WIP

python/pyarrow/includes/libarrow.pxd

@@ -370,6 +370,8 @@ cdef extern from "arrow/api.h" namespace "arrow" nogil:
         @staticmethod
         CResult[shared_ptr[CBuffer]] Copy(shared_ptr[CBuffer] source, const shared_ptr[CMemoryManager]& to)
 
+        CResult[shared_ptr[CBuffer]] View(shared_ptr[CBuffer] source, const shared_ptr[CMemoryManager]& to) const
+
     CResult[shared_ptr[CBuffer]] SliceBufferSafe(
         const shared_ptr[CBuffer]& buffer, int64_t offset)
     CResult[shared_ptr[CBuffer]] SliceBufferSafe(

python/pyarrow/io.pxi

@@ -1480,6 +1480,47 @@ cdef class Buffer(_Weakrefable):
         c_buffer = GetResultValue(CBuffer.Copy(self.buffer, c_memory_manager))
         return pyarrow_wrap_buffer(c_buffer)
 
+    def view(self, destination):
+        """
+        Zero-copy access this buffer, from destination.
+
+        The underlying mechanism is typically implemented by the kernel or device driver,
+        and may involve lazy caching of parts of the buffer contents on the destination
+        device's memory.
+
+        If a non-copy view is unsupported for the buffer on the given device,
+        an error is raised.
+
+        Parameters
+        ----------
+        destination : pyarrow.MemoryManager or pyarrow.Device
+            MemoryManager or device on which to view buffer contents
+
+        Returns
+        -------
+        Buffer or None
+        """
+        cdef:
+            shared_ptr[CBuffer] c_buffer
+            shared_ptr[CMemoryManager] c_memory_manager
+
+        if isinstance(destination, Device):
+            c_memory_manager = (<Device>destination).unwrap().get().default_memory_manager()
+        elif isinstance(destination, MemoryManager):
+            c_memory_manager = (<MemoryManager>destination).unwrap()
+        else:
+            raise TypeError(
+                "Argument 'destination' is incorrect type (expected pyarrow.Device or "
+                f"pyarrow.MemoryManager, got {type(destination)})"
+            )
+
+        c_buffer = GetResultValue(self.buffer.get().View(self.buffer, c_memory_manager))
+
+        if c_buffer.get() == nullptr:
+            return None
+
+        return pyarrow_wrap_buffer(c_buffer)
+
     @property
     def parent(self):
         cdef shared_ptr[CBuffer] parent_buf = self.buffer.get().parent()

python/pyarrow/tests/test_cuda.py

@@ -137,6 +137,28 @@ def test_copy_from_buffer():
         assert cudabuf2.device == mm2.device
 
 
+def test_view_of_buffer():
+    data = np.array([1, 2, 3, 4, 5])
+    buf = pa.py_buffer(data)
+    cudabuf = global_context.buffer_from_data(buf)
+
+    mm2 = global_context1.memory_manager
+    for dest in [mm2, mm2.device]:
+        buf2 = cudabuf.view(dest)
+        assert buf2.device_type == pa.DeviceAllocationType.CUDA
+        cudabuf2 = cuda.CudaBuffer.from_buffer(buf2)
+        assert cudabuf2.size == cudabuf.size
+        assert not cudabuf2.is_cpu
+        assert cudabuf2.device_type == pa.DeviceAllocationType.CUDA
+
+        assert cudabuf2.copy_to_host().equals(buf)
+        assert cudabuf2.device == mm2.device
+
+        # test that it is a view, and not a copy
+        data[1] = 20
+        assert np.frombuffer(buf2, dtype=np.int32).tolist() == [20, 2, 3, 4, 5]
+
+
 @pytest.mark.parametrize("size", [0, 1, 1000])
 def test_context_device_buffer(size):
     # Creating device buffer from host buffer;