uuid: github.com/gofrs/uuid Index | Files

package uuid

import "github.com/gofrs/uuid"

Package uuid provides implementations of the Universally Unique Identifier (UUID), as specified in RFC-4122 and DCE 1.1.

RFC-4122[1] provides the specification for versions 1, 3, 4, and 5.

DCE 1.1[2] provides the specification for version 2.

[1] https://tools.ietf.org/html/rfc4122 [2] http://pubs.opengroup.org/onlinepubs/9696989899/chap5.htm#tagcjh_08_02_01_01

Index

Package Files

codec.go generator.go sql.go uuid.go

Constants

❖
const (
    V1  byte // Version 1 (date-time and MAC address)
    V2       // Version 2 (date-time and MAC address, DCE security version)
    V3       // Version 3 (namespace name-based)
    V4       // Version 4 (random)
    V5       // Version 5 (namespace name-based)
)

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 the nil UUID, as specified in RFC-4122, that has all 128 bits set to zero.

type Gen Uses

❖
type Gen struct {
    // contains filtered or unexported fields
}

Gen is a reference UUID generator based on the specifications laid out in RFC-4122 and DCE 1.1: Authentication and Security Services. This type satisfies the Generator interface as defined in this package.

For consumers who are generating V1 UUIDs, but don't want to expose the MAC address of the node generating the UUIDs, the NewGenWithHWAF() function has been provided as a convenience. See the function's documentation for more info.

The authors of this package do not feel that the majority of users will need to obfuscate their MAC address, and so we recommend using NewGen() to create a new generator.

func NewGen Uses

❖
func NewGen() *Gen

NewGen returns a new instance of Gen with some default values set. Most people should use this.

func NewGenWithHWAF Uses

❖
func NewGenWithHWAF(hwaf HWAddrFunc) *Gen

NewGenWithHWAF builds a new UUID generator with the HWAddrFunc provided. Most consumers should use NewGen() instead.

This is used so that consumers can generate their own MAC addresses, for use in the generated UUIDs, if there is some concern about exposing the physical address of the machine generating the UUID.

The Gen generator will only invoke the HWAddrFunc once, and cache that MAC address for all the future UUIDs generated by it. If you'd like to switch the MAC address being used, you'll need to create a new generator using this function.

func (*Gen) NewV1 Uses

❖
func (g *Gen) NewV1() (UUID, error)

NewV1 returns a UUID based on the current timestamp and MAC address.

func (*Gen) NewV2 Uses

❖
func (g *Gen) NewV2(domain byte) (UUID, error)

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

func (*Gen) NewV3 Uses

❖
func (g *Gen) NewV3(ns UUID, name string) UUID

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

func (*Gen) NewV4 Uses

❖
func (g *Gen) NewV4() (UUID, error)

NewV4 returns a randomly generated UUID.

func (*Gen) NewV5 Uses

❖
func (g *Gen) NewV5(ns UUID, name string) UUID

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

type Generator Uses

❖
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 an interface for generating UUIDs.

❖
var DefaultGenerator Generator = NewGen()

DefaultGenerator is the default UUID Generator used by this package.

type HWAddrFunc Uses

❖
type HWAddrFunc func() (net.HardwareAddr, error)

HWAddrFunc is the function type used to provide hardware (MAC) addresses.

type NullUUID Uses

❖
type NullUUID struct {
    UUID  UUID
    Valid bool
}

NullUUID can be used with the standard sql package to represent a UUID value that can be NULL in the database.

func (NullUUID) MarshalJSON Uses

❖
func (u NullUUID) MarshalJSON() ([]byte, error)

MarshalJSON marshals the NullUUID as null or the nested UUID

func (*NullUUID) Scan Uses

❖
func (u *NullUUID) Scan(src interface{}) error

Scan implements the sql.Scanner interface.

func (*NullUUID) UnmarshalJSON Uses

❖
func (u *NullUUID) UnmarshalJSON(b []byte) error

UnmarshalJSON unmarshals a NullUUID

func (NullUUID) Value Uses

❖
func (u NullUUID) Value() (driver.Value, error)

Value implements the driver.Valuer interface.

type Timestamp Uses

❖
type Timestamp uint64

Timestamp is the count of 100-nanosecond intervals since 00:00:00.00, 15 October 1582 within a V1 UUID. This type has no meaning for V2-V5 UUIDs since they don't have an embedded timestamp.

