/phpuuid.php

<?php

/*

 *   phpUUID - pure PHP UUID implementation

 *   Copyright (C) 2011 Daniel J. Lauk

 *

 *   This program is free software: you can redistribute it and/or modify

 *   it under the terms of the GNU General Public License as published by

 *   the Free Software Foundation, either version 3 of the License, or

 *   (at your option) any later version.

 *

 *   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 General Public License for more details.

 *

 *   You should have received a copy of the GNU General Public License

 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */





/**

 * This file contains the UUID class.

 */





/**

 * A simple UUID class.

 *

 * The class is based on the information in RFC 4122.  There is one notable

 * difference though, which is the 'node' field:

 * According to the RFC the node field is 48 bits long (6 octets).  We split

 * it up into a high (16 bits) and low (32 bits) part, so that 32-bit

 * machines can easily deal with it.

 *

 * @see http://tools.ietf.org/html/rfc4122

 */

class UUID {



    protected $timeLow;

    protected $timeMid;

    protected $timeHighAndVersion;

    protected $clockSeqHighAndReserved;

    protected $clockSeqLow;

    protected $nodeHigh;

    protected $nodeLow;



    /**

     * Create a UUID object from a string.

     *

     * If the string is not in the correct format (e.g.

     * '6ba7b810-9dad-11d1-80b4-00c04fd430c8'), an `InvalidArgumentException`

     * will be thrown.

     *

     * @param string $str The UUID string

     * @return UUID The UUID object

     */

    public static function fromString($str) {

        $matches = null;

        $count = preg_match('/^([0-9a-f]{8})-([0-9a-f]{4})-([0-9a-f]{4})-([0-9a-f]{2})([0-9a-f]{2})-([0-9a-f]{4})([0-9a-f]{8})$/i', $str, $matches);

        if ($count === 0) throw new InvalidArgumentException(

            'Not a valid UUID: ' . $str);

        $i = 1;

        $uuid = new UUID();

        $uuid->timeLow = UUID::hexToInt($matches[$i++]);

        $uuid->timeMid = UUID::hexToInt($matches[$i++]);

        $uuid->timeHighAndVersion = UUID::hexToInt($matches[$i++]);

        $uuid->clockSeqHighAndReserved = UUID::hexToInt($matches[$i++]);

        $uuid->clockSeqLow = UUID::hexToInt($matches[$i++]);

        $uuid->nodeHigh = UUID::hexToInt($matches[$i++]);

        $uuid->nodeLow = UUID::hexToInt($matches[$i++]);



        return $uuid;

    }



    private static function hexToInt($str) {

        $rc = 0;

        foreach (str_split($str) as $c) {

            switch ($c) {

                case '0': $x = 0; break;

                case '1': $x = 1; break;

                case '2': $x = 2; break;

                case '3': $x = 3; break;

                case '4': $x = 4; break;

                case '5': $x = 5; break;

                case '6': $x = 6; break;

                case '7': $x = 7; break;

                case '8': $x = 8; break;

                case '9': $x = 9; break;

                case 'a':

                case 'A': $x = 10; break;

                case 'b':

                case 'B': $x = 11; break;

                case 'c':

                case 'C': $x = 12; break;

                case 'd':

                case 'D': $x = 13; break;

                case 'e':

                case 'E': $x = 14; break;

                case 'f':

                case 'F': $x = 15; break;

                default: throw new IvalidArgumentException(

                    "Invalid hex string: $str");

            }

            $rc = $rc << 4 | $x;

        }

        return $rc;

    }



    /**

     * Create a new UUID based on (pseudo) random numbers.

     *

     * This will set the version field on the UUID correctly.

     *

     * @return UUID A newly created (pseudo) random UUID.

     */

    public static function random() {

        $uuid = new UUID();

        $uuid->timeLow = mt_rand(0, 0xffff) << 16 | mt_rand(0, 0xffff);

        $uuid->timeMid = mt_rand(0, 0xffff);

        $uuid->timeHighAndVersion = mt_rand(0, 0xffff) & 0x0fff | 0x4000;

        $uuid->clockSeqHighAndReserved = mt_rand(0, 0xff) & 0x3f | 0xbf;

        $uuid->clockSeqLow = mt_rand(0, 0xff);

        $uuid->nodeHigh = mt_rand(0, 0xffff);

        $uuid->nodeLow = mt_rand(0, 0xffff) << 16 | mt_rand(0, 0xffff);

        return $uuid;

    }



    /**

     * Create a string representation of this UUID object.

     *

     * @return string The UUID string.

     */

    public function toString() {

        $str = sprintf('%08x-%04x-%04x-%02x%02x-%04x%08x',

            $this->timeLow, $this->timeMid,

            $this->timeHighAndVersion, $this->clockSeqHighAndReserved,

            $this->clockSeqLow, $this->nodeHigh, $this->nodeLow);

        return $str;

    }



}