26 lines
911 B
Go
26 lines
911 B
Go
|
// Copyright 2011 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
|
|||
|
|
|
|||
|
|
// Random returns a Random (Version 4) UUID or panics.
|
|||
|
|
//
|
|||
|
|
// The strength of the UUIDs is based on the strength of the crypto/rand
|
|||
|
|
// package.
|
|||
|
|
//
|
|||
|
|
// A note about uniqueness derived from 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 {
|
|||
|
|
uuid := make([]byte, 16)
|
|||
|
|
randomBits([]byte(uuid))
|
|||
|
|
uuid[6] = (uuid[6] & 0x0f) | 0x40 // Version 4
|
|||
|
|
uuid[8] = (uuid[8] & 0x3f) | 0x80 // Variant is 10
|
|||
|
|
return uuid
|
|||
|
|
}
|