package uuid // import "v2ray.com/core/common/uuid" import ( "bytes" "crypto/rand" "encoding/hex" "v2ray.com/core/common" "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 (u *UUID) String() string { bytes := u.Bytes() 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 } // Bytes returns the bytes representation of this UUID. func (u *UUID) Bytes() []byte { return u[:] } // Equals returns true if this UUID equals another UUID by value. func (u *UUID) Equals(another *UUID) bool { if u == nil && another == nil { return true } if u == nil || another == nil { return false } return bytes.Equal(u.Bytes(), another.Bytes()) } // New creates a UUID with random value. func New() UUID { var uuid UUID common.Must2(rand.Read(uuid.Bytes())) return uuid } // ParseBytes converts a UUID in byte form to object. func ParseBytes(b []byte) (UUID, error) { var uuid UUID if len(b) != 16 { return uuid, errors.New("invalid UUID: ", b) } copy(uuid[:], b) return uuid, nil } // ParseString converts a UUID in string form to object. func ParseString(str string) (UUID, error) { var uuid UUID text := []byte(str) if len(text) < 32 { return uuid, errors.New("invalid UUID: ", str) } b := uuid.Bytes() for _, byteGroup := range byteGroups { if text[0] == '-' { text = text[1:] } if _, err := hex.Decode(b[:byteGroup/2], text[:byteGroup]); err != nil { return uuid, err } text = text[byteGroup:] b = b[byteGroup/2:] } return uuid, nil }