Move \OC\Memcache to PSR-4

11 files changed, 1430 insertions, 0 deletions

diff --git a/lib/private/Memcache/APC.php b/lib/private/Memcache/APC.php
new file mode 100644
index 00000000000..2354ad07749
--- /dev/null
+++ b/lib/private/Memcache/APC.php
@@ -0,0 +1,135 @@
+<?php
+/**
+ * @author Andreas Fischer <bantu@owncloud.com>
+ * @author Clark Tomlinson <fallen013@gmail.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Otto Sabart <ottosabart@seberm.com>
+ * @author Robin Appelman <icewind@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+use OCP\IMemcache;
+
+class APC extends Cache implements IMemcache {
+	use CASTrait {
+		cas as casEmulated;
+	}
+
+	use CADTrait;
+
+	public function get($key) {
+		$result = apc_fetch($this->getPrefix() . $key, $success);
+		if (!$success) {
+			return null;
+		}
+		return $result;
+	}
+
+	public function set($key, $value, $ttl = 0) {
+		return apc_store($this->getPrefix() . $key, $value, $ttl);
+	}
+
+	public function hasKey($key) {
+		return apc_exists($this->getPrefix() . $key);
+	}
+
+	public function remove($key) {
+		return apc_delete($this->getPrefix() . $key);
+	}
+
+	public function clear($prefix = '') {
+		$ns = $this->getPrefix() . $prefix;
+		$ns = preg_quote($ns, '/');
+		$iter = new \APCIterator('user', '/^' . $ns . '/', APC_ITER_KEY);
+		return apc_delete($iter);
+	}
+
+	/**
+	 * Set a value in the cache if it's not already stored
+	 *
+	 * @param string $key
+	 * @param mixed $value
+	 * @param int $ttl Time To Live in seconds. Defaults to 60*60*24
+	 * @return bool
+	 */
+	public function add($key, $value, $ttl = 0) {
+		return apc_add($this->getPrefix() . $key, $value, $ttl);
+	}
+
+	/**
+	 * Increase a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function inc($key, $step = 1) {
+		$this->add($key, 0);
+		return apc_inc($this->getPrefix() . $key, $step);
+	}
+
+	/**
+	 * Decrease a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function dec($key, $step = 1) {
+		return apc_dec($this->getPrefix() . $key, $step);
+	}
+
+	/**
+	 * Compare and set
+	 *
+	 * @param string $key
+	 * @param mixed $old
+	 * @param mixed $new
+	 * @return bool
+	 */
+	public function cas($key, $old, $new) {
+		// apc only does cas for ints
+		if (is_int($old) and is_int($new)) {
+			return apc_cas($this->getPrefix() . $key, $old, $new);
+		} else {
+			return $this->casEmulated($key, $old, $new);
+		}
+	}
+
+	static public function isAvailable() {
+		if (!extension_loaded('apc')) {
+			return false;
+		} elseif (!\OC::$server->getIniWrapper()->getBool('apc.enabled')) {
+			return false;
+		} elseif (!\OC::$server->getIniWrapper()->getBool('apc.enable_cli') && \OC::$CLI) {
+			return false;
+		} else {
+			return true;
+		}
+	}
+}
+
+if (!function_exists('apc_exists')) {
+	function apc_exists($keys) {
+		$result = false;
+		apc_fetch($keys, $result);
+		return $result;
+	}
+}
diff --git a/lib/private/Memcache/APCu.php b/lib/private/Memcache/APCu.php
new file mode 100644
index 00000000000..350ce913ed8
--- /dev/null
+++ b/lib/private/Memcache/APCu.php
@@ -0,0 +1,140 @@
+<?php
+/**
+ * @author Andreas Fischer <bantu@owncloud.com>
+ * @author Bart Visscher <bartv@thisnet.nl>
+ * @author Clark Tomlinson <fallen013@gmail.com>
+ * @author Lukas Reschke <lukas@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+use OCP\IMemcache;
+
+class APCu extends Cache implements IMemcache {
+	use CASTrait {
+		cas as casEmulated;
+	}
+
+	use CADTrait;
+
+	public function get($key) {
+		$result = apcu_fetch($this->getPrefix() . $key, $success);
+		if (!$success) {
+			return null;
+		}
+		return $result;
+	}
+
+	public function set($key, $value, $ttl = 0) {
+		return apcu_store($this->getPrefix() . $key, $value, $ttl);
+	}
+
+	public function hasKey($key) {
+		return apcu_exists($this->getPrefix() . $key);
+	}
