var rng = require('./lib/rng');
var bytesToUuid = require('./lib/bytesToUuid');
// **`v1()` - Generate time-based UUID**
//
// Inspired by https://github.com/LiosK/UUID.js
// and http://docs.python.org/library/uuid.html
var _nodeId;
var _clockseq;
// Previous uuid creation time
var _lastMSecs = 0;
var _lastNSecs = 0;
// See https://github.com/uuidjs/uuid for API details
function v1(options, buf, offset) {
var i = buf && offset || 0;
var b = buf || [];
options = options || {};
var node = options.node || _nodeId;
var clockseq = options.clockseq !== undefined ? options.clockseq : _clockseq;
// node and clockseq need to be initialized to random values if they're not
// specified. We do this lazily to minimize issues related to insufficient
// system entropy. See #189
if (node == null || clockseq == null) {
var seedBytes = rng();
if (node == null) {
// Per 4.5, create and 48-bit node id, (47 random bits + multicast bit = 1)
node = _nodeId = [
seedBytes[0] | 0x01,
seedBytes[1], seedBytes[2], seedBytes[3], seedBytes[4], seedBytes[5]
];
}
if (clockseq == null) {
// Per 4.2.2, randomize (14 bit) clockseq
clockseq = _clockseq = (seedBytes[6] << 8 | seedBytes[7]) & 0x3fff;
}
}
// 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;