node-redis-pubsub

node-redis-pubsub copied to clipboard

I ended up writing a small node plugin to allow for many pub-sub clients but only require 2 redis connections instead of a new one on every single socketio connection, it should work in general, figured someone else may find use for it.

Easily installed using npm:

npm install rpsc

This code assumed you have socket.io running and setup, basically in this example any number of socket.io clients can connect and it will always still only use 2 redis connections, but all clients can subscribe to their own channels. In this example, all clients get a message 'sweet message!' after 10 seconds.

Example with socket.io:

var
    rPubSub = require('rpsc');

var 
    redOne = redis.createClient(port, host),
    redTwo = redis.createClient(port, host);

rPubSub.init(redOne);

io.sockets.on('connection', function(socket){
    var cps = rPubSub.createClient();
    cps.onMessage(function(channel, message){
        socket.emit('message', message);
    });
    io.sockets.on('disconnect', function(socket){
        // Dont actually need to unsub, because end() will cleanup all subs, 
        // but if you need to sometime during the connection lifetime, you can.
        cps.unsubscribe('cool_channel');
        cps.end();
    });
    cps.subscribe('cool_channel')
});

setTimeout(function(){
    redTwo.publish('cool_channel', 'sweet message!');
},10000);

Any issues please let me know :)