+
+	public function remove($key) {
+		return apcu_delete($this->getPrefix() . $key);
+	}
+
+	public function clear($prefix = '') {
+		$ns = $this->getPrefix() . $prefix;
+		$ns = preg_quote($ns, '/');
+		if(class_exists('\APCIterator')) {
+			$iter = new \APCIterator('user', '/^' . $ns . '/', APC_ITER_KEY);
+		} else {
+			$iter = new \APCUIterator('/^' . $ns . '/', APC_ITER_KEY);
+		}
+		return apcu_delete($iter);
+	}
+
+	/**
+	 * Set a value in the cache if it's not already stored
+	 *
+	 * @param string $key
+	 * @param mixed $value
+	 * @param int $ttl Time To Live in seconds. Defaults to 60*60*24
+	 * @return bool
+	 */
+	public function add($key, $value, $ttl = 0) {
+		return apcu_add($this->getPrefix() . $key, $value, $ttl);
+	}
+
+	/**
+	 * Increase a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function inc($key, $step = 1) {
+		$this->add($key, 0);
+		return apcu_inc($this->getPrefix() . $key, $step);
+	}
+
+	/**
+	 * Decrease a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function dec($key, $step = 1) {
+		return apcu_dec($this->getPrefix() . $key, $step);
+	}
+
+	/**
+	 * Compare and set
+	 *
+	 * @param string $key
+	 * @param mixed $old
+	 * @param mixed $new
+	 * @return bool
+	 */
+	public function cas($key, $old, $new) {
+		// apc only does cas for ints
+		if (is_int($old) and is_int($new)) {
+			return apcu_cas($this->getPrefix() . $key, $old, $new);
+		} else {
+			return $this->casEmulated($key, $old, $new);
+		}
+	}
+
+	/**
+	 * @return bool
+	 */
+	static public function isAvailable() {
+		if (!extension_loaded('apcu')) {
+			return false;
+		} elseif (!\OC::$server->getIniWrapper()->getBool('apc.enabled')) {
+			return false;
+		} elseif (!\OC::$server->getIniWrapper()->getBool('apc.enable_cli') && \OC::$CLI) {
+			return false;
+		} elseif (
+				version_compare(phpversion('apc'), '4.0.6') === -1 &&
+				version_compare(phpversion('apcu'), '5.1.0') === -1
+		) {
+			return false;
+		} else {
+			return true;
+		}
+	}
+}
diff --git a/lib/private/Memcache/ArrayCache.php b/lib/private/Memcache/ArrayCache.php
new file mode 100644
index 00000000000..837f888a307
--- /dev/null
+++ b/lib/private/Memcache/ArrayCache.php
@@ -0,0 +1,158 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+use OCP\IMemcache;
+
+class ArrayCache extends Cache implements IMemcache {
+	/** @var array Array with the cached data */
+	protected $cachedData = array();
+
+	use CADTrait;
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function get($key) {
+		if ($this->hasKey($key)) {
+			return $this->cachedData[$key];
+		}
+		return null;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function set($key, $value, $ttl = 0) {
+		$this->cachedData[$key] = $value;
+		return true;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function hasKey($key) {
+		return isset($this->cachedData[$key]);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function remove($key) {
+		unset($this->cachedData[$key]);
+		return true;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function clear($prefix = '') {
+		if ($prefix === '') {
+			$this->cachedData = [];
+			return true;
+		}
+
+		foreach ($this->cachedData as $key => $value) {
+			if (strpos($key, $prefix) === 0) {
+				$this->remove($key);
+			}
+		}
+		return true;
+	}
+
+	/**
+	 * Set a value in the cache if it's not already stored
+	 *
+	 * @param string $key
+	 * @param mixed $value
+	 * @param int $ttl Time To Live in seconds. Defaults to 60*60*24
+	 * @return bool
+	 */
+	public function add($key, $value, $ttl = 0) {
+		// since this cache is not shared race conditions aren't an issue
+		if ($this->hasKey($key)) {
+			return false;
+		} else {
+			return $this->set($key, $value, $ttl);
+		}
+	}
+
+	/**
+	 * Increase a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function inc($key, $step = 1) {
