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__doc__ = u"""
>>> b1 = UserBuffer1()
>>> m1 = memoryview(b1)
>>> m1.tolist()
[0, 1, 2, 3, 4]
>>> del m1, b1
>>> b2 = UserBuffer2()
>>> m2 = memoryview(b2)
UserBuffer2: getbuffer
>>> m2.tolist()
[5, 6, 7, 8, 9]
>>> del m2, b2
UserBuffer2: release
"""
cdef extern from *:
ctypedef struct Py_buffer # redeclared
enum: PyBUF_SIMPLE
int PyBuffer_FillInfo(Py_buffer *, object, void *, Py_ssize_t, bint, int) except -1
int PyObject_GetBuffer(object, Py_buffer *, int) except -1
void PyBuffer_Release(Py_buffer *)
cdef char global_buf[5]
global_buf[0:5] = [0, 1, 2, 3, 4]
cdef class UserBuffer1:
def __getbuffer__(self, Py_buffer* view, int flags):
PyBuffer_FillInfo(view, None, global_buf, 5, 1, flags)
cdef class UserBuffer2:
cdef char buf[5]
def __cinit__(self):
self.buf[0:5] = [5, 6, 7, 8, 9]
def __getbuffer__(self, Py_buffer* view, int flags):
print('UserBuffer2: getbuffer')
PyBuffer_FillInfo(view, self, self.buf, 5, 0, flags)
def __releasebuffer__(self, Py_buffer* view):
print('UserBuffer2: release')
cdef extern from *:
ctypedef struct PyBuffer"Py_buffer":
void *buf
Py_ssize_t len
bint readonly
cdef class _memoryview:
"""
Memory
"""
cdef PyBuffer view
def __cinit__(self, obj):
cdef Py_buffer *view = <Py_buffer*>&self.view
PyObject_GetBuffer(obj, view, PyBUF_SIMPLE)
def __dealloc__(self):
cdef Py_buffer *view = <Py_buffer*>&self.view
PyBuffer_Release(view )
def __getbuffer__(self, Py_buffer *view, int flags):
PyBuffer_FillInfo(view, self,
self.view.buf, self.view.len,
self.view.readonly, flags)
def tolist(self):
cdef char *b = <char *> self.view.buf
return [b[i] for i in range(self.view.len)]
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