--- loncom/Lond.pm	2022/02/01 23:13:21	1.18
+++ loncom/Lond.pm	2022/02/14 02:48:49	1.19
@@ -1,6 +1,6 @@
 # The LearningOnline Network
 #
-# $Id: Lond.pm,v 1.18 2022/02/01 23:13:21 raeburn Exp $
+# $Id: Lond.pm,v 1.19 2022/02/14 02:48:49 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -1039,6 +1039,56 @@ sub get_dom {
         }
         $qresult=~s/\&$//;
     }
+    &untie_user_hash($hashref) or
+        return "error: ".($!+0)." untie(GDBM) Failed while attempting $cmd";
+    return $qresult;
+}
+
+sub store_dom {
+    my ($userinput) = @_;
+    my ($cmd,$dom,$namespace,$rid,$what) =split(/:/,$userinput);
+    my $hashref  = &tie_domain_hash($dom,$namespace,&GDBM_WRCREAT(),"S","$rid:$what") or
+        return "error: ".($!+0)." tie(GDBM) Failed while attempting $cmd";
+    $hashref->{"version:$rid"}++;
+    my $version=$hashref->{"version:$rid"};
+    my $allkeys='';
+    my @pairs=split(/\&/,$what);
+    foreach my $pair (@pairs) {
+        my ($key,$value)=split(/=/,$pair);
+        $allkeys.=$key.':';
+        $hashref->{"$version:$rid:$key"}=$value;
+    }
+    my $now = time;
+    $hashref->{"$version:$rid:timestamp"}=$now;
+    $allkeys.='timestamp';
+    $hashref->{"$version:keys:$rid"}=$allkeys;
+    &untie_user_hash($hashref) or
+        return "error: ".($!+0)." untie(GDBM) Failed while attempting $cmd";    
+    return 'ok';
+}
+
+sub restore_dom {
+    my ($userinput) = @_;
+    my ($cmd,$dom,$namespace,$rid) = split(/:/,$userinput);
+    my $hashref = &tie_domain_hash($dom,$namespace,&GDBM_READER()) or
+        return "error: ".($!+0)." tie(GDBM) Failed while attempting $cmd";
+    my $qresult='';
+    if (ref($hashref)) {
+        chomp($rid);
+        my $version=$hashref->{"version:$rid"};
+        $qresult.="version=$version&";
+        my $scope;
+        for ($scope=1;$scope<=$version;$scope++) {
+            my $vkeys=$hashref->{"$scope:keys:$rid"};
+            my @keys=split(/:/,$vkeys);
+            my $key;
+            $qresult.="$scope:keys=$vkeys&";
+            foreach $key (@keys) {
+                $qresult.="$scope:$key=".$hashref->{"$scope:$rid:$key"}."&";
+            }
+        }
+        $qresult=~s/\&$//;
+    }
     &untie_user_hash($hashref) or
         return "error: ".($!+0)." untie(GDBM) Failed while attempting $cmd";
     return $qresult;