From 37498fc95012ba8e147db646b841bc3d36ddf4af Mon Sep 17 00:00:00 2001 From: Inada Naoki Date: Fri, 2 Jun 2023 10:12:40 +0900 Subject: [PATCH] gh-85275: Remove old buffer APIs (#105137) They are now abi-only. Co-authored-by: Victor Stinner --- Doc/c-api/abstract.rst | 1 - Doc/c-api/objbuffer.rst | 55 ------------------- Doc/data/refcounts.dat | 15 ----- Doc/data/stable_abi.dat | 4 -- Doc/whatsnew/3.13.rst | 36 ++++++++++++ Include/abstract.h | 49 ----------------- ...3-05-31-19-38-45.gh-issue-85275.doojgE.rst | 4 ++ Misc/stable_abi.toml | 4 ++ Objects/abstract.c | 44 ++++++++++++--- 9 files changed, 79 insertions(+), 133 deletions(-) delete mode 100644 Doc/c-api/objbuffer.rst create mode 100644 Misc/NEWS.d/next/C API/2023-05-31-19-38-45.gh-issue-85275.doojgE.rst diff --git a/Doc/c-api/abstract.rst b/Doc/c-api/abstract.rst index 1823f9d70c7..f5df09fa7fd 100644 --- a/Doc/c-api/abstract.rst +++ b/Doc/c-api/abstract.rst @@ -24,4 +24,3 @@ but whose items have not been set to some non-\ ``NULL`` value yet. mapping.rst iter.rst buffer.rst - objbuffer.rst diff --git a/Doc/c-api/objbuffer.rst b/Doc/c-api/objbuffer.rst deleted file mode 100644 index 6b82a642d7e..00000000000 --- a/Doc/c-api/objbuffer.rst +++ /dev/null @@ -1,55 +0,0 @@ -.. highlight:: 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 `, 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 ` 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 corresponding 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. - diff --git a/Doc/data/refcounts.dat b/Doc/data/refcounts.dat index 65ffb96d5c8..f5628abb904 100644 --- a/Doc/data/refcounts.dat +++ b/Doc/data/refcounts.dat @@ -1578,21 +1578,6 @@ PyOS_FSPath:PyObject*:path:0: PyObject_ASCII:PyObject*::+1: PyObject_ASCII:PyObject*:o:0: -PyObject_AsCharBuffer:int::: -PyObject_AsCharBuffer:PyObject*:obj:0: -PyObject_AsCharBuffer:const char**:buffer:: -PyObject_AsCharBuffer:Py_ssize_t*:buffer_len:: - -PyObject_AsReadBuffer:int::: -PyObject_AsReadBuffer:PyObject*:obj:0: -PyObject_AsReadBuffer:const void**:buffer:: -PyObject_AsReadBuffer:Py_ssize_t*:buffer_len:: - -PyObject_AsWriteBuffer:int::: -PyObject_AsWriteBuffer:PyObject*:obj:0: -PyObject_AsWriteBuffer:void**:buffer:: -PyObject_AsWriteBuffer:Py_ssize_t*:buffer_len:: - PyObject_Bytes:PyObject*::+1: PyObject_Bytes:PyObject*:o:0: diff --git a/Doc/data/stable_abi.dat b/Doc/data/stable_abi.dat index 767025b76f8..80806aedfcd 100644 --- a/Doc/data/stable_abi.dat +++ b/Doc/data/stable_abi.dat @@ -476,10 +476,7 @@ type,PyObject,3.2,,members member,PyObject.ob_refcnt,3.2,, member,PyObject.ob_type,3.2,, function,PyObject_ASCII,3.2,, -function,PyObject_AsCharBuffer,3.2,, function,PyObject_AsFileDescriptor,3.2,, -function,PyObject_AsReadBuffer,3.2,, -function,PyObject_AsWriteBuffer,3.2,, function,PyObject_Bytes,3.2,, function,PyObject_Call,3.2,, function,PyObject_CallFunction,3.2,, @@ -490,7 +487,6 @@ function,PyObject_CallNoArgs,3.10,, function,PyObject_CallObject,3.2,, function,PyObject_Calloc,3.7,, function,PyObject_CheckBuffer,3.11,, -function,PyObject_CheckReadBuffer,3.2,, function,PyObject_ClearWeakRefs,3.2,, function,PyObject_CopyData,3.11,, function,PyObject_DelItem,3.2,, diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst index e4b6e3b6ff9..04ac34e0926 100644 --- a/Doc/whatsnew/3.13.rst +++ b/Doc/whatsnew/3.13.rst @@ -395,6 +395,42 @@ Removed (Contributed by Victor Stinner in :gh:`105107`.) +* Remove old buffer protocols deprecated in Python 3.0. Use :ref:`bufferobjects` instead. + + * :c:func:`!PyObject_CheckReadBuffer`: Use :c:func:`PyObject_CheckBuffer` to + test if the object supports the buffer