<?php

/**

* CakePHP(tm) : Rapid Development Framework (https://cakephp.org)

* Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)

*

* Licensed under The MIT License

* For full copyright and license information, please see the LICENSE.txt

* Redistributions of files must retain the above copyright notice.

*

* @copyright Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)

* @link https://cakephp.org CakePHP(tm) Project

* @since 3.5.4

* @license https://opensource.org/licenses/mit-license.php MIT License

*/

namespace Cake\Cache\Engine;

use APCuIterator;

use Cake\Cache\CacheEngine;

/**

* APCu storage engine for cache

*/

class ApcuEngine extends CacheEngine

{

/**

* Contains the compiled group names

* (prefixed with the global configuration prefix)

*

* @var string[]

*/

protected $_compiledGroupNames = [];

/**

* Initialize the Cache Engine

*

* Called automatically by the cache frontend

*

* @param array $config array of setting for the engine

* @return bool True if the engine has been successfully initialized, false if not

*/

public function init(array $config = [])

{

if (!extension_loaded('apcu')) {

return false;

}

return parent::init($config);

}

/**

* Write data for key into cache

*

* @param string $key Identifier for the data

* @param mixed $value Data to be cached

* @return bool True if the data was successfully cached, false on failure

* @link https://secure.php.net/manual/en/function.apcu-store.php

*/

public function write($key, $value)

{

$key = $this->_key($key);

$duration = $this->_config['duration'];

return apcu_store($key, $value, $duration);

}

/**

* Read a key from the cache

*

* @param string $key Identifier for the data

* @return mixed The cached data, or false if the data doesn't exist,

* has expired, or if there was an error fetching it

* @link https://secure.php.net/manual/en/function.apcu-fetch.php

*/

public function read($key)

{

$key = $this->_key($key);

return apcu_fetch($key);

}

/**

* Increments the value of an integer cached key

*

* @param string $key Identifier for the data

* @param int $offset How much to increment

* @return bool|int New incremented value, false otherwise

* @link https://secure.php.net/manual/en/function.apcu-inc.php

*/

public function increment($key, $offset = 1)

{

$key = $this->_key($key);

return apcu_inc($key, $offset);

}

/**

* Decrements the value of an integer cached key

*

* @param string $key Identifier for the data

* @param int $offset How much to subtract

* @return bool|int New decremented value, false otherwise

* @link https://secure.php.net/manual/en/function.apcu-dec.php

*/

public function decrement($key, $offset = 1)

{

$key = $this->_key($key);

return apcu_dec($key, $offset);

}

/**

* Delete a key from the cache

*

* @param string $key Identifier for the data

* @return bool True if the value was successfully deleted, false if it didn't exist or couldn't be removed

* @link https://secure.php.net/manual/en/function.apcu-delete.php

*/

public function delete($key)

{

$key = $this->_key($key);

return apcu_delete($key);

}

/**

* Delete all keys from the cache. This will clear every cache config using APC.

*

* @param bool $check If true, nothing will be cleared, as entries are removed

* from APC as they expired. This flag is really only used by FileEngine.

* @return bool True Returns true.

* @link https://secure.php.net/manual/en/function.apcu-cache-info.php

* @link https://secure.php.net/manual/en/function.apcu-delete.php

*/

public function clear($check)

{

if ($check) {

return true;

}

if (class_exists('APCuIterator', false)) {

$iterator = new APCuIterator(

'/^' . preg_quote($this->_config['prefix'], '/') . '/',

APC_ITER_NONE

);

apcu_delete($iterator);

return true;

}

$cache = apcu_cache_info(); // Raises warning by itself already

foreach ($cache['cache_list'] as $key) {

if (strpos($key['info'], $this->_config['prefix']) === 0) {

apcu_delete($key['info']);

}

}

return true;

}

/**

* Write data for key into cache if it doesn't exist already.

* If it already exists, it fails and returns false.

*

* @param string $key Identifier for the data.

* @param mixed $value Data to be cached.

* @return bool True if the data was successfully cached, false on failure.

* @link https://secure.php.net/manual/en/function.apcu-add.php

*/

public function add($key, $value)

{

$key = $this->_key($key);

$duration = $this->_config['duration'];

return apcu_add($key, $value, $duration);

}

/**

* Returns the `group value` for each of the configured groups

* If the group initial value was not found, then it initializes

* the group accordingly.

*

* @return array

* @link https://secure.php.net/manual/en/function.apcu-fetch.php

* @link https://secure.php.net/manual/en/function.apcu-store.php

*/

public function groups()

{

if (empty($this->_compiledGroupNames)) {

foreach ($this->_config['groups'] as $group) {

$this->_compiledGroupNames[] = $this->_config['prefix'] . $group;

}

}

$success = false;

$groups = apcu_fetch($this->_compiledGroupNames, $success);

if ($success && count($groups) !== count($this->_config['groups'])) {

foreach ($this->_compiledGroupNames as $group) {

if (!isset($groups[$group])) {

$value = 1;

if (apcu_store($group, $value) === false) {

$this->warning(

sprintf('Failed to store key "%s" with value "%s" into APCu cache.', $group, $value)

);

}

$groups[$group] = $value;

}

}

ksort($groups);

}

$result = [];

$groups = array_values($groups);

foreach ($this->_config['groups'] as $i => $group) {

$result[] = $group . $groups[$i];

}

return $result;

}

/**

* Increments the group value to simulate deletion of all keys under a group

* old values will remain in storage until they expire.

*

* @param string $group The group to clear.

* @return bool success

* @link https://secure.php.net/manual/en/function.apcu-inc.php

*/

public function clearGroup($group)

{

$success = false;

apcu_inc($this->_config['prefix'] . $group, 1, $success);

return $success;

}

}