@redis/bloom

What is @redis/bloom?

@redis/bloom is an npm package that provides probabilistic data structures for Redis, such as Bloom filters, Cuckoo filters, Count-Min Sketch, and Top-K. These data structures are useful for efficiently handling large sets of data with minimal memory usage and are often used in scenarios like caching, deduplication, and approximate counting.

What are @redis/bloom's main functionalities?

Bloom Filter

This example demonstrates how to create a Bloom filter, add an item to it, and check for the existence of an item. Bloom filters are used to test whether an element is a member of a set with a possible false positive rate.

const { createClient } = require('@redis/bloom');

async function bloomFilterExample() {
  const client = createClient();
  await client.connect();

  await client.bf.reserve('myBloom', 0.01, 1000);
  await client.bf.add('myBloom', 'item1');
  const exists = await client.bf.exists('myBloom', 'item1');
  console.log(exists); // true

  await client.disconnect();
}

bloomFilterExample();

Cuckoo Filter

This example shows how to create a Cuckoo filter, add an item, and check for its existence. Cuckoo filters are similar to Bloom filters but support deletion of items.

const { createClient } = require('@redis/bloom');

async function cuckooFilterExample() {
  const client = createClient();
  await client.connect();

  await client.cf.reserve('myCuckoo', 1000);
  await client.cf.add('myCuckoo', 'item1');
  const exists = await client.cf.exists('myCuckoo', 'item1');
  console.log(exists); // true

  await client.disconnect();
}

cuckooFilterExample();

Count-Min Sketch

This example demonstrates how to initialize a Count-Min Sketch, increment the count of an item, and query the count. Count-Min Sketches are used for approximate frequency counting.

const { createClient } = require('@redis/bloom');

async function countMinSketchExample() {
  const client = createClient();
  await client.connect();

  await client.cms.initByDim('myCMS', 2000, 5);
  await client.cms.incrBy('myCMS', 'item1', 5);
  const count = await client.cms.query('myCMS', 'item1');
  console.log(count); // 5

  await client.disconnect();
}

countMinSketchExample();

Top-K

This example shows how to create a Top-K data structure, add items to it, and retrieve the top K items. Top-K is used to maintain a list of the most frequent items.

const { createClient } = require('@redis/bloom');

async function topKExample() {
  const client = createClient();
  await client.connect();

  await client.topk.reserve('myTopK', 3);
  await client.topk.add('myTopK', 'item1', 'item2', 'item3', 'item1');
  const list = await client.topk.list('myTopK');
  console.log(list); // ['item1', 'item2', 'item3']

  await client.disconnect();
}

topKExample();

Other packages similar to @redis/bloom

bloom-filter

The 'bloom-filter' package provides a simple implementation of Bloom filters in JavaScript. It is less feature-rich compared to @redis/bloom and does not integrate with Redis, making it suitable for in-memory operations only.

cuckoo-filter

The 'cuckoo-filter' package offers a JavaScript implementation of Cuckoo filters. Similar to 'bloom-filter', it does not integrate with Redis and is intended for in-memory use cases.

count-min-sketch

The 'count-min-sketch' package provides a JavaScript implementation of the Count-Min Sketch data structure. It is useful for approximate frequency counting but lacks the Redis integration provided by @redis/bloom.

README

@redis/bloom

This package provides support for the RedisBloom module, which adds additional probabilistic data structures to Redis.

Should be used with redis/@redis/client.

:warning: To use these extra commands, your Redis server must have the RedisBloom module installed.

RedisBloom provides the following probabilistic data structures:

• Bloom Filter: for checking set membership with a high degree of certainty.
• Cuckoo Filter: for checking set membership with a high degree of certainty.
• T-Digest: for estimating the quantiles of a stream of data.
• Top-K: Maintain a list of k most frequently seen items.
• Count-Min Sketch: Determine the frequency of events in a stream.

For some examples, see bloom-filter.js, cuckoo-filter.js, count-min-sketch.js and topk.js in the examples folder.