protocol. + Note that :c:func:`PyObject_CheckBuffer` doesn't guarantee that + :c:func:`PyObject_GetBuffer` will succeed. + To test if the object is actually readable, see the next example + of :c:func:`PyObject_GetBuffer`. + + * :c:func:`!PyObject_AsCharBuffer`, :c:func:`!PyObject_AsReadBuffer`: + :c:func:`PyObject_GetBuffer` and :c:func:`PyBuffer_Release` instead: + + .. code-block:: c + + Py_buffer view; + if (PyObject_GetBuffer(obj, &view, PyBUF_SIMPLE) < 0) { + return NULL; + } + // Use `view.buf` and `view.len` to read from the buffer. + // You may need to cast buf as `(const char*)view.buf`. + PyBuffer_Release(&view); + + * :c:func:`!PyObject_AsWriteBuffer`: Use + :c:func:`PyObject_GetBuffer` and :c:func:`PyBuffer_Release` instead: + + .. code-block:: c + + Py_buffer view; + if (PyObject_GetBuffer(obj, &view, PyBUF_WRITABLE) < 0) { + return NULL; + } + // Use `view.buf` and `view.len` to write to the buffer. + PyBuffer_Release(&view); + + (Contributed by Inada Naoki in :gh:`85275`.) + * Remove the following old functions to configure the Python initialization, deprecated in Python 3.11: diff --git a/Include/abstract.h b/Include/abstract.h index b4c2bedef44..016ace9bc89 100644 --- a/Include/abstract.h +++ b/Include/abstract.h @@ -320,55 +320,6 @@ PyAPI_FUNC(int) PyObject_DelItemString(PyObject *o, const char *key); PyAPI_FUNC(int) PyObject_DelItem(PyObject *o, PyObject *key); -/* === Old Buffer API ============================================ */ - -/* FIXME: usage of these should all be replaced in Python itself - but for backwards compatibility we will implement them. - Their usage without a corresponding "unlock" mechanism - may create issues (but they would already be there). */ - -/* Takes an arbitrary object which must support the (character, single segment) - buffer interface and returns a pointer to a read-only memory location - usable as character based input for subsequent processing. - - Return 0 on success. buffer and buffer_len are only set in case no error - occurs. Otherwise, -1 is returned and an exception set. */ -Py_DEPRECATED(3.0) -PyAPI_FUNC(int) PyObject_AsCharBuffer(PyObject *obj, - const char **buffer, - Py_ssize_t *buffer_len); - -/* Checks whether an arbitrary object supports the (character, single segment) - buffer interface. - - Returns 1 on success, 0 on failure. */ -Py_DEPRECATED(3.0) PyAPI_FUNC(int) PyObject_CheckReadBuffer(PyObject *obj); - -/* Same as PyObject_AsCharBuffer() except that this API expects (readable, - single segment) buffer interface and returns a pointer to a read-only memory - location which can contain arbitrary data. - - 0 is returned on success. buffer and buffer_len are only set in case no - error occurs. Otherwise, -1 is returned and an exception set. */ -Py_DEPRECATED(3.0) -PyAPI_FUNC(int) PyObject_AsReadBuffer(PyObject *obj, - const void **buffer, - Py_ssize_t *buffer_len); - -/* Takes an arbitrary object which must support the (writable, single segment) - buffer interface and returns a pointer to a writable memory location in - buffer of size 'buffer_len'. - - Return 0 on success. buffer and buffer_len are only set in case no error - occurs. Otherwise, -1 is returned and an exception set. */ -Py_DEPRECATED(3.0) -PyAPI_FUNC(int) PyObject_AsWriteBuffer(PyObject *obj, - void **buffer, - Py_ssize_t *buffer_len); - - -/* === New Buffer API ============================================ */ - /* Takes an arbitrary object and returns the result of calling obj.