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Issue #12834: Fix PyBuffer_ToContiguous() for non-contiguous arrays.

This commit is contained in:
Stefan Krah 2012-07-28 12:25:55 +02:00
parent 6c779ea553
commit 7d12d9df13
8 changed files with 410 additions and 68 deletions
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5
Include/abstract.h
View File

@ -535,11 +535,12 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
/* Implementation in memoryobject.c */
PyAPI_FUNC(int) PyBuffer_ToContiguous(void *buf, Py_buffer *view,
Py_ssize_t len, char fort);
Py_ssize_t len, char order);
PyAPI_FUNC(int) PyBuffer_FromContiguous(Py_buffer *view, void *buf,
Py_ssize_t len, char fort);
Py_ssize_t len, char order);
/* Copy len bytes of data from the contiguous chunk of memory

291
Lib/test/test_buffer.py
View File

@ -53,6 +53,11 @@ NATIVE = {
'f':0, 'd':0, 'P':0
}
# NumPy does not have 'n' or 'N':
if numpy_array:
del NATIVE['n']
del NATIVE['N']
if struct:
try:
# Add "qQ" if present in native mode.
@ -855,11 +860,49 @@ class TestBufferProtocol(unittest.TestCase):
is_contiguous(result, 'F') and order == 'C':
# The flattened list is already in C-order.
expected = ndarray(flattened, shape=shape, format=ff)
contig = get_contiguous(result, PyBUF_READ, order)
contig = get_contiguous(result, PyBUF_READ, order)
self.assertEqual(contig.tobytes(), b)
self.assertTrue(cmp_contig(contig, expected))
if ndim == 0:
continue
nmemb = len(flattened)
ro = 0 if readonly else ND_WRITABLE
### See comment in test_py_buffer_to_contiguous for an
### explanation why these tests are valid.
# To 'C'
contig = py_buffer_to_contiguous(result, 'C', PyBUF_FULL_RO)
self.assertEqual(len(contig), nmemb * itemsize)
initlst = [struct.unpack_from(fmt, contig, n*itemsize)[0]
for n in range(nmemb)]
y = ndarray(initlst, shape=shape, flags=ro, format=fmt)
self.assertEqual(memoryview(y), memoryview(result))
# To 'F'
contig = py_buffer_to_contiguous(result, 'F', PyBUF_FULL_RO)
self.assertEqual(len(contig), nmemb * itemsize)
initlst = [struct.unpack_from(fmt, contig, n*itemsize)[0]
for n in range(nmemb)]
y = ndarray(initlst, shape=shape, flags=ro|ND_FORTRAN,
format=fmt)
self.assertEqual(memoryview(y), memoryview(result))
# To 'A'
contig = py_buffer_to_contiguous(result, 'A', PyBUF_FULL_RO)
self.assertEqual(len(contig), nmemb * itemsize)
initlst = [struct.unpack_from(fmt, contig, n*itemsize)[0]
for n in range(nmemb)]
f = ND_FORTRAN if is_contiguous(result, 'F') else 0
y = ndarray(initlst, shape=shape, flags=f|ro, format=fmt)
self.assertEqual(memoryview(y), memoryview(result))
if is_memoryview_format(fmt):
try:
m = memoryview(result)
@ -1805,6 +1848,9 @@ class TestBufferProtocol(unittest.TestCase):
self.assertEqual(mvlist, ylist)
if numpy_array:
# XXX NumPy (as far as it compiles with 3.3) currently
# segfaults here. Wait for a stable 3.3 compatible version.
continue
shape = t[3]
if 0 in shape:
continue # http://projects.scipy.org/numpy/ticket/1910
@ -1884,6 +1930,9 @@ class TestBufferProtocol(unittest.TestCase):
self.assertEqual(mr.tolist(), yrlist)
if numpy_array:
# XXX NumPy (as far as it compiles with 3.3) currently
# segfaults here. Wait for a stable 3.3 compatible version.
continue
if 0 in lshape or 0 in rshape:
continue # http://projects.scipy.org/numpy/ticket/1910
@ -2020,6 +2069,246 @@ class TestBufferProtocol(unittest.TestCase):
nd = ndarray(list(range(12)), shape=[2,2,3], format='L')
self.assertEqual(hash(nd), hash(nd.tobytes()))
