--- loncom/interface/spreadsheet/studentcalc.pm	2005/04/07 06:56:23	1.30
+++ loncom/interface/spreadsheet/studentcalc.pm	2005/05/13 20:30:14	1.31
@@ -1,5 +1,5 @@
 #
-# $Id: studentcalc.pm,v 1.30 2005/04/07 06:56:23 albertel Exp $
+# $Id: studentcalc.pm,v 1.31 2005/05/13 20:30:14 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -101,22 +101,29 @@ sub initialize_sequence_cache {
     for my $sequence ($navmap->getById('0.0'), @all_sequences) {
 	if ($navmap->hasResource($sequence,sub { shift->is_problem(); }, 0)){
             push(@Sequences,$sequence);
+	    &get_resources($sequence);
         }
     }
 }
 
+my %res_memoize;
 sub get_resources {
     my ($seq) = @_;
+    if (exists($res_memoize{$seq->symb()})) {
+	return @{$res_memoize{$seq->symb()}};
+    }
     return () if (! defined($navmap) || ! ref($navmap));
     my @resources = $navmap->retrieveResources($seq,
                                                sub { shift->is_problem(); },
                                                0,0,0);
+    $res_memoize{$seq->symb()}=\@resources;
     return @resources;
 }
 
 sub clear_package {
     undef(@Sequences);
     undef(%Exportrows);
+    undef(%res_memoize);
     &Apache::assesscalc::clear_package();
 }