Detect/use APCu properly

In PHP 5.5 and above, userland APC caching moved to an extension

Bug: T140587
Change-Id: Ie0871776cd7e67838471a4fe95451cf4164079b7

autoload.php

@@ -5,6 +5,7 @@ global $wgAutoloadLocalClasses;
 
 $wgAutoloadLocalClasses = [
 	'APCBagOStuff' => __DIR__ . '/includes/libs/objectcache/APCBagOStuff.php',
+	'APCUBagOStuff' => __DIR__ . '/includes/libs/objectcache/APCUBagOStuff.php',
 	'AbstractContent' => __DIR__ . '/includes/content/AbstractContent.php',
 	'Action' => __DIR__ . '/includes/actions/Action.php',
 	'ActiveUsersPager' => __DIR__ . '/includes/specials/pagers/ActiveUsersPager.php',

includes/DefaultSettings.php

@@ -2211,7 +2211,7 @@ $wgCacheDirectory = false;
  *   - CACHE_NONE:       Do not cache
  *   - CACHE_DB:         Store cache objects in the DB
  *   - CACHE_MEMCACHED:  MemCached, must specify servers in $wgMemCachedServers
- *   - CACHE_ACCEL:      APC, XCache or WinCache
+ *   - CACHE_ACCEL:      APC, APCU, XCache or WinCache
  *   - (other):          A string may be used which identifies a cache
  *                       configuration in $wgObjectCaches.
  *
@@ -2288,6 +2288,7 @@ $wgObjectCaches = [
 	],
 
 	'apc' => [ 'class' => 'APCBagOStuff', 'reportDupes' => false ],
+	'apcu' => [ 'class' => 'APCUBagOStuff', 'reportDupes' => false ],
 	'xcache' => [ 'class' => 'XCacheBagOStuff', 'reportDupes' => false ],
 	'wincache' => [ 'class' => 'WinCacheBagOStuff', 'reportDupes' => false ],
 	'memcached-php' => [ 'class' => 'MemcachedPhpBagOStuff', 'loggroup' => 'memcached' ],

includes/installer/Installer.php

@@ -244,6 +244,7 @@ abstract class Installer {
 	protected $objectCaches = [
 		'xcache' => 'xcache_get',
 		'apc' => 'apc_fetch',
+		'apcu' => 'apcu_fetch',
 		'wincache' => 'wincache_ucache_get'
 	];
 

includes/installer/i18n/en.json

@@ -57,6 +57,7 @@
 	"config-memory-bad": "<strong>Warning:</strong> PHP's <code>memory_limit</code> is $1.\nThis is probably too low.\nThe installation may fail!",
 	"config-xcache": "[http://xcache.lighttpd.net/ XCache] is installed",
 	"config-apc": "[http://www.php.net/apc APC] is installed",
+	"config-apcu": "[http://www.php.net/apcu APCu] is installed",
 	"config-wincache": "[http://www.iis.net/download/WinCacheForPhp WinCache] is installed",
 	"config-no-cache-apcu": "<strong>Warning:</strong> Could not find [http://www.php.net/apcu APCu], [http://xcache.lighttpd.net/ XCache] or [http://www.iis.net/download/WinCacheForPhp WinCache].\nObject caching is not enabled.",
 	"config-mod-security": "<strong>Warning:</strong> Your web server has [http://modsecurity.org/ mod_security]/mod_security2 enabled. Many common configurations of this will cause problems for MediaWiki and other software that allows users to post arbitrary content.\nIf possible, this should be disabled. Otherwise, refer to [http://modsecurity.org/documentation/ mod_security documentation] or contact your host's support if you encounter random errors.",
@@ -246,7 +247,7 @@
 	"config-cache-options": "Settings for object caching:",
 	"config-cache-help": "Object caching is used to improve the speed of MediaWiki by caching frequently used data.\nMedium to large sites are highly encouraged to enable this, and small sites will see benefits as well.",
 	"config-cache-none": "No caching (no functionality is removed, but speed may be impacted on larger wiki sites)",
-	"config-cache-accel": "PHP object caching (APC, XCache or WinCache)",
+	"config-cache-accel": "PHP object caching (APC, APCu, XCache or WinCache)",
 	"config-cache-memcached": "Use Memcached (requires additional setup and configuration)",
 	"config-memcached-servers": "Memcached servers:",
 	"config-memcached-help": "List of IP addresses to use for Memcached.\nShould specify one per line and specify the port to be used. For example:\n 127.0.0.1:11211\n 192.168.1.25:1234",

