vendor/github.com/google/uuid/util.go

   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.
   4
   5 package uuid
   6
   7 import (
   8         "io"
   9 )
  10
  11 // randomBits completely fills slice b with random data.
  12 func randomBits(b []byte) {
  13         if _, err := io.ReadFull(rander, b); err != nil {
  14                 panic(err.Error()) // rand should never fail
  15         }
  16 }
  17
  18 // xvalues returns the value of a byte as a hexadecimal digit or 255.
  19 var xvalues = [256]byte{
  20         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  21         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  22         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  23         0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 255, 255, 255, 255, 255, 255,
  24         255, 10, 11, 12, 13, 14, 15, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  25         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  26         255, 10, 11, 12, 13, 14, 15, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  27         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  28         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  29         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  30         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  31         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  32         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  33         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  34         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  35         255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  36 }
  37
  38 // xtob converts hex characters x1 and x2 into a byte.
  39 func xtob(x1, x2 byte) (byte, bool) {
  40         b1 := xvalues[x1]
  41         b2 := xvalues[x2]
  42         return (b1 << 4) | b2, b1 != 255 && b2 != 255
  43 }