Does an implementation of RFC 3229 (Delta encoding for HTTP) exist?

Question

As mentioned briefly in this article:

http://en.wikipedia.org/wiki/Delta_encoding#Delta_encoding_in_HTTP

which is referenced from here:

https://www.rfc-editor.org/rfc/rfc3229

I'm currently a CompSci student and would like to try this out, partly for research and partly for fun. Google hasn't returned much in terms of further discussion or research.

Devito

Answer 1

This page:

http://www.nullege.com/codes/search/urllib2.Request.add_header/all

appears to be indirect evidence of an RFC 3229 implementation.

Tichonn

Answer 2

A server side example of Delta Encoding can be found here. It was written specifically for WordPress. The code is written in PHP and assumes Apache is the web server. For testing purposes, I would recommend setting up a copy of WordPress and installing this plugin. It would definitely get you started.

In addition, please remember that Delta encoding in HTTP is not yet a standard. If this is going to be used in an actual project, you may want to consider other alternatives. At least until web servers and/or web browsers begin adopting the protocol. Otherwise, you may need to create your own server side and client side code.

Barrows

The link above is broken. – Degeneration

Answer 3

Well, there's some information in a blog post. The net result is that there are no implementations, at least none that I can find any evidence of.

Inspiration

Well, that's not really an implementation of the RFC; more of a reuse (some would say misuse) of it. – Vogeley

Answer 4

I'm a fan of delta encoding, but not of this specification. I use an approach that treats deltas:

1. As resources in their own right,
2. As differences to the state of the resource rather than the bytes in a particular representation

In my experience this significantly simplifies implementation and makes the resulting mechanism more flexible and widely applicable. For example, it allows a delta encoding approach to be used in a static atom feed without php or other dynamic content behind it.

Stolid

Answer 5

AIUI AppliedTheory's DeltaEdge product was an implementation. Not sure what happened to it, though.

Vogeley

Answer 6

it is not implemented in any of the standard web servers, but the same can be achieved be achieved by designing your server side application to make use of ajax efficiently. check the magentocommerce as well as wordpress design for eg.

Agle