+		$oldValue = $this->get($key);
+		if (is_int($oldValue)) {
+			$this->set($key, $oldValue + $step);
+			return $oldValue + $step;
+		} else {
+			$success = $this->add($key, $step);
+			return ($success) ? $step : false;
+		}
+	}
+
+	/**
+	 * Decrease a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function dec($key, $step = 1) {
+		$oldValue = $this->get($key);
+		if (is_int($oldValue)) {
+			$this->set($key, $oldValue - $step);
+			return $oldValue - $step;
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * Compare and set
+	 *
+	 * @param string $key
+	 * @param mixed $old
+	 * @param mixed $new
+	 * @return bool
+	 */
+	public function cas($key, $old, $new) {
+		if ($this->get($key) === $old) {
+			return $this->set($key, $new);
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	static public function isAvailable() {
+		return true;
+	}
+}
diff --git a/lib/private/Memcache/CADTrait.php b/lib/private/Memcache/CADTrait.php
new file mode 100644
index 00000000000..d44d98cba0b
--- /dev/null
+++ b/lib/private/Memcache/CADTrait.php
@@ -0,0 +1,53 @@
+<?php
+/**
+ * @author Robin Appelman <icewind@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+trait CADTrait {
+	abstract public function get($key);
+
+	abstract public function remove($key);
+
+	abstract public function add($key, $value, $ttl = 0);
+
+	/**
+	 * Compare and delete
+	 *
+	 * @param string $key
+	 * @param mixed $old
+	 * @return bool
+	 */
+	public function cad($key, $old) {
+		//no native cas, emulate with locking
+		if ($this->add($key . '_lock', true)) {
+			if ($this->get($key) === $old) {
+				$this->remove($key);
+				$this->remove($key . '_lock');
+				return true;
+			} else {
+				$this->remove($key . '_lock');
+				return false;
+			}
+		} else {
+			return false;
+		}
+	}
+}
diff --git a/lib/private/Memcache/CASTrait.php b/lib/private/Memcache/CASTrait.php
new file mode 100644
index 00000000000..43253fc966b
--- /dev/null
+++ b/lib/private/Memcache/CASTrait.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * @author Robin Appelman <icewind@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+trait CASTrait {
+	abstract public function get($key);
+
+	abstract public function set($key, $value, $ttl = 0);
+
+	abstract public function remove($key);
+
+	abstract public function add($key, $value, $ttl = 0);
+
+	/**
+	 * Compare and set
+	 *
+	 * @param string $key
+	 * @param mixed $old
+	 * @param mixed $new
+	 * @return bool
+	 */
+	public function cas($key, $old, $new) {
+		//no native cas, emulate with locking
+		if ($this->add($key . '_lock', true)) {
+			if ($this->get($key) === $old) {
+				$this->set($key, $new);
+				$this->remove($key . '_lock');
+				return true;
+			} else {
+				$this->remove($key . '_lock');
+				return false;
+			}
+		} else {
+			return false;
+		}
+	}
+}
diff --git a/lib/private/Memcache/Cache.php b/lib/private/Memcache/Cache.php
new file mode 100644
index 00000000000..63d20721aac
--- /dev/null
+++ b/lib/private/Memcache/Cache.php
@@ -0,0 +1,96 @@
+<?php
+/**
+ * @author Lukas Reschke <lukas@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@owncloud.com>
+ * @author Robin McCorkell <robin@mccorkell.me.uk>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+abstract class Cache implements \ArrayAccess, \OCP\ICache {
+	/**
+	 * @var string $prefix
+	 */
+	protected $prefix;
+
+	/**
+	 * @param string $prefix
+	 */
+	public function __construct($prefix = '') {
+		$this->prefix = $prefix;
+	}
+
+	/**
+	 * @return string Prefix used for caching purposes
+	 */
+	public function getPrefix() {
+		return $this->prefix;
+	}
+
+	/**
+	 * @param string $key
+	 * @return mixed
+	 */
+	abstract public function get($key);
+
+	/**
+	 * @param string $key
+	 * @param mixed $value
+	 * @param int $ttl
