python/cpython

Co-Authored-By: Victor Stinner <vstinner@python.org>

SpooledTemporaryFile.rollback() might cause data corruption
when it is in text mode.

Co-Authored-By: Serhiy Storchaka <storchaka@gmail.com>

It should avoid dynamic lookup including `isinstance`.

This is a regression caused by GH-5351.

MSVC 2015 supports %zd / %zu.  "z" is portable enough nowadays.

It is deprecated since Python 3.4.

https://bugs.python.org/issue37055



Automerge-Triggered-By: @tiran

Use a tighter scope temporary variable to help register allocation.
1% speedup for large string.

Use PyDict_SetItemDefault() for memoizing keys.
At most 4% speedup when the cache hit ratio is low.

gc used several PySys_WriteStderr() calls to write stats.
It caused stats mixed up when stderr is shared by multiple
processes like this:

  gc: collecting generation 2...
  gc: objects in each generation: 0 0gc: collecting generation 2...
  gc: objects in each generation: 0 0 126077 126077
  gc: objects in permanent generation: 0

  gc: objects in permanent generation: 0
  gc: done, 112575 unreachable, 0 uncollectablegc: done, 112575 unreachable, 0 uncollectable, 0.2223s elapsed
  , 0.2344s elapsed

PyObject_Malloc() and PyObject_Free() inlines pymalloc_alloc and
pymalloc_free partially.
But when PGO is not used, compiler don't know where is the hot part
in pymalloc_alloc and pymalloc_free.

`_PyUnicode_Writer` is a relatively complex structure.  Initializing it is significant overhead when decoding short ASCII string.

It is alias to mac_latin2 now.

--with-pydebug is commonly used to find memory leaks.
But opcache makes it harder.
So disable opcache when Py_DEBUG is defined.

This code was for deoptimization, which is removed from
PR-12884.

This patch implements per opcode cache mechanism, and use it in
only LOAD_GLOBAL opcode.

Based on Yury's opcache3.patch in bpo-26219.

_osx_support and copyreg are not imported from site on macOS for now.

PyUnicode_AsUnicodeAndSize() -> PyUnicode_AsWideChar()

It reduces "data" segment in python about 200KB.

IPv4Interface and IPv6Interface did not has netmask and hostmask
attributes when its argument is bytes or int.

This commit extracts method for constructors of Network and Interface,
and ensure Interface class always provides them.

Keep the nudge towards DeprecationWarning, but remove the
"Note" markup and generally shorten the description.

Ref: https://github.com/python/cpython/pull/12505/files#r273978757

* cached_property is more efficient than hand crafted cache.
* In IPv[46]Network, `self.network.prefixlen` is same to `self._prefixlen`.