Memory-aware Array: Array Subclass in GPUData class

As explained in the Subclassing ndarray documentation, subclassing ndarray is complicated by the fact that new instances of ndarray classes can come about in three different ways:

• Explicit constructor call
• View casting
• New from template

However, our case is simpler because we’re only interested in the view casting. We thus only need to define the __new__ method that will be called at each instance creation. As such, the GPUData class will be equipped with two properties:

• extents: This represents the full extent of the view relatively to the base array. It is stored as a byte offset and a byte size.
• pending_data: This represents the contiguous dirty area as (byte offset, byte size) relatively to the extents property.