higgs-node

Higgs Boson - Node JS

Node JS implementation of the Boson protocol.

It allows for communication between any Boson server implementation from JavaScript.

Example

The example below users the server example found in the Scala demo

1. Start the Scala server
2. Run the example below

 
var higgs = require("./higgs.js")
var client = new higgs.BosonClient("localhost", 12001)
client.connect()
 
for (var i = 0; i < 1000; i++)
    client.invoke('nodejs', [
        1.2, 1, null,
        {a:1, v:12345},
        [1, 2, 3],
        true, "test"
    ], function (a) {
        console.log(a)
    })
 
 

Output

[ 1.2000000476837158,
  1,
  null,
  { a: 1, v: 12345 },
  [ 1, 2, 3 ],
  true,
  'test' ]
...

Protocol and Deviation from the specs

• JavaScript is powerful but limited in its own way, some of the data types the Boson protocol supports are not supported in JavaScript. Where possible, JavaScript equivalents are used.

Longs

JavaScript does not support longs. When de-serializing the 64 bits that would have otherwise been the entire contents of a long value are taken and broken into "high" and "low" bits.

• The "high" bits (left most 32 bits of the 64 bits) are discarded
• The "low" bits are then treated as an integer and returned. This means if a long value is received that cannot fit into 32 bits it won't give what you expect.
• If Longs must be sent to the Node JS client then send it as a string!
• I've considered doing something similar to mongo but it seems over kill if its not absolutely required. Open to suggestions on how to handle it.

Floats & Doubles

No matter what you try, no matter how much you yell floats are the only supported types WHEN SENDING, the server can send doubles back and they will be handled as expected. So on the server, don't expect Node JS to send a double, it'll always send a float.

It is possible for Node JS to send Doubles but to do that you'd have to be able to differentiate between a float and a double. Not found a sensible way to do that.

Maps & POLOs

A POLO is Boson's way of allowing a statically typed language such as Java/Scala to send any of its types. JavaScript doesn't really have static types and on most days everything is an "object".

• When the Node JS client receives a POLO it creates a JavaScript hash/map from it. In that hash, the keys are the variable names and the values are what were the values of the variable when the POLO was serialized.

Arrays & Lists

• Practically the only difference between an array and a list is that arrays are ordered and lists aren't. When the client receives a list it just de-serializes it into a JavaScript array.

Server

• TODO - Only a Boson client is implemented in JavaScript so far. It allows you to invoke methods on a Boson server and receive whatever response that method returned.