- Issue #10181: New memoryview implementation fixes multiple ownership
and lifetime issues of dynamically allocated Py_buffer members (#9990)
as well as crashes (#8305, #7433). Many new features have been added
(See whatsnew/3.3), and the documentation has been updated extensively.
The ndarray test object from _testbuffer.c implements all aspects of
PEP-3118, so further development towards the complete implementation
of the PEP can proceed in a test-driven manner.
Thanks to Nick Coghlan, Antoine Pitrou and Pauli Virtanen for review
and many ideas.
- Issue #12834: Fix incorrect results of memoryview.tobytes() for
non-contiguous arrays.
- Issue #5231: Introduce memoryview.cast() method that allows changing
format and shape without making a copy of the underlying memory.
diff --git a/Include/abstract.h b/Include/abstract.h
index 3946ec5..abb996f 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -559,7 +559,7 @@
/* Copy the data from the src buffer to the buffer of destination
*/
- PyAPI_FUNC(int) PyBuffer_IsContiguous(Py_buffer *view, char fort);
+ PyAPI_FUNC(int) PyBuffer_IsContiguous(const Py_buffer *view, char fort);
PyAPI_FUNC(void) PyBuffer_FillContiguousStrides(int ndims,
diff --git a/Include/memoryobject.h b/Include/memoryobject.h
index aff5d99..4ac6f65 100644
--- a/Include/memoryobject.h
+++ b/Include/memoryobject.h
@@ -6,70 +6,64 @@
extern "C" {
#endif
+#ifndef Py_LIMITED_API
+PyAPI_DATA(PyTypeObject) _PyManagedBuffer_Type;
+#endif
PyAPI_DATA(PyTypeObject) PyMemoryView_Type;
#define PyMemoryView_Check(op) (Py_TYPE(op) == &PyMemoryView_Type)
#ifndef Py_LIMITED_API
-/* Get a pointer to the underlying Py_buffer of a memoryview object. */
+/* Get a pointer to the memoryview's private copy of the exporter's buffer. */
#define PyMemoryView_GET_BUFFER(op) (&((PyMemoryViewObject *)(op))->view)
-/* Get a pointer to the PyObject from which originates a memoryview object. */
+/* Get a pointer to the exporting object (this may be NULL!). */
#define PyMemoryView_GET_BASE(op) (((PyMemoryViewObject *)(op))->view.obj)
#endif
-
-PyAPI_FUNC(PyObject *) PyMemoryView_GetContiguous(PyObject *base,
- int buffertype,
- char fort);
-
- /* Return a contiguous chunk of memory representing the buffer
- from an object in a memory view object. If a copy is made then the
- base object for the memory view will be a *new* bytes object.
-
- Otherwise, the base-object will be the object itself and no
- data-copying will be done.
-
- The buffertype argument can be PyBUF_READ, PyBUF_WRITE,
- PyBUF_SHADOW to determine whether the returned buffer
- should be READONLY, WRITABLE, or set to update the
- original buffer if a copy must be made. If buffertype is
- PyBUF_WRITE and the buffer is not contiguous an error will
- be raised. In this circumstance, the user can use
- PyBUF_SHADOW to ensure that a a writable temporary
- contiguous buffer is returned. The contents of this
- contiguous buffer will be copied back into the original
- object after the memoryview object is deleted as long as
- the original object is writable and allows setting an
- exclusive write lock. If this is not allowed by the
- original object, then a BufferError is raised.
-
- If the object is multi-dimensional and if fortran is 'F',
- the first dimension of the underlying array will vary the
- fastest in the buffer. If fortran is 'C', then the last
- dimension will vary the fastest (C-style contiguous). If
- fortran is 'A', then it does not matter and you will get
- whatever the object decides is more efficient.
-
- A new reference is returned that must be DECREF'd when finished.
- */
-
PyAPI_FUNC(PyObject *) PyMemoryView_FromObject(PyObject *base);
-
+PyAPI_FUNC(PyObject *) PyMemoryView_FromMemory(char *mem, Py_ssize_t size,
+ int flags);
#ifndef Py_LIMITED_API
PyAPI_FUNC(PyObject *) PyMemoryView_FromBuffer(Py_buffer *info);
- /* create new if bufptr is NULL
- will be a new bytesobject in base */
#endif
+PyAPI_FUNC(PyObject *) PyMemoryView_GetContiguous(PyObject *base,
+ int buffertype,
+ char order);
-/* The struct is declared here so that macros can work, but it shouldn't
- be considered public. Don't access those fields directly, use the macros
+/* The structs are declared here so that macros can work, but they shouldn't
+ be considered public. Don't access their fields directly, use the macros
and functions instead! */
#ifndef Py_LIMITED_API
+#define _Py_MANAGED_BUFFER_RELEASED 0x001 /* access to exporter blocked */
+#define _Py_MANAGED_BUFFER_FREE_FORMAT 0x002 /* free format */
typedef struct {
PyObject_HEAD
- Py_buffer view;
- Py_hash_t hash;
+ int flags; /* state flags */
+ Py_ssize_t exports; /* number of direct memoryview exports */
+ Py_buffer master; /* snapshot buffer obtained from the original exporter */
+} _PyManagedBufferObject;
+
+
+/* static storage used for casting between formats */
+#define _Py_MEMORYVIEW_MAX_FORMAT 3 /* must be >= 3 */
+
+/* memoryview state flags */
+#define _Py_MEMORYVIEW_RELEASED 0x001 /* access to master buffer blocked */
+#define _Py_MEMORYVIEW_C 0x002 /* C-contiguous layout */
+#define _Py_MEMORYVIEW_FORTRAN 0x004 /* Fortran contiguous layout */
+#define _Py_MEMORYVIEW_SCALAR 0x008 /* scalar: ndim = 0 */
+#define _Py_MEMORYVIEW_PIL 0x010 /* PIL-style layout */
+
+typedef struct {
+ PyObject_VAR_HEAD
+ _PyManagedBufferObject *mbuf; /* managed buffer */
+ Py_hash_t hash; /* hash value for read-only views */
+ int flags; /* state flags */
+ Py_ssize_t exports; /* number of buffer re-exports */
+ Py_buffer view; /* private copy of the exporter's view */
+ char format[_Py_MEMORYVIEW_MAX_FORMAT]; /* used for casting */
+ Py_ssize_t ob_array[1]; /* shape, strides, suboffsets */
} PyMemoryViewObject;
#endif
diff --git a/Include/object.h b/Include/object.h
index 71d9dc8..9b3055d 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -186,15 +186,16 @@
Py_ssize_t *shape;
Py_ssize_t *strides;
Py_ssize_t *suboffsets;
- Py_ssize_t smalltable[2]; /* static store for shape and strides of
- mono-dimensional buffers. */
void *internal;
} Py_buffer;
typedef int (*getbufferproc)(PyObject *, Py_buffer *, int);
typedef void (*releasebufferproc)(PyObject *, Py_buffer *);
- /* Flags for getting buffers */
+/* Maximum number of dimensions */
+#define PyBUF_MAX_NDIM 64
+
+/* Flags for getting buffers */
#define PyBUF_SIMPLE 0
#define PyBUF_WRITABLE 0x0001
/* we used to include an E, backwards compatible alias */