tree 325b626afcab60f08d6a8517961f7be0ae68f892
parent b015b3eb14583f53ea4c0381ff1a733746aed8fd
author Aurelien DARRAGON <adarragon@haproxy.com> 1673003788 +0100
committer Christopher Faulet <cfaulet@haproxy.com> 1674829139 +0100

OPTIM: http_ext/7239: introduce c_mode to save some space

forwarded header option (rfc7239) deals with sample expressions in two
steps: first a sample expression string is extracted from the config file
and later in startup sequence this string is converted into the resulting
sample_expr.

We need to perform these two steps because we cannot compile the expr
too early in the parsing sequence. (or we would miss some context)
Because of this, we have two dinstinct structure members (expr and expr_s)
for each 7239 field supporting sample expressions.
This is not cool, because we're bloating the http forwarded config structure,
and thus, bloating proxy config structure.

To address this, we now merge both expr and expr_s members inside a single
union to regain some space. This forces us to perform some additional logic
to make sure to use the proper structure member at different parsing steps.

Thanks to this, we're also able to free/release related config hints and
sample expression strings as soon as the sample expression
compilation is finished.