Adding upstream version 2.11.4.upstream/2.11.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 762 insertions, 0 deletions

diff --git a/library/vendor/Zend/Cache/Core.php b/library/vendor/Zend/Cache/Core.php
new file mode 100644
index 0000000..833f247
--- /dev/null
+++ b/library/vendor/Zend/Cache/Core.php
@@ -0,0 +1,762 @@
+<?php
+/**
+ * Zend Framework
+ *
+ * LICENSE
+ *
+ * This source file is subject to the new BSD license that is bundled
+ * with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * http://framework.zend.com/license/new-bsd
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@zend.com so we can send you a copy immediately.
+ *
+ * @category   Zend
+ * @package    Zend_Cache
+ * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ * @version    $Id$
+ */
+
+
+/**
+ * @package    Zend_Cache
+ * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ */
+class Zend_Cache_Core
+{
+    /**
+     * Messages
+     */
+    const BACKEND_NOT_SUPPORTS_TAG = 'tags are not supported by the current backend';
+    const BACKEND_NOT_IMPLEMENTS_EXTENDED_IF = 'Current backend doesn\'t implement the Zend_Cache_Backend_ExtendedInterface, so this method is not available';
+
+    /**
+     * Backend Object
+     *
+     * @var Zend_Cache_Backend_Interface $_backend
+     */
+    protected $_backend = null;
+
+    /**
+     * Available options
+     *
+     * ====> (boolean) write_control :
+     * - Enable / disable write control (the cache is read just after writing to detect corrupt entries)
+     * - Enable write control will lightly slow the cache writing but not the cache reading
+     * Write control can detect some corrupt cache files but maybe it's not a perfect control
+     *
+     * ====> (boolean) caching :
+     * - Enable / disable caching
+     * (can be very useful for the debug of cached scripts)
+     *
+     * =====> (string) cache_id_prefix :
+     * - prefix for cache ids (namespace)
+     *
+     * ====> (boolean) automatic_serialization :
+     * - Enable / disable automatic serialization
+     * - It can be used to save directly datas which aren't strings (but it's slower)
+     *
+     * ====> (int) automatic_cleaning_factor :
+     * - Disable / Tune the automatic cleaning process
+     * - The automatic cleaning process destroy too old (for the given life time)
+     *   cache files when a new cache file is written :
+     *     0               => no automatic cache cleaning
+     *     1               => systematic cache cleaning
+     *     x (integer) > 1 => automatic cleaning randomly 1 times on x cache write
+     *
+     * ====> (int) lifetime :
+     * - Cache lifetime (in seconds)
+     * - If null, the cache is valid forever.
+     *
+     * ====> (boolean) logging :
+     * - If set to true, logging is activated (but the system is slower)
+     *
+     * ====> (boolean) ignore_user_abort
+     * - If set to true, the core will set the ignore_user_abort PHP flag inside the
+     *   save() method to avoid cache corruptions in some cases (default false)
+     *
+     * @var array $_options available options
+     */
+    protected $_options = array(
+        'write_control'             => true,
+        'caching'                   => true,
+        'cache_id_prefix'           => null,
+        'automatic_serialization'   => false,
+        'automatic_cleaning_factor' => 10,
+        'lifetime'                  => 3600,
+        'logging'                   => false,
+        'logger'                    => null,
+        'ignore_user_abort'         => false
+    );
+
+    /**
+     * Array of options which have to be transfered to backend
+     *
+     * @var array $_directivesList
+     */
+    protected static $_directivesList = array('lifetime', 'logging', 'logger');
+
+    /**
+     * Not used for the core, just a sort a hint to get a common setOption() method (for the core and for frontends)
+     *
+     * @var array $_specificOptions
+     */
+    protected $_specificOptions = array();
+
+    /**
+     * Last used cache id
+     *
+     * @var string $_lastId
+     */
+    private $_lastId = null;
+
+    /**
+     * True if the backend implements Zend_Cache_Backend_ExtendedInterface
+     *
+     * @var boolean $_extendedBackend
+     */
+    protected $_extendedBackend = false;
+
+    /**
+     * Array of capabilities of the backend (only if it implements Zend_Cache_Backend_ExtendedInterface)
+     *
+     * @var array
+     */
+    protected $_backendCapabilities = array();
+
+    /**
+     * Constructor
+     *
+     * @param  array|Zend_Config $options Associative array of options or Zend_Config instance
