45 lines
1.2 KiB
Go
45 lines
1.2 KiB
Go
|
// Copyright 2016 Google Inc. All rights reserved.
|
||
|
|
// Use of this source code is governed by a BSD-style
|
||
|
|
// license that can be found in the LICENSE file.
|
||
|
|
|
||
|
|
package uuid
|
||
|
|
|
||
|
|
import (
|
||
|
|
"encoding/binary"
|
||
|
|
)
|
||
|
|
|
||
|
|
// NewUUID returns a Version 1 UUID based on the current NodeID and clock
|
||
|
|
// sequence, and the current time. If the NodeID has not been set by SetNodeID
|
||
|
|
// or SetNodeInterface then it will be set automatically. If the NodeID cannot
|
||
|
|
// be set NewUUID returns nil. If clock sequence has not been set by
|
||
|
|
// SetClockSequence then it will be set automatically. If GetTime fails to
|
||
|
|
// return the current NewUUID returns nil and an error.
|
||
|
|
//
|
||
|
|
// In most cases, New should be used.
|
||
|
|
func NewUUID() (UUID, error) {
|
||
|
|
nodeMu.Lock()
|
||
|
|
if nodeID == zeroID {
|
||
|
|
setNodeInterface("")
|
||
|
|
}
|
||
|
|
nodeMu.Unlock()
|
||
|
|
|
||
|
|
var uuid UUID
|
||
|
|
now, seq, err := GetTime()
|
||
|
|
if err != nil {
|
||
|
|
return uuid, err
|
||
|
|
}
|
||
|
|
|
||
|
|
timeLow := uint32(now & 0xffffffff)
|
||
|
|
timeMid := uint16((now >> 32) & 0xffff)
|
||
|
|
timeHi := uint16((now >> 48) & 0x0fff)
|
||
|
|
timeHi |= 0x1000 // Version 1
|
||
|
|
|
||
|
|
binary.BigEndian.PutUint32(uuid[0:], timeLow)
|
||
|
|
binary.BigEndian.PutUint16(uuid[4:], timeMid)
|
||
|
|
binary.BigEndian.PutUint16(uuid[6:], timeHi)
|
||
|
|
binary.BigEndian.PutUint16(uuid[8:], seq)
|
||
|
|
copy(uuid[10:], nodeID[:])
|
||
|
|
|
||
|
|
return uuid, nil
|
||
|
|
}
|