From 7aeb270474169d19617ca9fa7a5b8ceeb8e08eff Mon Sep 17 00:00:00 2001
From: Ori Livneh <ori@wikimedia.org>
Date: Wed, 22 Jul 2015 15:26:02 -0700
Subject: [PATCH] Don't double-serialize values for APC

The last time we had encountered APC errors related to serialization /
unserialization was 2011. PHP's implementation has had many bugfixes since
then, and HHVM's implementation is a complete rewrite. So let's stop working
around alleged bugs.

To prevent errors resulting from HHVM code receiving serialize()d values when
it isn't expecting them, add a key suffix.

Change-Id: I4b2cf1715538aa3d9163787f43eb31984a380d35
---
 includes/libs/objectcache/APCBagOStuff.php | 30 ++++++++++------------
 1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/includes/libs/objectcache/APCBagOStuff.php b/includes/libs/objectcache/APCBagOStuff.php
index eaf115570c..cc54fe7dd8 100644
--- a/includes/libs/objectcache/APCBagOStuff.php
+++ b/includes/libs/objectcache/APCBagOStuff.php
@@ -27,43 +27,39 @@
  * @ingroup Cache
  */
 class APCBagOStuff extends BagOStuff {
+
+	/**
+	 * @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 = ':1';
+
 	public function get( $key, &$casToken = null ) {
-		$val = apc_fetch( $key );
+		$val = apc_fetch( $key . self::KEY_SUFFIX );
 
 		$casToken = $val;
 
-		if ( is_string( $val ) ) {
-			if ( $this->isInteger( $val ) ) {
-				$val = intval( $val );
-			} else {
-				$val = unserialize( $val );
-			}
-		}
-
 		return $val;
 	}
 
 	public function set( $key, $value, $exptime = 0 ) {
-		if ( !$this->isInteger( $value ) ) {
-			$value = serialize( $value );
-		}
-
-		apc_store( $key, $value, $exptime );
+		apc_store( $key . self::KEY_SUFFIX, $value, $exptime );
 
 		return true;
 	}
 
 	public function delete( $key ) {
-		apc_delete( $key );
+		apc_delete( $key . self::KEY_SUFFIX );
 
 		return true;
 	}
 
 	public function incr( $key, $value = 1 ) {
-		return apc_inc( $key, $value );
+		return apc_inc( $key . self::KEY_SUFFIX, $value );
 	}
 
 	public function decr( $key, $value = 1 ) {
-		return apc_dec( $key, $value );
+		return apc_dec( $key . self::KEY_SUFFIX, $value );
 	}
 }
-- 
2.20.1