def test_py_buffer_to_contiguous(self):
# The requests are used in _testbuffer.c:py_buffer_to_contiguous
# to generate buffers without full information for testing.
requests = (
# distinct flags
PyBUF_INDIRECT, PyBUF_STRIDES, PyBUF_ND, PyBUF_SIMPLE,
# compound requests
PyBUF_FULL, PyBUF_FULL_RO,
PyBUF_RECORDS, PyBUF_RECORDS_RO,
PyBUF_STRIDED, PyBUF_STRIDED_RO,
PyBUF_CONTIG, PyBUF_CONTIG_RO,
)
# no buffer interface
self.assertRaises(TypeError, py_buffer_to_contiguous, {}, 'F',
PyBUF_FULL_RO)
# scalar, read-only request
nd = ndarray(9, shape=(), format="L", flags=ND_WRITABLE)
for order in ['C', 'F', 'A']:
for request in requests:
b = py_buffer_to_contiguous(nd, order, request)
self.assertEqual(b, nd.tobytes())
# zeros in shape
nd = ndarray([1], shape=[0], format="L", flags=ND_WRITABLE)
for order in ['C', 'F', 'A']:
for request in requests:
b = py_buffer_to_contiguous(nd, order, request)
self.assertEqual(b, b'')
nd = ndarray(list(range(8)), shape=[2, 0, 7], format="L",
flags=ND_WRITABLE)
for order in ['C', 'F', 'A']:
for request in requests:
b = py_buffer_to_contiguous(nd, order, request)
self.assertEqual(b, b'')
### One-dimensional arrays are trivial, since Fortran and C order
### are the same.
# one-dimensional
for f in [0, ND_FORTRAN]:
nd = ndarray([1], shape=[1], format="h", flags=f|ND_WRITABLE)
ndbytes = nd.tobytes()
for order in ['C', 'F', 'A']:
for request in requests:
b = py_buffer_to_contiguous(nd, order, request)
self.assertEqual(b, ndbytes)
nd = ndarray([1, 2, 3], shape=[3], format="b", flags=f|ND_WRITABLE)
ndbytes = nd.tobytes()
for order in ['C', 'F', 'A']:
for request in requests:
b = py_buffer_to_contiguous(nd, order, request)
self.assertEqual(b, ndbytes)
# one-dimensional, non-contiguous input
nd = ndarray([1, 2, 3], shape=[2], strides=[2], flags=ND_WRITABLE)
ndbytes = nd.tobytes()
for order in ['C', 'F', 'A']:
for request in [PyBUF_STRIDES, PyBUF_FULL]:
b = py_buffer_to_contiguous(nd, order, request)
self.assertEqual(b, ndbytes)
nd = nd[::-1]
ndbytes = nd.tobytes()
for order in ['C', 'F', 'A']:
for request in requests:
try:
b = py_buffer_to_contiguous(nd, order, request)
except BufferError:
continue
self.assertEqual(b, ndbytes)
###
### Multi-dimensional arrays:
###
### The goal here is to preserve the logical representation of the
### input array but change the physical representation if necessary.
###
### _testbuffer example:
### ====================
###
### C input array:
### --------------
### >>> nd = ndarray(list(range(12)), shape=[3, 4])
### >>> nd.tolist()
### [[0, 1, 2, 3],
### [4, 5, 6, 7],
### [8, 9, 10, 11]]
###
### Fortran output:
### ---------------
### >>> py_buffer_to_contiguous(nd, 'F', PyBUF_FULL_RO)
### >>> b'\x00\x04\x08\x01\x05\t\x02\x06\n\x03\x07\x0b'
###
### The return value corresponds to this input list for
### _testbuffer's ndarray:
### >>> nd = ndarray([0,4,8,1,5,9,2,6,10,3,7,11], shape=[3,4],
### flags=ND_FORTRAN)
### >>> nd.tolist()
### [[0, 1, 2, 3],
### [4, 5, 6, 7],
### [8, 9, 10, 11]]
###
### The logical array is the same, but the values in memory are now
### in Fortran order.
###
### NumPy example:
### ==============
### _testbuffer's ndarray takes lists to initialize the memory.
### Here's the same sequence in NumPy:
###
### C input:
### --------
### >>> nd = ndarray(buffer=bytearray(list(range(12))),
### shape=[3, 4], dtype='B')
### >>> nd
### array([[ 0, 1, 2, 3],
### [ 4, 5, 6, 7],
### [ 8, 9, 10, 11]], dtype=uint8)
###
### Fortran output:
### ---------------
### >>> fortran_buf = nd.tostring(order='F')
### >>> fortran_buf
### b'\x00\x04\x08\x01\x05\t\x02\x06\n\x03\x07\x0b'
###
### >>> nd = ndarray(buffer=fortran_buf, shape=[3, 4],
### dtype='B', order='F')
###
### >>> nd
### array([[ 0, 1, 2, 3],
### [ 4, 5, 6, 7],
### [ 8, 9, 10, 11]], dtype=uint8)
###
# multi-dimensional, contiguous input
lst = list(range(12))
for f in [0, ND_FORTRAN]:
nd = ndarray(lst, shape=[3, 4], flags=f|ND_WRITABLE)
if numpy_array:
na = numpy_array(buffer=bytearray(lst),
shape=[3, 4], dtype='B',
order='C' if f == 0 else 'F')
# 'C' request
if f == ND_FORTRAN: # 'F' to 'C'
x = ndarray(transpose(lst, [4, 3]), shape=[3, 4],
flags=ND_WRITABLE)
expected = x.tobytes()
else:
expected = nd.tobytes()
for request in requests:
try:
b = py_buffer_to_contiguous(nd, 'C', request)
except BufferError:
continue
self.assertEqual(b, expected)
# Check that output can be used as the basis for constructing
# a C array that is logically identical to the input array.
y = ndarray([v for v in b], shape=[3, 4], flags=ND_WRITABLE)
self.assertEqual(memoryview(y), memoryview(nd))
if numpy_array:
self.assertEqual(b, na.tostring(order='C'))
# 'F' request
if f == 0: # 'C' to 'F'
x = ndarray(transpose(lst, [3, 4]), shape=[4, 3],
flags=ND_WRITABLE)
else:
x = ndarray(lst, shape=[3, 4], flags=ND_WRITABLE)
expected = x.tobytes()
for request in [PyBUF_FULL, PyBUF_FULL_RO, PyBUF_INDIRECT,
PyBUF_STRIDES, PyBUF_ND]:
try:
b = py_buffer_to_contiguous(nd, 'F', request)
except BufferError:
continue
self.assertEqual(b, expected)
# Check that output can be used as the basis for constructing
# a Fortran array that is logically identical to the input array.
y = ndarray([v for v in b], shape=[3, 4], flags=ND_FORTRAN|ND_WRITABLE)
self.assertEqual(memoryview(y), memoryview(nd))
if numpy_array:
self.assertEqual(b, na.tostring(order='F'))
# 'A' request
if f == ND_FORTRAN:
x = ndarray(lst, shape=[3, 4], flags=ND_WRITABLE)
expected = x.tobytes()
else:
expected = nd.tobytes()
for request in [PyBUF_FULL, PyBUF_FULL_RO, PyBUF_INDIRECT,
PyBUF_STRIDES, PyBUF_ND]:
try:
b = py_buffer_to_contiguous(nd, 'A', request)
except BufferError:
continue
self.assertEqual(b, expected)
# Check that output can be used as the basis for constructing
# an array with order=f that is logically identical to the input
# array.
y = ndarray([v for v in b], shape=[3, 4], flags=f|ND_WRITABLE)
self.assertEqual(memoryview(y), memoryview(nd))
if numpy_array:
self.assertEqual(b, na.tostring(order='A'))
# multi-dimensional, non-contiguous input
nd = ndarray(list(range(12)), shape=[3, 4], flags=ND_WRITABLE|ND_PIL)
# 'C'
b = py_buffer_to_contiguous(nd, 'C', PyBUF_FULL_RO)
self.assertEqual(b, nd.tobytes())
y = ndarray([v for v in b], shape=[3, 4], flags=ND_WRITABLE)
self.assertEqual(memoryview(y), memoryview(nd))
# 'F'
b = py_buffer_to_contiguous(nd, 'F', PyBUF_FULL_RO)
x = ndarray(transpose(lst, [3, 4]), shape=[4, 3], flags=ND_WRITABLE)
self.assertEqual(b, x.tobytes())
y = ndarray([v for v in b], shape=[3, 4], flags=ND_FORTRAN|ND_WRITABLE)
self.assertEqual(memoryview(y), memoryview(nd))
# 'A'
b = py_buffer_to_contiguous(nd, 'A', PyBUF_FULL_RO)
self.assertEqual(b, nd.tobytes())
y = ndarray([v for v in b], shape=[3, 4], flags=ND_WRITABLE)
self.assertEqual(memoryview(y), memoryview(nd))
def test_memoryview_construction(self):
items_shape = [(9, []), ([1,2,3], [3]), (list(range(2*3*5)), [2,3,5])]

