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.