owncloud/core

<?php
/**
 * @author Joas Schilling <coding@schilljs.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @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 = [];

    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}
     */
    public static function isAvailable() {
        return true;
    }
}