func TimestampFromV1 Uses

❖
func TimestampFromV1(u UUID) (Timestamp, error)

TimestampFromV1 returns the Timestamp embedded within a V1 UUID. Returns an error if the UUID is any version other than 1.

func (Timestamp) Time Uses

❖
func (t Timestamp) Time() (time.Time, error)

Time returns the UTC time.Time representation of a Timestamp

type UUID Uses

❖
type UUID [Size]byte

UUID is an array type to represent the value of a UUID, as defined in RFC-4122.

func FromBytes Uses

❖
func FromBytes(input []byte) (UUID, error)

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

func FromBytesOrNil Uses

❖
func FromBytesOrNil(input []byte) UUID

FromBytesOrNil returns a UUID generated from the raw byte slice input. Same behavior as FromBytes(), but returns uuid.Nil instead of an error.

func FromString Uses

❖
func FromString(input string) (UUID, error)

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

func FromStringOrNil Uses

❖
func FromStringOrNil(input string) UUID

FromStringOrNil returns a UUID parsed from the input string. Same behavior as FromString(), but returns uuid.Nil instead of an error.

func Must Uses

❖
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 Uses

❖
func NewV1() (UUID, error)

NewV1 returns a UUID based on the current timestamp and MAC address.

func NewV2 Uses

❖
func NewV2(domain byte) (UUID, error)

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

func NewV3 Uses

❖
func NewV3(ns UUID, name string) UUID

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

func NewV4 Uses

❖
func NewV4() (UUID, error)

NewV4 returns a randomly generated UUID.

func NewV5 Uses

❖
func NewV5(ns UUID, name string) UUID

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

func (UUID) Bytes Uses

❖
func (u UUID) Bytes() []byte

Bytes returns a byte slice representation of the UUID.

func (UUID) MarshalBinary Uses

❖
func (u UUID) MarshalBinary() ([]byte, error)

MarshalBinary implements the encoding.BinaryMarshaler interface.

func (UUID) MarshalText Uses

❖
func (u UUID) MarshalText() ([]byte, error)

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

func (*UUID) Scan Uses

❖
func (u *UUID) Scan(src interface{}) error

Scan implements the sql.Scanner interface. A 16-byte slice will be handled by UnmarshalBinary, while a longer byte slice or a string will be handled by UnmarshalText.

func (*UUID) SetVariant Uses

❖
func (u *UUID) SetVariant(v byte)

SetVariant sets the variant bits.

func (*UUID) SetVersion Uses

❖
func (u *UUID) SetVersion(v byte)

SetVersion sets the version bits.

func (UUID) String Uses

❖
func (u UUID) String() string

String returns a canonical RFC-4122 string representation of the UUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.

func (*UUID) UnmarshalBinary Uses

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

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

func (*UUID) UnmarshalText Uses

❖
func (u *UUID) UnmarshalText(text []byte) 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"
"{6ba7b8109dad11d180b400c04fd430c8}",
"urn:uuid:6ba7b8109dad11d180b400c04fd430c8"

ABNF for supported UUID text representation follows: 

URN := 'urn'
UUID-NID := 'uuid'

hexdig := '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' |
          'a' | 'b' | 'c' | 'd' | 'e' | 'f' |
          'A' | 'B' | 'C' | 'D' | 'E' | 'F'

hexoct := hexdig hexdig
2hexoct := hexoct hexoct
4hexoct := 2hexoct 2hexoct
6hexoct := 4hexoct 2hexoct
12hexoct := 6hexoct 6hexoct

hashlike := 12hexoct
canonical := 4hexoct '-' 2hexoct '-' 2hexoct '-' 6hexoct

plain := canonical | hashlike
uuid := canonical | hashlike | braced | urn

braced := '{' plain '}' | '{' hashlike  '}'
urn := URN ':' UUID-NID ':' plain

func (UUID) Value Uses

❖
func (u UUID) Value() (driver.Value, error)

Value implements the driver.Valuer interface.

func (UUID) Variant Uses

❖
func (u UUID) Variant() byte

Variant returns the UUID layout variant.

func (UUID) Version Uses

❖
func (u UUID) Version() byte

Version returns the algorithm version used to generate the UUID.

Package uuid imports 15 packages (graph) and is imported by 175 packages. Updated 2018-11-28. Refresh now. Tools for package owners.