+	 * @return mixed
+	 */
+	abstract public function set($key, $value, $ttl = 0);
+
+	/**
+	 * @param string $key
+	 * @return mixed
+	 */
+	abstract public function hasKey($key);
+
+	/**
+	 * @param string $key
+	 * @return mixed
+	 */
+	abstract public function remove($key);
+
+	/**
+	 * @param string $prefix
+	 * @return mixed
+	 */
+	abstract public function clear($prefix = '');
+
+	//implement the ArrayAccess interface
+
+	public function offsetExists($offset) {
+		return $this->hasKey($offset);
+	}
+
+	public function offsetSet($offset, $value) {
+		$this->set($offset, $value);
+	}
+
+	public function offsetGet($offset) {
+		return $this->get($offset);
+	}
+
+	public function offsetUnset($offset) {
+		$this->remove($offset);
+	}
+}
diff --git a/lib/private/Memcache/Factory.php b/lib/private/Memcache/Factory.php
new file mode 100644
index 00000000000..a005f319b3e
--- /dev/null
+++ b/lib/private/Memcache/Factory.php
@@ -0,0 +1,189 @@
+<?php
+/**
+ * @author Andreas Fischer <bantu@owncloud.com>
+ * @author Lukas Reschke <lukas@owncloud.com>
+ * @author Markus Goetz <markus@woboq.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@owncloud.com>
+ * @author Robin McCorkell <robin@mccorkell.me.uk>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ * @author Vincent Petry <pvince81@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+use \OCP\ICacheFactory;
+use \OCP\ILogger;
+
+class Factory implements ICacheFactory {
+	const NULL_CACHE = '\\OC\\Memcache\\NullCache';
+
+	/**
+	 * @var string $globalPrefix
+	 */
+	private $globalPrefix;
+
+	/**
+	 * @var ILogger $logger
+	 */
+	private $logger;
+
+	/**
+	 * @var string $localCacheClass
+	 */
+	private $localCacheClass;
+
+	/**
+	 * @var string $distributedCacheClass
+	 */
+	private $distributedCacheClass;
+
+	/**
+	 * @var string $lockingCacheClass
+	 */
+	private $lockingCacheClass;
+
+	/**
+	 * @param string $globalPrefix
+	 * @param ILogger $logger
+	 * @param string|null $localCacheClass
+	 * @param string|null $distributedCacheClass
+	 * @param string|null $lockingCacheClass
+	 */
+	public function __construct($globalPrefix, ILogger $logger,
+		$localCacheClass = null, $distributedCacheClass = null, $lockingCacheClass = null)
+	{
+		$this->logger = $logger;
+		$this->globalPrefix = $globalPrefix;
+
+		if (!$localCacheClass) {
+			$localCacheClass = self::NULL_CACHE;
+		}
+		if (!$distributedCacheClass) {
+			$distributedCacheClass = $localCacheClass;
+		}
+
+		$missingCacheMessage = 'Memcache {class} not available for {use} cache';
+		$missingCacheHint = 'Is the matching PHP module installed and enabled?';
+		if (!$localCacheClass::isAvailable()) {
+			if (\OC::$CLI && !defined('PHPUNIT_RUN')) {
+				// CLI should not hard-fail on broken memcache
+				$this->logger->info($missingCacheMessage, [
+					'class' => $localCacheClass,
+					'use' => 'local',
+					'app' => 'cli'
+				]);
+				$localCacheClass = self::NULL_CACHE;
+			} else {
+				throw new \OC\HintException(strtr($missingCacheMessage, [
+					'{class}' => $localCacheClass, '{use}' => 'local'
+				]), $missingCacheHint);
+			}
+		}
+		if (!$distributedCacheClass::isAvailable()) {
+			if (\OC::$CLI && !defined('PHPUNIT_RUN')) {
+				// CLI should not hard-fail on broken memcache
+				$this->logger->info($missingCacheMessage, [
+					'class' => $distributedCacheClass,
+					'use' => 'distributed',
+					'app' => 'cli'
+				]);
+				$distributedCacheClass = self::NULL_CACHE;
+			} else {
+				throw new \OC\HintException(strtr($missingCacheMessage, [
+					'{class}' => $distributedCacheClass, '{use}' => 'distributed'
+				]), $missingCacheHint);
+			}
+		}
+		if (!($lockingCacheClass && $lockingCacheClass::isAvailable())) {
+			// don't fallback since the fallback might not be suitable for storing lock
+			$lockingCacheClass = self::NULL_CACHE;
