Merged revisions 85084 via svnmerge from

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........
  r85084 | antoine.pitrou | 2010-09-29 01:59:51 +0200 (mer., 29 sept. 2010) | 5 lines

  Give a dedicated page to memoryview objects, so that they can be part
  of the concrete objects layer, while the buffer protocol is part of
  the abstract objects layer.
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This commit is contained in:
Antoine Pitrou 2010-09-29 00:01:41 +00:00
parent debf4dbf07
commit 6ec5ed22b2
3 changed files with 55 additions and 48 deletions

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@ -65,7 +65,7 @@ in its native, in-memory format.
Contrary to most data types exposed by the Python interpreter, buffers
are not :ctype:`PyObject` pointers but rather simple C structures. This
allows them to be created and copied very simply. When a generic wrapper
around a buffer is needed, a :ref:`memoryview <memoryviewobjects>` object
around a buffer is needed, a :ref:`memoryview <memoryview-objects>` object
can be created.
@ -154,7 +154,7 @@ can be created.
value.
Buffer related functions
Buffer-related functions
========================
@ -330,49 +330,3 @@ Buffer related functions
only share a contiguous chunk of memory of "unsigned bytes" of the given
length. Return 0 on success and -1 (with raising an error) on error.
.. index::
object: memoryview
.. _memoryviewobjects:
MemoryView objects
==================
A :class:`memoryview` object exposes the C level buffer interface as a
Python object which can then be passed around like any other object.
.. cfunction:: PyObject *PyMemoryView_FromObject(PyObject *obj)
Create a memoryview object from an object that defines the buffer interface.
.. cfunction:: PyObject *PyMemoryView_FromBuffer(Py_buffer *view)
Create a memoryview object wrapping the given buffer-info structure *view*.
The memoryview object then owns the buffer, which means you shouldn't
try to release it yourself: it will be released on deallocation of the
memoryview object.
.. cfunction:: PyObject *PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char order)
Create a memoryview object to a contiguous chunk of memory (in either
'C' or 'F'ortran *order*) from an object that defines the buffer
interface. If memory is contiguous, the memoryview object points to the
original memory. Otherwise copy is made and the memoryview points to a
new bytes object.
.. cfunction:: int PyMemoryView_Check(PyObject *obj)
Return true if the object *obj* is a memoryview object. It is not
currently allowed to create subclasses of :class:`memoryview`.
.. cfunction:: Py_buffer *PyMemoryView_GET_BUFFER(PyObject *obj)
Return a pointer to the buffer-info structure wrapped by the given
object. The object **must** be a memoryview instance; this macro doesn't
check its type, you must do it yourself or you will risk crashes.

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@ -99,6 +99,7 @@ Other Objects
iterator.rst
descriptor.rst
slice.rst
memoryview.rst
weakref.rst
capsule.rst
cobject.rst

52
Doc/c-api/memoryview.rst Normal file
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@ -0,0 +1,52 @@
.. highlightlang:: c
.. _memoryview-objects:
.. index::
object: memoryview
MemoryView objects
------------------
A :class:`memoryview` object exposes the C level :ref:`buffer interface
<bufferobjects>` as a Python object which can then be passed around like
any other object.
.. cfunction:: PyObject *PyMemoryView_FromObject(PyObject *obj)
Create a memoryview object from an object that provides the buffer interface.
If *obj* supports writable buffer exports, the memoryview object will be
readable and writable, other it will be read-only.
.. cfunction:: PyObject *PyMemoryView_FromBuffer(Py_buffer *view)
Create a memoryview object wrapping the given buffer structure *view*.
The memoryview object then owns the buffer represented by *view*, which
means you shouldn't try to call :cfunc:`PyBuffer_Release` yourself: it
will be done on deallocation of the memoryview object.
.. cfunction:: PyObject *PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char order)
Create a memoryview object to a contiguous chunk of memory (in either
'C' or 'F'ortran *order*) from an object that defines the buffer
interface. If memory is contiguous, the memoryview object points to the
original memory. Otherwise copy is made and the memoryview points to a
new bytes object.
.. cfunction:: int PyMemoryView_Check(PyObject *obj)
Return true if the object *obj* is a memoryview object. It is not
currently allowed to create subclasses of :class:`memoryview`.
.. cfunction:: Py_buffer *PyMemoryView_GET_BUFFER(PyObject *obj)
Return a pointer to the buffer structure wrapped by the given
memoryview object. The object **must** be a memoryview instance;
this macro doesn't check its type, you must do it yourself or you
will risk crashes.