// Copyright (C) 2013-2018 by Maxim Bublis <b@codemonkey.ru>
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
package uuid
import (
"bytes"
"encoding/hex"
"fmt"
)
// FromBytes returns UUID converted from raw byte slice input.
// It will return error if the slice isn't 16 bytes long.
func FromBytes(input []byte) (u UUID, err error) {
err = u.UnmarshalBinary(input)
return
}
// FromBytesOrNil returns UUID converted from raw byte slice input.
// Same behavior as FromBytes, but returns a Nil UUID on error.
func FromBytesOrNil(input []byte) UUID {
uuid, err := FromBytes(input)
if err != nil {
return Nil
}
return uuid
}
// FromString returns UUID parsed from string input.
// Input is expected in a form accepted by UnmarshalText.
func FromString(input string) (u UUID, err error) {
err = u.UnmarshalText([]byte(input))
return
}
// FromStringOrNil returns UUID parsed from string input.
// Same behavior as FromString, but returns a Nil UUID on error.
func FromStringOrNil(input string) UUID {
uuid, err := FromString(input)
if err != nil {
return Nil
}
return uuid
}
// MarshalText implements the encoding.TextMarshaler interface.
// The encoding is the same as returned by String.
func (u UUID) MarshalText() (text []byte, err error) {
text = []byte(u.String())
return
}
// UnmarshalText implements the encoding.TextUnmarshaler interface.
// Following formats are supported:
// "6ba7b810-9dad-11d1-80b4-00c04fd430c8",
// "{6ba7b810-9dad-11d1-80b4-00c04fd430c8}",
// "urn:uuid:6ba7b810-9dad-11d1-80b4-00c04fd430c8"
// "6ba7b8109dad11d180b400c04fd430c8"
// ABNF for supported UUID text representation follows:
// uuid := canonical | hashlike | braced | urn
// plain := canonical | hashlike
// canonical := 4hexoct '-' 2hexoct '-' 2hexoct '-' 6hexoct
// hashlike := 12hexoct
// braced := '{' plain '}'
// urn := URN ':' UUID-NID ':' plain
// URN := 'urn'
// UUID-NID := 'uuid'
// 12hexoct := 6hexoct 6hexoct
// 6hexoct := 4hexoct 2hexoct
// 4hexoct := 2hexoct 2hexoct
// 2hexoct := hexoct hexoct
// hexoct := hexdig hexdig
// hexdig := '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' |
// 'a' | 'b' | 'c' | 'd' | 'e' | 'f' |
// 'A' | 'B' | 'C' | 'D' | 'E' | 'F'
func (u *UUID) UnmarshalText(text []byte) (err error) {
switch len(text) {
case 32:
return u.decodeHashLike(text)
case 36:
return u.decodeCanonical(text)
case 38:
return u.decodeBraced(text)
case 41:
fallthrough
case 45:
return u.decodeURN(text)
default:
return fmt.Errorf("uuid: incorrect UUID length: %s", text)
}
}
// decodeCanonical decodes UUID string in format
// "6ba7b810-9dad-11d1-80b4-00c04fd430c8".
func (u *UUID) decodeCanonical(t []byte) (err error) {
if t[8] != '-' || t[13] != '-' || t[18] != '-' || t[23] != '-' {
return fmt.Errorf("uuid: incorrect UUID format %s", t)
}
src := t[:]
dst := u[:]
for i, byteGroup := range byteGroups {
if i > 0 {
src = src[1:] // skip dash
}
_, err = hex.Decode(dst[:byteGroup/2], src[:byteGroup])
if err != nil {
return
}
src = src[byteGroup:]
dst = dst[byteGroup/2:]
}
return
}
// decodeHashLike decodes UUID string in format
// "6ba7b8109dad11d180b400c04fd430c8".
func (u *UUID) decodeHashLike(t []byte) (err error) {
src := t[:]
dst := u[:]
if _, err = hex.Decode(dst, src); err != nil {
return err
}
return
}
// decodeBraced decodes UUID string in format
// "{6ba7b810-9dad-11d1-80b4-00c04fd430c8}" or in format
// "{6ba7b8109dad11d180b400c04fd430c8}".
func (u *UUID) decodeBraced(t []byte) (err error) {
l := len(t)
if t[0] != '{' || t[l-1] != '}' {
return fmt.Errorf("uuid: incorrect UUID format %s", t)
}
return u.decodePlain(t[1 : l-1])
}
// decodeURN decodes UUID string in format
// "urn:uuid:6ba7b810-9dad-11d1-80b4-00c04fd430c8" or in format
// "urn:uuid:6ba7b8109dad11d180b400c04fd430c8".
func (u *UUID) decodeURN(t []byte) (err error) {
total := len(t)
urn_uuid_prefix := t[:9]
if !bytes.Equal(urn_uuid_prefix, urnPrefix) {
return fmt.Errorf("uuid: incorrect UUID format: %s", t)
}
return u.decodePlain(t[9:total])
}
// decodePlain decodes UUID string in canonical format
// "6ba7b810-9dad-11d1-80b4-00c04fd430c8" or in hash-like format
// "6ba7b8109dad11d180b400c04fd430c8".
func (u *UUID) decodePlain(t []byte) (err error) {
switch len(t) {
case 32:
return u.decodeHashLike(t)
case 36:
return u.decodeCanonical(t)
default:
return fmt.Errorf("uuid: incorrrect UUID length: %s", t)
}
}
// MarshalBinary implements the encoding.BinaryMarshaler interface.
func (u UUID) MarshalBinary() (data []byte, err error) {
data = u.Bytes()
return
}
// UnmarshalBinary implements the encoding.BinaryUnmarshaler interface.
// It will return error if the slice isn't 16 bytes long.
func (u *UUID) UnmarshalBinary(data []byte) (err error) {
if len(data) != Size {
err = fmt.Errorf("uuid: UUID must be exactly 16 bytes long, got %d bytes", len(data))
return
}
copy(u[:], data)
return
}
