1 // Copyright 2016 Google Inc. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
11 // NewUUID returns a Version 1 UUID based on the current NodeID and clock
12 // sequence, and the current time. If the NodeID has not been set by SetNodeID
13 // or SetNodeInterface then it will be set automatically. If the NodeID cannot
14 // be set NewUUID returns nil. If clock sequence has not been set by
15 // SetClockSequence then it will be set automatically. If GetTime fails to
16 // return the current NewUUID returns nil and an error.
18 // In most cases, New should be used.
19 func NewUUID() (UUID, error) {
27 now, seq, err := GetTime()
32 timeLow := uint32(now & 0xffffffff)
33 timeMid := uint16((now >> 32) & 0xffff)
34 timeHi := uint16((now >> 48) & 0x0fff)
35 timeHi |= 0x1000 // Version 1
37 binary.BigEndian.PutUint32(uuid[0:], timeLow)
38 binary.BigEndian.PutUint16(uuid[4:], timeMid)
39 binary.BigEndian.PutUint16(uuid[6:], timeHi)
40 binary.BigEndian.PutUint16(uuid[8:], seq)
41 copy(uuid[10:], nodeID[:])