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Diffstat (limited to 'scripts/external_libs/zmq/utils/buffers.pxd')
| -rw-r--r-- | scripts/external_libs/zmq/utils/buffers.pxd | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/scripts/external_libs/zmq/utils/buffers.pxd b/scripts/external_libs/zmq/utils/buffers.pxd new file mode 100644 index 00000000..998aa551 --- /dev/null +++ b/scripts/external_libs/zmq/utils/buffers.pxd @@ -0,0 +1,313 @@ +"""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) |