<?php
/**
 * php-token-stream
 *
 * Copyright (c) 2009-2012, Sebastian Bergmann <sb@sebastian-bergmann.de>.
 * 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 Sebastian Bergmann 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.
 *
 * @package   PHP_TokenStream
 * @author    Sebastian Bergmann <sb@sebastian-bergmann.de>
 * @copyright 2009-2012 Sebastian Bergmann <sb@sebastian-bergmann.de>
 * @license   http://www.opensource.org/licenses/BSD-3-Clause  The BSD 3-Clause License
 * @since     File available since Release 1.0.0
 */

/**
 * A caching factory for token stream objects.
 *
 * @author    Sebastian Bergmann <sb@sebastian-bergmann.de>
 * @copyright 2009-2012 Sebastian Bergmann <sb@sebastian-bergmann.de>
 * @license   http://www.opensource.org/licenses/BSD-3-Clause  The BSD 3-Clause License
 * @version   Release: 1.1.5
 * @link      http://github.com/sebastianbergmann/php-token-stream/tree
 * @since     Class available since Release 1.0.0
 */
class PHP_Token_Stream_CachingFactory
{
    /**
     * @var array
     */
    protected static $cache = array();

    /**
     * @param  string $filename
     * @return PHP_Token_Stream
     */
    public static function get($filename)
    {
        if (!isset(self::$cache[$filename])) {
            self::$cache[$filename] = new PHP_Token_Stream($filename);
        }

        return self::$cache[$filename];
    }

    /**
     * @param string $filename
     */
    public static function clear($filename = NULL)
    {
        if (is_string($filename)) {
            unset(self::$cache[$filename]);
        } else {
            self::$cache = array();
        }
    }
}
