Rainbond/vendor/github.com/pborman/uuid/uuid.go
zhoujunhao 4d2a50bf77 [ADD]
2018-09-26 14:42:01 +08:00

163 lines
3.9 KiB
Go

// Copyright 2011 Google Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package uuid
import (
"bytes"
"crypto/rand"
"encoding/hex"
"io"
guuid "github.com/google/uuid"
)
// Array is a pass-by-value UUID that can be used as an effecient key in a map.
type Array [16]byte
// UUID converts uuid into a slice.
func (uuid Array) UUID() UUID {
return uuid[:]
}
// String returns the string representation of uuid,
// xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.
func (uuid Array) String() string {
return guuid.UUID(uuid).String()
}
// A UUID is a 128 bit (16 byte) Universal Unique IDentifier as defined in RFC
// 4122.
type UUID []byte
// A Version represents a UUIDs version.
type Version = guuid.Version
// A Variant represents a UUIDs variant.
type Variant = guuid.Variant
// Constants returned by Variant.
const (
Invalid = guuid.Invalid // Invalid UUID
RFC4122 = guuid.RFC4122 // The variant specified in RFC4122
Reserved = guuid.Reserved // Reserved, NCS backward compatibility.
Microsoft = guuid.Microsoft // Reserved, Microsoft Corporation backward compatibility.
Future = guuid.Future // Reserved for future definition.
)
var rander = rand.Reader // random function
// New returns a new random (version 4) UUID as a string. It is a convenience
// function for NewRandom().String().
func New() string {
return NewRandom().String()
}
// Parse decodes s into a UUID or returns nil. See github.com/google/uuid for
// the formats parsed.
func Parse(s string) UUID {
gu, err := guuid.Parse(s)
if err == nil {
return gu[:]
}
return nil
}
// ParseBytes is like Parse, except it parses a byte slice instead of a string.
func ParseBytes(b []byte) (UUID, error) {
gu, err := guuid.ParseBytes(b)
if err == nil {
return gu[:], nil
}
return nil, err
}
// Equal returns true if uuid1 and uuid2 are equal.
func Equal(uuid1, uuid2 UUID) bool {
return bytes.Equal(uuid1, uuid2)
}
// Array returns an array representation of uuid that can be used as a map key.
// Array panics if uuid is not valid.
func (uuid UUID) Array() Array {
if len(uuid) != 16 {
panic("invalid uuid")
}
var a Array
copy(a[:], uuid)
return a
}
// String returns the string form of uuid, xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
// , or "" if uuid is invalid.
func (uuid UUID) String() string {
if len(uuid) != 16 {
return ""
}
var buf [36]byte
encodeHex(buf[:], uuid)
return string(buf[:])
}
// URN returns the RFC 2141 URN form of uuid,
// urn:uuid:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, or "" if uuid is invalid.
func (uuid UUID) URN() string {
if len(uuid) != 16 {
return ""
}
var buf [36 + 9]byte
copy(buf[:], "urn:uuid:")
encodeHex(buf[9:], uuid)
return string(buf[:])
}
func encodeHex(dst []byte, uuid UUID) {
hex.Encode(dst[:], uuid[:4])
dst[8] = '-'
hex.Encode(dst[9:13], uuid[4:6])
dst[13] = '-'
hex.Encode(dst[14:18], uuid[6:8])
dst[18] = '-'
hex.Encode(dst[19:23], uuid[8:10])
dst[23] = '-'
hex.Encode(dst[24:], uuid[10:])
}
// Variant returns the variant encoded in uuid. It returns Invalid if
// uuid is invalid.
func (uuid UUID) Variant() Variant {
if len(uuid) != 16 {
return Invalid
}
switch {
case (uuid[8] & 0xc0) == 0x80:
return RFC4122
case (uuid[8] & 0xe0) == 0xc0:
return Microsoft
case (uuid[8] & 0xe0) == 0xe0:
return Future
default:
return Reserved
}
}
// Version returns the version of uuid. It returns false if uuid is not
// valid.
func (uuid UUID) Version() (Version, bool) {
if len(uuid) != 16 {
return 0, false
}
return Version(uuid[6] >> 4), true
}
// SetRand sets the random number generator to r, which implements io.Reader.
// If r.Read returns an error when the package requests random data then
// a panic will be issued.
//
// Calling SetRand with nil sets the random number generator to the default
// generator.
func SetRand(r io.Reader) {
guuid.SetRand(r)
}