You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
39 lines
1.1 KiB
39 lines
1.1 KiB
4 years ago
|
// 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 "io"
|
||
|
|
|
||
|
|
// New creates a new random UUID or panics. New is equivalent to
|
||
|
|
// the expression
|
||
|
|
//
|
||
|
|
// uuid.Must(uuid.NewRandom())
|
||
|
|
func New() UUID {
|
||
|
|
return Must(NewRandom())
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewRandom returns a Random (Version 4) UUID.
|
||
|
|
//
|
||
|
|
// The strength of the UUIDs is based on the strength of the crypto/rand
|
||
|
|
// package.
|
||
|
|
//
|
||
|
|
// A note about uniqueness derived from the UUID Wikipedia entry:
|
||
|
|
//
|
||
|
|
// Randomly generated UUIDs have 122 random bits. One's annual risk of being
|
||
|
|
// hit by a meteorite is estimated to be one chance in 17 billion, that
|
||
|
|
// means the probability is about 0.00000000006 (6 × 10−11),
|
||
|
|
// equivalent to the odds of creating a few tens of trillions of UUIDs in a
|
||
|
|
// year and having one duplicate.
|
||
|
|
func NewRandom() (UUID, error) {
|
||
|
|
var uuid UUID
|
||
|
|
_, err := io.ReadFull(rander, uuid[:])
|
||
|
|
if err != nil {
|
||
|
|
return Nil, err
|
||
|
|
}
|
||
|
|
uuid[6] = (uuid[6] & 0x0f) | 0x40 // Version 4
|
||
|
|
uuid[8] = (uuid[8] & 0x3f) | 0x80 // Variant is 10
|
||
|
|
return uuid, nil
|
||
|
|
}
|