Parse catalog .dat files as a whole when compiling the backend

Previously Catalog.pm eval'd each individual hash reference
so that comments and whitespace can be preserved when running
reformat-dat-files. This is unnecessary when building, and we can save
~15% off the run time of genbki.pl by simply slurping and eval'-ing
the whole file at once. This saves a bit of time, especially in highly
parallel builds, since most build targets depend on this script's outputs.

Report and review by Andres Freund
Discussion: https://www.postgresql.org/message-id/CAFBsxsGW%3DWRbnxXrc8UqqR479XuxtukSFWV-hnmtgsbuNAUO6w%40mail.gmail.com

diff --git a/src/backend/catalog/Catalog.pm b/src/backend/catalog/Catalog.pm
index e91a8e10a8d6f880f30e444116b8d42d8be6e93c..7c869bad72e1b46651f0ab8f7faf297a5ef15882 100644 (file)
--- a/src/backend/catalog/Catalog.pm
+++ b/src/backend/catalog/Catalog.pm
@@ -287,6 +287,8 @@ sub ParseData
        my $catname = $1;
        my $data    = [];
 
+       if ($preserve_formatting)
+       {
        # Scan the input file.
        while (<$ifd>)
        {
@@ -341,16 +343,32 @@ sub ParseData
                # with --full-tuples to print autogenerated entries, which seems like
                # useful behavior for debugging.)
                #
-               # Only keep non-data strings if we are told to preserve formatting.
+               # Otherwise, we have a non-data string, which we need to keep in
+               # order to preserve formatting.
                if (defined $hash_ref)
                {
                        push @$data, $hash_ref if !$hash_ref->{autogenerated};
                }
-               elsif ($preserve_formatting)
+               else
                {
                        push @$data, $_;
                }
        }
+       }
+       else
+       {
+               # When we only care about the contents, it's faster to read and eval
+               # the whole file at once.
+               local $/;
+               my $full_file = <$ifd>;
+               eval '$data = ' . $full_file    ## no critic (ProhibitStringyEval)
+                 or die "error parsing $input_file\n";
+               foreach my $hash_ref (@{$data})
+               {
+                       AddDefaultValues($hash_ref, $schema, $catname);
+               }
+       }
+
        close $ifd;
 
        # If this is pg_type, auto-generate array types too.