flakeid/README.md

Time based 64-bit unique id generator, inspired by Twitter id (snowflake)

# FlakeId
A tiny module to generate time based 64-bit unique id, inspired by Twitter id (snowflake).

FlakeId takes 42 bit of timestamp, 10 bit of machine id (or any random number you provide), 12 bit of sequence number .  As javascript is limited to 53 bit integer precision, FlakeId generates id in string format like "285124269753503744", which can be easily type casted into 64 bit bigint in database.

# Installation

For Node
```js
npm install flakeid
```

For Browser
Include js file
```html
<script src="https://unpkg.com/flakeid/dist/flakeid.min.js"></script>
```

# Usage
Initializtion
```js
const FlakeId = require('flakeid'); /* on node js only */

//initiate flake
const flake = new FlakeId({
	mid : 42, //optional, define machine id
    timeOffset : (2013-1970)*31536000*1000 //optional, define a offset time
});
```
Create a instance of flake as shown above which will be used to generate flake ids afterward.

Id generation
```js
const id1 = flake.gen(); \\returns something like 285124269753503744
const id2 = flake.gen(); \\returns something like 285124417543999488
```

# Options

mid : (Default to 1) A machine id or any random id. If you are generating id in distributed system, its highly advised to provide a proper mid which is unique to different machines.

timeOffset : (Defaults to 0) Time offset will be  subtracted from current time to get the first 42 bit of id. This help in generating smaller ids.

# Method
gen : Method to generate id from FlakeId instance.

------
As js have 53bit integer precision, Flake Id uses a smart solution by Dan Vanderkam (http://www.danvk.org/hex2dec.html) to convert hex to decimal without loosing precision. 
*Source code for converting hex to decimal is taken from http://www.danvk.org/hex2dec.html which have APACHE LICENCE*