/src/PHPCR/Util/UUIDHelper.php

<?php

/**
 * This file is part of the PHPCR API and was originally ported from the Java
 * JCR API to PHP by Karsten Dambekalns for the FLOW3 project.
 *
 * Copyright 2008-2011 Karsten Dambekalns <karsten@typo3.org>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @license http://www.apache.org/licenses/LICENSE-2.0 Apache Software License 2.0
 * @link http://phpcr.github.com/
*/

namespace PHPCR\Util;

/**
 * static helper functions to deal with UUID's
 */
class UUIDHelper
{
    /**
     * Checks if the string could be a uuid.
     *
     * @param  string  $id Possible uuid
     * @return boolean True if the test was passed, else false.
     */
    public static function isUUID($id)
    {
        // UUID is HEX_CHAR{8}-HEX_CHAR{4}-HEX_CHAR{4}-HEX_CHAR{4}-HEX_CHAR{12}
        if (1 === preg_match('/^[[:xdigit:]]{8}-[[:xdigit:]]{4}-[[:xdigit:]]{4}-[[:xdigit:]]{4}-[[:xdigit:]]{12}$/', $id)) {
            return true;
        }

        return false;
    }

    /**
     * Generates a UUID.
     *
     * @return string
     */
    public static function generateUUID()
    {
        return sprintf( '%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
            // 32 bits for "time_low"
            mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ),

            // 16 bits for "time_mid"
            mt_rand( 0, 0xffff ),

            // 16 bits for "time_hi_and_version",
            // four most significant bits holds version number 4
            mt_rand( 0, 0x0fff ) | 0x4000,

            // 16 bits, 8 bits for "clk_seq_hi_res",
            // 8 bits for "clk_seq_low",
            // two most significant bits holds zero and one for variant DCE1.1
            mt_rand( 0, 0x3fff ) | 0x8000,

            // 48 bits for "node"
            mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff )
        );
    }
}