class.uuid.php

<?php
/*-
 * Copyright (c) 2011 Fredrik Lindberg - http://www.shapeshifter.se
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *	  notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 * Alternative this software might be licensed under the following license
 *
 *  Copyright 2011 Fredrik Lindberg
 *
 *  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.
 *
 */

/*
 * UUID (RFC4122) Generator
 * http://tools.ietf.org/html/rfc4122
 *
 * Implements version 1, 3, 4 and 5
 */
class UUID {
	/* UUID versions */
	const UUID_TIME	 = 1;	/* Time based UUID */
	const UUID_NAME_MD5	 = 3;	/* Name based (MD5) UUID */
	const UUID_RANDOM	 = 4;	/* Random UUID */
	const UUID_NAME_SHA1	 = 5;	/* Name based (SHA1) UUID */

	/* UUID formats */
	const FMT_FIELD	 = 100;
	const FMT_STRING	 = 101;
	const FMT_BINARY	 = 102;
	const FMT_QWORD	 = 1;	/* Quad-word, 128-bit (not impl.) */
	const FMT_DWORD	 = 2;	/* Double-word, 64-bit (not impl.) */
	const FMT_WORD		 = 4;	/* Word, 32-bit (not impl.) */
	const FMT_SHORT		= 8;	/* Short (not impl.) */
	const FMT_BYTE		= 16;	/* Byte */
	const FMT_DEFAULT	 = 16;

	/* Field UUID representation */
	static private $m_uuid_field = array(
		'time_low' => 0,		/* 32-bit */
		'time_mid' => 0,		/* 16-bit */
		'time_hi' => 0,			/* 16-bit */
		'clock_seq_hi' => 0,		/*  8-bit */
		'clock_seq_low' => 0,		/*  8-bit */
		'node' => array()		/* 48-bit */
	);

	static private $m_generate = array(
		self::UUID_TIME => "generateTime",
		self::UUID_RANDOM => "generateRandom",
		self::UUID_NAME_MD5 => "generateNameMD5",
		self::UUID_NAME_SHA1 => "generateNameSHA1"
	);

	static private $m_convert = array(
		self::FMT_FIELD => array(
			self::FMT_BYTE => "conv_field2byte",
			self::FMT_STRING => "conv_field2string",
			self::FMT_BINARY => "conv_field2binary"
		),
		self::FMT_BYTE => array(
			self::FMT_FIELD => "conv_byte2field",
			self::FMT_STRING => "conv_byte2string",
			self::FMT_BINARY => "conv_byte2binary"
		),
		self::FMT_STRING => array(
			self::FMT_BYTE => "conv_string2byte",
			self::FMT_FIELD => "conv_string2field",
			self::FMT_BINARY => "conv_string2binary"
		),
	);

	/* Swap byte order of a 32-bit number */
	static private function swap32($x) {
		return (($x & 0x000000ff) << 24) | (($x & 0x0000ff00) << 8) |
			(($x & 0x00ff0000) >> 8) | (($x & 0xff000000) >> 24);
	}

	/* Swap byte order of a 16-bit number */
	static private function swap16($x) {
		return (($x & 0x00ff) << 8) | (($x & 0xff00) >> 8);
	}

	/* Auto-detect UUID format */
	static private function detectFormat($src) {
		if (is_string($src))
			return self::FMT_STRING;
		else if (is_array($src)) {
			$len = count($src);
			if ($len == 1 || ($len % 2) == 0)
				return $len;
			else
				return (-1);
		}
		else
			return self::FMT_BINARY;
	}

	/*
	 * Public API, generate a UUID of 'type' in format 'fmt' for
	 * the given namespace 'ns' and node 'node'
	 */
	static public function generate($type, $fmt = self::FMT_BYTE,
		$node = "", $ns = "") {
		$func = self::$m_generate[$type];
		if (!isset($func))
			return null;
		$conv = self::$m_convert[self::FMT_FIELD][$fmt];

		$uuid = self::$func($ns, $node);
		return self::$conv($uuid);
	}

	/*
	 * Public API, convert a UUID from one format to another
	 */
	static public function convert($uuid, $from, $to) {
		$conv = self::$m_convert[$from][$to];
		if (!isset($conv))
			return ($uuid);

		return (self::$conv($uuid));
	}

	/*
	 * Generate an UUID version 4 (pseudo random)
	 */
	static private function generateRandom($ns, $node) {
		$uuid = self::$m_uuid_field;

		$uuid['time_hi'] = (4 << 12) | (mt_rand(0, 0x1000));
		$uuid['clock_seq_hi'] = (1 << 7) | mt_rand(0, 128);
		$uuid['time_low'] = mt_rand(0, 0xffff) + (mt_rand(0, 0xffff) << 16);
		$uuid['time_mid'] = mt_rand(0, 0xffff);
		$uuid['clock_seq_low'] = mt_rand(0, 255);
		for ($i = 0; $i < 6; $i++)
			$uuid['node'][$i] = mt_rand(0, 255);
		return ($uuid);
	}

	/*
	 * Generate UUID version 3 and 5 (name based)
	 */
	static private function generateName($ns, $node, $hash, $version) {
		$ns_fmt = self::detectFormat($ns);
		$field = self::convert($ns, $ns_fmt, self::FMT_FIELD);

		/* Swap byte order to keep it in big endian on all platforms */
		$field['time_low'] = self::swap32($field['time_low']);
		$field['time_mid'] = self::swap16($field['time_mid']);
		$field['time_hi'] = self::swap16($field['time_hi']);

		/* Convert the namespace to binary and concatenate node */
		$raw = self::convert($field, self::FMT_FIELD, self::FMT_BINARY);
		$raw .= $node;

