public static SplitOutcome TrySplitRange(PartitionKeyHashRange partitionKeyHashRange, int rangeCount, out PartitionKeyHashRanges splitRanges)
{
if (rangeCount < 1)
{
splitRanges = default;
return(SplitOutcome.NumRangesNeedsToBeGreaterThanZero);
}
UInt128 actualEnd = partitionKeyHashRange.EndExclusive.HasValue ? partitionKeyHashRange.EndExclusive.Value.Value : UInt128.MaxValue;
UInt128 actualStart = partitionKeyHashRange.StartInclusive.HasValue ? partitionKeyHashRange.StartInclusive.Value.Value : UInt128.MinValue;
UInt128 rangeLength = actualEnd - actualStart;
if (rangeLength < rangeCount)
{
splitRanges = default;
return(SplitOutcome.RangeNotWideEnough);
}
if (rangeCount == 1)
{
// Just return the range as is:
splitRanges = PartitionKeyHashRanges.Create(new PartitionKeyHashRange[] { partitionKeyHashRange });
return(SplitOutcome.Success);
}
List <PartitionKeyHashRange> childRanges = new List <PartitionKeyHashRange>();
UInt128 childRangeLength = rangeLength / rangeCount;
// First range should start at the user supplied range (since the input might have an open range and we don't want to return 0)
{
PartitionKeyHash?start = partitionKeyHashRange.StartInclusive;
PartitionKeyHash end = new PartitionKeyHash(actualStart + childRangeLength);
childRanges.Add(new PartitionKeyHashRange(start, end));
}
for (int i = 1; i < rangeCount - 1; i++)
{
PartitionKeyHash start = new PartitionKeyHash(actualStart + (childRangeLength * i));
PartitionKeyHash end = new PartitionKeyHash(start.Value + childRangeLength);
childRanges.Add(new PartitionKeyHashRange(start, end));
}
// Last range will have remaining EPKs, since the range might not be divisible.
{
PartitionKeyHash start = new PartitionKeyHash(actualStart + (childRangeLength * (rangeCount - 1)));
PartitionKeyHash?end = partitionKeyHashRange.EndExclusive;
childRanges.Add(new PartitionKeyHashRange(start, end));
}
splitRanges = PartitionKeyHashRanges.Create(childRanges);
return(SplitOutcome.Success);
}
public static PartitionKeyHashRanges SplitRange(PartitionKeyHashRange partitionKeyHashRange, int rangeCount)
{
SplitOutcome splitOutcome = PartitionKeyHashRangeSplitterAndMerger.TrySplitRange(
partitionKeyHashRange,
rangeCount,
out PartitionKeyHashRanges splitRanges);
return(splitOutcome switch
{
SplitOutcome.Success => splitRanges,
SplitOutcome.NumRangesNeedsToBeGreaterThanZero => throw new ArgumentOutOfRangeException($"{nameof(rangeCount)} must be a positive integer"),
SplitOutcome.RangeNotWideEnough => throw new ArgumentOutOfRangeException($"{nameof(partitionKeyHashRange)} is not wide enough to split into {rangeCount} ranges."),
_ => throw new ArgumentOutOfRangeException($"Unknown {nameof(SplitOutcome)}: {splitOutcome}."),
});