mirror of https://github.com/prometheus/prometheus
26 lines
911 B
Go
26 lines
911 B
Go
// Copyright 2011 Google Inc. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package uuid
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// Random returns a Random (Version 4) UUID or panics.
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//
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// The strength of the UUIDs is based on the strength of the crypto/rand
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// package.
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//
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// A note about uniqueness derived from from the UUID Wikipedia entry:
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//
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// Randomly generated UUIDs have 122 random bits. One's annual risk of being
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// hit by a meteorite is estimated to be one chance in 17 billion, that
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// means the probability is about 0.00000000006 (6 × 10−11),
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// equivalent to the odds of creating a few tens of trillions of UUIDs in a
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// year and having one duplicate.
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func NewRandom() UUID {
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uuid := make([]byte, 16)
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randomBits([]byte(uuid))
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uuid[6] = (uuid[6] & 0x0f) | 0x40 // Version 4
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uuid[8] = (uuid[8] & 0x3f) | 0x80 // Variant is 10
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return uuid
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}
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