+		}
+
+		$this->localCacheClass = $localCacheClass;
+		$this->distributedCacheClass = $distributedCacheClass;
+		$this->lockingCacheClass = $lockingCacheClass;
+	}
+
+	/**
+	 * create a cache instance for storing locks
+	 *
+	 * @param string $prefix
+	 * @return \OCP\IMemcache
+	 */
+	public function createLocking($prefix = '') {
+		return new $this->lockingCacheClass($this->globalPrefix . '/' . $prefix);
+	}
+
+	/**
+	 * create a distributed cache instance
+	 *
+	 * @param string $prefix
+	 * @return \OC\Memcache\Cache
+	 */
+	public function createDistributed($prefix = '') {
+		return new $this->distributedCacheClass($this->globalPrefix . '/' . $prefix);
+	}
+
+	/**
+	 * create a local cache instance
+	 *
+	 * @param string $prefix
+	 * @return \OC\Memcache\Cache
+	 */
+	public function createLocal($prefix = '') {
+		return new $this->localCacheClass($this->globalPrefix . '/' . $prefix);
+	}
+
+	/**
+	 * @see \OC\Memcache\Factory::createDistributed()
+	 * @param string $prefix
+	 * @return \OC\Memcache\Cache
+	 */
+	public function create($prefix = '') {
+		return $this->createDistributed($prefix);
+	}
+
+	/**
+	 * check memcache availability
+	 *
+	 * @return bool
+	 */
+	public function isAvailable() {
+		return ($this->distributedCacheClass !== self::NULL_CACHE);
+	}
+
+	/**
+	 * @see \OC\Memcache\Factory::createLocal()
+	 * @param string $prefix
+	 * @return Cache
+	 */
+	public function createLowLatency($prefix = '') {
+		return $this->createLocal($prefix);
+	}
+
+	/**
+	 * check local memcache availability
+	 *
+	 * @return bool
+	 */
+	public function isAvailableLowLatency() {
+		return ($this->localCacheClass !== self::NULL_CACHE);
+	}
+}
diff --git a/lib/private/Memcache/Memcached.php b/lib/private/Memcache/Memcached.php
new file mode 100644
index 00000000000..a30f9da7ed7
--- /dev/null
+++ b/lib/private/Memcache/Memcached.php
@@ -0,0 +1,189 @@
+<?php
+/**
+ * @author Andreas Fischer <bantu@owncloud.com>
+ * @author Bart Visscher <bartv@thisnet.nl>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@owncloud.com>
+ * @author Robin McCorkell <robin@mccorkell.me.uk>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+use OCP\IMemcache;
+
+class Memcached extends Cache implements IMemcache {
+	use CASTrait;
+
+	/**
+	 * @var \Memcached $cache
+	 */
+	private static $cache = null;
+
+	use CADTrait;
+
+	public function __construct($prefix = '') {
+		parent::__construct($prefix);
+		if (is_null(self::$cache)) {
+			self::$cache = new \Memcached();
+			$servers = \OC::$server->getSystemConfig()->getValue('memcached_servers');
+			if (!$servers) {
+				$server = \OC::$server->getSystemConfig()->getValue('memcached_server');
+				if ($server) {
+					$servers = array($server);
+				} else {
+					$servers = array(array('localhost', 11211));
+				}
+			}
+			self::$cache->addServers($servers);
+		}
+	}
+
+	/**
+	 * entries in XCache gets namespaced to prevent collisions between owncloud instances and users
+	 */
+	protected function getNameSpace() {
+		return $this->prefix;
+	}
+
+	public function get($key) {
+		$result = self::$cache->get($this->getNamespace() . $key);
+		if ($result === false and self::$cache->getResultCode() == \Memcached::RES_NOTFOUND) {
+			return null;
+		} else {
+			return $result;
+		}
+	}
+
+	public function set($key, $value, $ttl = 0) {
+		if ($ttl > 0) {
+			$result =  self::$cache->set($this->getNamespace() . $key, $value, $ttl);
+		} else {
+			$result = self::$cache->set($this->getNamespace() . $key, $value);
+		}
+		$this->verifyReturnCode();
+		return $result;
+	}
+
+	public function hasKey($key) {
+		self::$cache->get($this->getNamespace() . $key);
+		return self::$cache->getResultCode() === \Memcached::RES_SUCCESS;
+	}
+
+	public function remove($key) {
