<?php
/**
 * This file is part of PDepend.
 *
 * PHP Version 5
 *
 * Copyright (c) 2008-2017 Manuel Pichler <mapi@pdepend.org>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *
 *   * Neither the name of Manuel Pichler nor the names of his
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * 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.
 *
 * @copyright 2008-2017 Manuel Pichler. All rights reserved.
 * @license http://www.opensource.org/licenses/bsd-license.php BSD License
 *
 * @since 0.10.0
 */

namespace PDepend\Util\Cache;

/**
 * Base interface for a concrete cache driver.
 *
 * @copyright 2008-2017 Manuel Pichler. All rights reserved.
 * @license http://www.opensource.org/licenses/bsd-license.php BSD License
 *
 * @since 0.10.0
 */
interface CacheDriver
{
    /**
     * The current cache version.
     */
    const VERSION = '@version:a31e9e344aac643e20751f6d915114eb:@';

    /**
     * Sets the type for the next <em>store()</em> or <em>restore()</em> method
     * call. A type is something like a namespace or group for cache entries.
     *
     * Note that the cache type will be reset after each storage method call, so
     * you must invoke right before every call to <em>restore()</em> or
     * <em>store()</em>.
     *
     * @param string $type
     *
     * @return CacheDriver
     */
    public function type($type);

    /**
     * This method will store the given <em>$data</em> under <em>$key</em>. This
     * method can be called with a third parameter that will be used as a
     * verification token, when the a cache entry gets restored. If the stored
     * hash and the supplied hash are not identical, that cache entry will be
     * removed and not returned.
     *
     * @param string $key  The cache key for the given data.
     * @param mixed  $data Any data that should be cached.
     * @param string $hash Optional hash that will be used for verification.
     *
     * @return void
     */
    public function store($key, $data, $hash = null);

    /**
     * This method tries to restore an existing cache entry for the given
     * <em>$key</em>. If a matching entry exists, this method verifies that the
     * given <em>$hash</em> and the the value stored with cache entry are equal.
     * Then it returns the cached entry. Otherwise this method will return
     * <b>NULL</b>.
     *
     * @param string $key  The cache key for the given data.
     * @param string $hash Optional hash that will be used for verification.
     *
     * @return mixed
     */
    public function restore($key, $hash = null);

    /**
     * This method will remove an existing cache entry for the given identifier.
     * It will delete all cache entries where the cache key start with the given
     * <b>$pattern</b>. If no matching entry exists, this method simply does
     * nothing.
     *
     * @param string $pattern The cache key pattern.
     *
     * @return void
     */
    public function remove($pattern);
}
