construct( $params );
-	}
+	const KEY_SUFFIX = ':3';
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
 		$casToken = null;
@@ -100,4 +102,12 @@ class APCUBagOStuff extends APCBagOStuff {
 			return false;
 		}
 	}
+
+	protected function serialize( $value ) {
+		return $this->isInteger( $value ) ? (int)$value : serialize( $value );
+	}
+
+	protected function unserialize( $value ) {
+		return $this->isInteger( $value ) ? (int)$value : unserialize( $value );
+	}
 }
-- 
2.20.1