+		$result= self::$cache->delete($this->getNamespace() . $key);
+		if (self::$cache->getResultCode() !== \Memcached::RES_NOTFOUND) {
+			$this->verifyReturnCode();
+		}
+		return $result;
+	}
+
+	public function clear($prefix = '') {
+		$prefix = $this->getNamespace() . $prefix;
+		$allKeys = self::$cache->getAllKeys();
+		if ($allKeys === false) {
+			// newer Memcached doesn't like getAllKeys(), flush everything
+			self::$cache->flush();
+			return true;
+		}
+		$keys = array();
+		$prefixLength = strlen($prefix);
+		foreach ($allKeys as $key) {
+			if (substr($key, 0, $prefixLength) === $prefix) {
+				$keys[] = $key;
+			}
+		}
+		if (method_exists(self::$cache, 'deleteMulti')) {
+			self::$cache->deleteMulti($keys);
+		} else {
+			foreach ($keys as $key) {
+				self::$cache->delete($key);
+			}
+		}
+		return true;
+	}
+
+	/**
+	 * Set a value in the cache if it's not already stored
+	 *
+	 * @param string $key
+	 * @param mixed $value
+	 * @param int $ttl Time To Live in seconds. Defaults to 60*60*24
+	 * @return bool
+	 * @throws \Exception
+	 */
+	public function add($key, $value, $ttl = 0) {
+		$result = self::$cache->add($this->getPrefix() . $key, $value, $ttl);
+		if (self::$cache->getResultCode() !== \Memcached::RES_NOTSTORED) {
+			$this->verifyReturnCode();
+		}
+		return $result;
+	}
+
+	/**
+	 * Increase a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function inc($key, $step = 1) {
+		$this->add($key, 0);
+		$result = self::$cache->increment($this->getPrefix() . $key, $step);
+
+		if (self::$cache->getResultCode() !== \Memcached::RES_SUCCESS) {
+			return false;
+		}
+
+		return $result;
+	}
+
+	/**
+	 * Decrease a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function dec($key, $step = 1) {
+		$result = self::$cache->decrement($this->getPrefix() . $key, $step);
+
+		if (self::$cache->getResultCode() !== \Memcached::RES_SUCCESS) {
+			return false;
+		}
+
+		return $result;
+	}
+
+	static public function isAvailable() {
+		return extension_loaded('memcached');
+	}
+
+	/**
+	 * @throws \Exception
+	 */
+	private function verifyReturnCode() {
+		$code = self::$cache->getResultCode();
+		if ($code === \Memcached::RES_SUCCESS) {
+			return;
+		}
+		$message = self::$cache->getResultMessage();
+		throw new \Exception("Error $code interacting with memcached : $message");
+	}
+}
diff --git a/lib/private/Memcache/NullCache.php b/lib/private/Memcache/NullCache.php
new file mode 100644
index 00000000000..c490ca7e03c
--- /dev/null
+++ b/lib/private/Memcache/NullCache.php
@@ -0,0 +1,72 @@
+<?php
+/**
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@owncloud.com>
+ * @author Robin McCorkell <robin@mccorkell.me.uk>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ * @author Vincent Petry <pvince81@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+class NullCache extends Cache implements \OCP\IMemcache {
+	public function get($key) {
+		return null;
+	}
+
+	public function set($key, $value, $ttl = 0) {
+		return true;
+	}
+
+	public function hasKey($key) {
+		return false;
+	}
+
+	public function remove($key) {
+		return true;
+	}
+
+	public function add($key, $value, $ttl = 0) {
+		return true;
+	}
+
+	public function inc($key, $step = 1) {
+		return true;
+	}
+
+	public function dec($key, $step = 1) {
+		return true;
+	}
+
+	public function cas($key, $old, $new) {
+		return true;
+	}
+
+	public function cad($key, $old) {
+		return true;
+	}
+
+	public function clear($prefix = '') {
+		return true;
+	}
+
+	static public function isAvailable() {
+		return true;
+	}
+}
diff --git a/lib/private/Memcache/Redis.php b/lib/private/Memcache/Redis.php
new file mode 100644
index 00000000000..b3444a2b4e9
--- /dev/null
+++ b/lib/private/Memcache/Redis.php
@@ -0,0 +1,208 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Jörn Friedrich Dreyer <jfd@butonic.de>
