From: Allen Day <allenday@users.sourceforge.net>
Date: Thu, 7 Aug 2003 03:51:48 +0000 (+0000)
Subject: no longer using set_up_table method.  it incurs an overhead penalty by making
X-Git-Tag: v0.04~354
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=b789c7907b13149a692a57b8c7b4aaa6cf9a4d58;p=dbsrgits%2FSQL-Translator.git

no longer using set_up_table method.  it incurs an overhead penalty by making
it possible to define the class with less code.  why bother doing this when we
are autogenerating code anyway?

we now also do lazy-loading on FK fields so that vivification of an object does
not pay the penalty to vivify has-a objects (ie FK objects) until they are
explicitly asked for.

bottom line: performance increase overally.  huge performance increase for
heavily linked tables.
---

diff --git a/lib/SQL/Translator/Producer/ClassDBI.pm b/lib/SQL/Translator/Producer/ClassDBI.pm
index 64ebfc8..8623e8f 100755
--- a/lib/SQL/Translator/Producer/ClassDBI.pm
+++ b/lib/SQL/Translator/Producer/ClassDBI.pm
@@ -1,7 +1,7 @@
 package SQL::Translator::Producer::ClassDBI;
 
 # -------------------------------------------------------------------
-# $Id: ClassDBI.pm,v 1.28 2003-07-09 17:48:12 allenday Exp $
+# $Id: ClassDBI.pm,v 1.29 2003-08-07 03:51:48 allenday Exp $
 # -------------------------------------------------------------------
 # Copyright (C) 2003 Allen Day <allenday@ucla.edu>,
 #                    Ying Zhang <zyolive@yahoo.com>
@@ -23,7 +23,7 @@ package SQL::Translator::Producer::ClassDBI;
 
 use strict;
 use vars qw[ $VERSION $DEBUG ];
-$VERSION = sprintf "%d.%02d", q$Revision: 1.28 $ =~ /(\d+)\.(\d+)/;
+$VERSION = sprintf "%d.%02d", q$Revision: 1.29 $ =~ /(\d+)\.(\d+)/;
 $DEBUG   = 1 unless defined $DEBUG;
 
 use SQL::Translator::Schema::Constants;
@@ -121,6 +121,8 @@ sub produce {
                 my $field          = ($constraint->fields)[0];
                 my $pk_name        = $pk_xform->($table_pkg_name, $field);
 
+				$packages{ $table_pkg_name }{'_columns_primary'} = $field;
+
                 $packages{ $table_pkg_name }{'pk_accessor'} = 
                     "#\n# Primary key accessor\n#\n".
                     "sub $pk_name {\n    shift->$field\n}\n\n"
@@ -130,7 +132,12 @@ sub produce {
 
         my $is_data = 0;
         foreach my $field ( $table->get_fields ) {
-		  $is_data++ if !$field->is_foreign_key and !$field->is_primary_key;
+		  if ( !$field->is_foreign_key and !$field->is_primary_key ) {
+			push @{ $packages{ $table_pkg_name }{'_columns_essential'} }, $field->name;
+			$is_data++;
+		  } elsif ( !$field->is_primary_key ) {
+			push @{ $packages{ $table_pkg_name }{'_columns_others'} }, $field->name;
+		  }
 		}
 
 		my %linked;
@@ -278,20 +285,47 @@ sub produce {
             "use Class::DBI::Pager;\n\n",
         );    
 
-        if ( $from ) {
-            $create .= 
-                $pkg->{'pkg_name'}."->set_up_table('".$pkg->{'table'}."');\n\n";
-        }
-        else {
-            my $table       = $schema->get_table( $pkg->{'table'} );
-            my @field_names = map { $_->name } $table->get_fields;
-
-            $create .= join("\n",
-                $pkg_name."->table('".$pkg->{'table'}."');\n",
-                $pkg_name."->columns(All => qw/".
-                join(' ', @field_names)."/);\n\n",
-            );
-        }
+#        if ( $from ) {
+#            $create .= 
+#                $pkg->{'pkg_name'}."->set_up_table('".$pkg->{'table'}."');\n\n";
+#        }
+#        else {
+#            my $table       = $schema->get_table( $pkg->{'table'} );
+#            my @field_names = map { $_->name } $table->get_fields;
+#
+#            $create .= join("\n",
+#                $pkg_name."->table('".$pkg->{'table'}."');\n",
+#                $pkg_name."->columns(All => qw/".
+#                join(' ', @field_names)."/);\n\n",
+#            );
+#        }
+
+
+		#the approach here is to do lazy loading on the expensive columns
+		#(expensive defined as those columns which require construction of a referenced object)
+		#fields which are strictly data (ie, not references) are treated as essential b/c they
+		#don't require much time to set up.
+
+		$create .= $pkg_name."->table('".$pkg->{'table'}."');\n";
+
+		#set up primary key field
+		if( $pkg->{'_columns_primary'} ) {
+		  $create .= $pkg_name."->columns(Primary   => qw/".              $pkg->{'_columns_primary'}      ."/);\n";
+		} else {
+		  die "Class::DBI isn't going to like that you don't have a primary key field for table ".$pkg->{'table'};
+		}
+
+		#set up non-FK fields to be populated at construction
+		if( $pkg->{'_columns_essential'} ) {
+		  $create .= $pkg_name."->columns(Essential => qw/". join(' ', @{ $pkg->{'_columns_essential'} }) ."/);\n";
+		}
+
+		#set up FK fields for lazy loading on request
+		if( $pkg->{'_columns_others'} ) {
+		  $create .= $pkg_name."->columns(Others    => qw/".    join(' ', @{ $pkg->{'_columns_others'}    }) ."/);\n";
+		}
+
+		$create .= "\n";
 
         if ( my $pk = $pkg->{'pk_accessor'} ) {
             $create .= $pk;