stream-clone: disable gc for the initial section for the v3 format
The number of small container created turn Python in a gc-frenzy that seriously
impact performance.
This significantly boost performance. The following number comes from a large
private repository using perf::stream-locked-section:
base-line: 35.04 seconds
prev-change: 24.51 seconds (-30%)
prev-change: 20.88 seconds (-40%)
this-change: 14.22 seconds (-60% from baseline; -31% from prev)
# typelib.py - type hint aliases and support
#
# Copyright 2022 Matt Harbison <matt_harbison@yahoo.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import typing
# Note: this is slightly different from pycompat.TYPE_CHECKING, as using
# pycompat causes the BinaryIO_Proxy type to be resolved to ``object`` when
# used as the base class during a pytype run.
TYPE_CHECKING = typing.TYPE_CHECKING
# The BinaryIO class provides empty methods, which at runtime means that
# ``__getattr__`` on the proxy classes won't get called for the methods that
# should delegate to the internal object. So to avoid runtime changes because
# of the required typing inheritance, just use BinaryIO when typechecking, and
# ``object`` otherwise.
if TYPE_CHECKING:
from typing import (
BinaryIO,
)
BinaryIO_Proxy = BinaryIO
else:
BinaryIO_Proxy = object