[ILUG] mod_gzip tutorial/introduction

[Padraig Brady]

While working on content filtering code for squid I
came across this little beauty (i.e. gzipped compressed
HTTP streams). Example sites that use it are www.oracle.com
and search results from google (not the main page).
All major browsers support this of course, but as you
can imagine it complicates content filtering a little :-)
In mozilla if you go to: Edit->Preferences->Debug->Networking
you can see the "Accept-Encoding" field which
by default is set to: gzip,deflate,compress,identity

It's interesting what you say about some servers not
sending the content-encoding header entry. Are you sure
about this? If so I'll probably have to have some heuristic
for determining the stream contents when the encoding field
is not present :-( I can rip it from file easy enough, but
it'll slow things down a bit.

Padraig.

> -----Original Message-----
> From: Donncha O Caoimh [mailto:donncha.ocaoimh at tradesignals.com]
> Sent: 19 February 2001 10:58
> To: ilug at linux.ie
> Subject: Re: [ILUG] mod_gzip tutorial/introduction
> 
> "John P . Looney" wrote:
> > 
> > On Sat, Feb 17, 2001 at 08:26:44PM +0000, Donncha O Caoimh 
> mentioned:
> > > There's a new tutorial on the site. Actually, it's more 
> an introduction,
> > > to mod_gzip, It's at 
> http://www.linux.ie/articles/tutorials/mod_gzip.php
> > >
> > > It'll be expanded on tomorrow as I glean some more info from the
> > > mod_gzip mail archive.
> > 
> >  Oooh...netscape supports this already ? Anywhere I could 
> test it ? (Does
> > squid have to support it too ?)
> > 
> 
> Netscape and MSIE support it since 1999 or so. Konqueror works too.
> Squid doesn't matter, except that it can't do any checking on the
> "freshness" of a file since it's compressed. There's an interesting
> thread on the mod_gzip list about that very subject..
> As I said in the article, MSIE tends to be fairly hit-or-miss. Some of
> them obviously don't send the "Content encoding" header :|
> 
> Check out http://www.tradesignals.com/ to test it :) Look for the
> "quoteboard" link on the right bar. It's a 100k file and compresses to
> 12k!
> 
> Donncha.