JV> But many servers [don't implement on-the-fly Content-Encoding compression]
And rightly so.
HTTP/1.1 defines two distinct methods for doing compression. There's
instance-level compression, declared by the Content-Encoding header,
which is ``end-to-end'' compression: it is a way of declaring that a
file on the origin server is compressed. For example, an html.gz file
should be served with Content-Type: text/html, Content-Encoding: gzip.
There is also entity-level compression, declared by the
Transfer-Encoding header, which can be correctly used for hop-to-hop
compression, as done by WWWOFFLE. Unfortunately, entity-level
compression is not widely deployed yet.
As entity-level compression is not deployed, Andrew did the courageous
thing: hacking hop-to-hop support at the instance level. If you look
at his code, you'll realise how difficult it is to do reliably. A
better solution, however, than getting sysadmins to use the hack known
as mod_gzip would be to get the Apache developers to implement proper
hop-to-hop compression.
Juliusz
