summaryrefslogtreecommitdiffstats
path: root/scripts/external_libs/pyzmq-14.5.0/python2/ucs2/32bit/zmq/utils/buffers.pxd
blob: 998aa55119161ad044fa82da0ea43cc8b2cdafb2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
"""Python version-independent methods for C/Python buffers.

This file was copied and adapted from mpi4py.

Authors
-------
* MinRK
"""

#-----------------------------------------------------------------------------
#  Copyright (c) 2010 Lisandro Dalcin
#  All rights reserved.
#  Used under BSD License: http://www.opensource.org/licenses/bsd-license.php
#
#  Retrieval:
#  Jul 23, 2010 18:00 PST (r539)
#  http://code.google.com/p/mpi4py/source/browse/trunk/src/MPI/asbuffer.pxi
#
#  Modifications from original:
#  Copyright (c) 2010-2012 Brian Granger, Min Ragan-Kelley
#
#  Distributed under the terms of the New BSD License.  The full license is in
#  the file COPYING.BSD, distributed as part of this software.
#-----------------------------------------------------------------------------


#-----------------------------------------------------------------------------
# Python includes.
#-----------------------------------------------------------------------------

# get version-independent aliases:
cdef extern from "pyversion_compat.h":
    pass

# Python 3 buffer interface (PEP 3118)
cdef extern from "Python.h":
    int PY_MAJOR_VERSION
    int PY_MINOR_VERSION
    ctypedef int Py_ssize_t
    ctypedef struct PyMemoryViewObject:
        pass
    ctypedef struct Py_buffer:
        void *buf
        Py_ssize_t len
        int readonly
        char *format
        int ndim
        Py_ssize_t *shape
        Py_ssize_t *strides
        Py_ssize_t *suboffsets
        Py_ssize_t itemsize
        void *internal
    cdef enum:
        PyBUF_SIMPLE
        PyBUF_WRITABLE
        PyBUF_FORMAT
        PyBUF_ANY_CONTIGUOUS
    int  PyObject_CheckBuffer(object)
    int  PyObject_GetBuffer(object, Py_buffer *, int) except -1
    void PyBuffer_Release(Py_buffer *)
    
    int PyBuffer_FillInfo(Py_buffer *view, object obj, void *buf,
                Py_ssize_t len, int readonly, int infoflags) except -1
    object PyMemoryView_FromBuffer(Py_buffer *info)
    
    object PyMemoryView_FromObject(object)

# Python 2 buffer interface (legacy)
cdef extern from "Python.h":
    ctypedef void const_void "const void"
    Py_ssize_t Py_END_OF_BUFFER
    int PyObject_CheckReadBuffer(object)
    int PyObject_AsReadBuffer (object, const_void **, Py_ssize_t *) except -1
    int PyObject_AsWriteBuffer(object, void **, Py_ssize_t *) except -1
    
    object PyBuffer_FromMemory(void *ptr, Py_ssize_t s)
    object PyBuffer_FromReadWriteMemory(void *ptr, Py_ssize_t s)

    object PyBuffer_FromObject(object, Py_ssize_t offset, Py_ssize_t size)
    object PyBuffer_FromReadWriteObject(object, Py_ssize_t offset, Py_ssize_t size)


#-----------------------------------------------------------------------------
# asbuffer: C buffer from python object
#-----------------------------------------------------------------------------


cdef inline int memoryview_available():
    return PY_MAJOR_VERSION >= 3 or (PY_MAJOR_VERSION >=2 and PY_MINOR_VERSION >= 7)

cdef inline int oldstyle_available():
    return PY_MAJOR_VERSION < 3


cdef inline int check_buffer(object ob):
    """Version independent check for whether an object is a buffer.
    
    Parameters
    ----------
    object : object
        Any Python object

    Returns
    -------
    int : 0 if no buffer interface, 3 if newstyle buffer interface, 2 if oldstyle.
    """
    if PyObject_CheckBuffer(ob):
        return 3
    if oldstyle_available():
        return PyObject_CheckReadBuffer(ob) and 2
    return 0


cdef inline object asbuffer(object ob, int writable, int format,
                            void **base, Py_ssize_t *size,
                            Py_ssize_t *itemsize):
    """Turn an object into a C buffer in a Python version-independent way.
    
    Parameters
    ----------
    ob : object
        The object to be turned into a buffer.
        Must provide a Python Buffer interface
    writable : int
        Whether the resulting buffer should be allowed to write
        to the object.
    format : int
        The format of the buffer.  See Python buffer docs.
    base : void **
        The pointer that will be used to store the resulting C buffer.
    size : Py_ssize_t *
        The size of the buffer(s).
    itemsize : Py_ssize_t *
        The size of an item, if the buffer is non-contiguous.
    