+ * @author Lukas Reschke <lukas@owncloud.com>
+ * @author Michael Telatynski <7t3chguy@gmail.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+use OCP\IMemcacheTTL;
+
+class Redis extends Cache implements IMemcacheTTL {
+	/**
+	 * @var \Redis $cache
+	 */
+	private static $cache = null;
+
+	public function __construct($prefix = '') {
+		parent::__construct($prefix);
+		if (is_null(self::$cache)) {
+			// TODO allow configuring a RedisArray, see https://github.com/nicolasff/phpredis/blob/master/arrays.markdown#redis-arrays
+			self::$cache = new \Redis();
+			$config = \OC::$server->getSystemConfig()->getValue('redis', array());
+			if (isset($config['host'])) {
+				$host = $config['host'];
+			} else {
+				$host = '127.0.0.1';
+			}
+			if (isset($config['port'])) {
+				$port = $config['port'];
+			} else {
+				$port = 6379;
+			}
+			if (isset($config['timeout'])) {
+				$timeout = $config['timeout'];
+			} else {
+				$timeout = 0.0; // unlimited
+			}
+
+			self::$cache->connect($host, $port, $timeout);
+			if(isset($config['password']) && $config['password'] !== '') {
+				self::$cache->auth($config['password']);
+			}
+
+			if (isset($config['dbindex'])) {
+				self::$cache->select($config['dbindex']);
+			}
+		}
+	}
+
+	/**
+	 * entries in redis get namespaced to prevent collisions between ownCloud instances and users
+	 */
+	protected function getNameSpace() {
+		return $this->prefix;
+	}
+
+	public function get($key) {
+		$result = self::$cache->get($this->getNamespace() . $key);
+		if ($result === false && !self::$cache->exists($this->getNamespace() . $key)) {
+			return null;
+		} else {
+			return json_decode($result, true);
+		}
+	}
+
+	public function set($key, $value, $ttl = 0) {
+		if ($ttl > 0) {
+			return self::$cache->setex($this->getNamespace() . $key, $ttl, json_encode($value));
+		} else {
+			return self::$cache->set($this->getNamespace() . $key, json_encode($value));
+		}
+	}
+
+	public function hasKey($key) {
+		return self::$cache->exists($this->getNamespace() . $key);
+	}
+
+	public function remove($key) {
+		if (self::$cache->delete($this->getNamespace() . $key)) {
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+	public function clear($prefix = '') {
+		$prefix = $this->getNamespace() . $prefix . '*';
+		$it = null;
+		self::$cache->setOption(\Redis::OPT_SCAN, \Redis::SCAN_RETRY);
+		while ($keys = self::$cache->scan($it, $prefix)) {
+			self::$cache->delete($keys);
+		}
+		return true;
+	}
+
+	/**
+	 * Set a value in the cache if it's not already stored
+	 *
+	 * @param string $key
+	 * @param mixed $value
+	 * @param int $ttl Time To Live in seconds. Defaults to 60*60*24
+	 * @return bool
+	 */
+	public function add($key, $value, $ttl = 0) {
+		// don't encode ints for inc/dec
+		if (!is_int($value)) {
+			$value = json_encode($value);
+		}
+		return self::$cache->setnx($this->getPrefix() . $key, $value);
+	}
+
+	/**
+	 * Increase a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function inc($key, $step = 1) {
+		return self::$cache->incrBy($this->getNamespace() . $key, $step);
+	}
+
+	/**
+	 * Decrease a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function dec($key, $step = 1) {
+		if (!$this->hasKey($key)) {
+			return false;
+		}
+		return self::$cache->decrBy($this->getNamespace() . $key, $step);
+	}
+
+	/**
+	 * Compare and set
+	 *
+	 * @param string $key
+	 * @param mixed $old
+	 * @param mixed $new
+	 * @return bool
+	 */
+	public function cas($key, $old, $new) {
+		if (!is_int($new)) {
+			$new = json_encode($new);
+		}
+		self::$cache->watch($this->getNamespace() . $key);
+		if ($this->get($key) === $old) {
+			$result = self::$cache->multi()
+				->set($this->getNamespace() . $key, $new)
+				->exec();
+			return ($result === false) ? false : true;
+		}
