goSnowFlake

README

goSnowFlake

A threadsafe unique ID generator inspired by Twitter SnowFlake theory

根据 Twitter SnowFlake 算法， 实现的分布式线程安全 UID 生成器

Feature

• ThreadSafe unique id generator
• Green pluggable, without external storage like Redis or MySQL
• Suitable for distributed systems
• Implement Twitter's SnowFlake theory

Description

+---------------+----------------+----------------+
|timestamp(ms)42  | worker id(10) | sequence(12)  |
+---------------+----------------+----------------+

id  = timestamp | workerid | sequence (eg. 1451063443347648410)

An unique ID contains 3 parts:

• a timestamp in nanosecond
• a worker ID
• a sequence number

Installation

go get github.com/zheng-ji/goSnowFlake

Example

import (
	"fmt"
	"github.com/zheng-ji/goSnowFlake"
)

func main() {
    // Params: Given the workerId, 0 < workerId < 1024
	iw, err := goSnowFlake.NewIdWorker(1) 
	if err!= nil {
		fmt.Println(err)
	}
	for i := 0; i < 100; i++ {
		if id, err := iw.NextId(); err != nil {
            fmt.Println(err)
        } else{
            fmt.Println(id)
        }
	}
}

Documentation

• Twitter Blog Reference
• Reddit Discuss

License

Copyright (c) 2016 by zheng-ji released under MIT License.

Documentation

Index

• Constants
• func ParseId(id int64) (t time.Time, ts int64, workerId int64, seq int64)
• type IdWorker
  • func NewIdWorker(workerid int64) (iw *IdWorker, err error)
  • func (iw *IdWorker) NextId() (ts int64, err error)

Constants

const (
	CEpoch         = 1474802888000
	CWorkerIdBits  = 10 // Num of WorkerId Bits
	CSenquenceBits = 12 // Num of Sequence Bits

	CWorkerIdShift  = 12
	CTimeStampShift = 22

	CSequenceMask = 0xfff // equal as getSequenceMask()
	CMaxWorker    = 0x3ff // equal as getMaxWorkerId()
)

Functions

func ParseId

func ParseId(id int64) (t time.Time, ts int64, workerId int64, seq int64)

ParseId Func: reverse uid to timestamp, workid, seq

Types

type IdWorker

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

IdWorker Struct

func NewIdWorker

func NewIdWorker(workerid int64) (iw *IdWorker, err error)

NewIdWorker Func: Generate NewIdWorker with Given workerid

func (*IdWorker) NextId

func (iw *IdWorker) NextId() (ts int64, err error)

NewId Func: Generate next id