+     * @throws Zend_Cache_Exception
+     * @return void
+     */
+    public function __construct($options = array())
+    {
+        if ($options instanceof Zend_Config) {
+            $options = $options->toArray();
+        }
+        if (!is_array($options)) {
+            Zend_Cache::throwException("Options passed were not an array"
+            . " or Zend_Config instance.");
+        }
+        foreach ($options as $name => $value) {
+            $this->setOption($name, $value);
+        }
+        $this->_loggerSanity();
+    }
+
+    /**
+     * Set options using an instance of type Zend_Config
+     *
+     * @param Zend_Config $config
+     * @return Zend_Cache_Core
+     */
+    public function setConfig(Zend_Config $config)
+    {
+        $options = $config->toArray();
+        foreach ($options as $name => $value) {
+            $this->setOption($name, $value);
+        }
+        return $this;
+    }
+
+    /**
+     * Set the backend
+     *
+     * @param  Zend_Cache_Backend $backendObject
+     * @throws Zend_Cache_Exception
+     * @return void
+     */
+    public function setBackend(Zend_Cache_Backend $backendObject)
+    {
+        $this->_backend= $backendObject;
+        // some options (listed in $_directivesList) have to be given
+        // to the backend too (even if they are not "backend specific")
+        $directives = array();
+        foreach (Zend_Cache_Core::$_directivesList as $directive) {
+            $directives[$directive] = $this->_options[$directive];
+        }
+        $this->_backend->setDirectives($directives);
+        if (in_array('Zend_Cache_Backend_ExtendedInterface', class_implements($this->_backend))) {
+            $this->_extendedBackend = true;
+            $this->_backendCapabilities = $this->_backend->getCapabilities();
+        }
+
+    }
+
+    /**
+     * Returns the backend
+     *
+     * @return Zend_Cache_Backend backend object
+     */
+    public function getBackend()
+    {
+        return $this->_backend;
+    }
+
+    /**
+     * Public frontend to set an option
+     *
+     * There is an additional validation (relatively to the protected _setOption method)
+     *
+     * @param  string $name  Name of the option
+     * @param  mixed  $value Value of the option
+     * @throws Zend_Cache_Exception
+     * @return void
+     */
+    public function setOption($name, $value)
+    {
+        if (!is_string($name)) {
+            Zend_Cache::throwException("Incorrect option name!");
+        }
+        $name = strtolower($name);
+        if (array_key_exists($name, $this->_options)) {
+            // This is a Core option
+            $this->_setOption($name, $value);
+            return;
+        }
+        if (array_key_exists($name, $this->_specificOptions)) {
+            // This a specic option of this frontend
+            $this->_specificOptions[$name] = $value;
+            return;
+        }
+    }
+
+    /**
+     * Public frontend to get an option value
+     *
+     * @param  string $name  Name of the option
+     * @throws Zend_Cache_Exception
+     * @return mixed option value
+     */
+    public function getOption($name)
+    {
+        $name = strtolower($name);
+
+        if (array_key_exists($name, $this->_options)) {
+            // This is a Core option
+            return $this->_options[$name];
+        }
+
+        if (array_key_exists($name, $this->_specificOptions)) {
+            // This a specic option of this frontend
+            return $this->_specificOptions[$name];
+        }
+
+        Zend_Cache::throwException("Incorrect option name : $name");
+    }
+
+    /**
+     * Set an option
+     *
+     * @param  string $name  Name of the option
+     * @param  mixed  $value Value of the option
+     * @throws Zend_Cache_Exception
+     * @return void
+     */
+    private function _setOption($name, $value)
+    {
+        if (!is_string($name) || !array_key_exists($name, $this->_options)) {
+            Zend_Cache::throwException("Incorrect option name : $name");
+        }
+        if ($name == 'lifetime' && empty($value)) {
+            $value = null;
+        }
+        $this->_options[$name] = $value;
+    }
+
+    /**
+     * Force a new lifetime
+     *
+     * The new value is set for the core/frontend but for the backend too (directive)
+     *
+     * @param  int $newLifetime New lifetime (in seconds)
+     * @return void
+     */
+    public function setLifetime($newLifetime)
+    {
+        $this->_options['lifetime'] = $newLifetime;
+        $this->_backend->setDirectives(array(
+            'lifetime' => $newLifetime
+        ));
+    }
