[RFC] Removing most use of #if USE_IPV6 conditional

I'd like to see most uses of the USE_IPV6 conditional removed, limiting
it to just the parts dealing with IPv6 networking.

Having conditionals sprinkled out over the code is bad, and even badder
if the conditional isn't really needed. The basic "IPv6" functionality
like being able to parse IPv6 URLs, ACLs and even AAAA lookups (for ACL
processing) all works perfectly fine even in an IPv4-only setup.

Removing this artificial limit from our code will add two things:

a) We get less conditional code which means less risk for things
bitrotting etc.

b) Users gets another smooth option for IPv6 transition as their
IPv4-only Squids will be perfectly capable of forwarding requests to an
IPv6 enabled proxy, something which we aren't really capable of today
due to even the URL parser being IPv4/IPv6 dependent..

What we loose is the binary size reduction when IPv6 is disabled, but
given that this size reduction is relatively small, only marginally
performance related and also subtly disabling use cases not dependent on
IPv6 support I do not think size optimization by completely removing
everything related to IPv6 is a desirable goal.

Quite many of these conditionals can be removed straight away with no
code changes other than removing the conditional.

Regards
Henrik
Received on Sat Jun 26 2010 - 08:26:49 MDT