Provide Etag and/or Last-Modified HTTP headers to ease cache control

[Giuseppe Bilotta <giuseppe.bilotta@…>]

Trac serves pages without any Etag or Last-Modified header, which makes cache management rather troublesome, and increases the server load. This is particularly important for RSS feeds, which might be checked relatively often.

(In one of the comments for #663 it was mentioned that conditional GET was planned for 0.9, but one of Trac setups I'm checking on is based on 0.10 and the functionality seems to be missing.)

I think most pages could be served with a Last-Modified header containing the date of the last change (for wiki and ticket pages) or the date of the most recent thing changed (for RSS feeds).

[mark@…]

I second this one.

It would also help if these headers wouldn't be send (which is with 0.10 the case):

Cache-Control: must-revalidate
Expires: Fri, 01 Jan 1999 00:00:00 GMT

[betatim]

it should be trivial todo for the wiki

after line 135 in source:/trunk/trac/wiki/web_ui.py add

req.check_modified(page.time)

this only sends a etag for pages without a query part, except for ?format options, not quite sure how to handle those. maybe

req.check_modified(page.time, format)

is a better idea. sorry for not diffing.

[cboos]

Seems like the check_modified is gone from the wiki web_ui, need to check this.