+
+    /**
+     * Test if a cache is available for the given id and (if yes) return it (false else)
+     *
+     * @param  string  $id                     Cache id
+     * @param  boolean $doNotTestCacheValidity If set to true, the cache validity won't be tested
+     * @param  boolean $doNotUnserialize       Do not serialize (even if automatic_serialization is true) => for internal use
+     * @return mixed|false Cached datas
+     */
+    public function load($id, $doNotTestCacheValidity = false, $doNotUnserialize = false)
+    {
+        if (!$this->_options['caching']) {
+            return false;
+        }
+        $id = $this->_id($id); // cache id may need prefix
+        $this->_lastId = $id;
+        $this->_validateIdOrTag($id);
+
+        $this->_log("Zend_Cache_Core: load item '{$id}'", 7);
+        $data = $this->_backend->load($id, $doNotTestCacheValidity);
+        if ($data===false) {
+            // no cache available
+            return false;
+        }
+        if ((!$doNotUnserialize) && $this->_options['automatic_serialization']) {
+            // we need to unserialize before sending the result
+            return unserialize($data);
+        }
+        return $data;
+    }
+
+    /**
+     * Test if a cache is available for the given id
+     *
+     * @param  string $id Cache id
+     * @return int|false Last modified time of cache entry if it is available, false otherwise
+     */
+    public function test($id)
+    {
+        if (!$this->_options['caching']) {
+            return false;
+        }
+        $id = $this->_id($id); // cache id may need prefix
+        $this->_validateIdOrTag($id);
+        $this->_lastId = $id;
+
+        $this->_log("Zend_Cache_Core: test item '{$id}'", 7);
+        return $this->_backend->test($id);
+    }
+
+    /**
+     * Save some data in a cache
+     *
+     * @param  mixed $data           Data to put in cache (can be another type than string if automatic_serialization is on)
+     * @param  string $id             Cache id (if not set, the last cache id will be used)
+     * @param  array $tags           Cache tags
+     * @param  int $specificLifetime If != false, set a specific lifetime for this cache record (null => infinite lifetime)
+     * @param  int   $priority         integer between 0 (very low priority) and 10 (maximum priority) used by some particular backends
+     * @throws Zend_Cache_Exception
+     * @return boolean True if no problem
+     */
+    public function save($data, $id = null, $tags = array(), $specificLifetime = false, $priority = 8)
+    {
+        if (!$this->_options['caching']) {
+            return true;
+        }
+        if ($id === null) {
+            $id = $this->_lastId;
+        } else {
+            $id = $this->_id($id);
+        }
+        $this->_validateIdOrTag($id);
+        $this->_validateTagsArray($tags);
+        if ($this->_options['automatic_serialization']) {
+            // we need to serialize datas before storing them
+            $data = serialize($data);
+        } else {
+            if (!is_string($data)) {
+                Zend_Cache::throwException("Datas must be string or set automatic_serialization = true");
+            }
+        }
+
+        // automatic cleaning
+        if ($this->_options['automatic_cleaning_factor'] > 0) {
+            $rand = rand(1, $this->_options['automatic_cleaning_factor']);
+            if ($rand==1) {
+                //  new way                 || deprecated way
+                if ($this->_extendedBackend || method_exists($this->_backend, 'isAutomaticCleaningAvailable')) {
+                    $this->_log("Zend_Cache_Core::save(): automatic cleaning running", 7);
+                    $this->clean(Zend_Cache::CLEANING_MODE_OLD);
+                } else {
+                    $this->_log("Zend_Cache_Core::save(): automatic cleaning is not available/necessary with current backend", 4);
+                }
+            }
+        }
+
+        $this->_log("Zend_Cache_Core: save item '{$id}'", 7);
+        if ($this->_options['ignore_user_abort']) {
+            $abort = ignore_user_abort(true);
+        }
+        if (($this->_extendedBackend) && ($this->_backendCapabilities['priority'])) {
+            $result = $this->_backend->save($data, $id, $tags, $specificLifetime, $priority);
+        } else {
+            $result = $this->_backend->save($data, $id, $tags, $specificLifetime);
+        }
+        if ($this->_options['ignore_user_abort']) {
+            ignore_user_abort($abort);
+        }
+
+        if (!$result) {
+            // maybe the cache is corrupted, so we remove it !