includes/installer/i18n/qqq.json

@@ -75,6 +75,7 @@
 	"config-memory-bad": "Parameters:\n* $1 is the configured <code>memory_limit</code>.",
 	"config-xcache": "Message indicates if this program is available",
 	"config-apc": "Message indicates if this program is available",
+	"config-apcu": "Message indicates if this program is available",
 	"config-wincache": "Message indicates if this program is available",
 	"config-no-cache-apcu": "Status message in the MediaWiki installer environment checks.",
 	"config-mod-security": "Status message in the MediaWiki installer environment checks.",

includes/libs/MemoizedCallable.php

@@ -1,6 +1,6 @@
 <?php
 /**
- * APC-backed function memoization
+ * APC-backed and APCu-backed function memoization
  *
  * This class provides memoization for pure functions. A function is pure
  * if its result value depends on nothing other than its input parameters
@@ -8,7 +8,7 @@
  *
  * The first invocation of the memoized callable with a particular set of
  * arguments will be delegated to the underlying callable. Repeat invocations
- * with the same input parameters will be served from APC.
+ * with the same input parameters will be served from APC or APCu.
  *
  * @par Example:
  * @code
@@ -70,7 +70,7 @@ class MemoizedCallable {
 	}
 
 	/**
-	 * Fetch the result of a previous invocation from APC.
+	 * Fetch the result of a previous invocation from APC or APCu.
 	 *
 	 * @param string $key
 	 * @param bool &$success
@@ -79,12 +79,14 @@ class MemoizedCallable {
 		$success = false;
 		if ( function_exists( 'apc_fetch' ) ) {
 			return apc_fetch( $key, $success );
+		} elseif ( function_exists( 'apcu_fetch' ) ) {
+			return apcu_fetch( $key, $success );
 		}
 		return false;
 	}
 
 	/**
-	 * Store the result of an invocation in APC.
+	 * Store the result of an invocation in APC or APCu.
 	 *
 	 * @param string $key
 	 * @param mixed $result
@@ -92,6 +94,8 @@ class MemoizedCallable {
 	protected function storeResult( $key, $result ) {
 		if ( function_exists( 'apc_store' ) ) {
 			apc_store( $key, $result, $this->ttl );
+		} elseif ( function_exists( 'apcu_store' ) ) {
+			apcu_store( $key, $result, $this->ttl );
 		}
 	}
 

includes/libs/objectcache/APCBagOStuff.php

@@ -75,25 +75,35 @@ class APCBagOStuff extends BagOStuff {
 	}
 
 	protected function doGet( $key, $flags = 0 ) {
-		$val = apc_fetch( $key . self::KEY_SUFFIX );
+		return $this->getUnserialize(
+			apc_fetch( $key . self::KEY_SUFFIX )
+		);
+	}
 
-		if ( is_string( $val ) && !$this->nativeSerialize ) {
+	protected function getUnserialize( $value ) {
-			$val = $this->isInteger( $val )
+		if ( is_string( $value ) && !$this->nativeSerialize ) {
-				? intval( $val )
+			$value = $this->isInteger( $value )
-				: unserialize( $val );
+				? intval( $value )
+				: unserialize( $value );
 		}
-
+		return $value;
-		return $val;
 	}
 
 	public function set( $key, $value, $exptime = 0, $flags = 0 ) {
+		apc_store(
+			$key . self::KEY_SUFFIX,
+			$this->setSerialize( $value ),
+			$exptime
+		);
+
+		return true;
+	}
+
+	protected function setSerialize( $value ) {
 		if ( !$this->nativeSerialize && !$this->isInteger( $value ) ) {
 			$value = serialize( $value );
 		}
-
+		return $value;
-		apc_store( $key . self::KEY_SUFFIX, $value, $exptime );
-
-		return true;
 	}
 
