[issue10803] ctypes: better support of bytearray objects
Changes by Stefan Krah stefan-use...@bytereef.org: -- nosy: -skrah ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10803 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10803] ctypes: better support of bytearray objects
Serhiy Storchaka added the comment: Existing inconsistency was fixed in issue22161. Patch updated, synchronized with tip. Added new tests. -- Added file: http://bugs.python.org/file36326/ctypes_bytearray_2.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10803 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10803] ctypes: better support of bytearray objects
Serhiy Storchaka added the comment: Here are things which support bytes instances only: 1. Constructor and setter of the value attribute of NUL terminated char buffer. p = create_string_buffer(bHello) p.value b'Hello' p.raw b'Hello\x00' p.value = b'Bye' p.value b'Bye' p.raw b'Bye\x00o\x00' create_string_buffer(bytearray(bHello)) Traceback (most recent call last): File stdin, line 1, in module File /home/serhiy/py/cpython-3.4/Lib/ctypes/__init__.py, line 63, in create_string_buffer raise TypeError(init) TypeError: bytearray(b'Hello') p.value = bytearray(b'Hi') Traceback (most recent call last): File stdin, line 1, in module TypeError: bytes expected instead of bytearray instance But setter of the raw attribute accepts arbitrary bytes-like objects. p.raw = bytearray(b'Hi') p.raw b'Hie\x00o\x00' The patch adds support of bytearray here. It would be not so easy to add support for arbitrary bytes-like objects, and due to NUL-terminating it can be confused. I even not sure that support of bytearray is needed here. 2. Constructor of NUL terminated wchar buffer (create_unicode_buffer). Actually this doesn't work. Bytes argument is accepted, but then rejected in internal setting function. This is a bug, bytes should be removed here. 3. c_wchar_p.from_param() accepts bytes argument, but then reject it in internal function. This is a bug, bytes should be removed here. 4. c_void_p.from_param() accepts bytes and bytearray arguments, but then reject bytearray in internal function. This is a bug, either bytearray should be rejected here, or support of bytearray should be added in internal function (very easy, the patch does this). Adding support of arbitrary bytes-like objects is more complicated. 5. c_char_p.from_param() accepts bytes argument. Adding support for bytearray or arbitrary bytes-like objects has same complexity as in c_void_p.from_param(). 6. Bytes arguments of call_function(), call_cdeclfunction() and CopyComPointer() are implicitly converted to pointers. It is easy to add support of bytearray, and more complicated for arbitrary bytes-like objects. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10803 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10803] ctypes: better support of bytearray objects
Changes by Serhiy Storchaka storch...@gmail.com: -- dependencies: +Remove unsupported code from ctypes ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10803 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10803] ctypes: better support of bytearray objects
Changes by Serhiy Storchaka storch...@gmail.com: -- keywords: +needs review ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10803 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10803] ctypes: better support of bytearray objects
Antoine Pitrou added the comment: Why not use the buffer API instead? -- assignee: theller - nosy: +pitrou, skrah ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10803 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10803] ctypes: better support of bytearray objects
Serhiy Storchaka added the comment: Because it is simpler and more efficient. The buffer API requires the releasing of buffer. Correct tracking the ownership of the buffer requires larger and more complicated patch. Even if support for general buffers will be added, I suppose it will be worth to left specialized paths for bytes and bytearrays in some places. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10803 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10803] ctypes: better support of bytearray objects
Changes by Martin Panter vadmium...@gmail.com: -- nosy: +vadmium ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10803 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10803] ctypes: better support of bytearray objects
Serhiy Storchaka added the comment: Here is preliminary patch which makes bytearray support in ctypes better. -- keywords: +patch nosy: +amaury.forgeotdarc, belopolsky, meador.inge, serhiy.storchaka stage: - patch review versions: +Python 3.5 -Python 3.2 Added file: http://bugs.python.org/file32921/ctype_bytearray.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10803 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10803] ctypes: better support of bytearray objects
New submission from Markus F.X.J. Oberhumer mar...@oberhumer.com:
Python 3.2b2 does not properly support accessing bytearrays from
ctypes, which makes dealing with large buffers somewhat unpleasant.
A very first fix - a simple patch for the z_set() function - is given here.
build/Python-3.2b2 $ quilt diff
Index: b/Modules/_ctypes/cfield.c
===
--- a/Modules/_ctypes/cfield.c
+++ b/Modules/_ctypes/cfield.c
@@ -1363,6 +1363,10 @@
*(char **)ptr = PyBytes_AsString(value);
Py_INCREF(value);
return value;
+} else if (PyByteArray_Check(value)) {
+*(char **)ptr = PyByteArray_AsString(value);
+Py_INCREF(value);
+return value;
} else if (PyLong_Check(value)) {
#if SIZEOF_VOID_P == SIZEOF_LONG_LONG
*(char **)ptr = (char *)PyLong_AsUnsignedLongLongMask(value);
--
assignee: theller
components: ctypes
messages: 125032
nosy: mfxmfx, theller
priority: normal
severity: normal
status: open
title: ctypes: better support of bytearray objects
type: feature request
versions: Python 3.2
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