		/* Hash the namespace and node and convert to a byte array */
		$val = $hash($raw, true);	
		$tmp = unpack('C16', $val);
		foreach (array_keys($tmp) as $key)
			$byte[$key - 1] = $tmp[$key];

		/* Convert byte array to a field array */
		$field = self::conv_byte2field($byte);

		$field['time_low'] = self::swap32($field['time_low']);
		$field['time_mid'] = self::swap16($field['time_mid']);
		$field['time_hi'] = self::swap16($field['time_hi']);

		/* Apply version and constants */
		$field['clock_seq_hi'] &= 0x3f;
		$field['clock_seq_hi'] |= (1 << 7);
		$field['time_hi'] &= 0x0fff;
		$field['time_hi'] |= ($version << 12);

		return ($field);	
	}
	static private function generateNameMD5($ns, $node) {
		return self::generateName($ns, $node, "md5",
			self::UUID_NAME_MD5);
	}
	static private function generateNameSHA1($ns, $node) {
		return self::generateName($ns, $node, "sha1",
			self::UUID_NAME_SHA1);
	}

	/*
	 * Generate UUID version 1 (time based)
	 */
	static private function generateTime($ns, $node) {
		$uuid = self::$m_uuid_field;

		/*
		 * Get current time in 100 ns intervals. The magic value
		 * is the offset between UNIX epoch and the UUID UTC
		 * time base October 15, 1582.
		 */
		$tp = gettimeofday();
		$time = ($tp['sec'] * 10000000) + ($tp['usec'] * 10) +
			0x01B21DD213814000;

		$uuid['time_low'] = $time & 0xffffffff;
		/* Work around PHP 32-bit bit-operation limits */
		$high = intval($time / 0xffffffff);
		$uuid['time_mid'] = $high & 0xffff;
		$uuid['time_hi'] = (($high >> 16) & 0xfff) | (self::UUID_TIME << 12);
		
		/*
		 * We don't support saved state information and generate
		 * a random clock sequence each time.
		 */
		$uuid['clock_seq_hi'] = 0x80 | mt_rand(0, 64);
		$uuid['clock_seq_low'] = mt_rand(0, 255);

		/*
		 * Node should be set to the 48-bit IEEE node identifier, but
		 * we leave it for the user to supply the node.
		 */
		for ($i = 0; $i < 6; $i++)
			$uuid['node'][$i] = ord(substr($node, $i, 1));

		return ($uuid);
	}

	/* Assumes correct byte order */
	static private function conv_field2byte($src) {
		$uuid[0] = ($src['time_low'] & 0xff000000) >> 24;
		$uuid[1] = ($src['time_low'] & 0x00ff0000) >> 16;
		$uuid[2] = ($src['time_low'] & 0x0000ff00) >> 8;
		$uuid[3] = ($src['time_low'] & 0x000000ff);
		$uuid[4] = ($src['time_mid'] & 0xff00) >> 8;
		$uuid[5] = ($src['time_mid'] & 0x00ff);
		$uuid[6] = ($src['time_hi'] & 0xff00) >> 8;
		$uuid[7] = ($src['time_hi'] & 0x00ff);
		$uuid[8] = $src['clock_seq_hi'];
		$uuid[9] = $src['clock_seq_low'];

		for ($i = 0; $i < 6; $i++)
			$uuid[10+$i] = $src['node'][$i];

		return ($uuid);
	}

	static private function conv_field2string($src) {
		$str = sprintf(
			'%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x',
			($src['time_low']), ($src['time_mid']), ($src['time_hi']),
			$src['clock_seq_hi'], $src['clock_seq_low'],
			$src['node'][0], $src['node'][1], $src['node'][2],
			$src['node'][3], $src['node'][4], $src['node'][5]);
		return ($str);
	}

	static private function conv_field2binary($src) {
		$byte = self::conv_field2byte($src);
		return self::conv_byte2binary($byte);
	}

	static private function conv_byte2field($uuid) {
		$field = self::$m_uuid_field;
		$field['time_low'] = ($uuid[0] << 24) | ($uuid[1] << 16) |
			($uuid[2] << 8) | $uuid[3];
		$field['time_mid'] = ($uuid[4] << 8) | $uuid[5];
		$field['time_hi'] = ($uuid[6] << 8) | $uuid[7];
		$field['clock_seq_hi'] = $uuid[8];
		$field['clock_seq_low'] = $uuid[9];

		for ($i = 0; $i < 6; $i++)
			$field['node'][$i] = $uuid[10+$i];
		return ($field);
	}

	static public function conv_byte2string($src) {
		$field = self::conv_byte2field($src);
		return self::conv_field2string($field);
	}

	static private function conv_byte2binary($src) {
		$raw = pack('C16', $src[0], $src[1], $src[2], $src[3],
			$src[4], $src[5], $src[6], $src[7], $src[8], $src[9],
			$src[10], $src[11], $src[12], $src[13], $src[14], $src[15]);
		return ($raw);
	}

	static private function conv_string2field($src) {
		$parts = sscanf($src, '%x-%x-%x-%x-%02x%02x%02x%02x%02x%02x');
		$field = self::$m_uuid_field;
		$field['time_low'] = ($parts[0]);
		$field['time_mid'] = ($parts[1]);
		$field['time_hi'] = ($parts[2]);
		$field['clock_seq_hi'] = ($parts[3] & 0xff00) >> 8;
		$field['clock_seq_low'] = $parts[3] & 0x00ff;
		for ($i = 0; $i < 6; $i++)
			$field['node'][$i] = $parts[4+$i];

		return ($field);
	}

	static private function conv_string2byte($src) {
		$field = self::conv_string2field($src);
		return self::conv_field2byte($field);
	}

	static private function conv_string2binary($src) {
		$byte = self::conv_string2byte($src);
		return self::conv_byte2binary($byte);
	}
}

?>