Fix test_copyreg when numpy is installed: test.pickletester now
saves/restores warnings.filters when importing numpy, to ignore
filters installed by numpy.
Add the save_restore_warnings_filters() function to the
test.support.warnings_helper module.
The previous code was raising a `KeyError` for both the Python and C implementation.
This was caused by the specified index of an invalid input which did not exist
in the memo structure, where the pickle stores what objects it has seen.
The malformed input would have caused either a `BINGET` or `LONG_BINGET` load
from the memo, leading to a `KeyError` as the determined index was bogus.
https://bugs.python.org/issue38876https://bugs.python.org/issue38876
Mark some individual tests to skip when --pgo is used. The tests
marked increase the PGO task time significantly and likely don't
help improve optimization of the final executable.
Allow reduction methods to return a 6-item tuple where the 6th item specifies a
custom state-setting method that's called instead of the regular
``__setstate__`` method.
PyMemoryView_FromMemory() created a memoryview referring to
the internal data of the string. When the string is destroyed
the memoryview become referring to a freed memory.
when serialize into memory buffer with C pickle implementations.
This optimization already is performed when serialize into memory
with Python pickle implementations or into a file with both
implementations.
The picklers do no longer allocate temporary memory when dumping large
bytes and str objects into a file object. Instead the data is
directly streamed into the underlying file object.
Previously the C implementation would buffer all content and issue a
single call to file.write() at the end of the dump. With protocol 4
this behavior has changed to issue one call to file.write() per frame.
The Python pickler with protocol 4 now dumps each frame content as a
memoryview to an IOBytes instance that is never reused and the
memoryview is no longer released after the call to write. This makes it
possible for the file object to delay access to the memoryview of
previous frames without forcing any additional memory copy as was
already possible with the C pickler.
