From: Peter Rabbitson <ribasushi@cpan.org>
Date: Mon, 18 Mar 2013 06:33:23 +0000 (+0100)
Subject: Another parser microoptimisation - lose nullability checks where possible
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=5e6d06f41642ba24ec94fd9eff7d373fefe24f76;p=dbsrgits%2FDBIx-Class-Historic.git

Another parser microoptimisation - lose nullability checks where possible
---

diff --git a/lib/DBIx/Class/ResultSource/RowParser/Util.pm b/lib/DBIx/Class/ResultSource/RowParser/Util.pm
index f80fd7d..7d8f6a7 100644
--- a/lib/DBIx/Class/ResultSource/RowParser/Util.pm
+++ b/lib/DBIx/Class/ResultSource/RowParser/Util.pm
@@ -152,8 +152,11 @@ sub assemble_collapsing_parser {
   my @idcol_args = $no_rowid_container ? ('', '') : (
     ', %cur_row_ids', # only declare the variable if we'll use it
     join ("\n", map {
-      qq(\$cur_row_ids{$_} = defined(\$cur_row_data->[$_]) ? \$cur_row_data->[$_] : "\0NULL\xFF\$rows_pos\xFF$_\0";)
-    } sort { $a <=> $b } keys %{ $stats->{idcols_seen} } )
+      # in case we prune - we will never hit these undefs
+      $args->{prune_null_branches}
+        ? qq(\$cur_row_ids{$_} = \$cur_row_data->[$_];)
+        : qq(\$cur_row_ids{$_} = defined(\$cur_row_data->[$_]) ? \$cur_row_data->[$_] : "\0NULL\xFF\$rows_pos\xFF$_\0";)
+    } sort { $a <=> $b } keys %{ $stats->{idcols_seen} } ),
   );
 
   my $parser_src = sprintf (<<'EOS', @idcol_args, $top_node_key_assembler||'', $top_node_key, join( "\n", @{$data_assemblers||[]} ) );
@@ -173,7 +176,9 @@ sub assemble_collapsing_parser {
     ( $_[1] and $rows_pos = -1 and $_[1]->() )
   ) ) {
 
-    # this code exists only when we are *not* assembling direct to HRI
+    # this code exists only when we are using a cur_row_ids
+    # furthermore the undef checks may or may not be there
+    # depending on whether we prune or not
     #
     # due to left joins some of the ids may be NULL/undef, and
     # won't play well when used as hash lookups
diff --git a/t/resultset/rowparser_internals.t b/t/resultset/rowparser_internals.t
index 848b3a7..146c036 100644
--- a/t/resultset/rowparser_internals.t
+++ b/t/resultset/rowparser_internals.t
@@ -684,11 +684,12 @@ is_same_src (
       ( $_[1] and $rows_pos = -1 and $_[1]->() )
     ) ) {
 
-      $cur_row_ids{0} = defined $cur_row_data->[0] ? $cur_row_data->[0] : "\0NULL\xFF$rows_pos\xFF0\0";
-      $cur_row_ids{2} = defined $cur_row_data->[2] ? $cur_row_data->[2] : "\0NULL\xFF$rows_pos\xFF2\0";
-      $cur_row_ids{3} = defined $cur_row_data->[3] ? $cur_row_data->[3] : "\0NULL\xFF$rows_pos\xFF3\0";
-      $cur_row_ids{4} = defined $cur_row_data->[4] ? $cur_row_data->[4] : "\0NULL\xFF$rows_pos\xFF4\0";
-      $cur_row_ids{8} = defined $cur_row_data->[8] ? $cur_row_data->[8] : "\0NULL\xFF$rows_pos\xFF8\0";
+      # do not care about nullability here
+      $cur_row_ids{0} = $cur_row_data->[0];
+      $cur_row_ids{2} = $cur_row_data->[2];
+      $cur_row_ids{3} = $cur_row_data->[3];
+      $cur_row_ids{4} = $cur_row_data->[4];
+      $cur_row_ids{8} = $cur_row_data->[8];
 
       # cache expensive set of ops in a non-existent rowid slot
       $cur_row_ids{10} = (