flake

README

go-flake

This is a simple go implementation of the twitter snowflake id generator.

The id breakdown is:

• 48 bits of a epoch time in milliseconds
• 5 bits of a worker id
• 12 bits of sequence

There are two ways to use the generator

• straight call to generate the id
  • this method will allow the user to pass the worker and seqeunce
• use the generator struct
  • this is for one worker id and will handle auto update of the sequence and check for rollover
  • Errors can help with identifying possible id collision

Examples

The following are the two implementation examples.

Function Generation

import (
	"fmt"

	"github.com/g8rswimmer/go-flake"
)

const (
	worker = uint64(10)
	seq    = uint64(1000)
)

func main() {
	id, err := flake.Generate(worker, seq)
	if err != nil {
		panic(err)
	}
	fmt.Printf("The generated id %v\n", id)
}

Generator

package main

import (
	"fmt"

	"github.com/g8rswimmer/go-flake"
)

const (
	worker = uint64(10)
)

func main() {
	gen, err := flake.New(worker)
	if err != nil {
		panic(err)
	}

	for i := 0; i < 10; i++ {
		id, err := gen.Generate()
		if err != nil {
			panic(err)
		}
		fmt.Printf("The generated id %v\n", id)
	}
}

Documentation

Index

• Variables
• type Generator
  • func New(worker uint64) (*Generator, error)
  • func (g *Generator) Generate() (ID, error)
  • func (g *Generator) Wait()
• type ID
  • func Generate(worker, seq uint64) (ID, error)
  • func (i ID) Decimal() string
  • func (i ID) String() string

Variables

var ErrSequenceRollover = errors.New("flake generator sequence rollover")

ErrSequenceRollover is an error when the sequence number rolls over and the epoch time has not incremented

Types

type Generator

type Generator struct {
	// contains filtered or unexported fields
}

Generator will create a new id from the worker

func New

func New(worker uint64) (*Generator, error)

New will create a new generator for the worker

func (*Generator) Generate

func (g *Generator) Generate() (ID, error)

Generate will create a new id

func (*Generator) Wait

func (g *Generator) Wait()

Wait will sleep for a millisecond, if there was an error on generate, this will help make sure that the sequence rollover will be handled.

type ID

type ID uint64

ID is the flake id 46 bits of time, 6 bits of worker and 12 bits of sequence

const (
	// InvalidID is an invalid id
	InvalidID ID = 0
)

func Generate

func Generate(worker, seq uint64) (ID, error)

Generate will create an id from the worker and sequence requested

func (ID) Decimal

func (i ID) Decimal() string

Decimal is the ID decimal string

func (ID) String

func (i ID) String() string