--- loncom/homework/bridgetask.pm	2005/12/21 19:10:33	1.93
+++ loncom/homework/bridgetask.pm	2006/01/21 08:27:09	1.97
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA 
 # definition of tags that give a structure to a document
 #
-# $Id: bridgetask.pm,v 1.93 2005/12/21 19:10:33 albertel Exp $
+# $Id: bridgetask.pm,v 1.97 2006/01/21 08:27:09 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -554,6 +554,8 @@ DONESCREEN
 		    $result.=&show_queue($env{'form.queue'},1);
 		} elsif ($status_code eq 'select_user') {
 		    $result.=&select_user();
+		} elsif ($status_code eq 'unable') {
+		    $result.='<b>'.&mt("Unable to aqcuire a user to grade.").'</b>'.$back;
 		} else {
 		    $result.='<b>'.&mt("No user to be graded.").'</b>'.$back;
 		}
@@ -689,6 +691,17 @@ sub get_key_todo {
     }
     return (undef,undef)
 }
+
+sub minimize_storage {
+    foreach my $key (keys(%Apache::lonhomework::results)) {
+	if ($key =~ /regrader$/) { next; }
+	if ($Apache::lonhomework::results{$key} eq
+	    $Apache::lonhomework::history{$key}) {
+	    delete($Apache::lonhomework::results{$key});
+	}
+    }
+}
+
 sub end_Task {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
     my $result='';
@@ -897,6 +910,7 @@ DONEBUTTON
 		$Apache::lonhomework::results{"resource.0.solved"}=
 		    $Apache::lonhomework::results{"resource.$version.0.solved"};
 	    }
+	    &minimize_storage();
 	    &Apache::structuretags::finalize_storage();
 	}
     } elsif ($target eq 'webgrade') {
@@ -1166,6 +1180,7 @@ sub get_queue_counts {
 	return (0,0,0);
     }
     my ($entries,$ready_to_grade,$locks)=(0,0,0);
+    my %slot_cache;
     foreach my $key (sort(keys(%queue))) {
 	if ($key=~/locked$/) {
 	    $locks++;
@@ -1175,8 +1190,11 @@ sub get_queue_counts {
 	    my ($symb,$uname,$udom) = &decode_queue_key($key);
 	    $entries++;
 	    my $slot=$queue{$key}->[0];
-	    my %slot_data=&Apache::lonnet::get_slot($slot);
-	    if (time > $slot_data{'endtime'}) {
+	    if (!exists($slot_cache{$slot})) {
+		my %slot_data=&Apache::lonnet::get_slot($slot);
+		$slot_cache{$slot} = \%slot_data;
+	    }
+	    if (time > $slot_cache{$slot}{'endtime'}) {
 		$ready_to_grade++;
 	    }
 	}
@@ -1305,13 +1323,20 @@ sub get_from_queue {
     my $todo=&find_mid_grade($queue,$symb,$cdom,$cnum);
     &Apache::lonxml::debug("found ".join(':',&decode_queue_key($todo)));
     if ($todo) { return $todo; }
+    my $attempts=0;
     while (1) {
+	if ($attempts > 2) {
+	    # tried twice to get a queue entry, giving up
+	    return (undef,'unable');
+	}
 	my $starttime=time;
 	&Apache::lonnet::cput($queue,{"$symb\0timestamp"=>$starttime},
 			      $cdom,$cnum);
 	&Apache::lonxml::debug("$starttime");
 	my $regexp="^$symb\0queue\0";
-	my %queue=&Apache::lonnet::dump($queue,$cdom,$cnum,$regexp);
+	my $range= ($attempts < 1 ) ? '0-100' : '0-400';
+
+	my %queue=&Apache::lonnet::dump($queue,$cdom,$cnum,$regexp,$range);
 	#make a pass looking for a user _not_ in my section
 	if ($env{'request.course.sec'}) {
 	    &Apache::lonxml::debug("sce");
@@ -1332,7 +1357,10 @@ sub get_from_queue {
 	&Apache::lonxml::debug("got $todo");
 	# otherwise found someone so lets try to lock them
 	# unless someone else already picked them
-	if (!&lock_key($queue,$todo)) { next; }
+	if (!&lock_key($queue,$todo)) {
+	    $attempts++;
+	    next;
+	}
 	my (undef,$endtime)=
 	    &Apache::lonnet::get($queue,["$symb\0timestamp"],
 				 $cdom,$cnum);
@@ -1351,6 +1379,7 @@ sub get_from_queue {
 		&Apache::lonnet::del($queue,["$todo\0locked"],
 				     $cdom,$cnum);
 		&Apache::lonxml::debug("del");
+		$attempts++;
 		next;
 	    }
 	}