public ViewStorage(IStorage dataStorage, params Slice[] slices)
{
if (dataStorage == null)
{
throw new ArgumentException("dataStorage must not be null");
}
if (slices == null)
{
throw new ArgumentException("slices must not be null");
}
if (slices.Length == 0)
{
// if now slices are given the view returns all of all dimensions
slices = new Slice[dataStorage.Shape.NDim];
for (int dim = 0; dim < dataStorage.Shape.NDim; dim++)
{
slices[dim] = Slice.All();
}
}
_data = (IStorage)dataStorage; //all types must inheriet IInternalStorage
_slices = slices;
Engine = dataStorage.Engine;
EnsureValidSlicingDefinitions();
}
private void EnsureValidSlicingDefinitions()
{
// we need to be working with the original shape here because Slicing changes the own shape!
var shape = _data.Shape;
// we need at least one slice per dimension in order to correctly handle multi-dimensional arrays, if not given, extend by Slice.All() which returns the whole dimension
var temp_slices = _slices;
if (_slices == null)
{
temp_slices = new Slice[0];
}
_slices = new Slice[shape.NDim];
for (int dim = 0; dim < shape.NDim; dim++)
{
if (temp_slices.Length > dim)
{
_slices[dim] = temp_slices[dim] ?? Slice.All(); // <-- allow to pass null for Slice.All()
}
else
{
_slices[dim] = Slice.All();
}
}
for (int dim = 0; dim < shape.NDim; dim++)
{
var slice = _slices[dim];
var size = shape.Dimensions[dim];
if (slice.IsIndex)
{
// special case: reduce this dimension
if (slice.Start < 0 || slice.Start >= size)
{
throw new IndexOutOfRangeException($"Index {slice.Start} is out of bounds for axis {dim} with size {size}");
}
}
slice.Start = Math.Max(0, slice.Start ?? 0);
slice.Stop = Math.Min(size, slice.Stop ?? size);
}
// internal shape contains axis with only 1 element that will be reduced in public shape.
internal_shape = _data.Shape.Slice(_slices, reduce: false);
Shape = _data.Shape.Slice(_slices, reduce: true);
}