zzzhan / js-shortid

Short id generator. UUID generator. Url-friendly. Non-predictable.
172 stars 18 forks source link

js-shortid

Short id generator. UUID generator. Url-friendly. Non-predictable.

Quick Start

npm test

Install

If you are using bower, you can download the source like this:

bower install js-shortid --save

js-shortid is available in the npm repository.

npm install js-shortid --save

Usage

Short ID Samples

R6zw8Hly
R6AhD4Jw
R6Cip4M3
R6Ej09A1
R6Fjw3Q4
R6FP04jv
R6IlvZRb
R6LCSXn8
R6NT1Syx
R6O8RN67

Overview

The solution of shortid is clearly the simplest. It is constructed by the character strings:timeseq+salts.

The timeseq is a time sequence since 2016-04-11(default initial time), and converted it to Base 62 string.The time sequence can be increased per millisecond, per second, per minute so on that depends on the option value interval, default value is 1(increase per millisecond).

The salts is constructed by salt1+salt2+..., each salt is a random number and converted to Base 62 string(only two charaters).How many salts will be append to that depends on the option values salts,default is 2(four charaters).More salts of the id more closed to be a UUID, but more longer of the id.

Generally,if the timeseq is increased per millisecond and the salts is 4,the id is almost closed to a UUID.

Options

options.salts

Type: Integer

Default value: '2'

The value that is used to generate the salts count.

options.interval

Type: Integer

Default value: '1'

The value that is the timeseq increased millisecond interval.1000 is increased per second,1000*60 is per minute, so on.If less than zero, there are not timeseq.

options.initTime

Type: Long

Default value: '1460332800000'

The value that is the epoch of the timeseq.The default is millisecond of 2016-04-11.

Options Usage Examples

General

var inst = shortid.inst({salts:3,interval:1000});
console.log(inst.gen());

Quick Style

//default option {salts:2,interval:1}
console.log(shortid.gen());
//custom option
console.log(shortid.gen({salts:3,interval:1000}));
//default option {salts:4,interval:1}
console.log(shortid.uuid());