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 // GenerateUUID is used to generate a random UUID
  10 func GenerateUUID() (string, error) {
  11         buf := make([]byte, 16)
  12         if _, err := rand.Read(buf); err != nil {
  13                 return "", fmt.Errorf("failed to read random bytes: %v", err)
  14         }
  15
  16         return FormatUUID(buf)
  17 }
  18
  19 func FormatUUID(buf []byte) (string, error) {
  20         if len(buf) != 16 {
  21                 return "", fmt.Errorf("wrong length byte slice (%d)", len(buf))
  22         }
  23
  24         return fmt.Sprintf("%08x-%04x-%04x-%04x-%12x",
  25                 buf[0:4],
  26                 buf[4:6],
  27                 buf[6:8],
  28                 buf[8:10],
  29                 buf[10:16]), nil
  30 }
  31
  32 func ParseUUID(uuid string) ([]byte, error) {
  33         if len(uuid) != 36 {
  34                 return nil, fmt.Errorf("uuid string is wrong length")
  35         }
  36
  37         hyph := []byte("-")
  38
  39         if uuid[8] != hyph[0] ||
  40                 uuid[13] != hyph[0] ||
  41                 uuid[18] != hyph[0] ||
  42                 uuid[23] != hyph[0] {
  43                 return nil, fmt.Errorf("uuid is improperly formatted")
  44         }
  45
  46         hexStr := uuid[0:8] + uuid[9:13] + uuid[14:18] + uuid[19:23] + uuid[24:36]
  47
  48         ret, err := hex.DecodeString(hexStr)
  49         if err != nil {
  50                 return nil, err
  51         }
  52         if len(ret) != 16 {
  53                 return nil, fmt.Errorf("decoded hex is the wrong length")
  54         }
  55
  56         return ret, nil
  57 }