internal MemoryView(IBufferProtocol @object, int start, int?end, int step, string format, PythonTuple shape)
{
_buffer = @object;
_format = format;
_shape = shape;
_start = start;
_end = end;
_step = step;
if (!TypecodeOps.TryGetTypecodeWidth(format, out _itemsize))
{
_itemsize = (int)_buffer.ItemSize;
}
_matchesBuffer = _format == _buffer.Format && _start % itemsize == 0;
}
public MemoryView cast(object format, [NotNull] object shape)
{
if (!(format is string formatAsString))
{
throw PythonOps.TypeError("memoryview: format argument must be a string");
}
if (_step != 1)
{
throw PythonOps.TypeError("memoryview: casts are restricted to C-contiguous views");
}
if ((shape != null || ndim != 0) && this.shape.Contains(0))
{
throw PythonOps.TypeError("memoryview: cannot cast view with zeros in shape or strides");
}
PythonTuple shapeAsTuple = null;
if (shape != null)
{
if (!(shape is PythonList) && !(shape is PythonTuple))
{
throw PythonOps.TypeError("shape must be a list or a tuple");
}
shapeAsTuple = PythonOps.MakeTupleFromSequence(shape);
int newNDim = shapeAsTuple.Count;
if (newNDim > MaximumDimensions)
{
throw PythonOps.TypeError("memoryview: number of dimensions must not exceed {0}", MaximumDimensions);
}
if (ndim != 1 && newNDim != 1)
{
throw PythonOps.TypeError("memoryview: cast must be 1D -> ND or ND -> 1D");
}
}
int newItemsize;
if (!TypecodeOps.TryGetTypecodeWidth(formatAsString, out newItemsize))
{
throw PythonOps.ValueError(
"memoryview: destination format must be a native single character format prefixed with an optional '@'");
}
bool thisIsBytes = this.format == "B" || this.format == "b" || this.format == "c";
bool otherIsBytes = formatAsString == "B" || formatAsString == "b" || formatAsString == "c";
if (!thisIsBytes && !otherIsBytes)
{
throw PythonOps.TypeError("memoryview: cannot cast between two non-byte formats");
}
int length = numberOfElements();
if (length % newItemsize != 0)
{
throw PythonOps.TypeError("memoryview: length is not a multiple of itemsize");
}
int newLength = length * _itemsize / newItemsize;
if (shapeAsTuple != null)
{
int lengthGivenShape = 1;
for (int i = 0; i < shapeAsTuple.Count; i++)
{
lengthGivenShape *= Converter.ConvertToInt32(shapeAsTuple[i]);
}
if (lengthGivenShape != newLength)
{
throw PythonOps.TypeError("memoryview: product(shape) * itemsize != buffer size");
}
}
return(new MemoryView(_buffer, _start, _end, _step, formatAsString, shapeAsTuple ?? PythonOps.MakeTuple(newLength)));
}
public MemoryView cast([NotNull] string format, [NotNull, AllowNull] object shape)
{
if (!_isCContig)
{
throw PythonOps.TypeError("memoryview: casts are restricted to C-contiguous views");
}
if (_shape.Contains(0) || _strides.Contains(0))
{
throw PythonOps.TypeError("memoryview: cannot cast view with zeros in shape or strides");
}
PythonTuple?shapeAsTuple = null;
if (shape != null)
{
if (!(shape is PythonList) && !(shape is PythonTuple))
{
throw PythonOps.TypeError("shape must be a list or a tuple");
}
shapeAsTuple = PythonTuple.Make(shape);
int newNDim = shapeAsTuple.Count;
if (newNDim > MaximumDimensions)
{
throw PythonOps.TypeError("memoryview: number of dimensions must not exceed {0}", MaximumDimensions);
}
if (_numDims != 1 && newNDim != 1)
{
throw PythonOps.TypeError("memoryview: cast must be 1D -> ND or ND -> 1D");
}
}
int newItemsize;
if (!TypecodeOps.TryGetTypecodeWidth(format, out newItemsize))
{
throw PythonOps.ValueError(
"memoryview: destination format must be a native single character format prefixed with an optional '@'");
}
if (!TypecodeOps.IsByteFormat(this._format) && !TypecodeOps.IsByteFormat(format))
{
throw PythonOps.TypeError("memoryview: cannot cast between two non-byte formats");
}
if ((_numItems * _itemSize) % newItemsize != 0)
{
throw PythonOps.TypeError("memoryview: length is not a multiple of itemsize");
}
int newLength = _numItems * _itemSize / newItemsize;
int[] newShape;
if (shapeAsTuple != null)
{
newShape = new int[shapeAsTuple.Count];
int lengthGivenShape = 1;
for (int i = 0; i < shapeAsTuple.Count; i++)
{
newShape[i] = Converter.ConvertToInt32(shapeAsTuple[i]);
lengthGivenShape *= newShape[i];
}
if (lengthGivenShape != newLength)
{
throw PythonOps.TypeError("memoryview: product(shape) * itemsize != buffer size");
}
}
else
{
newShape = new int[] { newLength };
}
return(new MemoryView(this, format, newItemsize, newShape));
}
