public TimeSliceAsyncEnumerator(TimeSliceAsyncEnumerable <TValue, TAggr> source)
{
_source = source;
_enumerator = _source._series.GetEnumerator();
_current = default(KeyValuePair <DateTime, TAggr>);
_position = TimeSlicePosition.NotStarted;
}
public async Task <bool> MoveNext(CancellationToken cancellationToken)
{
var e = _enumerator as IAsyncEnumerator <KeyValuePair <DateTime, TValue> >;
if (e == null)
{
return(false);
}
switch (_position)
{
case TimeSlicePosition.NotStarted:
if (await e.MoveNext(cancellationToken))
{
var slice = StartOfSlice(_enumerator.Current.Key);
_current = new KeyValuePair <DateTime, TAggr>(slice, _source._initState(_enumerator.Current.Value));
_position = TimeSlicePosition.Aggregating;
goto case TimeSlicePosition.Aggregating;
}
return(false);
case TimeSlicePosition.FinishedSync:
case TimeSlicePosition.Aggregating:
var prev = _current;
while (await e.MoveNext(cancellationToken))
{
var slice = StartOfSlice(_enumerator.Current.Key);
if (slice == prev.Key)
{
_current = new KeyValuePair <DateTime, TAggr>(slice, _source._aggregator(prev.Value, _enumerator.Current.Value));
prev = _current;
}
else
{
_position = TimeSlicePosition.PassedToNext;
return(true);
}
}
_position = TimeSlicePosition.FinishedAsync;
return(true);
case TimeSlicePosition.PassedToNext:
// here we have one unused value at the current position
{
var slice = StartOfSlice(_enumerator.Current.Key);
_current = new KeyValuePair <DateTime, TAggr>(slice, _source._initState(_enumerator.Current.Value));
_position = TimeSlicePosition.Aggregating;
goto case TimeSlicePosition.Aggregating;
}
case TimeSlicePosition.FinishedAsync:
return(false);
default:
throw new ArgumentOutOfRangeException();
}
}
public bool MoveNext()
{
switch (_position)
{
case TimeSlicePosition.NotStarted:
if (_enumerator.MoveNext())
{
var slice = StartOfSlice(_enumerator.Current.Key);
_current = new KeyValuePair <DateTime, TAggr>(slice, _source._initState(_enumerator.Current.Value));
_position = TimeSlicePosition.Aggregating;
goto case TimeSlicePosition.Aggregating;
}
_position = TimeSlicePosition.FinishedSync;
return(false);
case TimeSlicePosition.Aggregating:
var prev = _current;
while (_enumerator.MoveNext())
{
var slice = StartOfSlice(_enumerator.Current.Key);
if (slice == prev.Key)
{
_current = new KeyValuePair <DateTime, TAggr>(slice, _source._aggregator(prev.Value, _enumerator.Current.Value));
prev = _current;
}
else
{
_position = TimeSlicePosition.PassedToNext;
return(true);
}
}
_position = TimeSlicePosition.FinishedSync;
// at least one move was OK, need to return true
return(true);
case TimeSlicePosition.PassedToNext:
// here we have one unused value at the current position
{
var slice = StartOfSlice(_enumerator.Current.Key);
_current = new KeyValuePair <DateTime, TAggr>(slice, _source._initState(_enumerator.Current.Value));
_position = TimeSlicePosition.Aggregating;
goto case TimeSlicePosition.Aggregating;
}
case TimeSlicePosition.FinishedSync:
return(false);
default:
throw new ArgumentOutOfRangeException();
}
}
