+$max = 0;
+
+sub count
+{
+ my $n = scalar (keys %list);
+ $max = $n if $n > $max;
+ return $n;
+}
+
+sub max
+{
+ count();
+ return $max;
+}
+
+# link a node to this node and mark the route as available thru
+# this dxchan, any users must be linked separately
+#
+# call as $node->link_node($neighbour, $dxchan);
+#
+
+sub link_node
+{
+ my ($self, $neighbour, $dxchan) = @_;
+
+ my $r = $neighbour->is_empty('dxchan');
+ $self->_addlist('nodes', $neighbour);
+ $neighbour->_addlist('nodes', $self);
+ $neighbour->_addlist('dxchan', $dxchan);
+ return $r ? ($neighbour) : ();
+}
+
+# unlink a node from a neighbour and remove any
+# routes, if this node becomes orphaned (no routes
+# and no nodes) then return it
+#
+
+sub unlink_node
+{
+ my ($self, $neighbour, $dxchan) = @_;
+ $self->_dellist('nodes', $neighbour);
+ $neighbour->_dellist('nodes', $self);
+ $neighbour->_dellist('dxchan', $dxchan) if $dxchan;
+ return $neighbour->is_empty('dxchan') ? ($neighbour) : ();
+}
+
+sub add_route
+{
+ my ($self, $neighbour, $dxchan) = @_;
+
+ # add the dxchan link
+ # add the node link
+ my @rout;
+ push @rout, $self->link_node($neighbour, $dxchan);
+ dbg("Adding $neighbour->{call}") if isdbg('routelow');
+
+ # then run down the tree removing this dxchan link from
+ # all the referenced nodes that use this interface
+ my %visited;
+ my @in = map { Route::Node::get($_) } $neighbour->nodes;
+ foreach my $r (@in) {
+ next unless $r;
+ next if $visited{$r->call};
+ next if $r->{call} eq $main::mycall;
+ next if $r->{call} eq $self->{call};
+ my ($o) = $r->add_dxchan($dxchan);
+ if ($o) {
+ dbg("Connecting new node $o->{call}") if isdbg('routelow');
+ push @rout, $o;
+ }
+ push @in, map{ Route::Node::get($_) } $r->nodes;
+ $visited{$r->call} = $r;
+ }
+
+ # @rout should contain any nodes that have now been de-orphaned
+ # ie have had their first dxchan added.
+ return @rout;
+}
+
+sub remove_route
+{
+ my ($self, $neighbour, $dxchan) = @_;
+
+ # cut the dxchan link
+ # cut the node link
+ my @rout;
+ push @rout, $self->unlink_node($neighbour, $dxchan);
+ dbg("Orphanning $neighbour->{call}") if isdbg('routelow');
+
+ # then run down the tree removing this dxchan link from
+ # all the referenced nodes that use this interface
+ my %visited;
+ my @in = map { Route::Node::get($_) } $neighbour->nodes;
+ foreach my $r (@in) {
+ next unless $r;
+ next if $visited{$r->call};
+ next if $r->{call} eq $main::mycall;
+ next if $r->{call} eq $self->{call};
+ my ($o) = $r->del_dxchan($dxchan);
+ if ($o) {
+ dbg("Orphanning $o->{call}") if isdbg('routelow');
+ push @rout, $o;
+ }
+ push @in, map{ Route::Node::get($_) } $r->nodes;
+ $visited{$r->call} = $r;
+ }
+
+ # in @rout there should be a list of orphaned (in dxchan terms)
+ # nodes. Now go thru and make sure that all their links are
+ # broken (they should be, but this is to check).
+
+ foreach my $r (@rout) {
+ my @nodes = map { Route::Node::get($_)} $r->nodes;
+ for (@nodes) {
+ next unless $_;
+ dbg("Orphaned node $_->{call}: breaking link to $_->{call}") if isdbg('routelow');
+ $r->unlink_node($_);
+ }
+ }
+ return @rout;
+}
+
+# add a user to this node
+# returns Route::User if it is a new user;
+sub add_user
+{
+ my ($self, $uref) = @_;
+ my $r = $uref->is_empty('nodes');
+ $self->_addlist('users', $uref);
+ $uref->_addlist('nodes', $self);
+ $self->{usercount} = scalar @{$self->{users}};
+ return $r ? ($uref) : ();
+}
+
+# delete a user from this node
+sub del_user
+{
+ my ($self, $uref) = @_;
+
+ $self->_dellist('users', $uref);
+ $uref->_dellist('nodes', $self);
+ $self->{usercount} = scalar @{$self->{users}};
+ return $uref->is_empty('nodes') ? ($uref) : ();
+}
+
+# add a single dxchan link
+sub add_dxchan
+{
+ my ($self, $dxchan) = @_;
+ return $self->_addlist('dxchan', $dxchan);
+}
+
+# remove a single dxchan link
+sub del_dxchan
+{
+ my ($self, $dxchan) = @_;
+ $self->_dellist('dxchan', $dxchan);
+ return $self->is_empty('dxchan') ? ($self) : ();
+}
+
+sub usercount
+{
+ my $self = shift;
+ if (@_ && @{$self->{users}} == 0) {
+ $self->{usercount} = shift;
+ }
+ return $self->{usercount};
+}
+
+sub users
+{
+ my $self = shift;
+ return @{$self->{users}};
+}
+
+sub nodes
+{
+ my $self = shift;
+ return @{$self->{nodes}};
+}