redis-streams

redis-streams

Extends the official node_redis client with additional functionality to support streaming data into and out of Redis avoiding buffering the entire contents in memory. The real work is powered by the redis-rstream and redis-wstream by @jeffbski.

Installation

npm install redis-streams

Usage

var redis = require('redis');
require('redis-streams')(redis);

This will extend the RedisClient prototype with two additional functions:

readStream(key) - get a Readable stream from redis.

writeStream(key, maxAge) - get a Writable stream from redis.

writeThrough(key, maxAge) - write to redis and pass the stream through.

var redis = require('redis');
require('redis-streams')(redis);

var redisClient = redis.createClient();

redisClient.readStream(key)
	.pipe(process.stdout);

fs.createReadStream('file.txt')
	.pipe(redisClient.writeStream(key, maxAge))
	.on('finish', done);

fs.createReadStream('file.txt')
	.pipe(redisClient.writeThrough(key, maxAge))
	.pipe(process.stdout);

See the unit tests for additional usage examples.

Caching Proxy

You could also implement a Connect caching proxy middleware.

var redis = require('redis');
var request = require('request');
require('redis-streams')(redis);

var redisClient = redis.createClient();

app.get('/cache/:key', function(req, res, next) {
	redis.exists(req.params.key, function(err, exists) {
	   if (err) return next(err);

		if (exists)
			return redis.readStream(req.params.key).pipe(res);

		// Cache the remote http call for 60 seconds
		request.get('http://somewhere.com/' + req.params.key)
			.pipe(redis.writeThrough(req.params.key, 60))
			.pipe(res);
	});
});

The express-api-proxy module utilizes redis-streams for this purpose, but in a more advanced way.