uuid

package module
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 Go to latest Published: Oct 13, 2019 License: MIT Imports: 16 Imported by: 0

README

go-uuid is UUID package for Go language

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

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)

History

This repository based on from github.com/satori/go.uuid after it seems to be no longer maintained. Then I decided to make a little modification and maintenance because there were many issues that hadn't been completed in more than a year. And I get a few issues while working on a product.

Hopefully this repository can help other people who want to use uuid on Go.

Installation

Use the go command:

$ go get github.com/budhip/go-uuid

Requirements

UUID package requires Go >= 1.2.

Documentation

Index

Constants

View Source 
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.

View Source 
const (
	VariantNCS byte = iota
	VariantRFC4122
	VariantMicrosoft
	VariantFuture
)

UUID layout variants.

View Source 
const (
	DomainPerson = iota
	DomainGroup
	DomainOrg
)

UUID DCE domains.

View Source 
const Size = 16

Size of a UUID in bytes.

Variables

View Source 
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.

View Source 
var Nil = UUID{}

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

Functions

This section is empty.

Types

type Gen 

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 

func NewGen() *Gen

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

func NewGenWithHWAF 

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 

func (g *Gen) NewV1() (UUID, error)

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

func (*Gen) NewV2 

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

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

func (*Gen) NewV3 

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 

func (g *Gen) NewV4() (UUID, error)

NewV4 returns a randomly generated UUID.

func (*Gen) NewV5 

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 

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 

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

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

type NullUUID 

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 

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

MarshalJSON marshals the NullUUID as null or the nested UUID

func (*NullUUID) Scan 

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

Scan implements the sql.Scanner interface.

func (*NullUUID) UnmarshalJSON 

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

UnmarshalJSON unmarshals a NullUUID

func (NullUUID) Value 

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

Value implements the driver.Valuer interface.

type Timestamp 

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 

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 

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

Time returns the UTC time.Time representation of a Timestamp

type UUID 

type UUID [Size]byte

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

func FromBytes 

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 

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 

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 

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 

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 a UUID based on the current timestamp and MAC address.

func NewV2 

func NewV2(domain byte) (UUID, error)

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

func NewV3 

func NewV3(ns UUID, name string) UUID

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

func NewV4 

func NewV4() (UUID, error)

NewV4 returns a randomly generated UUID.

func NewV5 

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 

func (u UUID) Bytes() []byte

Bytes returns a byte slice representation of the UUID.

func (UUID) Format 

func (u UUID) Format(f fmt.State, c rune)

Format implements fmt.Formatter for UUID values.

The behavior is as follows: The 'x' and 'X' verbs output only the hex digits of the UUID, using a-f for 'x' and A-F for 'X'. The 'v', '+v', 's' and 'q' verbs return the canonical RFC-4122 string representation. The 'S' verb returns the RFC-4122 format, but with capital hex digits. The '#v' verb returns the "Go syntax" representation, which is a 16 byte array initializer. All other verbs not handled directly by the fmt package (like '%p') are unsupported and will return "%!verb(uuid.UUID=value)" as recommended by the fmt package.

func (UUID) MarshalBinary 

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

MarshalBinary implements the encoding.BinaryMarshaler interface.

func (UUID) MarshalText 

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 

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 

func (u *UUID) SetVariant(v byte)

SetVariant sets the variant bits.

func (*UUID) SetVersion 

func (u *UUID) SetVersion(v byte)

SetVersion sets the version bits.

func (UUID) String 

func (u UUID) String() string

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

func (*UUID) UnmarshalBinary 

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 

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 

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

Value implements the driver.Valuer interface.

func (UUID) Variant 

func (u UUID) Variant() byte

Variant returns the UUID layout variant.

func (UUID) Version 

func (u UUID) Version() byte

Version returns the algorithm version used to generate the UUID.

Source Files

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