public static async Task <T[]> GetRangeAsync <T>(this BlockSlots <T> blockSlots, int from, int?to)
where T : class
{
if (blockSlots is null)
{
throw new ArgumentNullException(nameof(blockSlots));
}
if (from < 0 || to < 0 || to > blockSlots.Size || from > blockSlots.Size || from > to || blockSlots.Size == 0)
{
throw new ArgumentOutOfRangeException($"to must less {blockSlots.Size}");
}
var t = to ?? (blockSlots.Size - 1);
if (from >= t)
{
#if NET461 || NETSTANDARD2_0
return(Array.Empty <T>());
#else
return(new T[0]);
#endif
}
var rets = new T[t - from + 1];
for (int i = from; i <= t; i++)
{
rets[i] = await blockSlots.GetAsync(i);
}
return(rets);
}
public static IEnumerable <Func <Task <T> > > ToLoadEnumerable <T>(this BlockSlots <T> blockSlots, int start = 0, int?end = null)
where T : class
{
if (blockSlots is null)
{
throw new ArgumentNullException(nameof(blockSlots));
}
if (start < 0 || end > blockSlots.Size || end < 0 || start > blockSlots.Size || start > end || blockSlots.Size == 0)
{
throw new ArgumentOutOfRangeException($"Must [{0},{blockSlots.Size}]");
}
while (start < blockSlots.Size && (end == null || start < end))
{
var i = start;
yield return(() => blockSlots.GetAsync(i));
start++;
}
}
protected override Task <TValue> LoadAsync(int index)
{
return(blockSlots.GetAsync(index));
}
