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