IEnumerable <T> GetEnumerable <U, V, T> (IEnumerable <U> first,
IEnumerable <V> second,
TemporaryArea <TKey, Tuple <VSlot <U>, VSlot <V> > > store,
Func <U, TKey> fKeySelect,
Func <V, TKey> sKeySelect,
Func <U, V, T> resultor)
{
IEnumerator <U> eFirst = first.GetEnumerator();
IEnumerator <V> eSecond = second.GetEnumerator();
try {
while (eFirst.MoveNext())
{
if (!eSecond.MoveNext())
{
yield break;
}
U e1 = eFirst.Current;
V e2 = eSecond.Current;
TKey key1 = fKeySelect(e1);
TKey key2 = sKeySelect(e2);
if (comparer.Equals(key1, key2))
{
yield return(resultor(e1, e2));
continue;
}
Tuple <VSlot <U>, VSlot <V> > kvp;
do
{
if (store.TryRemove(key1, out kvp) && kvp.Item2.HasValue)
{
yield return(resultor(e1, kvp.Item2.Value));
break;
}
} while (!store.TryAdd(key1, Tuple.Create(new VSlot <U> (e1), new VSlot <V> ())));
do
{
if (store.TryRemove(key2, out kvp) && kvp.Item1.HasValue)
{
yield return(resultor(kvp.Item1.Value, e2));
break;
}
} while (!store.TryAdd(key2, Tuple.Create(new VSlot <U> (), new VSlot <V> (e2))));
}
} finally {
eFirst.Dispose();
eSecond.Dispose();
}
}
internal override IList <IEnumerable <TResult> > GetEnumerables(QueryOptions options)
{
var first = Parent.GetEnumerables(options);
var second = Second.GetEnumerables(options);
if (first.Count != second.Count)
{
throw new InvalidOperationException("Internal size mismatch");
}
var store = new TemporaryArea <TKey, Tuple <VSlot <TFirst>, VSlot <TSecond> > > (comparer);
return(first
.Select((f, i) => GetEnumerable(f, second[i], store, firstKeySelector, secondKeySelector, resultSelector))
.ToList());
}
internal override IList <IEnumerable <KeyValuePair <long, TResult> > > GetOrderedEnumerables(QueryOptions options)
{
var first = Parent.GetOrderedEnumerables(options);
var second = Second.GetOrderedEnumerables(options);
if (first.Count != second.Count)
{
throw new InvalidOperationException("Internal size mismatch");
}
var store = new TemporaryArea <TKey, Tuple <VSlot <KeyValuePair <long, TFirst> >, VSlot <KeyValuePair <long, TSecond> > > > (comparer);
return(first
.Select((f, i) => GetEnumerable <KeyValuePair <long, TFirst>, KeyValuePair <long, TSecond>, KeyValuePair <long, TResult> > (f,
second[i],
store,
(e) => firstKeySelector(e.Value),
(e) => secondKeySelector(e.Value),
(e1, e2) => new KeyValuePair <long, TResult> (e1.Key, resultSelector(e1.Value, e2.Value))))
.ToList());
}
