PHP/C++ server to handle socket.io clients

Question

There is a website which uses socket.io as its 'API'. Essentially, anyone can download the source code of the website and modify it to make their own client with little difficulty. For example, I have such six clients that all run the same custom client side script. The script is hosted on my own domain, not the one with the socket.io API.

I want to be able to keep track of who is connected, and keep a total of certain data. For example if each individual client has 0.5 balance, I want them to be able to know that the total is 3 balance, because of the server.

The most obvious approach I can think of is to do AJAX couple with calls to MySQL to keep track of things, but that seems long-winded.

I could also do CURL but that would be technically challenging.

Is there a simple and straight forward way of simply totaling a balance from six different socket.io clients and sending the information back to them?

Answer 1

Use an object caching layer like APC or memcached as shared memory, in your PHP backend. That way, you can maintain synchronization between different instances/clients.

Bear in mind that you will have to implement some multiprocessing security as this is not thread safe.

For instance:

/* PHP application 1: */
(($value = apc_fetch("IncrementValue")) != FALSE) ? apc_store("IncrementValue",$value+1) : apc_store("IncrementValue",1);

Another can then access it just like this:

echo apc_fetch("IncrementValue");

It is a fast although crude way to communicate between sessions.