mirror of https://github.com/python/cpython
56 lines
2.4 KiB
ReStructuredText
56 lines
2.4 KiB
ReStructuredText
.. highlightlang:: c
|
|
|
|
Old Buffer Protocol
|
|
-------------------
|
|
|
|
.. deprecated:: 3.0
|
|
|
|
These functions were part of the "old buffer protocol" API in Python 2.
|
|
In Python 3, this protocol doesn't exist anymore but the functions are still
|
|
exposed to ease porting 2.x code. They act as a compatibility wrapper
|
|
around the :ref:`new buffer protocol <bufferobjects>`, but they don't give
|
|
you control over the lifetime of the resources acquired when a buffer is
|
|
exported.
|
|
|
|
Therefore, it is recommended that you call :c:func:`PyObject_GetBuffer`
|
|
(or the ``y*`` or ``w*`` :ref:`format codes <arg-parsing>` with the
|
|
:c:func:`PyArg_ParseTuple` family of functions) to get a buffer view over
|
|
an object, and :c:func:`PyBuffer_Release` when the buffer view can be released.
|
|
|
|
|
|
.. c:function:: int PyObject_AsCharBuffer(PyObject *obj, const char **buffer, Py_ssize_t *buffer_len)
|
|
|
|
Returns a pointer to a read-only memory location usable as character-based
|
|
input. The *obj* argument must support the single-segment character buffer
|
|
interface. On success, returns ``0``, sets *buffer* to the memory location
|
|
and *buffer_len* to the buffer length. Returns ``-1`` and sets a
|
|
:exc:`TypeError` on error.
|
|
|
|
|
|
.. c:function:: int PyObject_AsReadBuffer(PyObject *obj, const void **buffer, Py_ssize_t *buffer_len)
|
|
|
|
Returns a pointer to a read-only memory location containing arbitrary data.
|
|
The *obj* argument must support the single-segment readable buffer
|
|
interface. On success, returns ``0``, sets *buffer* to the memory location
|
|
and *buffer_len* to the buffer length. Returns ``-1`` and sets a
|
|
:exc:`TypeError` on error.
|
|
|
|
|
|
.. c:function:: int PyObject_CheckReadBuffer(PyObject *o)
|
|
|
|
Returns ``1`` if *o* supports the single-segment readable buffer interface.
|
|
Otherwise returns ``0``. This function always succeeds.
|
|
|
|
Note that this function tries to get and release a buffer, and exceptions
|
|
which occur while calling correspoding functions will get suppressed.
|
|
To get error reporting use :c:func:`PyObject_GetBuffer()` instead.
|
|
|
|
|
|
.. c:function:: int PyObject_AsWriteBuffer(PyObject *obj, void **buffer, Py_ssize_t *buffer_len)
|
|
|
|
Returns a pointer to a writable memory location. The *obj* argument must
|
|
support the single-segment, character buffer interface. On success,
|
|
returns ``0``, sets *buffer* to the memory location and *buffer_len* to the
|
|
buffer length. Returns ``-1`` and sets a :exc:`TypeError` on error.
|
|
|