Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Sergey B Kirpichev <skirpichev@gmail.com>
Co-authored-by: Carol Willing <carolcode@willingconsulting.com>
* gh-117151: increase default buffer size of shutil.copyfileobj() to 256k.
it was set to 16k in the 1990s.
it was raised to 64k in 2019. the discussion at the time mentioned another 5% improvement by raising to 128k and settled for a very conservative setting.
it's 2024 now, I think it should be revisited to match modern hardware. I am measuring 0-15% performance improvement when raising to 256k on various types of disk. there is no downside as far as I can tell.
this function is only intended for sequential copy of full files (or file like objects). it's the typical use case that benefits from larger operations.
for reference, I came across this function while trying to profile pip that is using it to copy files when installing python packages.
* add news
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Co-authored-by: rmorotti <romain.morotti@man.com>
Cache in C PEG-generator reworked:
we save artificial rules in cache by Node string representation as a key instead of Node object itself.
As a result total count of artificial rules in parsers.c is lowered from 283 to 170.
More natural number ordering is used for the names of artificial rules.
Auxiliary method CCallMakerVisitor._generate_artificial_rule_call is added.
Its purpose is abstracting work with artificial rules cache.
Explicit using of "is_repeat1" kwarg is added to visit_Repeat0 and visit_Repeat1 methods.
Its slightly improve code readabitily.
Instead of surprise crashes and memory corruption, we now hang threads that attempt to re-enter the Python interpreter after Python runtime finalization has started. These are typically daemon threads (our long standing mis-feature) but could also be threads spawned by extension modules that then try to call into Python. This marks the `PyThread_exit_thread` public C API as deprecated as there is no plausible safe way to accomplish that on any supported platform in the face of things like C++ code with finalizers anywhere on a thread's stack. Doing this was the least bad option.
Co-authored-by: Gregory P. Smith <greg@krypto.org>
Fix the incorrect use of `os.open()` result as a context manager,
while it is actually a numeric file descriptor.
I have missed the problem, because in the original version the
`os.open()` call would always fail, and I failed to test the final
version in all possible scenarios properly.
This is actually an upstream problem in curses, and has been reported
to them already:
https://lists.gnu.org/archive/html/bug-ncurses/2024-09/msg00101.html
This is a nice workaround in the meantime to prevent the segfault.
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Previously when executing ``test_functattrs.test___builtins__`` directly, it failed because the fact, that ``__builtins__`` is refers to the built-in module ``builtins`` while it's expects a ``__builtins__.__dict__``. But when this test is being run from another module, then ``__builtins__`` is refers to ``builtins.__dict__``. Now this part of the behaviour is covered.
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Co-authored-by: Victor Stinner <vstinner@python.org>
Previously, formatting help output or error message for positional argument
with a tuple metavar raised exception.
Co-authored-by: Cyker Way <cykerway@gmail.com>