Caching the useful headers

[Dirk-Willem van Gulik]

Right now we have a nice utility function:

        ap_cache_cacheable_hdrs_out()
                Make a copy of the headers, and remove from
                the copy any hop-by-hop headers, as defined in Section
                13.5.1 of RFC 2616
(in cache_util.c, part of mod_cache.h public headers) which we can  
apply to both the in and outbound headers.

Now as far as I can see -every- caching module will have to take care  
of the error headers and the content -- and filtering both in-and-out  
that way.

So how about changing this to:

-       ap_cache_cacheable_hdrs_out(r);
                calls ap_cache_cacheable_hdrs
        AND
                Set Content-Type if not set
        AND
                overlays r->err_headers_out

-       ap_cache_cacheable_hdrs_in(r);
                calles ap_cache_cacheable_hdrs

-       ap_cache_cacheable_hdrs(pool, headers, server) (private)
                delete/cleanse as per RFC 2616
        and as per CacheIgnoreHeaders

Or is there a fundamental reason as to why some caches will not want  
to do the 'usual'* ?

Thoughts ?

Dw


 if (r->headers_out) {
                /* Table with just the cachable headers */
                headers_out = ap_cache_cacheable_hdrs_out(
                                        r->pool, r->headers_out, r- 
>server);

                /* If not set in headers_out, set Content-Type */
                if (!apr_table_get(headers_out, "Content-Type")
                    && r->content_type) {
                        apr_table_setn(headers_out, "Content-Type",
                                  ap_make_content_type(r, r- 
>content_type));
                }
                headers_out = apr_table_overlay(r->pool, headers_out,  
r->err_headers_out);
        }
        if (r->headers_in) {
                apr_table_t    *headers_in;
                headers_in = ap_cache_cacheable_hdrs_out(r->pool, r- 
>headers_in, r->server);
        };