cpython/Include/pybuffer.h

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/* Public Py_buffer API */
#ifndef Py_BUFFER_H
#define Py_BUFFER_H
#ifdef __cplusplus
extern "C" {
#endif
#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x030b0000
/* === New Buffer API ============================================
* Limited API and stable ABI since Python 3.11
*
* Py_buffer struct layout and size is now part of the stable abi3. The
* struct layout and size must not be changed in any way, as it would
* break the ABI.
*
*/
typedef struct {
void *buf;
PyObject *obj; /* owned reference */
Py_ssize_t len;
Py_ssize_t itemsize; /* This is Py_ssize_t so it can be
pointed to by strides in simple case.*/
int readonly;
int ndim;
char *format;
Py_ssize_t *shape;
Py_ssize_t *strides;
Py_ssize_t *suboffsets;
void *internal;
} Py_buffer;
typedef int (*getbufferproc)(PyObject *, Py_buffer *, int);
typedef void (*releasebufferproc)(PyObject *, Py_buffer *);
/* Return 1 if the getbuffer function is available, otherwise return 0. */
PyAPI_FUNC(int) PyObject_CheckBuffer(PyObject *obj);
/* This is a C-API version of the getbuffer function call. It checks
to make sure object has the required function pointer and issues the
call.
Returns -1 and raises an error on failure and returns 0 on success. */
PyAPI_FUNC(int) PyObject_GetBuffer(PyObject *obj, Py_buffer *view,
int flags);
/* Get the memory area pointed to by the indices for the buffer given.
Note that view->ndim is the assumed size of indices. */
PyAPI_FUNC(void *) PyBuffer_GetPointer(const Py_buffer *view, const Py_ssize_t *indices);
/* Return the implied itemsize of the data-format area from a
struct-style description. */
PyAPI_FUNC(Py_ssize_t) PyBuffer_SizeFromFormat(const char *format);
/* Implementation in memoryobject.c */
PyAPI_FUNC(int) PyBuffer_ToContiguous(void *buf, const Py_buffer *view,
Py_ssize_t len, char order);
PyAPI_FUNC(int) PyBuffer_FromContiguous(const Py_buffer *view, const void *buf,
Py_ssize_t len, char order);
/* Copy len bytes of data from the contiguous chunk of memory
pointed to by buf into the buffer exported by obj. Return
0 on success and return -1 and raise a PyBuffer_Error on
error (i.e. the object does not have a buffer interface or
it is not working).
If fort is 'F', then if the object is multi-dimensional,
then the data will be copied into the array in
Fortran-style (first dimension varies the fastest). If
fort is 'C', then the data will be copied into the array
in C-style (last dimension varies the fastest). If fort
is 'A', then it does not matter and the copy will be made
in whatever way is more efficient. */
PyAPI_FUNC(int) PyObject_CopyData(PyObject *dest, PyObject *src);
/* Copy the data from the src buffer to the buffer of destination. */
PyAPI_FUNC(int) PyBuffer_IsContiguous(const Py_buffer *view, char fort);
/*Fill the strides array with byte-strides of a contiguous
(Fortran-style if fort is 'F' or C-style otherwise)
array of the given shape with the given number of bytes
per element. */
PyAPI_FUNC(void) PyBuffer_FillContiguousStrides(int ndims,
Py_ssize_t *shape,
Py_ssize_t *strides,
int itemsize,
char fort);
/* Fills in a buffer-info structure correctly for an exporter
that can only share a contiguous chunk of memory of
"unsigned bytes" of the given length.
Returns 0 on success and -1 (with raising an error) on error. */
PyAPI_FUNC(int) PyBuffer_FillInfo(Py_buffer *view, PyObject *o, void *buf,
Py_ssize_t len, int readonly,
int flags);
/* Releases a Py_buffer obtained from getbuffer ParseTuple's "s*". */
PyAPI_FUNC(void) PyBuffer_Release(Py_buffer *view);
/* Maximum number of dimensions */
#define PyBUF_MAX_NDIM 64
/* Flags for getting buffers. Keep these in sync with inspect.BufferFlags. */
#define PyBUF_SIMPLE 0
#define PyBUF_WRITABLE 0x0001
#ifndef Py_LIMITED_API
/* we used to include an E, backwards compatible alias */
#define PyBUF_WRITEABLE PyBUF_WRITABLE
#endif
#define PyBUF_FORMAT 0x0004
#define PyBUF_ND 0x0008
#define PyBUF_STRIDES (0x0010 | PyBUF_ND)
#define PyBUF_C_CONTIGUOUS (0x0020 | PyBUF_STRIDES)
#define PyBUF_F_CONTIGUOUS (0x0040 | PyBUF_STRIDES)
#define PyBUF_ANY_CONTIGUOUS (0x0080 | PyBUF_STRIDES)
#define PyBUF_INDIRECT (0x0100 | PyBUF_STRIDES)
#define PyBUF_CONTIG (PyBUF_ND | PyBUF_WRITABLE)
#define PyBUF_CONTIG_RO (PyBUF_ND)
#define PyBUF_STRIDED (PyBUF_STRIDES | PyBUF_WRITABLE)
#define PyBUF_STRIDED_RO (PyBUF_STRIDES)
#define PyBUF_RECORDS (PyBUF_STRIDES | PyBUF_WRITABLE | PyBUF_FORMAT)
#define PyBUF_RECORDS_RO (PyBUF_STRIDES | PyBUF_FORMAT)
#define PyBUF_FULL (PyBUF_INDIRECT | PyBUF_WRITABLE | PyBUF_FORMAT)
#define PyBUF_FULL_RO (PyBUF_INDIRECT | PyBUF_FORMAT)
#define PyBUF_READ 0x100
#define PyBUF_WRITE 0x200
#endif /* !Py_LIMITED_API || Py_LIMITED_API >= 3.11 */
#ifdef __cplusplus
}
#endif
#endif /* Py_BUFFER_H */