[Lazarus] The future of desktop

[Andrew Brunner]

On 11/29/2013 03:28 AM, Michael Schnell wrote:
> "Responsiveness" (the program reacts to user input) is not the problem 
> I meant to describe but the ability of the program to issue "state" 
> messages spontaneously.  This is hampered by the missing symmetry of 
> the http protocol: The client needs to poll for such "reverse" messages.
>
I wanted to make 2 points here...
     1.) This can be mitigated with existing HTTP protocol if you have 
control over the server.   For instance, with Aurawin SCS if a request 
comes in with access to the "core" I set a flag in the sockets engine 
that says keep this socket stream infinitely open. This way HTTPS 
re-negotiation is a thing of the past, and requests are instant.
     2.) Your web browser is key here.  Chrome keeps socket sessions 
cached.  So more often than not there already is a connection made. 
Meaning in the JS code, if you say XMLHTTPRequest(/server/core/command) 
it just creates a string and sends it to the server.  That 
XMLHTTPRequest does not imply a new HTTP connection.

> This can partly be improved by techniques like "comet" that leave a 
> http protocol open in a somewhat "non-standard" way. But AFAIK, this 
> does result in certain problems.

"Non-standard" is a subjective term.  However, there is presently 
WebSockets that standardizes HTML5 event driven socket communication to 
exactly address this entire point.


-- 
Andrew Brunner

Aurawin LLC
512.850.3117
https://aurawin.com/

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