<?php

/*

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * This software consists of voluntary contributions made by many individuals

 * and is licensed under the LGPL. For more information, see

 * <http://www.doctrine-project.org>.

 */

namespace Doctrine\Common\Cache;

/**

 * Base class for cache driver implementations.

 *

 * @since 2.0

 * @author  Benjamin Eberlei <kontakt@beberlei.de>

 * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>

 * @author  Jonathan Wage <jonwage@gmail.com>

 * @author  Roman Borschel <roman@code-factory.org>

 */

abstract class AbstractCache implements Cache

{

    /** @var string The namespace to prefix all cache ids with */

    private $_namespace = '';

    /**

     * Set the namespace to prefix all cache ids with.

     *

     * @param string $namespace

     * @return void

     */

    public function setNamespace($namespace)

    {

        $this->_namespace = (string) $namespace;

    }

    /**

     * {@inheritdoc}

     */

    public function fetch($id)

    {

        return $this->_doFetch($this->_getNamespacedId($id));

    }

    /**

     * {@inheritdoc}

     */

    public function contains($id)

    {

        return $this->_doContains($this->_getNamespacedId($id));

    }

    /**

     * {@inheritdoc}

     */

    public function save($id, $data, $lifeTime = 0)

    {

        return $this->_doSave($this->_getNamespacedId($id), $data, $lifeTime);

    }

    /**

     * {@inheritdoc}

     */

    public function delete($id)

    {

        $id = $this->_getNamespacedId($id);

        if (strpos($id, '*') !== false) {

            return $this->deleteByRegex('/' . str_replace('*', '.*', $id) . '/');

        }

        return $this->_doDelete($id);

    }

    /**

     * Delete all cache entries.

     *

     * @return array $deleted  Array of the deleted cache ids

     */

    public function deleteAll()

    {

        $ids = $this->getIds();

        foreach ($ids as $id) {

            $this->delete($id);

        }

        return $ids;

    }

    /**

     * Delete cache entries where the id matches a PHP regular expressions

     *

     * @param string $regex

     * @return array $deleted  Array of the deleted cache ids

     */

    public function deleteByRegex($regex)

    {

        $deleted = array();

        $ids = $this->getIds();

        foreach ($ids as $id) {

            if (preg_match($regex, $id)) {

                $this->delete($id);

                $deleted[] = $id;

            }

        }

        return $deleted;

    }

    /**

     * Delete cache entries where the id has the passed prefix

     *

     * @param string $prefix

     * @return array $deleted  Array of the deleted cache ids

     */

    public function deleteByPrefix($prefix)

    {

        $deleted = array();

        $prefix = $this->_getNamespacedId($prefix);

        $ids = $this->getIds();

        foreach ($ids as $id) {

            if (strpos($id, $prefix) === 0) {

                $this->delete($id);

                $deleted[] = $id;

            }

        }

        return $deleted;

    }

    /**

     * Delete cache entries where the id has the passed suffix

     *

     * @param string $suffix

     * @return array $deleted  Array of the deleted cache ids

     */

    public function deleteBySuffix($suffix)

    {

        $deleted = array();

        $ids = $this->getIds();

        foreach ($ids as $id) {

            if (substr($id, -1 * strlen($suffix)) === $suffix) {

                $this->delete($id);

                $deleted[] = $id;

            }

        }

        return $deleted;

    }

    /**

     * Prefix the passed id with the configured namespace value

     *

     * @param string $id  The id to namespace

     * @return string $id The namespaced id

     */

    private function _getNamespacedId($id)

    {

        return $this->_namespace . $id;

    }

    /**

     * Fetches an entry from the cache.

     *

     * @param string $id cache id The id of the cache entry to fetch.

     * @return string The cached data or FALSE, if no cache entry exists for the given id.

     */

    abstract protected function _doFetch($id);

    /**

     * Test if an entry exists in the cache.

     *

     * @param string $id cache id The cache id of the entry to check for.

     * @return boolean TRUE if a cache entry exists for the given cache id, FALSE otherwise.

     */

    abstract protected function _doContains($id);

    /**

     * Puts data into the cache.

     *

     * @param string $id The cache id.

     * @param string $data The cache entry/data.

     * @param int $lifeTime The lifetime. If != false, sets a specific lifetime for this cache entry (null => infinite lifeTime).

     * @return boolean TRUE if the entry was successfully stored in the cache, FALSE otherwise.

     */

    abstract protected function _doSave($id, $data, $lifeTime = false);

    /**

     * Deletes a cache entry.

     *

     * @param string $id cache id

     * @return boolean TRUE if the cache entry was successfully deleted, FALSE otherwise.

     */

    abstract protected function _doDelete($id);

    /**

     * Get an array of all the cache ids stored

     *

     * @return array $ids

     */

    abstract public function getIds();

}