vendor/github.com/hashicorp/go-uuid/uuid.go

   1 package uuid
   2
   3 import (
   4         "crypto/rand"
   5         "encoding/hex"
   6         "fmt"
   7 )
   8
   9 // GenerateRandomBytes is used to generate random bytes of given size.
  10 func GenerateRandomBytes(size int) ([]byte, error) {
  11         buf := make([]byte, size)
  12         if _, err := rand.Read(buf); err != nil {
  13                 return nil, fmt.Errorf("failed to read random bytes: %v", err)
  14         }
  15         return buf, nil
  16 }
  17
  18 const uuidLen = 16
  19
  20 // GenerateUUID is used to generate a random UUID
  21 func GenerateUUID() (string, error) {
  22         buf, err := GenerateRandomBytes(uuidLen)
  23         if err != nil {
  24                 return "", err
  25         }
  26         return FormatUUID(buf)
  27 }
  28
  29 func FormatUUID(buf []byte) (string, error) {
  30         if buflen := len(buf); buflen != uuidLen {
  31                 return "", fmt.Errorf("wrong length byte slice (%d)", buflen)
  32         }
  33
  34         return fmt.Sprintf("%x-%x-%x-%x-%x",
  35                 buf[0:4],
  36                 buf[4:6],
  37                 buf[6:8],
  38                 buf[8:10],
  39                 buf[10:16]), nil
  40 }
  41
  42 func ParseUUID(uuid string) ([]byte, error) {
  43         if len(uuid) != 2 * uuidLen + 4 {
  44                 return nil, fmt.Errorf("uuid string is wrong length")
  45         }
  46
  47         if uuid[8] != '-' ||
  48                 uuid[13] != '-' ||
  49                 uuid[18] != '-' ||
  50                 uuid[23] != '-' {
  51                 return nil, fmt.Errorf("uuid is improperly formatted")
  52         }
  53
  54         hexStr := uuid[0:8] + uuid[9:13] + uuid[14:18] + uuid[19:23] + uuid[24:36]
  55
  56         ret, err := hex.DecodeString(hexStr)
  57         if err != nil {
  58                 return nil, err
  59         }
  60         if len(ret) != uuidLen {
  61                 return nil, fmt.Errorf("decoded hex is the wrong length")
  62         }
  63
  64         return ret, nil
  65 }