MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / includes / libs / objectcache / APCBagOStuff.php

diff --git a/includes/libs/objectcache/APCBagOStuff.php b/includes/libs/objectcache/APCBagOStuff.php
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+++ b/includes/libs/objectcache/APCBagOStuff.php
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+<?php
+/**
+ * Object caching using PHP's APC 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 APC's shared memory functions
+ *
+ * @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;
+               }
+       }
+
+       protected function doGet( $key, $flags = 0 ) {
+               return $this->getUnserialize(
+                       apc_fetch( $key . self::KEY_SUFFIX )
+               );
+       }
+
+       protected function getUnserialize( $value ) {
+               if ( is_string( $value ) && !$this->nativeSerialize ) {
+                       $value = $this->isInteger( $value )
+                               ? intval( $value )
+                               : unserialize( $value );
+               }
+               return $value;
+       }
+
+       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;
+       }
+
+       public function delete( $key ) {
+               apc_delete( $key . self::KEY_SUFFIX );
+
+               return true;
+       }
+
+       public function incr( $key, $value = 1 ) {
+               return apc_inc( $key . self::KEY_SUFFIX, $value );
+       }
+
+       public function decr( $key, $value = 1 ) {
+               return apc_dec( $key . self::KEY_SUFFIX, $value );
+       }
+}