package uuid import ( "bytes" "crypto/md5" "crypto/rand" "encoding/hex" "v2ray.com/core/common/errors" ) var ( byteGroups = []int{8, 4, 4, 4, 12} ) type UUID [16]byte // String returns the string representation of this UUID. func (v *UUID) String() string { return bytesToString(v.Bytes()) } // Bytes returns the bytes representation of this UUID. func (v *UUID) Bytes() []byte { return v[:] } // Equals returns true if this UUID equals another UUID by value. func (v *UUID) Equals(another *UUID) bool { if v == nil && another == nil { return true } if v == nil || another == nil { return false } return bytes.Equal(v.Bytes(), another.Bytes()) } // Next generates a deterministic random UUID based on this UUID. func (v *UUID) Next() *UUID { md5hash := md5.New() md5hash.Write(v.Bytes()) md5hash.Write([]byte("16167dc8-16b6-4e6d-b8bb-65dd68113a81")) newid := new(UUID) for { md5hash.Sum(newid[:0]) if !newid.Equals(v) { return newid } md5hash.Write([]byte("533eff8a-4113-4b10-b5ce-0f5d76b98cd2")) } } func bytesToString(bytes []byte) string { result := hex.EncodeToString(bytes[0 : byteGroups[0]/2]) start := byteGroups[0] / 2 for i := 1; i < len(byteGroups); i++ { nBytes := byteGroups[i] / 2 result += "-" result += hex.EncodeToString(bytes[start : start+nBytes]) start += nBytes } return result } // New creates an UUID with random value. func New() *UUID { uuid := new(UUID) rand.Read(uuid.Bytes()) return uuid } // PraseBytes converts an UUID in byte form to object. func ParseBytes(b []byte) (*UUID, error) { if len(b) != 16 { return nil, errors.New("Invalid UUID: ", b) } uuid := new(UUID) copy(uuid[:], b) return uuid, nil } // ParseString converts an UUID in string form to object. func ParseString(str string) (*UUID, error) { text := []byte(str) if len(text) < 32 { return nil, errors.New("Invalid UUID: ", str) } uuid := new(UUID) b := uuid.Bytes() for _, byteGroup := range byteGroups { if text[0] == '-' { text = text[1:] } _, err := hex.Decode(b[:byteGroup/2], text[:byteGroup]) if err != nil { return nil, err } text = text[byteGroup:] b = b[byteGroup/2:] } return uuid, nil }