public static DateTime ToTimeFrameStart(this DateTime moment, UnitPeriod unitPeriod, uint length = 1)
{
// TODO (low): support offset, e.g. 1 hours that starts at 15th minute
if (length == 0)
{
throw new InvalidOperationException("Length is zero");
}
long divisor;
switch (unitPeriod)
{
case UnitPeriod.Tick:
if (length != 1)
{
throw new InvalidOperationException("Tick length != 1 is meaningless");
}
return(moment);
case UnitPeriod.Millisecond:
divisor = TimeSpan.TicksPerMillisecond * length;
return(new DateTime((moment.Ticks / (divisor)) * (divisor), moment.Kind));
case UnitPeriod.Second:
divisor = TimeSpan.TicksPerSecond * length;
return(new DateTime((moment.Ticks / (divisor)) * (divisor), moment.Kind));
case UnitPeriod.Minute:
divisor = TimeSpan.TicksPerMinute * length;
return(new DateTime((moment.Ticks / (divisor)) * (divisor), moment.Kind));
case UnitPeriod.Hour:
divisor = TimeSpan.TicksPerHour * length;
return(new DateTime((moment.Ticks / (divisor)) * (divisor), moment.Kind));
case UnitPeriod.Day:
divisor = TimeSpan.TicksPerDay * length;
return(new DateTime((moment.Ticks / (divisor)) * (divisor), moment.Kind));
case UnitPeriod.Month:
if (length != 1)
{
throw new NotSupportedException();
}
return(new DateTime(moment.Year, moment.Month, 1, 0, 0, 0, moment.Kind));
case UnitPeriod.Eternity:
return(DateTime.MinValue);
default:
throw new ArgumentOutOfRangeException(nameof(unitPeriod), unitPeriod, null);
}
}
public TimeSliceAsyncEnumerable(IEnumerable <KeyValuePair <DateTime, TValue> > series, Func <TValue, TAggr> initState,
Func <TAggr, TValue, TAggr> aggregator, UnitPeriod unitPeriod, int periodLength = 1, int offset = 0)
{
if (periodLength <= 0)
{
throw new ArgumentOutOfRangeException(nameof(periodLength));
}
if (offset < 0)
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
if (offset >= periodLength)
{
throw new ArgumentException("Offset must be smaller that period length");
}
_series = series;
_initState = initState;
_aggregator = aggregator;
_unitPeriod = unitPeriod;
_periodLength = periodLength;
_offset = offset;
}
public static IAsyncEnumerable <KeyValuePair <DateTime, TAggr> > TimeSlice <TValue, TAggr>(
this IEnumerable <KeyValuePair <DateTime, TValue> > series, Func <TValue, TAggr> initState,
Func <TAggr, TValue, TAggr> aggregator, UnitPeriod unitPeriod, int periodLength = 1, int offset = 0)
{
return(new TimeSliceAsyncEnumerable <TValue, TAggr>(series, initState, aggregator, unitPeriod, periodLength, offset));
}
