- memory optimizations

diff --git a/dbxrecover b/dbxrecover
index 7ce528a..c6915d2 100755
--- a/dbxrecover
+++ b/dbxrecover
@@ -179,8 +179,6 @@ use strict;
       # it also helps in cases when there are dbx files contained inside dbx

       $self->{file}->seek($chunksize, 1);
-      $self->{hash} = undef;
-      ($self->{id}, $self->{chunksize}, $self->{datasize}, $self->{next}) = ($id, $chunksize, $datasize, $next);
       bless ($self, $class);
       return $self;
     }
@@ -215,22 +213,23 @@ use strict;
   sub data
   {
     my $self = shift;
+    my $datasize = unpack("V", substr($self->{header}, 8, 4));
     my $data;
     $self->{file}->setpos($self->{filepos});
-    $self->{file}->read($data, $self->{datasize});
+    $self->{file}->read($data, $datasize);
     return $data;
   }

   sub id
   {
     my $self = shift;
-    return $self->{id};
+    return scalar unpack("V", $self->{header});
   }

   sub next
   {
     my $self = shift;
-    return $self->{next};
+    return scalar unpack("V", substr($self->{header}, 12, 4));
   }

 }