// uuid.js // // Copyright (c) 2010-2012 Robert Kieffer // MIT License - http://opensource.org/licenses/mit-license.php // Unique ID creation requires a high quality random # generator. We feature // detect to determine the best RNG source, normalizing to a function that // returns 128-bits of randomness, since that's what's usually required var _rng = require('./rng'); // Buffer class to use, // we can't use `Buffer || Array` otherwise Buffer would be // shimmed by browserify and added to the browser build var BufferClass = require('./buffer'); // Maps for number <-> hex string conversion var _byteToHex = []; var _hexToByte = {}; for (var i = 0; i < 256; i++) { _byteToHex[i] = (i + 0x100).toString(16).substr(1); _hexToByte[_byteToHex[i]] = i; } // **`parse()` - Parse a UUID into it's component bytes** function parse(s, buf, offset) { var i = (buf && offset) || 0, ii = 0; buf = buf || []; s.toLowerCase().replace(/[0-9a-f]{2}/g, function(oct) { if (ii < 16) { // Don't overflow! buf[i + ii++] = _hexToByte[oct]; } }); // Zero out remaining bytes if string was short while (ii < 16) { buf[i + ii++] = 0; } return buf; } // **`unparse()` - Convert UUID byte array (ala parse()) into a string** function unparse(buf, offset) { var i = offset || 0, bth = _byteToHex; return bth[buf[i++]] + bth[buf[i++]] + bth[buf[i++]] + bth[buf[i++]] + '-' + bth[buf[i++]] + bth[buf[i++]] + '-' + bth[buf[i++]] + bth[buf[i++]] + '-' + bth[buf[i++]] + bth[buf[i++]] + '-' + bth[buf[i++]] + bth[buf[i++]] + bth[buf[i++]] + bth[buf[i++]] + bth[buf[i++]] + bth[buf[i++]]; } // **`v1()` - Generate time-based UUID** // // Inspired by https://github.com/LiosK/UUID.js // and http://docs.python.org/library/uuid.html // random #'s we need to init node and clockseq var _seedBytes = _rng(); // Per 4.5, create and 48-bit node id, (47 random bits + multicast bit = 1) var _nodeId = [ _seedBytes[0] | 0x01, _seedBytes[1], _seedBytes[2], _seedBytes[3], _seedBytes[4], _seedBytes[5] ]; // Per 4.2.2, randomize (14 bit) clockseq var _clockseq = (_seedBytes[6] << 8 | _seedBytes[7]) & 0x3fff; // Previous uuid creation time var _lastMSecs = 0, _lastNSecs = 0; // See https://github.com/broofa/node-uuid for API details function v1(options, buf, offset) { var i = buf && offset || 0; var b = buf || []; options = options || {}; var clockseq = options.clockseq !== undefined ? options.clockseq : _clockseq; // UUID timestamps are 100 nano-second units since the Gregorian epoch, // (1582-10-15 00:00). JSNumbers aren't precise enough for this, so // time is handled internally as 'msecs' (integer milliseconds) and 'nsecs' // (100-nanoseconds offset from msecs) since unix epoch, 1970-01-01 00:00. var msecs = options.msecs !== undefined ? options.msecs : new Date().getTime(); // Per 4.2.1.2, use count of uuid's generated during the current clock // cycle to simulate higher resolution clock var nsecs = options.nsecs !== undefined ? options.nsecs : _lastNSecs + 1; // Time since last uuid creation (in msecs) var dt = (msecs - _lastMSecs) + (nsecs - _lastNSecs)/10000; // Per 4.2.1.2, Bump clockseq on clock regression if (dt < 0 && options.clockseq === undefined) { clockseq = clockseq + 1 & 0x3fff; } // Reset nsecs if clock regresses (new clockseq) or we've moved onto a new // time interval if ((dt < 0 || msecs > _lastMSecs) && options.nsecs === undefined) { nsecs = 0; } // Per 4.2.1.2 Throw error if too many uuids are requested if (nsecs >= 10000) { throw new Error('uuid.v1(): Can\'t create more than 10M uuids/sec'); } _lastMSecs = msecs; _lastNSecs = nsecs; _clockseq = clockseq; // Per 4.1.4 - Convert from unix epoch to Gregorian epoch msecs += 12219292800000; // `time_low` var tl = ((msecs & 0xfffffff) * 10000 + nsecs) % 0x100000000; b[i++] = tl >>> 24 & 0xff; b[i++] = tl >>> 16 & 0xff; b[i++] = tl >>> 8 & 0xff; b[i++] = tl & 0xff; // `time_mid` var tmh = (msecs / 0x100000000 * 10000) & 0xfffffff; b[i++] = tmh >>> 8 & 0xff; b[i++] = tmh & 0xff; // `time_high_and_version` b[i++] = tmh >>> 24 & 0xf | 0x10; // include version b[i++] = tmh >>> 16 & 0xff; // `clock_seq_hi_and_reserved` (Per 4.2.2 - include variant) b[i++] = clockseq >>> 8 | 0x80; // `clock_seq_low` b[i++] = clockseq & 0xff; // `node` var node = options.node || _nodeId; for (var n = 0; n < 6; n++) { b[i + n] = node[n]; } return buf ? buf : unparse(b); } // **`v4()` - Generate random UUID** // See https://github.com/broofa/node-uuid for API details function v4(options, buf, offset) { // Deprecated - 'format' argument, as supported in v1.2 var i = buf && offset || 0; if (typeof(options) == 'string') { buf = options == 'binary' ? new BufferClass(16) : null; options = null; } options = options || {}; var rnds = options.random || (options.rng || _rng)(); // Per 4.4, set bits for version and `clock_seq_hi_and_reserved` rnds[6] = (rnds[6] & 0x0f) | 0x40; rnds[8] = (rnds[8] & 0x3f) | 0x80; // Copy bytes to buffer, if provided if (buf) { for (var ii = 0; ii < 16; ii++) { buf[i + ii] = rnds[ii]; } } return buf || unparse(rnds); } // Export public API var uuid = v4; uuid.v1 = v1; uuid.v4 = v4; uuid.parse = parse; uuid.unparse = unparse; uuid.BufferClass = BufferClass; module.exports = uuid;