+            $this->_log("Zend_Cache_Core::save(): failed to save item '{$id}' -> removing it", 4);
+            $this->_backend->remove($id);
+            return false;
+        }
+
+        if ($this->_options['write_control']) {
+            $data2 = $this->_backend->load($id, true);
+            if ($data!=$data2) {
+                $this->_log("Zend_Cache_Core::save(): write control of item '{$id}' failed -> removing it", 4);
+                $this->_backend->remove($id);
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Remove a cache
+     *
+     * @param  string $id Cache id to remove
+     * @return boolean True if ok
+     */
+    public function remove($id)
+    {
+        if (!$this->_options['caching']) {
+            return true;
+        }
+        $id = $this->_id($id); // cache id may need prefix
+        $this->_validateIdOrTag($id);
+
+        $this->_log("Zend_Cache_Core: remove item '{$id}'", 7);
+        return $this->_backend->remove($id);
+    }
+
+    /**
+     * Clean cache entries
+     *
+     * Available modes are :
+     * 'all' (default)  => remove all cache entries ($tags is not used)
+     * 'old'            => remove too old cache entries ($tags is not used)
+     * 'matchingTag'    => remove cache entries matching all given tags
+     *                     ($tags can be an array of strings or a single string)
+     * 'notMatchingTag' => remove cache entries not matching one of the given tags
+     *                     ($tags can be an array of strings or a single string)
+     * 'matchingAnyTag' => remove cache entries matching any given tags
+     *                     ($tags can be an array of strings or a single string)
+     *
+     * @param  string       $mode
+     * @param  array|string $tags
+     * @throws Zend_Cache_Exception
+     * @return boolean True if ok
+     */
+    public function clean($mode = 'all', $tags = array())
+    {
+        if (!$this->_options['caching']) {
+            return true;
+        }
+        if (!in_array($mode, array(Zend_Cache::CLEANING_MODE_ALL,
+                                   Zend_Cache::CLEANING_MODE_OLD,
+                                   Zend_Cache::CLEANING_MODE_MATCHING_TAG,
+                                   Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG,
+                                   Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG))) {
+            Zend_Cache::throwException('Invalid cleaning mode');
+        }
+        $this->_validateTagsArray($tags);
+
+        return $this->_backend->clean($mode, $tags);
+    }
+
+    /**
+     * Return an array of stored cache ids which match given tags
+     *
+     * In case of multiple tags, a logical AND is made between tags
+     *
+     * @param array $tags array of tags
+     * @return array array of matching cache ids (string)
+     */
+    public function getIdsMatchingTags($tags = array())
+    {
+        if (!$this->_extendedBackend) {
+            Zend_Cache::throwException(self::BACKEND_NOT_IMPLEMENTS_EXTENDED_IF);
+        }
+        if (!($this->_backendCapabilities['tags'])) {
+            Zend_Cache::throwException(self::BACKEND_NOT_SUPPORTS_TAG);
+        }
+
+        $ids = $this->_backend->getIdsMatchingTags($tags);
+
+        // we need to remove cache_id_prefix from ids (see #ZF-6178, #ZF-7600)
+        if (isset($this->_options['cache_id_prefix']) && $this->_options['cache_id_prefix'] !== '') {
+            $prefix    = & $this->_options['cache_id_prefix'];
+            $prefixLen = strlen($prefix);
+            foreach ($ids as &$id) {
+                if (strpos($id, $prefix) === 0) {
+                    $id = substr($id, $prefixLen);
+                }
+            }
+        }
+
+        return $ids;
+    }
+
+    /**
+     * Return an array of stored cache ids which don't match given tags
+     *
+     * In case of multiple tags, a logical OR is made between tags
+     *
+     * @param array $tags array of tags
+     * @return array array of not matching cache ids (string)
+     */
+    public function getIdsNotMatchingTags($tags = array())
+    {
+        if (!$this->_extendedBackend) {
+            Zend_Cache::throwException(self::BACKEND_NOT_IMPLEMENTS_EXTENDED_IF);
+        }
+        if (!($this->_backendCapabilities['tags'])) {
+            Zend_Cache::throwException(self::BACKEND_NOT_SUPPORTS_TAG);
+        }
+
+        $ids = $this->_backend->getIdsNotMatchingTags($tags);
+
+        // we need to remove cache_id_prefix from ids (see #ZF-6178, #ZF-7600)
+        if (isset($this->_options['cache_id_prefix']) && $this->_options['cache_id_prefix'] !== '') {
