refresh patterns & reload

I have now extended my refresh_pattern options with two additional
options to tweak reload (no-cache) behaviour.

reload-into-ims no-cache is changed to IMS
  and
ignore-reload no-cache is ignored

and at the same time fixed reload_into_ims to actually generate IMS
queries (previously it was more like "ignore-reload").

A diff is submitted to squid-bugs, and also available from my web
page as usual. The complete patch is two parts files: first the part
that adds override-X, and then the reload options part.

All my current refresh_pattern options:

# TAG: refresh_pattern
# usage: refresh_pattern regex min percent max [options]
#
# min and max are specified in MINUTES.
# percent is an integer number.
#
# options: override-expire
# override-lastmod
# reload-into-ims
# ignore-reload
#
# override-expire enforces min age even if the server
# sent a Expires: header. Doing this VIOLATES the HTTP
# standard. Enabling this feature could make you liable
# for problems which it causes.
#
# override-lastmod enforces min age even on objects
# that was modified recently.
#
# reload-into-ims changes client no-cache or ``reload''
# to If-Modified-Since requests. Doing this VIOLATES the
# HTTP standard. Enabling this feature could make you
# liable for problems which it causes.
#
# ignore-reload ignores a client no-cache or ``reload''
# header. Doing this VIOLATES the HTTP standard. Enabling
# this feature could make you liable for problems which
# it causes.

This gives a great deal of freedom when tweaking refresh rules, and
requires at least a basic understanding of what the effects are when
violating HTTP rules.

The refresh_pattern without any options does not violate any HTTP rules,
except possibly the Last-Modified fraction recommendation (only a small
fraction).

min age is not really the correct name anymore. The correct name is
probably something like default age, as the "min" parameter is only used
if the server provided no expiry/modification times, or when one of the
override-* options are used to enforce at least the "min" age.

/Henrik
Received on Tue Jul 29 2003 - 13:15:51 MDT