[pypy-commit] pypy default: have frombuffer actually use buffer's storage

[bdkearns]

Author: Brian Kearns <bdkearns at gmail.com>
Branch: 
Changeset: r71689:e115979b6395
Date: 2014-05-23 18:27 -0400
http://bitbucket.org/pypy/pypy/changeset/e115979b6395/

Log:	have frombuffer actually use buffer's storage

diff --git a/pypy/module/micronumpy/ctors.py b/pypy/module/micronumpy/ctors.py
--- a/pypy/module/micronumpy/ctors.py
+++ b/pypy/module/micronumpy/ctors.py
@@ -215,7 +215,8 @@
     except OperationError as e:
         if not e.match(space, space.w_TypeError):
             raise
-        buf = _getbuffer(space, space.getattr(w_buffer, space.wrap('__buffer__')))
+        w_buffer = space.getattr(w_buffer, space.wrap('__buffer__'))
+        buf = _getbuffer(space, w_buffer)
 
     ts = buf.getlength()
     if offset < 0 or offset > ts:
@@ -240,6 +241,13 @@
             raise oefmt(space.w_ValueError,
                         "buffer is smaller than requested size")
 
-    a = W_NDimArray.from_shape(space, [n], dtype=dtype)
-    loop.fromstring_loop(space, a, dtype, itemsize, buf.as_str())
-    return space.wrap(a)
+    try:
+        storage = buf.get_raw_address()
+    except ValueError:
+        a = W_NDimArray.from_shape(space, [n], dtype=dtype)
+        loop.fromstring_loop(space, a, dtype, itemsize, buf.as_str())
+        return a
+    else:
+        writable = not buf.readonly
+    return W_NDimArray.from_shape_and_storage(space, [n], storage, dtype=dtype,
+                                              w_base=w_buffer, writable=writable)
diff --git a/pypy/module/micronumpy/test/test_ndarray.py b/pypy/module/micronumpy/test/test_ndarray.py
--- a/pypy/module/micronumpy/test/test_ndarray.py
+++ b/pypy/module/micronumpy/test/test_ndarray.py
@@ -3132,6 +3132,8 @@
 
 
 class AppTestSupport(BaseNumpyAppTest):
+    spaceconfig = {'usemodules': ['micronumpy', 'array']}
+
     def setup_class(cls):
         import struct
         BaseNumpyAppTest.setup_class.im_func(cls)
@@ -3159,6 +3161,19 @@
             for i in range(4):
                 assert a[i] == i + 1
 
+        import array
+        data = array.array('c', 'testing')
+        a = np.frombuffer(data, 'c')
+        assert a.base is data
+        a[2] = 'Z'
+        assert data.tostring() == 'teZting'
+
+        data = buffer(data)
+        a = np.frombuffer(data, 'c')
+        assert a.base is data
+        exc = raises(ValueError, "a[2] = 'Z'")
+        assert str(exc.value) == "assignment destination is read-only"
+
     def test_fromstring(self):
         import sys
         from numpypy import fromstring, dtype