public IObservable <Tuple <Target, Message> > Map <Source, Target>(IObservable <Tuple <Source, Message> > source, IDictionary <Source, Target> target_by_source)
{
return(RX.Create <Tuple <Target, Message> >(observer =>
{
return source.Subscribe(
source_node_message =>
{
try
{
Target target_node;
bool found_target;
using (Concurrency.ReaderLock(_mutex))
{
found_target = target_by_source.TryGetValue(source_node_message.Item1, out target_node);
}
if (found_target)
{
var target_node_message = Tuple.Create(target_node, source_node_message.Item2);
observer.OnNext(target_node_message);
}
}
catch (Exception error)
{
observer.OnError(error);
}
},
observer.OnError,
observer.OnCompleted
);
}));
}