+            $prefix    = & $this->_options['cache_id_prefix'];
+            $prefixLen = strlen($prefix);
+            foreach ($ids as &$id) {
+                if (strpos($id, $prefix) === 0) {
+                    $id = substr($id, $prefixLen);
+                }
+            }
+        }
+
+        return $ids;
+    }
+
+    /**
+     * Return an array of stored cache ids which match any given tags
+     *
+     * In case of multiple tags, a logical OR is made between tags
+     *
+     * @param array $tags array of tags
+     * @return array array of matching any cache ids (string)
+     */
+    public function getIdsMatchingAnyTags($tags = array())
+    {
+        if (!$this->_extendedBackend) {
+            Zend_Cache::throwException(self::BACKEND_NOT_IMPLEMENTS_EXTENDED_IF);
+        }
+        if (!($this->_backendCapabilities['tags'])) {
+            Zend_Cache::throwException(self::BACKEND_NOT_SUPPORTS_TAG);
+        }
+
+        $ids = $this->_backend->getIdsMatchingAnyTags($tags);
+
+        // we need to remove cache_id_prefix from ids (see #ZF-6178, #ZF-7600)
+        if (isset($this->_options['cache_id_prefix']) && $this->_options['cache_id_prefix'] !== '') {
+            $prefix    = & $this->_options['cache_id_prefix'];
+            $prefixLen = strlen($prefix);
+            foreach ($ids as &$id) {
+                if (strpos($id, $prefix) === 0) {
+                    $id = substr($id, $prefixLen);
+                }
+            }
+        }
+
+        return $ids;
+    }
+
+    /**
+     * Return an array of stored cache ids
+     *
+     * @return array array of stored cache ids (string)
+     */
+    public function getIds()
+    {
+        if (!$this->_extendedBackend) {
+            Zend_Cache::throwException(self::BACKEND_NOT_IMPLEMENTS_EXTENDED_IF);
+        }
+
+        $ids = $this->_backend->getIds();
+
+        // we need to remove cache_id_prefix from ids (see #ZF-6178, #ZF-7600)
+        if (isset($this->_options['cache_id_prefix']) && $this->_options['cache_id_prefix'] !== '') {
+            $prefix    = & $this->_options['cache_id_prefix'];
+            $prefixLen = strlen($prefix);
+            foreach ($ids as &$id) {
+                if (strpos($id, $prefix) === 0) {
+                    $id = substr($id, $prefixLen);
+                }
+            }
+        }
+
+        return $ids;
+    }
+
+    /**
+     * Return an array of stored tags
+     *
+     * @return array array of stored tags (string)
+     */
+    public function getTags()
+    {
+        if (!$this->_extendedBackend) {
+            Zend_Cache::throwException(self::BACKEND_NOT_IMPLEMENTS_EXTENDED_IF);
+        }
+        if (!($this->_backendCapabilities['tags'])) {
+            Zend_Cache::throwException(self::BACKEND_NOT_SUPPORTS_TAG);
+        }
+        return $this->_backend->getTags();
+    }
+
+    /**
+     * Return the filling percentage of the backend storage
+     *
+     * @return int integer between 0 and 100
+     */
+    public function getFillingPercentage()
+    {
+        if (!$this->_extendedBackend) {
+            Zend_Cache::throwException(self::BACKEND_NOT_IMPLEMENTS_EXTENDED_IF);
+        }
+        return $this->_backend->getFillingPercentage();
+    }
+
+    /**
+     * Return an array of metadatas for the given cache id
+     *
+     * The array will include these keys :
+     * - expire : the expire timestamp
+     * - tags : a string array of tags
+     * - mtime : timestamp of last modification time
+     *
+     * @param string $id cache id
+     * @return array array of metadatas (false if the cache id is not found)
+     */
+    public function getMetadatas($id)
+    {
+        if (!$this->_extendedBackend) {
+            Zend_Cache::throwException(self::BACKEND_NOT_IMPLEMENTS_EXTENDED_IF);
+        }
+        $id = $this->_id($id); // cache id may need prefix
+        return $this->_backend->getMetadatas($id);
+    }
+
+    /**
+     * Give (if possible) an extra lifetime to the given cache id
+     *
+     * @param string $id cache id
+     * @param int $extraLifetime
+     * @return boolean true if ok
+     */
+    public function touch($id, $extraLifetime)
+    {
+        if (!$this->_extendedBackend) {
+            Zend_Cache::throwException(self::BACKEND_NOT_IMPLEMENTS_EXTENDED_IF);
+        }
+        $id = $this->_id($id); // cache id may need prefix
+
+        $this->_log("Zend_Cache_Core: touch item '{$id}'", 7);
+        return $this->_backend->touch($id, $extraLifetime);
+    }
+
+    /**
+     * Validate a cache id or a tag (security, reliable filenames, reserved prefixes...)
