Merge pull request #267 from esmf-org/esmpy_support_large_arrays

ESMPy: Fix type cast to support large Arrays

In a few places, the size of an Array was being cast to a c_int. This caused an overflow if the size exceeded 32 bits. An example of the issue is reported here, and I have reproduced this:
https://github.com/orgs/esmf-org/discussions/263

From some reading, I think the correct cast here should be to ssize_t, which resolves to a long int (64 bits) on a 64-bit architecture. I am not 100% positive of this, but this seems consistent with what I have found; e.g., see:

Argument list in the PyMemoryView_FromMemory function: https://docs.python.org/3/c-api/memoryview.html
https://docs.python.org/3/c-api/intro.html#c.Py_ssize_t
https://stackoverflow.com/questions/20987390/cython-why-when-is-it-preferable-to-use-py-ssize-t-for-indexing

Author: billsacks

src/addon/esmpy/src/esmpy/util/esmpyarray.py

@@ -29,7 +29,7 @@ def ndarray_from_esmf(data, dtype, shape):
     if sys.version_info[0] >= 3:
         buffer = ct.pythonapi.PyMemoryView_FromMemory
         buffer.restype = ct.py_object
-        buffer = buffer(data, ct.c_int(size), 0x200)
+        buffer = buffer(data, ct.c_ssize_t(size), 0x200)
     else:
         buffer = np.core.multiarray.int_asbuffer(
             ct.addressof(data.contents), size)
@@ -65,7 +65,7 @@ def __new__(cls, data, mask, dtype, shape):
         if sys.version_info[0] >= 3:
             buffer = ct.pythonapi.PyMemoryView_FromMemory
             buffer.restype = ct.py_object
-            buffer = buffer(data, ct.c_int(size), 0x200)
+            buffer = buffer(data, ct.c_ssize_t(size), 0x200)
         else:
             buffer = np.core.multiarray.int_asbuffer(
                 ct.addressof(data.contents), size)
@@ -108,7 +108,7 @@ def __new__(cls, data, dtype, shape):
         if sys.version_info[0] >= 3:
             buffer = ct.pythonapi.PyMemoryView_FromMemory
             buffer.restype = ct.py_object
-            buffer = buffer(data, ct.c_int(size), 0x200)
+            buffer = buffer(data, ct.c_ssize_t(size), 0x200)
         else:
             buffer = np.core.multiarray.int_asbuffer(
                 ct.addressof(data.contents), size)