Refactor requests between nodes and add clientRooms method

[darrachequesne]

This PR refactors the way requests are sent between nodes. The subJson
client has been removed, the subClient now listens to three channels by
default:

• the usual channel, where the message are broadcast
• the request channel, where any node can request information (for now,
  the clients in a given rooms or the rooms for a given client)
• the response channel, where a node will receive answer to its requests

Fixes #138 (no more subJson)
Closes #143 (add clientRooms() method)

@artofspeed would that suit your needs?

[darrachequesne]

Also, it should allow to add other useful requests, like making any socket.id join/leave a room, even on another node.

[barisusakli]

This is nice, been waiting for this for a while now. socketio/socket.io#1884

[artofspeed]

Absolutely. Thank you @darrachequesne this PR would be really useful!

[darrachequesne]

Released as 2.0.0, any feedback is welcome!

[barisusakli]

I can't seem to get .clients and .clientRooms to work after I upgrade socket.io dependencies.

These are my dependencies

 "socket.io": "1.7.1",
 "socket.io-client": "1.7.1",
 "socket.io-redis": "2.0.0",

Both .clients and .clientRooms result in

Error: timeout reached while waiting for clients response
    at Timeout._onTimeout (/home/baris/node-forum/node_modules/socket.io-redis/index.js:422:48)
    at ontimeout (timers.js:365:14)
    at tryOnTimeout (timers.js:237:5)

If I drop socket.io-redis dependency to 1.1.1 it works but I can't use .clientRooms.

The code is below.

// init
var redisAdapter = require('socket.io-redis');
var redis = require('../database/redis');
var pub = redis.connect();
var sub = redis.connect({return_buffers: true});
io.adapter(redisAdapter({pubClient: pub, subClient: sub}));

//usage
io.in('topic_1').clients(function (err, socketids) {
});

[barisusakli]

Manually went through commits to find the first one that is causing .clients to stop working and its this PR 84261b2

[darrachequesne]

That is the change induced by this very PR.

Both server1.in('woot').clients(function(err, clients){ and server1.adapter.clients(['woot'], function(err, clients){ should work though.

Could you debug with DEBUG=socket.io-redis* please?

[barisusakli]

See my PR #155 that fixed the issue for me.