[PyCS-devel] added ETag headers to comments.py and trackback.py

[Georg B. <gb...@mu...>]

Hi!

I just checked in a change to modules/system/comments.py and trackback.py
to add an ETag header and to respect If-None-Match headers. This could
preserve bandwidth if RSS aggregators reading the comment feeds respect
the ETag header.

Don't know how much aggregators support it, though. Last-Modified headers
(and If-Modified-Since) would be possible, too - but would require more
work.

The way the ETag is generated: it's just a MD5 hex digest on the HTML
source. So if it has the same content, it generates the same ETag. The
ETag header is always added, so it will help with caches when accessing
the normal HTML pages, too - as some browsers nowadays respect the ETag
header (and many proxies do).

The _content_ is allways generated, so this doesn't preserve CPU usage. It
just preserves bandwidth by sending out a 304 instead of the content, when
nothing changed. So it shouldn't break anything.

bye, Georg