Re: Maintaining HTTP connections...

Christian L. Mogensen (mogens@CS.Stanford.EDU)
Thu, 28 Jul 1994 01:41:15 +0200

Daniel W. Connolly writes:

> In message <>, Dave Jones writes:
> >On dealing with the icons issue: I always thought it would be nice if
> >browsers could deal with multi-image GIF files, making a pseudo-anchor

This is one of the good reasons for having multipart messages:
Problems with it are:
no browsers support it
servers don't support it
You can't send multiple requests at once.

However, it would be nice if the server were smart enough to understand
'compound objects' like pages:
THis is an HTML page and these are the GIFs that go along with it,
served as a Multipart msg: HTML, gif, gif, gif

Unfortunately this doesn't work too well (doesn't allow client side cache,
what if I'm using a text-only browser).

A nicer method would be to allow multiple GETs within a request.
(or have I missed something) - so
1. get page
2. figure out which components need to be fetched. (modulo cached objs)
3. issue one request for all these objects
4. Receive one multipart mesg.

This should shorten retrieval considerably since the biggest problem with
current multiple imgs is that they depend on separate HTTP connects and
the setup time for each new HTTP connect is rather large (especially
when compared to the time to blast over the 2048 bytes of data for an icon).

So - any chance of this becoming useful?

> >each image by it's image number (e.g. <IMG SRC="icons.gif#3> would mean
> >the third image in icons.gif).

Eeek - where would this info be stored?
GIF does not support named sections.
Who would be doing the extraction - the server?
That doesn't fix anything: call setup time will still bite you.
The client?
Time to extract info from large gif would be small compared to
multiple GETs. However, it is (IMHO) a worse solution than multiple
distinct messages.

> <IMG SRC="chemistry-font.gif#100,0,15,6">
> Perhaps it's wise to use named, rather than positional, parameters, so
> that somebody could pass font metric data too:
> <IMG SRC="chemistry-font.gif#x=100;y=0;w=15;h=6;baseline=22;kern=0.6">

Ignoring for the moment the fact that no fonts are distributed as gifs,
and that gifs are stupid way of distributing fonts, _what_ would this do?

Cause subsequent text to be rendered in this font (if possible?)
Cause the font to be displayed on the screen? Install the font on
your system???

Ick no! HTML should not be about sending bitmaps around, but about
sending _information_. If I wanted you to have a bitmap, I would
have used a fax...

Christian "still reeling"