__format__(format_spec). */ PyAPI_FUNC(PyObject *) PyObject_Format(PyObject *obj, diff --git a/Misc/NEWS.d/next/C API/2023-05-31-19-38-45.gh-issue-85275.doojgE.rst b/Misc/NEWS.d/next/C API/2023-05-31-19-38-45.gh-issue-85275.doojgE.rst new file mode 100644 index 00000000000..082b77b9035 --- /dev/null +++ b/Misc/NEWS.d/next/C API/2023-05-31-19-38-45.gh-issue-85275.doojgE.rst @@ -0,0 +1,4 @@ +``PyObject_AsCharBuffer()``, ``PyObject_AsReadBuffer()``, +``PyObject_CheckReadBuffer()``, and ``PyObject_AsWriteBuffer()`` are +removed. Please migrate to new buffer protocol; :c:func:`PyObject_GetBuffer` +and :c:func:`PyBuffer_Release`. diff --git a/Misc/stable_abi.toml b/Misc/stable_abi.toml index 2209f6e02cf..4d833878734 100644 --- a/Misc/stable_abi.toml +++ b/Misc/stable_abi.toml @@ -1755,12 +1755,16 @@ [function.PyObject_AsCharBuffer] added = '3.2' + abi_only = true [function.PyObject_AsReadBuffer] added = '3.2' + abi_only = true [function.PyObject_AsWriteBuffer] added = '3.2' + abi_only = true [function.PyObject_CheckReadBuffer] added = '3.2' + abi_only = true # Flags are implicitly part of the ABI: diff --git a/Objects/abstract.c b/Objects/abstract.c index e95785900c9..00087bd8662 100644 --- a/Objects/abstract.c +++ b/Objects/abstract.c @@ -294,11 +294,17 @@ PyObject_CheckBuffer(PyObject *obj) return (tp_as_buffer != NULL && tp_as_buffer->bf_getbuffer != NULL); } +// Old buffer protocols (deprecated, abi only) -/* We release the buffer right after use of this function which could +/* Checks whether an arbitrary object supports the (character, single segment) + buffer interface. + + Returns 1 on success, 0 on failure. + + We release the buffer right after use of this function which could cause issues later on. Don't use these functions in new code. */ -int +PyAPI_FUNC(int) /* abi_only */ PyObject_CheckReadBuffer(PyObject *obj) { PyBufferProcs *pb = Py_TYPE(obj)->tp_as_buffer; @@ -333,7 +339,13 @@ as_read_buffer(PyObject *obj, const void **buffer, Py_ssize_t *buffer_len) return 0; } -int +/* Takes an arbitrary object which must support the (character, single segment) + buffer interface and returns a pointer to a read-only memory location + usable as character based input for subsequent processing. + + Return 0 on success. buffer and buffer_len are only set in case no error + occurs. Otherwise, -1 is returned and an exception set. */ +PyAPI_FUNC(int) /* abi_only */ PyObject_AsCharBuffer(PyObject *obj, const char **buffer, Py_ssize_t *buffer_len) @@ -341,16 +353,30 @@ PyObject_AsCharBuffer(PyObject *obj, return as_read_buffer(obj, (const void **)buffer, buffer_len); } -int PyObject_AsReadBuffer(PyObject *obj, - const void **buffer, - Py_ssize_t *buffer_len) +/* Same as PyObject_AsCharBuffer() except that this API expects (readable, + single segment) buffer interface and returns a pointer to a read-only memory + location which can contain arbitrary data. + + 0 is returned on success. buffer and buffer_len are only set in case no + error occurs. Otherwise, -1 is returned and an exception set. */ +PyAPI_FUNC(int) /* abi_only */ +PyObject_AsReadBuffer(PyObject *obj, + const void **buffer, + Py_ssize_t *buffer_len) { return as_read_buffer(obj, buffer, buffer_len); } -int PyObject_AsWriteBuffer(PyObject *obj, - void **buffer, - Py_ssize_t *buffer_len) +/* Takes an arbitrary object which must support the (writable, single segment) + buffer interface and returns a pointer to a writable memory location in + buffer of size 'buffer_len'. + + Return 0 on success. buffer and buffer_len are only set in case no error + occurs. Otherwise, -1 is returned and an exception set. */ +PyAPI_FUNC(int) /* abi_only */ +PyObject_AsWriteBuffer(PyObject *obj, + void **buffer, + Py_ssize_t *buffer_len) { PyBufferProcs *pb; Py_buffer view;