2
Misc/NEWS
View File

@ -10,6 +10,8 @@ What's New in Python 3.3.0 Beta 2?
Core and Builtins
-----------------
- Issue #12834: Fix PyBuffer_ToContiguous() for non-contiguous arrays.
- Issue #15456: Fix code __sizeof__ after #12399 change.
Patch by Serhiy Storchaka.

44
Modules/_testbuffer.c
View File

@ -2397,6 +2397,49 @@ get_contiguous(PyObject *self, PyObject *args)
return PyMemoryView_GetContiguous(obj, (int)type, ord);
}
/* PyBuffer_ToContiguous() */
static PyObject *
py_buffer_to_contiguous(PyObject *self, PyObject *args)
{
PyObject *obj;
PyObject *order;
PyObject *ret = NULL;
int flags;
char ord;
Py_buffer view;
char *buf = NULL;
if (!PyArg_ParseTuple(args, "OOi", &obj, &order, &flags)) {
return NULL;
}
if (PyObject_GetBuffer(obj, &view, flags) < 0) {
return NULL;
}
ord = get_ascii_order(order);
if (ord == CHAR_MAX) {
goto out;
}
buf = PyMem_Malloc(view.len);
if (buf == NULL) {
PyErr_NoMemory();
goto out;
}
if (PyBuffer_ToContiguous(buf, &view, view.len, ord) < 0) {
goto out;
}
ret = PyBytes_FromStringAndSize(buf, view.len);
out:
PyBuffer_Release(&view);
PyMem_XFree(buf);
return ret;
}
static int
fmtcmp(const char *fmt1, const char *fmt2)
{
@ -2734,6 +2777,7 @@ static struct PyMethodDef _testbuffer_functions[] = {
{"get_pointer", get_pointer, METH_VARARGS, NULL},
{"get_sizeof_void_p", (PyCFunction)get_sizeof_void_p, METH_NOARGS, NULL},
{"get_contiguous", get_contiguous, METH_VARARGS, NULL},
{"py_buffer_to_contiguous", py_buffer_to_contiguous, METH_VARARGS, NULL},
{"is_contiguous", is_contiguous, METH_VARARGS, NULL},
{"cmp_contig", cmp_contig, METH_VARARGS, NULL},
{NULL, NULL}

56
Objects/abstract.c
View File

@ -445,62 +445,6 @@ _Py_add_one_to_index_C(int nd, Py_ssize_t *index, const Py_ssize_t *shape)
}
}
/* view is not checked for consistency in either of these. It is
assumed that the size of the buffer is view->len in
view->len / view->itemsize elements.
*/
int
PyBuffer_ToContiguous(void *buf, Py_buffer *view, Py_ssize_t len, char fort)
{
int k;
void (*addone)(int, Py_ssize_t *, const Py_ssize_t *);
Py_ssize_t *indices, elements;
char *dest, *ptr;
if (len > view->len) {
len = view->len;
}
if (PyBuffer_IsContiguous(view, fort)) {
/* simplest copy is all that is needed */
memcpy(buf, view->buf, len);
return 0;
}
/* Otherwise a more elaborate scheme is needed */
/* XXX(nnorwitz): need to check for overflow! */
indices = (Py_ssize_t *)PyMem_Malloc(sizeof(Py_ssize_t)*(view->ndim));
if (indices == NULL) {
PyErr_NoMemory();
return -1;
}
for (k=0; k<view->ndim;k++) {
indices[k] = 0;
}
if (fort == 'F') {
addone = _Py_add_one_to_index_F;
}
else {
addone = _Py_add_one_to_index_C;
}
dest = buf;
/* XXX : This is not going to be the fastest code in the world
several optimizations are possible.
*/
elements = len / view->itemsize;
while (elements--) {
addone(view->ndim, indices, view->shape);
ptr = PyBuffer_GetPointer(view, indices);
memcpy(dest, ptr, view->itemsize);
dest += view->itemsize;
}
PyMem_Free(indices);
return 0;
}
int
PyBuffer_FromContiguous(Py_buffer *view, void *buf, Py_ssize_t len, char fort)
{