    Returns
    -------
    An object describing the buffer format. Generally a str, such as 'B'.
    """

    cdef void *bptr = NULL
    cdef Py_ssize_t blen = 0, bitemlen = 0
    cdef Py_buffer view
    cdef int flags = PyBUF_SIMPLE
    cdef int mode = 0
    
    bfmt = None

    mode = check_buffer(ob)
    if mode == 0:
        raise TypeError("%r does not provide a buffer interface."%ob)

    if mode == 3:
        flags = PyBUF_ANY_CONTIGUOUS
        if writable:
            flags |= PyBUF_WRITABLE
        if format:
            flags |= PyBUF_FORMAT
        PyObject_GetBuffer(ob, &view, flags)
        bptr = view.buf
        blen = view.len
        if format:
            if view.format != NULL:
                bfmt = view.format
                bitemlen = view.itemsize
        PyBuffer_Release(&view)
    else: # oldstyle
        if writable:
            PyObject_AsWriteBuffer(ob, &bptr, &blen)
        else:
            PyObject_AsReadBuffer(ob, <const_void **>&bptr, &blen)
        if format:
            try: # numpy.ndarray
                dtype = ob.dtype
                bfmt = dtype.char
                bitemlen = dtype.itemsize
            except AttributeError:
                try: # array.array
                    bfmt = ob.typecode
                    bitemlen = ob.itemsize
                except AttributeError:
                    if isinstance(ob, bytes):
                        bfmt = b"B"
                        bitemlen = 1
                    else:
                        # nothing found
                        bfmt = None
                        bitemlen = 0
    if base: base[0] = <void *>bptr
    if size: size[0] = <Py_ssize_t>blen
    if itemsize: itemsize[0] = <Py_ssize_t>bitemlen
    
    if PY_MAJOR_VERSION >= 3 and bfmt is not None:
        return bfmt.decode('ascii')
    return bfmt


cdef inline object asbuffer_r(object ob, void **base, Py_ssize_t *size):
    """Wrapper for standard calls to asbuffer with a readonly buffer."""
    asbuffer(ob, 0, 0, base, size, NULL)
    return ob


cdef inline object asbuffer_w(object ob, void **base, Py_ssize_t *size):
    """Wrapper for standard calls to asbuffer with a writable buffer."""
    asbuffer(ob, 1, 0, base, size, NULL)
    return ob

#------------------------------------------------------------------------------
# frombuffer: python buffer/view from C buffer
#------------------------------------------------------------------------------


cdef inline object frombuffer_3(void *ptr, Py_ssize_t s, int readonly):
    """Python 3 version of frombuffer.

    This is the Python 3 model, but will work on Python >= 2.6. Currently,
    we use it only on >= 3.0.
    """
    cdef Py_buffer pybuf
    cdef Py_ssize_t *shape = [s]
    cdef str astr=""
    PyBuffer_FillInfo(&pybuf, astr, ptr, s, readonly, PyBUF_SIMPLE)
    pybuf.format = "B"
    pybuf.shape = shape
    return PyMemoryView_FromBuffer(&pybuf)


cdef inline object frombuffer_2(void *ptr, Py_ssize_t s, int readonly):
    """Python 2 version of frombuffer. 

    This must be used for Python <= 2.6, but we use it for all Python < 3.
    """
    
    if oldstyle_available():
        if readonly:
            return PyBuffer_FromMemory(ptr, s)
        else:
            return PyBuffer_FromReadWriteMemory(ptr, s)
    else:
        raise NotImplementedError("Old style buffers not available.")


cdef inline object frombuffer(void *ptr, Py_ssize_t s, int readonly):
    """Create a Python Buffer/View of a C array. 
    
    Parameters
    ----------
    ptr : void *
        Pointer to the array to be copied.
    s : size_t
        Length of the buffer.
    readonly : int
        whether the resulting object should be allowed to write to the buffer.
    
    Returns
    -------
    Python Buffer/View of the C buffer.
    """
    # oldstyle first priority for now
    if oldstyle_available():
        return frombuffer_2(ptr, s, readonly)
    else:
        return frombuffer_3(ptr, s, readonly)


cdef inline object frombuffer_r(void *ptr, Py_ssize_t s):
    """Wrapper for readonly view frombuffer."""
    return frombuffer(ptr, s, 1)


cdef inline object frombuffer_w(void *ptr, Py_ssize_t s):
    """Wrapper for writable view frombuffer."""
    return frombuffer(ptr, s, 0)

#------------------------------------------------------------------------------
# viewfromobject: python buffer/view from python object, refcounts intact
# frombuffer(asbuffer(obj)) would lose track of refs
#------------------------------------------------------------------------------

cdef inline object viewfromobject(object obj, int readonly):
    """Construct a Python Buffer/View object from another Python object.

    This work in a Python version independent manner.
    
    Parameters
    ----------
    obj : object
        The input object to be cast as a buffer
    readonly : int
        Whether the result should be prevented from overwriting the original.
    
    Returns
    -------
    Buffer/View of the original object.
    """
    if not memoryview_available():
        if readonly:
            return PyBuffer_FromObject(obj, 0, Py_END_OF_BUFFER)
        else:
            return PyBuffer_FromReadWriteObject(obj, 0, Py_END_OF_BUFFER)
    else:
        return PyMemoryView_FromObject(obj)


cdef inline object viewfromobject_r(object obj):
    """Wrapper for readonly viewfromobject."""
    return viewfromobject(obj, 1)


cdef inline object viewfromobject_w(object obj):
    """Wrapper for writable viewfromobject."""
    return viewfromobject(obj, 0)