+     *
+     * Throw an exception if a problem is found
+     *
+     * @param  string $string Cache id or tag
+     * @throws Zend_Cache_Exception
+     * @return void
+     */
+    protected function _validateIdOrTag($string)
+    {
+        if (!is_string($string)) {
+            Zend_Cache::throwException('Invalid id or tag : must be a string');
+        }
+        if (substr($string, 0, 9) == 'internal-') {
+            Zend_Cache::throwException('"internal-*" ids or tags are reserved');
+        }
+        if (!preg_match('~^[a-zA-Z0-9_]+$~D', $string)) {
+            Zend_Cache::throwException("Invalid id or tag '$string' : must use only [a-zA-Z0-9_]");
+        }
+    }
+
+    /**
+     * Validate a tags array (security, reliable filenames, reserved prefixes...)
+     *
+     * Throw an exception if a problem is found
+     *
+     * @param  array $tags Array of tags
+     * @throws Zend_Cache_Exception
+     * @return void
+     */
+    protected function _validateTagsArray($tags)
+    {
+        if (!is_array($tags)) {
+            Zend_Cache::throwException('Invalid tags array : must be an array');
+        }
+        foreach($tags as $tag) {
+            $this->_validateIdOrTag($tag);
+        }
+        reset($tags);
+    }
+
+    /**
+     * Make sure if we enable logging that the Zend_Log class
+     * is available.
+     * Create a default log object if none is set.
+     *
+     * @throws Zend_Cache_Exception
+     * @return void
+     */
+    protected function _loggerSanity()
+    {
+        if (!isset($this->_options['logging']) || !$this->_options['logging']) {
+            return;
+        }
+
+        if (isset($this->_options['logger']) && $this->_options['logger'] instanceof Zend_Log) {
+            return;
+        }
+
+        // Create a default logger to the standard output stream
+        $logger = new Zend_Log(new Zend_Log_Writer_Stream('php://output'));
+        $logger->addFilter(new Zend_Log_Filter_Priority(Zend_Log::WARN, '<='));
+        $this->_options['logger'] = $logger;
+    }
+
+    /**
+     * Log a message at the WARN (4) priority.
+     *
+     * @param string $message
+     * @throws Zend_Cache_Exception
+     * @return void
+     */
+    protected function _log($message, $priority = 4)
+    {
+        if (!$this->_options['logging']) {
+            return;
+        }
+        if (!(isset($this->_options['logger']) || $this->_options['logger'] instanceof Zend_Log)) {
+            Zend_Cache::throwException('Logging is enabled but logger is not set');
+        }
+        $logger = $this->_options['logger'];
+        $logger->log($message, $priority);
+    }
+
+    /**
+     * Make and return a cache id
+     *
+     * Checks 'cache_id_prefix' and returns new id with prefix or simply the id if null
+     *
+     * @param  string $id Cache id
+     * @return string Cache id (with or without prefix)
+     */
+    protected function _id($id)
+    {
+        if (($id !== null) && isset($this->_options['cache_id_prefix'])) {
+            return $this->_options['cache_id_prefix'] . $id; // return with prefix
+        }
+        return $id; // no prefix, just return the $id passed
+    }
+
+}