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Differential D7953

hgdemandimport: disable on Python 3.5
ClosedPublic

Authored by indygreg on Jan 21 2020, 2:48 AM.

Details

Reviewers
pulkit
Group Reviewers
hg-reviewers
Commits
rHGc5e0a9b97b8a: hgdemandimport: disable on Python 3.5
rHG1292386dd05c: hgdemandimport: disable on Python 3.5
Summary

The demand importer functionality isn't working at all on Python 3.5.
I'm not sure what's wrong.

Since it isn't working, let's disable it completely.

$ HGRCPATH= hyperfine -w 1 -r 50 -- "~/.pyenv/versions/3.5.9/bin/python ./hg version" \
  "HGDEMANDIMPORT=disable ~/.pyenv/versions/3.5.9/bin/python ./hg version"
Benchmark #1: ~/.pyenv/versions/3.5.9/bin/python ./hg version
  Time (mean ± σ):     163.7 ms ±   2.2 ms    [User: 148.5 ms, System: 15.7 ms]
  Range (min … max):   161.0 ms … 170.2 ms    50 runs

Benchmark #2: HGDEMANDIMPORT=disable ~/.pyenv/versions/3.5.9/bin/python ./hg version
  Time (mean ± σ):     164.3 ms ±   1.4 ms    [User: 148.2 ms, System: 16.6 ms]
  Range (min … max):   161.4 ms … 169.8 ms    50 runs

Diff Detail

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default
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Revision Contents
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Diff 19460

hgdemandimport/demandimportpy3.py

import importlib.machinery import importlib.machinery
import importlib.util import importlib.util
import sys import sys
from . import tracing from . import tracing
_deactivated = False _deactivated = False
# Python 3.5's LazyLoader doesn't work for some reason.
# https://bugs.python.org/issue26186 is a known issue with extension
# importing. But it appears to not have a meaningful effect with
# Mercurial.
_supported = sys.version_info[0:2] >= (3, 6)
class _lazyloaderex(importlib.util.LazyLoader): class _lazyloaderex(importlib.util.LazyLoader):
"""This is a LazyLoader except it also follows the _deactivated global and """This is a LazyLoader except it also follows the _deactivated global and
the ignore list. the ignore list.
""" """
def exec_module(self, module): def exec_module(self, module):
"""Make the module load lazily.""" """Make the module load lazily."""
with tracing.log('demandimport %s', module): with tracing.log('demandimport %s', module):
if _deactivated or module.__name__ in ignores: if _deactivated or module.__name__ in ignores:
self.loader.exec_module(module) self.loader.exec_module(module)
else: else:
super().exec_module(module) super().exec_module(module)
# This is 3.6+ because with Python 3.5 it isn't possible to lazily load
# extensions. See the discussion in https://bugs.python.org/issue26186 for more.
if sys.version_info[0:2] >= (3, 6):
_extensions_loader = _lazyloaderex.factory( _extensions_loader = _lazyloaderex.factory(
importlib.machinery.ExtensionFileLoader importlib.machinery.ExtensionFileLoader
) )
else:
_extensions_loader = importlib.machinery.ExtensionFileLoader
_bytecode_loader = _lazyloaderex.factory( _bytecode_loader = _lazyloaderex.factory(
importlib.machinery.SourcelessFileLoader importlib.machinery.SourcelessFileLoader
) )
_source_loader = _lazyloaderex.factory(importlib.machinery.SourceFileLoader) _source_loader = _lazyloaderex.factory(importlib.machinery.SourceFileLoader)
def _makefinder(path): def _makefinder(path):
return importlib.machinery.FileFinder( return importlib.machinery.FileFinder(
try: try:
while True: while True:
sys.path_hooks.remove(_makefinder) sys.path_hooks.remove(_makefinder)
except ValueError: except ValueError:
pass pass
def enable(): def enable():
if not _supported:
return
sys.path_hooks.insert(0, _makefinder) sys.path_hooks.insert(0, _makefinder)
@contextlib.contextmanager @contextlib.contextmanager
def deactivated(): def deactivated():
# This implementation is a bit different from Python 2's. Python 3 # This implementation is a bit different from Python 2's. Python 3
# maintains a per-package finder cache in sys.path_importer_cache (see # maintains a per-package finder cache in sys.path_importer_cache (see
# PEP 302). This means that we can't just call disable + enable. # PEP 302). This means that we can't just call disable + enable.

tests/test-demandimport.py

['python', '%s/hghave' % os.environ['TESTDIR'], 'demandimport'] ['python', '%s/hghave' % os.environ['TESTDIR'], 'demandimport']
): ):
sys.exit(80) sys.exit(80)
# We rely on assert, which gets optimized out. # We rely on assert, which gets optimized out.
if sys.flags.optimize: if sys.flags.optimize:
sys.exit(80) sys.exit(80)
# The demand importer doesn't work on Python 3.5.
if sys.version_info[0:2] == (3, 5):
sys.exit(80)
if ispy3: if ispy3:
from importlib.util import _LazyModule from importlib.util import _LazyModule
try: try:
from importlib.util import _Module as moduletype from importlib.util import _Module as moduletype
except ImportError: except ImportError:
moduletype = types.ModuleType moduletype = types.ModuleType
else: else: