1 /* Public Py_buffer API */
2
3 #ifndef Py_BUFFER_H
4 #define Py_BUFFER_H
5 #ifdef __cplusplus
6 extern "C" {
7 #endif
8
9 #if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x030b0000
10
11 /* === New Buffer API ============================================
12 * Limited API and stable ABI since Python 3.11
13 *
14 * Py_buffer struct layout and size is now part of the stable abi3. The
15 * struct layout and size must not be changed in any way, as it would
16 * break the ABI.
17 *
18 */
19
20 typedef struct {
21 void *buf;
22 PyObject *obj; /* owned reference */
23 Py_ssize_t len;
24 Py_ssize_t itemsize; /* This is Py_ssize_t so it can be
25 pointed to by strides in simple case.*/
26 int readonly;
27 int ndim;
28 char *format;
29 Py_ssize_t *shape;
30 Py_ssize_t *strides;
31 Py_ssize_t *suboffsets;
32 void *internal;
33 } Py_buffer;
34
35 /* Return 1 if the getbuffer function is available, otherwise return 0. */
36 PyAPI_FUNC(int) PyObject_CheckBuffer(PyObject *obj);
37
38 /* This is a C-API version of the getbuffer function call. It checks
39 to make sure object has the required function pointer and issues the
40 call.
41
42 Returns -1 and raises an error on failure and returns 0 on success. */
43 PyAPI_FUNC(int) PyObject_GetBuffer(PyObject *obj, Py_buffer *view,
44 int flags);
45
46 /* Get the memory area pointed to by the indices for the buffer given.
47 Note that view->ndim is the assumed size of indices. */
48 PyAPI_FUNC(void *) PyBuffer_GetPointer(const Py_buffer *view, const Py_ssize_t *indices);
49
50 /* Return the implied itemsize of the data-format area from a
51 struct-style description. */
52 PyAPI_FUNC(Py_ssize_t) PyBuffer_SizeFromFormat(const char *format);
53
54 /* Implementation in memoryobject.c */
55 PyAPI_FUNC(int) PyBuffer_ToContiguous(void *buf, const Py_buffer *view,
56 Py_ssize_t len, char order);
57
58 PyAPI_FUNC(int) PyBuffer_FromContiguous(const Py_buffer *view, const void *buf,
59 Py_ssize_t len, char order);
60
61 /* Copy len bytes of data from the contiguous chunk of memory
62 pointed to by buf into the buffer exported by obj. Return
63 0 on success and return -1 and raise a PyBuffer_Error on
64 error (i.e. the object does not have a buffer interface or
65 it is not working).
66
67 If fort is 'F', then if the object is multi-dimensional,
68 then the data will be copied into the array in
69 Fortran-style (first dimension varies the fastest). If
70 fort is 'C', then the data will be copied into the array
71 in C-style (last dimension varies the fastest). If fort
72 is 'A', then it does not matter and the copy will be made
73 in whatever way is more efficient. */
74 PyAPI_FUNC(int) PyObject_CopyData(PyObject *dest, PyObject *src);
75
76 /* Copy the data from the src buffer to the buffer of destination. */
77 PyAPI_FUNC(int) PyBuffer_IsContiguous(const Py_buffer *view, char fort);
78
79 /*Fill the strides array with byte-strides of a contiguous
80 (Fortran-style if fort is 'F' or C-style otherwise)
81 array of the given shape with the given number of bytes
82 per element. */
83 PyAPI_FUNC(void) PyBuffer_FillContiguousStrides(int ndims,
84 Py_ssize_t *shape,
85 Py_ssize_t *strides,
86 int itemsize,
87 char fort);
88
89 /* Fills in a buffer-info structure correctly for an exporter
90 that can only share a contiguous chunk of memory of
91 "unsigned bytes" of the given length.
92
93 Returns 0 on success and -1 (with raising an error) on error. */
94 PyAPI_FUNC(int) PyBuffer_FillInfo(Py_buffer *view, PyObject *o, void *buf,
95 Py_ssize_t len, int readonly,
96 int flags);
97
98 /* Releases a Py_buffer obtained from getbuffer ParseTuple's "s*". */
99 PyAPI_FUNC(void) PyBuffer_Release(Py_buffer *view);
100
101 /* Maximum number of dimensions */
102 #define PyBUF_MAX_NDIM 64
103
104 /* Flags for getting buffers */
105 #define PyBUF_SIMPLE 0
106 #define PyBUF_WRITABLE 0x0001
107
108 #ifndef Py_LIMITED_API
109 /* we used to include an E, backwards compatible alias */
110 #define PyBUF_WRITEABLE PyBUF_WRITABLE
111 #endif
112
113 #define PyBUF_FORMAT 0x0004
114 #define PyBUF_ND 0x0008
115 #define PyBUF_STRIDES (0x0010 | PyBUF_ND)
116 #define PyBUF_C_CONTIGUOUS (0x0020 | PyBUF_STRIDES)
117 #define PyBUF_F_CONTIGUOUS (0x0040 | PyBUF_STRIDES)
118 #define PyBUF_ANY_CONTIGUOUS (0x0080 | PyBUF_STRIDES)
119 #define PyBUF_INDIRECT (0x0100 | PyBUF_STRIDES)
120
121 #define PyBUF_CONTIG (PyBUF_ND | PyBUF_WRITABLE)
122 #define PyBUF_CONTIG_RO (PyBUF_ND)
123
124 #define PyBUF_STRIDED (PyBUF_STRIDES | PyBUF_WRITABLE)
125 #define PyBUF_STRIDED_RO (PyBUF_STRIDES)
126
127 #define PyBUF_RECORDS (PyBUF_STRIDES | PyBUF_WRITABLE | PyBUF_FORMAT)
128 #define PyBUF_RECORDS_RO (PyBUF_STRIDES | PyBUF_FORMAT)
129
130 #define PyBUF_FULL (PyBUF_INDIRECT | PyBUF_WRITABLE | PyBUF_FORMAT)
131 #define PyBUF_FULL_RO (PyBUF_INDIRECT | PyBUF_FORMAT)
132
133
134 #define PyBUF_READ 0x100
135 #define PyBUF_WRITE 0x200
136
137 #endif /* !Py_LIMITED_API || Py_LIMITED_API >= 3.11 */
138
139 #ifdef __cplusplus
140 }
141 #endif
142 #endif /* Py_BUFFER_H */