Re: An MGET proposal for HTTP

Steinar Bang ([email protected])
Mon, 31 Oct 94 09:11:22 +0100


> Proposal for an HTTP MGET Method

> A much discussed pressing need for HTTP is a mechanism for the client
> to request and the server to deliver multiple files in a single
> transaction. The primary (but not sole) motivation is the need to
> improve efficiency of downloading an HTML file and multiple inline
> images for that file. Here is a concrete proposal for the addition of
> an MGET method to HTTP to meet this need. An HTML version of this
> proposal is available at <http://hopf.math.nwu.edu/mget.html>

> _Design Objectives_

> 1. The number of transactions to download an HTML file with inline
> images should be minimized.
> 2. The client should have the option of downloading all, some or none
> of the inline images. It should be able to request some or all
> files with an "If-Modified-Since:" header.
> 3. Additions to the protocol should be simple to implement for
> servers and browsers.
> 4. The statelessness of the server should be preserved.
> 5. New client / old server and old client / new server transactions
> should work.
> 6. The server must be able to transmit the multiple files "on the
> fly" without knowing their size in advance and without making a
> copy of the whole package before transmission.
> 7. The server must have the option of returning some of the requested
> files while denying access or reporting an error for others. In
> particular, it must return a separate status header for each
> requested file.

There is one more objective I can think of. The client should be able
to look at the first bytes of inline images. Enough to determine the
size of the image and, if possible, enough to determine the colour map
of the inline image.

A feature like this would probably complicate all suggested simple
protocol suggestions, so,... would it be worth it?

- Steinar