1
Objects/bytesobject.c
View File

@ -2591,7 +2591,6 @@ PyBytes_FromObject(PyObject *x)
new = PyBytes_FromStringAndSize(NULL, view.len);
if (!new)
goto fail;
/* XXX(brett.cannon): Better way to get to internal buffer? */
if (PyBuffer_ToContiguous(((PyBytesObject *)new)->ob_sval,
&view, view.len, 'C') < 0)
goto fail;

75
Objects/memoryobject.c
View File

@ -438,15 +438,17 @@ init_fortran_strides_from_shape(Py_buffer *view)
view->strides[i] = view->strides[i-1] * view->shape[i-1];
}
/* Copy src to a C-contiguous representation. Assumptions:
/* Copy src to a contiguous representation. order is one of 'C', 'F' (Fortran)
or 'A' (Any). Assumptions: src has PyBUF_FULL information, src->ndim >= 1,
len(mem) == src->len. */
static int
buffer_to_c_contiguous(char *mem, Py_buffer *src)
buffer_to_contiguous(char *mem, Py_buffer *src, char order)
{
Py_buffer dest;
Py_ssize_t *strides;
int ret;
assert(src->ndim >= 1);
assert(src->shape != NULL);
assert(src->strides != NULL);
@ -456,12 +458,22 @@ buffer_to_c_contiguous(char *mem, Py_buffer *src)
return -1;
}
/* initialize dest as a C-contiguous buffer */
/* initialize dest */
dest = *src;
dest.buf = mem;
/* shape is constant and shared */
/* shape is constant and shared: the logical representation of the
array is unaltered. */
/* The physical representation determined by strides (and possibly
suboffsets) may change. */
dest.strides = strides;
if (order == 'C' || order == 'A') {
init_strides_from_shape(&dest);
}
else {
init_fortran_strides_from_shape(&dest);
}
dest.suboffsets = NULL;
ret = copy_buffer(&dest, src);
@ -921,6 +933,57 @@ memory_new(PyTypeObject *subtype, PyObject *args, PyObject *kwds)
}
/****************************************************************************/
/* Previously in abstract.c */
/****************************************************************************/
typedef struct {
Py_buffer view;
Py_ssize_t array[1];
} Py_buffer_full;
int
PyBuffer_ToContiguous(void *buf, Py_buffer *src, Py_ssize_t len, char order)
{
Py_buffer_full *fb = NULL;
int ret;
assert(order == 'C' || order == 'F' || order == 'A');
if (len != src->len) {
PyErr_SetString(PyExc_ValueError,
"PyBuffer_ToContiguous: len != view->len");
return -1;
}
if (PyBuffer_IsContiguous(src, order)) {
memcpy((char *)buf, src->buf, len);
return 0;
}
/* buffer_to_contiguous() assumes PyBUF_FULL */
fb = PyMem_Malloc(sizeof *fb + 3 * src->ndim * (sizeof *fb->array));
if (fb == NULL) {
PyErr_NoMemory();
return -1;
}
fb->view.ndim = src->ndim;
fb->view.shape = fb->array;
fb->view.strides = fb->array + src->ndim;
fb->view.suboffsets = fb->array + 2 * src->ndim;
init_shared_values(&fb->view, src);
init_shape_strides(&fb->view, src);
init_suboffsets(&fb->view, src);
src = &fb->view;
ret = buffer_to_contiguous(buf, src, order);
PyMem_Free(fb);
return ret;
}
/****************************************************************************/
/* Release/GC management */
/****************************************************************************/
@ -1889,7 +1952,7 @@ memory_tobytes(PyMemoryViewObject *self, PyObject *dummy)
if (bytes == NULL)
return NULL;
if (buffer_to_c_contiguous(PyBytes_AS_STRING(bytes), src) < 0) {
if (buffer_to_contiguous(PyBytes_AS_STRING(bytes), src, 'C') < 0) {
Py_DECREF(bytes);
return NULL;
}
@ -2423,7 +2486,7 @@ memory_hash(PyMemoryViewObject *self)
PyErr_NoMemory();
return -1;
}
if (buffer_to_c_contiguous(mem, view) < 0) {
if (buffer_to_contiguous(mem, view, 'C') < 0) {
PyMem_Free(mem);
return -1;
}