stream-buffer-cache

Cache for node.js streams. Stores stream results in a memory allowing to immediatly replay the stream.

Speed up your services.

Can be applied to any cache that implements Map interface e.g. regular Map or LRU-cache. It redefines get and set methods to make a Map works with streams.

Usefull for caching slow repetitive streaming connections, such as S3 requests or complex database queries.

Installation

npm i @hqjs/stream-buffer-cache

Example

// You can pass any class that implements Map interface
const LRUMap = require('lru-cache');
const Cache = require('@hqjs/stream-buffer-cache')(LRUMap);

// LRU cache options
const options = {
  max: 500,
  maxAge: 1000 * 60 * 60,
};

// Pass your Map class option to Cache constructor
const cache = new Cache(options);
const fs = require('fs');

fs.createReadStream('./buffer-cache.js', { encoding: 'utf8' })
  .pipe(cache.set('test'));

cache.get('test')
  .pipe(fs.createWriteStream('./buffer-cache.js.test'));

API

This methods from parent Map class are overriden

set(key)

returns a Duplex stream

fileStream.pipe(cache.set('key')).pipe(res);

get(key) => ReadableStream

const cached = cache.get('key');
if (cached) {
	cached.pipe(res);
}