nuid

README

NUID

A highly performant unique identifier generator.

Installation

Use the go command:

$ go get github.com/nats-io/nuid

Basic Usage

// Utilize the global locked instance
nuid := nuid.Next()

// Create an instance, these are not locked.
n := nuid.New()
nuid = n.Next()

// Generate a new crypto/rand seeded prefix.
// Generally not needed, happens automatically.
n.RandomizePrefix()

Performance

NUID needs to be very fast to generate and be truly unique, all while being entropy pool friendly. NUID uses 12 bytes of crypto generated data (entropy draining), and 10 bytes of pseudo-random sequential data that increments with a pseudo-random increment.

Total length of a NUID string is 22 bytes of base 62 ascii text, so 62^22 or 2707803647802660400290261537185326956544 possibilities.

NUID can generate identifiers as fast as 60ns, or ~16 million per second. There is an associated benchmark you can use to test performance on your own hardware.

License

Unless otherwise noted, the NATS source files are distributed under the Apache Version 2.0 license found in the LICENSE file.

Documentation

Overview

A unique identifier generator that is high performance, very fast, and tries to be entropy pool friendly.

Index

• Constants
• func Next() string
• type NUID
  • func New() *NUID
  • func (n *NUID) Next() string
  • func (n *NUID) RandomizePrefix()

Constants

const Version = "1.0.1"

Version of the library

Functions

func Next

func Next() string

Generate the next NUID string from the global locked NUID instance.

Types

type NUID

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

func New

func New() *NUID

New will generate a new NUID and properly initialize the prefix, sequential start, and sequential increment.

func (*NUID) Next

func (n *NUID) Next() string

Generate the next NUID string.

func (*NUID) RandomizePrefix

func (n *NUID) RandomizePrefix()

Generate a new prefix from crypto/rand. This call *can* drain entropy and will be called automatically when we exhaust the sequential range. Will panic if it gets an error from rand.Int()