/// <summary>
/// TBD
/// </summary>
/// <param name="sender">TBD</param>
/// <returns>TBD</returns>
public ImmutableHashSet <UniqueAddress> Receivers(UniqueAddress sender)
{
if (_useAllAsReceivers)
{
return(NodeRing().Remove(sender).ToImmutableHashSet());
}
else
{
// Pick nodes from the iterator until n nodes that are not unreachable have been selected.
// Intermediate unreachable nodes up to `monitoredByNrOfMembers` are also included in the result.
// The reason for not limiting it to strictly monitoredByNrOfMembers is that the leader must
// be able to continue its duties (e.g. removal of downed nodes) when many nodes are shutdown
// at the same time and nobody in the remaining cluster is monitoring some of the shutdown nodes.
Func <int, IEnumerator <UniqueAddress>, ImmutableSortedSet <UniqueAddress>, Tuple <int, ImmutableSortedSet <UniqueAddress> > > take = null;
take = (n, iter, acc) =>
{
if (iter.MoveNext() == false || n == 0)
{
return(Tuple.Create(n, acc));
}
else
{
UniqueAddress next = iter.Current;
var isUnreachable = Unreachable.Contains(next);
if (isUnreachable && acc.Count >= MonitoredByNumberOfNodes)
{
return(take(n, iter, acc)); // skip the unreachable, since we have already picked `MonitoredByNumberOfNodes`
}
else if (isUnreachable)
{
return(take(n, iter, acc.Add(next))); // include the unreachable, but don't count it
}
else
{
return(take(n - 1, iter, acc.Add(next))); // include the reachable
}
}
};
var tuple = take(MonitoredByNumberOfNodes, NodeRing().From(sender).Skip(1).GetEnumerator(), ImmutableSortedSet <UniqueAddress> .Empty);
var remaining = tuple.Item1;
var slice1 = tuple.Item2;
IImmutableSet <UniqueAddress> slice = remaining == 0
? slice1
: take(remaining, NodeRing().Until(sender).Where(c => !c.Equals(sender)).GetEnumerator(), slice1).Item2;
return(slice.ToImmutableHashSet());
}
}
public ClusterHeartbeatSenderState HeartbeatRsp(UniqueAddress from)
{
if (ActiveReceivers.Contains(from))
{
FailureDetector.Heartbeat(from.Address);
if (Unreachable.Contains(from))
{
//back from unreachable, ok to stop heartbeating to it
if (!Ring.MyReceivers.Value.Contains(from))
{
FailureDetector.Remove(from.Address);
}
return(Copy(unreachable: Unreachable.Remove(from)));
}
return(this);
}
return(this);
}
