+ return HTTP::Date::time2str($mtime_newest);
+}
+
+
+sub cache_finish()
+{
+ # Do not: return if !$W->{"uri_args_frozen"};
+ # as we may have just gave 304 and 'exit 0;' without starting the caching.
+ return if !$W->{"cache_active"};
+
+ # Fill-in/check: %uri_args_frozen_to_headers_in_keys
+ my $headers_in_keys_stored_arrayref_ref=\$uri_args_frozen_to_headers_in_keys{$W->{"uri_args_frozen"}};
+ my @headers_in_keys=tied(%{$W->{"headers_in_RecordKeys"}})->accessed();
+ if (!$$headers_in_keys_stored_arrayref_ref
+ || !Data::Compare::Compare(\@headers_in_keys,$$headers_in_keys_stored_arrayref_ref)) {
+ cluck "Non-matching generated 'headers_in_keys' per 'uri_args_frozen' key:\n"
+ .Dumper(\@headers_in_keys,$$headers_in_keys_stored_arrayref_ref)
+ if $$headers_in_keys_stored_arrayref_ref;
+ # Build or possibly prevent such further warn dupes:
+ $$headers_in_keys_stored_arrayref_ref=\@headers_in_keys;
+ # Build or regenerate as obsoleted now:
+ $W->{"uri_args_headers_in_frozen"}=uri_args_headers_in_frozen_get(\@headers_in_keys);
+ }
+
+ # Prepare 'headers_out' for the future reusal:
+ my %headers_out;
+ $headers_out{"Content-MD5"}=$W->{"digest-md5"}->b64digest();
+ # In fact we could also use MD5 for ETag as if we know ETag we also know MD5.
+ # But this way we do not need to calculate MD5 and we still can provide such ETag. So.
+ # $W->{"r"}->set_etag() ?
+ $headers_out{"ETag"}='"'.Digest::MD5::md5_base64($W->{"uri_args_headers_in_frozen"}).'"';
+ # $W->{"r"}->set_content_length() ?
+ $headers_out{"Content-Length"}=$W->{"r"}->bytes_sent();
+ my %Vary=map(($_=>1),(@headers_in_keys));
+ for (keys(%Vary)) {
+ next if !/^_/;
+ $Vary{"*"}=1;
+ delete $Vary{$_};
+ }
+ %Vary=("*"=>1) if $Vary{"*"};
+ $headers_out{"Vary"}=join(", ",sort keys(%Vary));
+ # $W->{"r"}->set_last_modified() ?
+ $headers_out{"Last-Modified"}=cache_finish_last_modified();
+
+ # Fill-in/check: %uri_args_headers_in_frozen_to_headers_out
+ my $headers_out_stored_hashref_ref=\$uri_args_headers_in_frozen_to_headers_out{$W->{"uri_args_headers_in_frozen"}};
+ if (!$$headers_out_stored_hashref_ref
+ || !Data::Compare::Compare(\%headers_out,$$headers_out_stored_hashref_ref)) {
+ cluck "Non-matching generated 'headers_out' per 'uri_args_headers_in_frozen' key:\n"
+ .Dumper(\%headers_out,$$headers_out_stored_hashref_ref)
+ if $$headers_out_stored_hashref_ref;
+ # Build or possibly prevent such further warn dupes:
+ $$headers_out_stored_hashref_ref=\%headers_out;
+ }
+
+###print STDERR Dumper(\%uri_args_frozen_to_headers_in_keys,\%uri_args_headers_in_frozen_to_headers_out);