B-filters

Javascript implementation of Bloom Filters

A Bloom filter is a space-efficient probabilistic data structure, conceived by Burton Howard Bloom in 1970, that is used to test whether an element is a member of a set. False positive matches are possible, but false negatives are not. Elements can only be be added to the set.

:package: Installation

npm install b-filter --save

:rocket: Load

// using es modules
import BloomFilter from 'b-filter';

// common.js
const BloomFilter = require('b-filter');

// UMD
const BloomFilter = bfilter.default';
const filter = new BloomFilter(20);

:bulb: Usage

//...n numbers of items
const data = ['word 1', 'my second word 2', 'random chars 3'];
const filter = new BloomFilter(data.length);

for (const item in data) {
  filter.add(item);
}

filter.test('word 1'); // true (probably)
filter.test('random'); // false

API

BloomFilter(size: number, falsePositiveRate: number); Default falsePositiveRate 0.005

BloomFilter.test(item: string) returns boolean

Local Development

Below is a list of commands you will probably find useful.

npm start or yarn start

Runs the project in development/watch mode. Your project will be rebuilt upon changes. TSDX has a special logger for you convenience. Error messages are pretty printed and formatted for compatibility VS Code's Problems tab.

npm run build or yarn build

Bundles the package to the dist folder.

npm test or yarn test

Runs the test watcher (Jest) in an interactive mode. By default, runs tests related to files changed since the last commit.

This project was bootstrapped with TSDX.