Merge 'trunk' into 'sybase'

r5334@hlagh (orig r6501):  ribasushi | 2009-06-04 06:38:21 -0700
Really delegate counting to the storage class - now we have either a grouped count or a regular one

diff --combined lib/DBIx/Class/Storage/DBI.pm
index f3ea456,c20a931..0141e1c
--- 1/lib/DBIx/Class/Storage/DBI.pm
--- 2/lib/DBIx/Class/Storage/DBI.pm
+++ b/lib/DBIx/Class/Storage/DBI.pm
@@@ -926,22 -926,6 +926,22 @@@ sub _fix_bind_params 
          } @bind;
  }
  
 +sub _flatten_bind_params {
 +    my ($self, @bind) = @_;
 +
 +    ### Turn @bind from something like this:
 +    ###   ( [ "artist", 1 ], [ "cdid", 1, 3 ] )
 +    ### to this:
 +    ###   ( 1, 1, 3 )
 +    return
 +        map {
 +            if ( defined( $_ && $_->[1] ) ) {
 +                @{$_}[ 1 .. $#$_ ];
 +            }
 +            else { undef; }
 +        } @bind;
 +}
 +
  sub _query_start {
      my ( $self, $sql, @bind ) = @_;
  
@@@ -1245,30 -1229,57 +1245,66 @@@ sub _select_args 
    return @args;
  }
  
 -sub count {
 +sub _trim_attributes_for_count {
    my ($self, $source, $attrs) = @_;
 -
 -  my $tmp_attrs = { %$attrs };
 +  my %attrs = %$attrs;
  
    # take off any column specs, any pagers, record_filter is cdbi, and no point of ordering a count
-   delete $attrs{$_} for (qw/columns +columns select +select as +as rows offset page pager order_by record_filter/);
 -  delete $tmp_attrs->{$_} for (qw/columns +columns select +select as +as rows offset page pager order_by record_filter/);
++  delete @attrs{qw/
++    columns +columns select +select as +as rows offset page pager order_by
++    record_filter/)};
 +
 +  return \%attrs;
 +}
 +
 +sub count {
 +  my ($self, $source, $attrs) = @_;
 +
 +  my $new_attrs = $self->_trim_attributes_for_count($source, $attrs);
  
 -  $tmp_attrs->{select} = { count => '*' };
 -  $tmp_attrs->{as} = [qw/count/];
 +  $new_attrs->{select} = { count => '*' };
 +  $new_attrs->{as} = [qw/count/];
  
 -  my $tmp_rs = $source->resultset_class->new($source, $tmp_attrs);
 +  my $tmp_rs = $source->resultset_class->new($source, $new_attrs);
    my ($count) = $tmp_rs->cursor->next;
  
+   # if the offset/rows attributes are still present, we did not use
+   # a subquery, so we need to make the calculations in software
+   $count -= $attrs->{offset} if $attrs->{offset};
+   $count = $attrs->{rows} if $attrs->{rows} and $attrs->{rows} < $count;
+   $count = 0 if ($count < 0);
+ 
    return $count;
  }
  
+ sub count_grouped {
+   my ($self, $source, $attrs) = @_;
+ 
+   # copy for the subquery, we need to do some adjustments to it too
+   my $sub_attrs = { %$attrs };
+ 
+   # these can not go in the subquery, and there is no point of ordering it
+   delete $sub_attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns order_by/;
+ 
+   # if we prefetch, we group_by primary keys only as this is what we would get out of the rs via ->next/->all
+   # simply deleting group_by suffices, as the code below will re-fill it
+   # Note: we check $attrs, as $sub_attrs has collapse deleted
+   if (ref $attrs->{collapse} and keys %{$attrs->{collapse}} ) {
+     delete $sub_attrs->{group_by};
+   }
+ 
+   $sub_attrs->{columns} = $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($source->primary_columns) ];
+ 
+   $attrs->{from} = [{
+     count_subq => $source->resultset_class->new ($source, $sub_attrs )->as_query
+   }];
+ 
+   # the subquery replaces this
+   delete $attrs->{$_} for qw/where bind prefetch collapse distinct group_by having having_bind rows offset page pager/;
+ 
+   return $self->count ($source, $attrs);
+ }
+ 
  sub source_bind_attributes {
    my ($self, $source) = @_;