uuid

README

UUID package for Go language

This package provides pure Go implementation of Universally Unique Identifier (UUID). Supported both creation and parsing of UUIDs.

With 100% test coverage and benchmarks out of box.

Supported versions:

• Version 1, based on timestamp and MAC address (RFC 4122)
• Version 2, based on timestamp, MAC address and POSIX UID/GID (DCE 1.1)
• Version 3, based on MD5 hashing (RFC 4122)
• Version 4, based on random numbers (RFC 4122)
• Version 5, based on SHA-1 hashing (RFC 4122)

Installation

Use the go command:

$ go get github.com/satori/go.uuid

Requirements

UUID package requires Go >= 1.2.

Example

package main

import (
	"fmt"
	"github.com/satori/go.uuid"
)

func main() {
	// Creating UUID Version 4
	// panic on error
	u1 := uuid.Must(uuid.NewV4())
	fmt.Printf("UUIDv4: %s\n", u1)

	// or error handling
	u2, err := uuid.NewV4()
	if err != nil {
		fmt.Printf("Something went wrong: %s", err)
		return
	}
	fmt.Printf("UUIDv4: %s\n", u2)

	// Parsing UUID from string input
	u2, err := uuid.FromString("6ba7b810-9dad-11d1-80b4-00c04fd430c8")
	if err != nil {
		fmt.Printf("Something went wrong: %s", err)
	}
	fmt.Printf("Successfully parsed: %s", u2)
}

Documentation

Documentation is hosted at GoDoc project.

Links

• RFC 4122
• DCE 1.1: Authentication and Security Services

Copyright

Copyright (C) 2013-2018 by Maxim Bublis b@codemonkey.ru.

UUID package released under MIT License. See LICENSE for details.

Documentation

Overview

Package uuid provides implementation of Universally Unique Identifier (UUID). Supported versions are 1, 3, 4 and 5 (as specified in RFC 4122) and version 2 (as specified in DCE 1.1).

Index

• Constants
• Variables
• func Equal(u1 UUID, u2 UUID) bool
• type Generator
• type UUID
  • func FromBytes(input []byte) (u UUID, err error)
  • func FromBytesOrNil(input []byte) UUID
  • func FromString(input string) (u UUID, err error)
  • func FromStringOrNil(input string) UUID
  • func Must(u UUID, err error) UUID
  • func NewV1() (UUID, error)
  • func NewV2(domain byte) (UUID, error)
  • func NewV3(ns UUID, name string) UUID
  • func NewV4() (UUID, error)
  • func NewV5(ns UUID, name string) UUID
  • func (u UUID) Bytes() []byte
  • func (u UUID) MarshalBinary() (data []byte, err error)
  • func (u UUID) MarshalText() (text []byte, err error)
  • func (u *UUID) SetVariant(v byte)
  • func (u *UUID) SetVersion(v byte)
  • func (u UUID) String() string
  • func (u *UUID) UnmarshalBinary(data []byte) (err error)
  • func (u *UUID) UnmarshalText(text []byte) (err error)
  • func (u UUID) Variant() byte
  • func (u UUID) Version() byte

Constants

const (
	V1 byte
	V2
	V3
	V4
	V5
)

UUID versions

const (
	VariantNCS byte = iota
	VariantRFC4122
	VariantMicrosoft
	VariantFuture
)

UUID layout variants.

const (
	DomainPerson = iota
	DomainGroup
	DomainOrg
)

UUID DCE domains.

const Size = 16

Size of a UUID in bytes.

Variables

var (
	NamespaceDNS  = Must(FromString("6ba7b810-9dad-11d1-80b4-00c04fd430c8"))
	NamespaceURL  = Must(FromString("6ba7b811-9dad-11d1-80b4-00c04fd430c8"))
	NamespaceOID  = Must(FromString("6ba7b812-9dad-11d1-80b4-00c04fd430c8"))
	NamespaceX500 = Must(FromString("6ba7b814-9dad-11d1-80b4-00c04fd430c8"))
)

Predefined namespace UUIDs.

var Nil = UUID{}

Nil is special form of UUID that is specified to have all 128 bits set to zero.

Functions

func Equal

func Equal(u1 UUID, u2 UUID) bool

Equal returns true if u1 and u2 equals, otherwise returns false.

Types

type Generator

type Generator interface {
	NewV1() (UUID, error)
	NewV2(domain byte) (UUID, error)
	NewV3(ns UUID, name string) UUID
	NewV4() (UUID, error)
	NewV5(ns UUID, name string) UUID
}

Generator provides interface for generating UUIDs.

type UUID

type UUID [Size]byte

UUID representation compliant with specification described in RFC 4122.

func FromBytes

func FromBytes(input []byte) (u UUID, err error)

FromBytes returns UUID converted from raw byte slice input. It will return error if the slice isn't 16 bytes long.

func FromBytesOrNil

func FromBytesOrNil(input []byte) UUID

FromBytesOrNil returns UUID converted from raw byte slice input. Same behavior as FromBytes, but returns a Nil UUID on error.

func FromString

func FromString(input string) (u UUID, err error)

FromString returns UUID parsed from string input. Input is expected in a form accepted by UnmarshalText.

func FromStringOrNil

func FromStringOrNil(input string) UUID

FromStringOrNil returns UUID parsed from string input. Same behavior as FromString, but returns a Nil UUID on error.

func Must

func Must(u UUID, err error) UUID

Must is a helper that wraps a call to a function returning (UUID, error) and panics if the error is non-nil. It is intended for use in variable initializations such as

var packageUUID = uuid.Must(uuid.FromString("123e4567-e89b-12d3-a456-426655440000"));

func NewV1

func NewV1() (UUID, error)

NewV1 returns UUID based on current timestamp and MAC address.

func NewV2

func NewV2(domain byte) (UUID, error)

NewV2 returns DCE Security UUID based on POSIX UID/GID.

func NewV3

func NewV3(ns UUID, name string) UUID

NewV3 returns UUID based on MD5 hash of namespace UUID and name.

func NewV4

func NewV4() (UUID, error)

NewV4 returns random generated UUID.

func NewV5

func NewV5(ns UUID, name string) UUID

NewV5 returns UUID based on SHA-1 hash of namespace UUID and name.

func (UUID) Bytes

func (u UUID) Bytes() []byte

Bytes returns bytes slice representation of UUID.

func (UUID) MarshalBinary

func (u UUID) MarshalBinary() (data []byte, err error)

MarshalBinary implements the encoding.BinaryMarshaler interface.

func (UUID) MarshalText

func (u UUID) MarshalText() (text []byte, err error)

MarshalText implements the encoding.TextMarshaler interface. The encoding is the same as returned by String.

func (*UUID) SetVariant

func (u *UUID) SetVariant(v byte)

SetVariant sets variant bits.

func (*UUID) SetVersion

func (u *UUID) SetVersion(v byte)

SetVersion sets version bits.

func (UUID) String

func (u UUID) String() string

Returns canonical string representation of UUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.

func (*UUID) UnmarshalBinary

func (u *UUID) UnmarshalBinary(data []byte) (err error)

UnmarshalBinary implements the encoding.BinaryUnmarshaler interface. It will return error if the slice isn't 16 bytes long.

func (*UUID) UnmarshalText

func (u *UUID) UnmarshalText(text []byte) (err error)

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 (UUID) Variant

func (u UUID) Variant() byte

Variant returns UUID layout variant.

func (UUID) Version

func (u UUID) Version() byte

Version returns algorithm version used to generate UUID.