+		self::$cache->unwatch();
+		return false;
+	}
+
+	/**
+	 * Compare and delete
+	 *
+	 * @param string $key
+	 * @param mixed $old
+	 * @return bool
+	 */
+	public function cad($key, $old) {
+		self::$cache->watch($this->getNamespace() . $key);
+		if ($this->get($key) === $old) {
+			$result = self::$cache->multi()
+				->del($this->getNamespace() . $key)
+				->exec();
+			return ($result === false) ? false : true;
+		}
+		self::$cache->unwatch();
+		return false;
+	}
+
+	public function setTTL($key, $ttl) {
+		self::$cache->expire($this->getNamespace() . $key, $ttl);
+	}
+
+	static public function isAvailable() {
+		return extension_loaded('redis')
+		&& version_compare(phpversion('redis'), '2.2.5', '>=');
+	}
+}
+
diff --git a/lib/private/Memcache/XCache.php b/lib/private/Memcache/XCache.php
new file mode 100644
index 00000000000..e80901faadc
--- /dev/null
+++ b/lib/private/Memcache/XCache.php
@@ -0,0 +1,134 @@
+<?php
+/**
+ * @author Andreas Fischer <bantu@owncloud.com>
+ * @author Bart Visscher <bartv@thisnet.nl>
+ * @author Clark Tomlinson <fallen013@gmail.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@owncloud.com>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Memcache;
+
+use OCP\IMemcache;
+
+/**
+ * See http://xcache.lighttpd.net/wiki/XcacheApi for provided constants and
+ * functions etc.
+ */
+class XCache extends Cache implements IMemcache {
+	use CASTrait;
+
+	use CADTrait;
+
+	/**
+	 * entries in XCache gets namespaced to prevent collisions between ownCloud instances and users
+	 */
+	protected function getNameSpace() {
+		return $this->prefix;
+	}
+
+	public function get($key) {
+		return xcache_get($this->getNamespace() . $key);
+	}
+
+	public function set($key, $value, $ttl = 0) {
+		if ($ttl > 0) {
+			return xcache_set($this->getNamespace() . $key, $value, $ttl);
+		} else {
+			return xcache_set($this->getNamespace() . $key, $value);
+		}
+	}
+
+	public function hasKey($key) {
+		return xcache_isset($this->getNamespace() . $key);
+	}
+
+	public function remove($key) {
+		return xcache_unset($this->getNamespace() . $key);
+	}
+
+	public function clear($prefix = '') {
+		if (function_exists('xcache_unset_by_prefix')) {
+			return xcache_unset_by_prefix($this->getNamespace() . $prefix);
+		} else {
+			// Since we can not clear by prefix, we just clear the whole cache.
+			xcache_clear_cache(\XC_TYPE_VAR, 0);
+		}
+		return true;
+	}
+
+	/**
+	 * Set a value in the cache if it's not already stored
+	 *
+	 * @param string $key
+	 * @param mixed $value
+	 * @param int $ttl Time To Live in seconds. Defaults to 60*60*24
+	 * @return bool
+	 */
+	public function add($key, $value, $ttl = 0) {
+		if ($this->hasKey($key)) {
+			return false;
+		} else {
+			return $this->set($key, $value, $ttl);
+		}
+	}
+
+	/**
+	 * Increase a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function inc($key, $step = 1) {
+		return xcache_inc($this->getPrefix() . $key, $step);
+	}
+
+	/**
+	 * Decrease a stored number
+	 *
+	 * @param string $key
+	 * @param int $step
+	 * @return int | bool
+	 */
+	public function dec($key, $step = 1) {
+		return xcache_dec($this->getPrefix() . $key, $step);
+	}
+
+	static public function isAvailable() {
+		if (!extension_loaded('xcache')) {
+			return false;
+		}
+		if (\OC::$CLI && !getenv('XCACHE_TEST')) {
+			return false;
+		}
+		if (!function_exists('xcache_unset_by_prefix') && \OC::$server->getIniWrapper()->getBool('xcache.admin.enable_auth')) {
+			// We do not want to use XCache if we can not clear it without
+			// using the administration function xcache_clear_cache()
+			// AND administration functions are password-protected.
+			return false;
+		}
+		$var_size = \OC::$server->getIniWrapper()->getBytes('xcache.var_size');
+		if (!$var_size) {
+			return false;
+		}
+		return true;
+	}
+}