 	public function delete( $key ) {

includes/libs/objectcache/APCUBagOStuff.php

@@ -0,0 +1,91 @@
+<?php
+/**
+ * Object caching using PHP's APCU accelerator.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Cache
+ */
+
+/**
+ * This is a wrapper for APCU's shared memory functions
+ *
+ * @ingroup Cache
+ */
+class APCUBagOStuff extends APCBagOStuff {
+	/**
+	 * Constructor
+	 *
+	 * 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
+	 */
+	public function __construct( array $params = [] ) {
+		parent::__construct( $params );
+	}
+
+	protected function doGet( $key, $flags = 0 ) {
+		return $this->getUnserialize(
+			apcu_fetch( $key . self::KEY_SUFFIX )
+		);
+	}
+
+	public function set( $key, $value, $exptime = 0, $flags = 0 ) {
+		apcu_store(
+			$key . self::KEY_SUFFIX,
+			$this->setSerialize( $value ),
+			$exptime
+		);
+
+		return true;
+	}
+
+	public function delete( $key ) {
+		apcu_delete( $key . self::KEY_SUFFIX );
+
+		return true;
+	}
+
+	public function incr( $key, $value = 1 ) {
+		/**
+		 * @todo When we only support php 7 or higher remove this hack
+		 *
+		 * https://github.com/krakjoe/apcu/issues/166
+		 */
+		if ( apcu_exists( $key . self::KEY_SUFFIX ) ) {
+			return apcu_inc( $key . self::KEY_SUFFIX, $value );
+		} else {
+			return apcu_set( $key . self::KEY_SUFFIX, $value );
+		}
+	}
+
+	public function decr( $key, $value = 1 ) {
+		/**
+		 * @todo When we only support php 7 or higher remove this hack
+		 *
+		 * https://github.com/krakjoe/apcu/issues/166
+		 */
+		if ( apcu_exists( $key . self::KEY_SUFFIX ) ) {
+			return apcu_dec( $key . self::KEY_SUFFIX, $value );
+		} else {
+			return apcu_set( $key . self::KEY_SUFFIX, -$value );
+		}
+	}
+}

includes/objectcache/ObjectCache.php

@@ -50,7 +50,7 @@ use MediaWiki\MediaWikiServices;
  *
  * - ObjectCache::getLocalServerInstance( $fallbackType )
  *   Purpose: Memory cache for very hot keys.
- *   Stored only on the individual web server (typically APC for web requests,
+ *   Stored only on the individual web server (typically APC or APCu for web requests,
  *   and EmptyBagOStuff in CLI mode).
  *   Not replicated to the other servers.
  *
@@ -265,7 +265,7 @@ class ObjectCache {
 	/**
 	 * Factory function for CACHE_ACCEL (referenced from DefaultSettings.php)
 	 *
-	 * This will look for any APC style server-local cache.
+	 * This will look for any APC or APCu style server-local cache.
 	 * A fallback cache can be specified if none is found.
 	 *
 	 *     // Direct calls
@@ -282,6 +282,8 @@ class ObjectCache {
 	public static function getLocalServerInstance( $fallback = CACHE_NONE ) {
 		if ( function_exists( 'apc_fetch' ) ) {
 			$id = 'apc';
+		} elseif ( function_exists( 'apcu_fetch' ) ) {
+			$id = 'apcu';
 		} elseif ( function_exists( 'xcache_get' ) && wfIniGetBool( 'xcache.var_size' ) ) {
 			$id = 'xcache';
 		} elseif ( function_exists( 'wincache_ucache_get' ) ) {

tests/phpunit/includes/libs/MemoizedCallableTest.php

@@ -1,7 +1,7 @@
 <?php
 /**
  * A MemoizedCallable subclass that stores function return values
- * in an instance property rather than APC.
+ * in an instance property rather than APC or APCu.
  */
 class ArrayBackedMemoizedCallable extends MemoizedCallable {
 	private $cache = [];
@@ -44,7 +44,7 @@ class MemoizedCallableTest extends PHPUnit_Framework_TestCase {
 	 * Consecutive calls to the memoized callable with the same arguments
 	 * should result in just one invocation of the underlying callable.
 	 *
-	 * @requires function apc_store
+	 * @requires function apc_store/apcu_store
 	 */
 	public function testCallableMemoized() {
 		$observer = $this->getMock( 'stdClass', [ 'computeSomething' ] );