https://github.com/ceejbot/jumphash

Really remarkably trivial node bindings for Google's jump consistent hash.
https://github.com/ceejbot/jumphash

Last synced: about 1 year ago
JSON representation

Really remarkably trivial node bindings for Google's jump consistent hash.

• Host: GitHub
• URL: https://github.com/ceejbot/jumphash
• Owner: ceejbot
• License: isc
• Created: 2015-03-16T00:18:03.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2017-07-25T04:41:07.000Z (almost 9 years ago)
• Last Synced: 2025-06-20T13:33:48.372Z (about 1 year ago)
• Language: JavaScript
• Size: 24.4 KB
• Stars: 4
• Watchers: 2
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

          
# @ceejbot/jumphash

Really remarkably trivial node bindings for Google's [jump consistent hash](http://arxiv.org/pdf/1406.2294v1.pdf).

[![Build Status](http://img.shields.io/travis/ceejbot/jumphash/master.svg?style=flat)](http://travis-ci.org/ceejbot/jumphash) [![on npm](http://img.shields.io/npm/v/@ceejbot/jumphash.svg?style=flat)](https://www.npmjs.com/package/@ceejbot/jumphash)

Tested on nodes 4, 6, and 7. Is probably just fine on node 0.10 too.

```

npm install --save @ceejbot/jumphash

```

## Usage

This module provides one function: `jumphash(key, bucketCount)`. `key` must be a non-negative integer or a buffer. `bucketCount` must be a positive integer (0 is an invalid bucket count).

The return value is a integer in the range `[0, bucketCount)` that you can use as you wish. The paper linked above describes the intended data storage use.

```javascript

var jumphash = require('@ceejbot/jumphash')

    assert = require('assert'),

    crypto = require('crypto');

var location = jumphash(23102, 16);

assert(location >= 0);

assert(location < 16);

var buffer = crypto

    .createHash('md5')

    .update('my-string-key-for-some-resource')

    .digest();

var location2 = jumphash(buffer, 16);

```

Only the first 64 bits of the buffer are considered, with the most significant bit first.

## License

ISC