public Dictionary <TKey, HashSet <IDictionaryObserver <TKey, TValue> > > AddPartialObserver(
IDictionaryObserver <TKey, TValue> observer, params TKey[] keys)
{
if (observer is null)
{
throw new ArgumentNullException(nameof(observer));
}
if (keys is null)
{
throw new ArgumentNullException(nameof(keys));
}
foreach (var key in keys)
{
_observers.AddOrUpdate(key, new HashSet <IDictionaryObserver <TKey, TValue> > {
observer
}, (k, o) =>
{
o.Add(observer);
return(o);
});
}
return(keys.ToDictionary(k => k, k => new HashSet <IDictionaryObserver <TKey, TValue> > {
observer
}));
}
public Dictionary <TKey, HashSet <IDictionaryObserver <TKey, TValue> > > RemovePartialObserver(
IDictionaryObserver <TKey, TValue> observer)
{
if (observer is null)
{
throw new ArgumentNullException(nameof(observer));
}
var removed = _observers.Where(pair => pair.Value.Contains(observer) && pair.Value.Remove(observer)).Select(pair => pair.Key);
return(removed.ToDictionary(k => k, k => new HashSet <IDictionaryObserver <TKey, TValue> > {
observer
}));
}
public Dictionary <TKey, HashSet <IDictionaryObserver <TKey, TValue> > > RemovePartialObserver(
IDictionaryObserver <TKey, TValue> observer, params TKey[] keys)
{
if (observer is null)
{
throw new ArgumentNullException(nameof(observer));
}
if (keys is null)
{
throw new ArgumentNullException(nameof(keys));
}
var removed = keys.Where(key =>
_observers.TryGetValue(key, out var observers) && observers.Contains(observer) && observers.Remove(observer));
return(removed.ToDictionary(k => k, k => new HashSet <IDictionaryObserver <TKey, TValue> > {
observer
}));
}
