1var rng = require('./lib/rng'); 2var bytesToUuid = require('./lib/bytesToUuid'); 3 4function v4(options, buf, offset) { 5 var i = buf && offset || 0; 6 7 if (typeof(options) == 'string') { 8 buf = options === 'binary' ? new Array(16) : null; 9 options = null; 10 } 11 options = options || {}; 12 13 var rnds = options.random || (options.rng || rng)(); 14 15 // Per 4.4, set bits for version and `clock_seq_hi_and_reserved` 16 rnds[6] = (rnds[6] & 0x0f) | 0x40; 17 rnds[8] = (rnds[8] & 0x3f) | 0x80; 18 19 // Copy bytes to buffer, if provided 20 if (buf) { 21 for (var ii = 0; ii < 16; ++ii) { 22 buf[i + ii] = rnds[ii]; 23 } 24 } 25 26 return buf || bytesToUuid(rnds); 27} 28 29module.exports = v4; 30