[pypy-commit] pypy buffer-interface: PyMemoryView_GET_BUFFER wip, len(memorview()) is prod(shape), but getlength() is number of bytes

[mattip]

Author: Matti Picus <matti.picus at gmail.com>
Branch: buffer-interface
Changeset: r86668:3ec8f09e764d
Date: 2016-08-29 09:24 +1000
http://bitbucket.org/pypy/pypy/changeset/3ec8f09e764d/

Log:	PyMemoryView_GET_BUFFER wip, len(memorview()) is prod(shape), but
	getlength() is number of bytes

diff --git a/pypy/module/cpyext/memoryobject.py b/pypy/module/cpyext/memoryobject.py
--- a/pypy/module/cpyext/memoryobject.py
+++ b/pypy/module/cpyext/memoryobject.py
@@ -1,7 +1,8 @@
 from pypy.module.cpyext.api import (cpython_api, Py_buffer, CANNOT_FAIL,
-                                    build_type_checkers)
-from pypy.module.cpyext.pyobject import PyObject
-from rpython.rtyper.lltypesystem import lltype
+                                    build_type_checkers, Py_ssize_tP)
+from pypy.module.cpyext.pyobject import PyObject, as_pyobj, incref
+from rpython.rtyper.lltypesystem import lltype, rffi
+from pypy.objspace.std.memoryobject import W_MemoryView
 
 PyMemoryView_Check, PyMemoryView_CheckExact = build_type_checkers("MemoryView", "w_memoryview")
 
@@ -20,21 +21,29 @@
     object.  The object must be a memoryview instance; this macro doesn't
     check its type, you must do it yourself or you will risk crashes."""
     view = lltype.malloc(Py_buffer, flavor='raw', zero=True)
-    # TODO - fill in fields
-    '''
-    view.c_buf = buf
-    view.c_len = length
-    view.c_obj = obj
-    Py_IncRef(space, obj)
-    view.c_itemsize = 1
-    rffi.setintfield(view, 'c_readonly', readonly)
-    rffi.setintfield(view, 'c_ndim', 0)
-    view.c_format = lltype.nullptr(rffi.CCHARP.TO)
-    view.c_shape = lltype.nullptr(Py_ssize_tP.TO)
-    view.c_strides = lltype.nullptr(Py_ssize_tP.TO)
+    if not isinstance(w_obj, W_MemoryView):
+        return view
+    try:
+        view.c_buf = rffi.cast(rffi.VOIDP, w_obj.buf.get_raw_address())
+    except ValueError:
+        return view
+    view.c_len = w_obj.getlength()
+    view.c_obj = as_pyobj(space, w_obj)
+    incref(space, view.c_obj)
+    view.c_itemsize = w_obj.buf.getitemsize()
+    rffi.setintfield(view, 'c_readonly', w_obj.buf.readonly)
+    ndim = w_obj.buf.getndim()
+    rffi.setintfield(view, 'c_ndim', ndim)
+    view.c_format = rffi.str2charp(w_obj.buf.getformat())
+    view.c_shape = lltype.malloc(Py_ssize_tP.TO, ndim, flavor='raw')
+    view.c_strides = lltype.malloc(Py_ssize_tP.TO, ndim, flavor='raw')
+    shape = w_obj.buf.getshape()
+    strides = w_obj.buf.getstrides()
+    for i in range(ndim):
+        view.c_shape[i] = shape[i]
+        view.c_strides[i] = strides[i]
     view.c_suboffsets = lltype.nullptr(Py_ssize_tP.TO)
     view.c_internal = lltype.nullptr(rffi.VOIDP.TO)
-    ''' 
     return view
 
 
diff --git a/pypy/module/cpyext/object.py b/pypy/module/cpyext/object.py
--- a/pypy/module/cpyext/object.py
+++ b/pypy/module/cpyext/object.py
@@ -508,10 +508,9 @@
 @cpython_api([lltype.Ptr(Py_buffer)], lltype.Void, error=CANNOT_FAIL)
 def PyBuffer_Release(space, view):
     """
-    Releases a Py_buffer obtained from getbuffer ParseTuple's s*.
-
-    This is not a complete re-implementation of the CPython API; it only
-    provides a subset of CPython's behavior.
+    Release the buffer view. This should be called when the buffer is 
+    no longer being used as it may free memory from it
     """
     Py_DecRef(space, view.c_obj)
     view.c_obj = lltype.nullptr(PyObject.TO)
+    # XXX do other fields leak memory?
diff --git a/pypy/module/cpyext/test/test_memoryobject.py b/pypy/module/cpyext/test/test_memoryobject.py
--- a/pypy/module/cpyext/test/test_memoryobject.py
+++ b/pypy/module/cpyext/test/test_memoryobject.py
@@ -21,6 +21,7 @@
         y = memoryview(arr)
         assert y.format == 'i'
         assert y.shape == (10,)
+        assert len(y) == 10
         s = y[3]
         assert len(s) == struct.calcsize('i')
         assert s == struct.pack('i', 3)
diff --git a/pypy/objspace/std/memoryobject.py b/pypy/objspace/std/memoryobject.py
--- a/pypy/objspace/std/memoryobject.py
+++ b/pypy/objspace/std/memoryobject.py
@@ -115,7 +115,7 @@
             self.buf.setslice(start, value.as_str())
 
     def descr_len(self, space):
-        return space.wrap(self.buf.getlength())
+        return space.wrap(self.buf.getlength() / self.buf.getitemsize())
 
     def w_get_format(self, space):
         return space.wrap(self.buf.getformat())