public bool MoveNext()
{
if (_completed == _length)
{
_current = Memory<T>.Empty;
return false;
}
if (_completed == 0)
{
var firstSegment = _offset >> SegmentedArrayHelper.GetSegmentShift<T>();
var offset = _offset & SegmentedArrayHelper.GetOffsetMask<T>();
var segment = _segments[firstSegment];
var remainingInSegment = segment.Length - offset;
_current = segment.AsMemory().Slice(offset, Math.Min(remainingInSegment, _length));
_completed = _current.Length;
return true;
}
else
{
var segment = _segments[(_completed + _offset) >> SegmentedArrayHelper.GetSegmentShift<T>()];
_current = segment.AsMemory().Slice(0, Math.Min(SegmentedArrayHelper.GetSegmentSize<T>(), _length - _completed));
_completed += _current.Length;
return true;
}
}
public void CalculateOffsetMask(int segmentSize)
{
var expected = segmentSize switch
{
1024 => 0x3FF,
2048 => 0x7FF,
4096 => 0xFFF,
8192 => 0x1FFF,
16384 => 0x3FFF,
32768 => 0x7FFF,
65536 => 0xFFFF,
_ => throw ExceptionUtilities.Unreachable,
};
Assert.Equal(expected, SegmentedArrayHelper.CalculateOffsetMask(segmentSize));
}
public void CalculateSegmentShift(int segmentSize)
{
var expected = segmentSize switch
{
1024 => 10,
2048 => 11,
4096 => 12,
8192 => 13,
16384 => 14,
32768 => 15,
65536 => 16,
_ => throw ExceptionUtilities.Unreachable,
};
Assert.Equal(expected, SegmentedArrayHelper.CalculateSegmentShift(segmentSize));
}
public void CalculateSegmentSize(int elementSize)
{
var expected = elementSize switch
{
1 => 65536,
2 => 32768,
3 => 16384,
4 => 16384,
5 => 16384,
6 => 8192,
7 => 8192,
8 => 8192,
9 => 8192,
10 => 8192,
16 => 4096,
32 => 2048,
_ => throw ExceptionUtilities.Unreachable,
};
Assert.Equal(expected, SegmentedArrayHelper.CalculateSegmentSize(elementSize));
}
