eureka

#Eureka

RPC and boardcast networks based on ZMQ

##RPC

###Creating server

var srv = Server.create({

name: "s2",

endpoint: {
pub: "tcp://*:6061",
router: "tcp://*:6611"
}

});

###Registering methods

Server.register() accepts a simple object that has a "\__symbols__" map describing the methods avaiable. Method requests are checked against this map in case of illegal purpose.

srv.register({
ns: "bar",
foo: function(id) {},
col: function(name) {},
kar: function(file) {},

__symbols__: {
"bar.foo": {
params: [{
name: "id",
type: "number"
}],
type: "method"
},

"bar.col": {
params: [{
name: "name",
type: "string"
}],
type: "method"
},

"bar.kar": {
params: [{
name: "file",
type: "string"
}],
type: "method"
}
}
});


You could specify a json file to clean up the mess:

srv.register(require("./foo"));

In foo.js

var Foo = {

ns: "foo",

bar: function(drip) {
setTimeout(function() {
console.log("%@ from %@".fmt(drip.req.params.greetings, drip.id));
drip.out("nice");
drip.end();
}, 200);
},

__symbols__: require("./foo.json")

};

module.exports = Foo;

And we put method descriptions in foo.json.

###Method invocation

var client = Client.create({

name: "c1",

endpoint: {
sub: "tcp://127.0.0.1:60601",
dealer: "tcp://127.0.0.1:60611"
}

});

####Client.request(api, params, cb)

Client#request method is the main entry point of method invocation, where cb is passed with single argument:

* resp: a response stream object, which have "error", "data", "end " events

####Client.get(api, params, cb)
This shortcut method is used to retrieve simple response from remote method. Cb is passed with two arugments:

* error: an error object if any
* data: stringified content of response stream

###Relfection
There's a special API that can tell clients about the detailed info about avaliable methods on remote server.

client.get("core.reflection", "all", function(err, list) {
//list contains all methods avaliable on server
});

###Event boardcast

####Server.boardcast(type, msg)

Boardcasting message to all clients is quite straight forward.

####Client.subscribe(type, cb)

where cb is passed with message from server, and it's called when events of type is published by server.

##Heartbeat

Heartbeat ping-pong requests are secretly handled by RPC.Server and RPC.Client. First heartbeat ping is sent after client's connection request. Server pong response will be replied immediately.

NextPingInterval = LastPingInterval * Math.E, LastPingInterval defaults to 5 seconds