From: Moritz Onken <onken@netcubed.de>
Date: Wed, 12 Jan 2011 16:56:48 +0000 (+0100)
Subject: implemented _collapse_result and _merge_result
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=01272eb81fe3a43e0a2f7befa465cc669945d543;p=dbsrgits%2FDBIx-Class-Historic.git

implemented _collapse_result and _merge_result

fixed inflate_result and some calling arguments
---

diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm
index aa64774..39207b6 100644
--- a/lib/DBIx/Class/ResultSet.pm
+++ b/lib/DBIx/Class/ResultSet.pm
@@ -986,7 +986,6 @@ sub next {
 #
 sub _construct_objects {
   my ($self, @row) = @_;
-
   my $attrs = $self->_resolved_attrs;
   my $keep_collapsing = $attrs->{collapse};
 
@@ -1040,16 +1039,15 @@ sub _construct_objects {
   }
 =cut
 
-  my $mepref_structs = $self->_collapse_result(\@row)
+  my $mepref_structs = $self->_collapse_result($attrs->{as}, \@row, $keep_collapsing)
     or return ();
 
   my $rsrc = $self->result_source;
   my $res_class = $self->result_class;
   my $inflator = $res_class->can ('inflate_result');
 
-  my @objs = map {
-    $res_class->$inflator ($rsrc, @$_)
-  } (@$mepref_structs);
+  my @objs =
+    $res_class->$inflator ($rsrc, @$mepref_structs);
 
   if (my $f = $attrs->{record_filter}) {
     @objs = map { $f->($_) } @objs;
@@ -1058,6 +1056,83 @@ sub _construct_objects {
   return @objs;
 }
 
+
+sub _collapse_result {
+  my ( $self, $as_proto, $row_ref, $keep_collapsing ) = @_;
+  my $collapse = $self->_resolved_attrs->{collapse};
+  my $parser   = $self->result_source->_mk_row_parser( $as_proto, $collapse );
+  my $result   = [];
+  my $register = {};
+  my $rel_register = {};
+
+  my @row = @$row_ref;
+  do {
+    my $row = $parser->( \@row );
+
+    # init register
+    $self->_check_register( $register, $row ) unless ( keys %$register );
+
+    $self->_merge_result( $result, $row, $rel_register )
+      if ( !$collapse
+      || ( $collapse = $self->_check_register( $register, $row ) ) );
+
+    } while (
+    $collapse
+    && do { @row = $self->cursor->next; $self->{stashed_row} = \@row if @row; }
+
+  # run this as long as there is a next row and we are not yet done collapsing
+    );
+  return $result;
+}
+
+
+
+# Taubenschlag
+sub _check_register {
+  my ( $self, $register, $obj ) = @_;
+  return undef unless ( ref $obj eq 'ARRAY' && ref $obj->[2] eq 'ARRAY' );
+  my @ids = @{ $obj->[2] };
+  while ( defined( my $id = shift @ids ) ) {
+    return $register->{$id} if ( exists $register->{$id} && !@ids );
+    $register->{$id} = @ids ? {} : $obj unless ( exists $register->{$id} );
+    $register = $register->{$id};
+  }
+  return undef;
+}
+
+
+sub _merge_result {
+  my ( $self, $result, $row, $register ) = @_;
+  return @$result = @$row if ( @$result == 0 );  # initialize with $row
+
+  my ( undef, $rels,   $ids )   = @$result;
+  my ( undef, $new_rels, $new_ids ) = @$row;
+
+  use List::MoreUtils;
+  my @rels = List::MoreUtils::uniq( keys %$rels, keys %$new_rels );
+  foreach my $rel (@rels) {
+    $register = $register->{$rel} ||= {};
+
+    my $new_data = $new_rels->{$rel};
+    my $data   = $rels->{$rel};
+    @$data = [@$data] unless ( ref $data->[0] eq 'ARRAY' );
+
+    $self->_check_register( $register, $data->[0] )
+      unless ( keys %$register );
+
+    if ( my $found = $self->_check_register( $register, $new_data ) ) {
+      $self->_merge_result( $found, $new_data, $register );
+    }
+    else {
+      push( @$data, $new_data );
+    }
+  }
+  return 1;
+}
+
+
+
+
 =begin
 
 # two arguments: $as_proto is an arrayref of column names,
@@ -1504,7 +1579,7 @@ sub all {
                : $self->cursor->next);
     }
   } else {
-    @objects = map { $self->_construct_objects($_) } $self->cursor->all;
+    @objects = map { $self->_construct_objects(@$_) } $self->cursor->all;
   }
 
   $self->set_cache(\@objects) if $self->{attrs}{cache};
@@ -3173,12 +3248,6 @@ sub _resolved_attrs {
     }
   }
 
-  # the row parser generates differently depending on whether collapsing is requested
-  # the need to look at {select} is temporary
-  $attrs->{_row_parser} = $source->_mk_row_parser (
-    @{$attrs}{qw/as collapse select/}
-  );
-
   # if both page and offset are specified, produce a combined offset
   # even though it doesn't make much sense, this is what pre 081xx has
   # been doing
diff --git a/lib/DBIx/Class/ResultSource.pm b/lib/DBIx/Class/ResultSource.pm
index 1cf2123..43419dc 100644
--- a/lib/DBIx/Class/ResultSource.pm
+++ b/lib/DBIx/Class/ResultSource.pm
@@ -1818,7 +1818,8 @@ sub _mk_row_parser {
       map { $_ => "__VALPOS__$my_cols->{$_}__" } (keys %$my_cols)
     };
 
-    my $clps = [
+    my $clps = undef; # funny thing, but this prevents a memory leak, I guess it's Data::Dumper#s fault (mo)
+    $clps = [
       map { "__VALPOS__${_}__" } ( sort { $a <=> $b } (values %{$collapse_on->{-collapse_on}}) )
     ] if $collapse_on->{-collapse_on};
 
@@ -1855,7 +1856,6 @@ sub _mk_row_parser {
     # change the quoted placeholders to unquoted alias-references
     $_ =~ s/ \' __VALPOS__(\d+)__ \' /sprintf ('$_[0][%d]', $1)/gex
       for grep { defined $_ } @rv_list;
-
     return sprintf '[%s]', join (',', @rv_list);
   }
 }
diff --git a/lib/DBIx/Class/Row.pm b/lib/DBIx/Class/Row.pm
index a397ceb..16e7e59 100644
--- a/lib/DBIx/Class/Row.pm
+++ b/lib/DBIx/Class/Row.pm
@@ -1086,28 +1086,12 @@ sub inflate_result {
     if (ref $prefetch->{$pre}[0] eq 'ARRAY') {
       @pre_vals = @{$prefetch->{$pre}};
     }
-    elsif ($accessor eq 'multi') {
-      $class->throw_exception("Implicit prefetch (via select/columns) not supported with accessor 'multi'");
-    }
     else {
       @pre_vals = $prefetch->{$pre};
     }
 
     my @pre_objects;
     for my $me_pref (@pre_vals) {
-
-        # FIXME - this should not be necessary
-        # the collapser currently *could* return bogus elements with all
-        # columns set to undef
-        my $has_def;
-        for (values %{$me_pref->[0]}) {
-          if (defined $_) {
-            $has_def++;
-            last;
-          }
-        }
-        next unless $has_def;
-
         push @pre_objects, $pre_source->result_class->inflate_result(
           $pre_source, @$me_pref
         );