Mercurial > hg
view hgdemandimport/__init__.py @ 39141:c89e2fb207a1 stable
remotephase: fast path newheads computation in simple case (issue5964)
Changeset 88efb7d6bcb6 fixed the logic of `phases.newheads` but greatly
regressed its performance (up to many order of magnitude). The first step to
fix the regression is to exit early when there is no work to do. If there are
no heads to filter or not roots to filter them, we don't have to do any work.
This fixes the regression when talking to an all public changeset. The
performance is even better than before.
pypy, compared to an all public repo
------------------------------------
8eeed92475d5: 0.005758 seconds
88efb7d6bcb6: 0.602517 seconds (x104)
this code: 0.001508 seconds (-74% from base)
mercurial compared to an all public repo
----------------------------------------
8eeed92475d5: 0.000577 seconds
88efb7d6bcb6: 0.185316 seconds (x321)
this code: 0.000150 seconds (-74% from base)
The performance of newheads, when actual computations are required, is fixed
in the next changeset.
author | Boris Feld <boris.feld@octobus.net> |
---|---|
date | Fri, 17 Aug 2018 16:00:32 -0700 |
parents | 670eb4fa1b86 |
children | 2372284d9457 |
line wrap: on
line source
# hgdemandimport - global demand-loading of modules for Mercurial # # Copyright 2017 Facebook Inc. # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. '''demandimport - automatic demand-loading of modules''' # This is in a separate package from mercurial because in Python 3, # demand loading is per-package. Keeping demandimport in the mercurial package # would disable demand loading for any modules in mercurial. from __future__ import absolute_import import os import sys if sys.version_info[0] >= 3: from . import demandimportpy3 as demandimport else: from . import demandimportpy2 as demandimport # Full module names which can't be lazy imported. # Extensions can add to this set. IGNORES = { '__future__', '_hashlib', # ImportError during pkg_resources/__init__.py:fixup_namespace_package '_imp', '_xmlplus', 'fcntl', 'nt', # pathlib2 tests the existence of built-in 'nt' module 'win32com.gen_py', 'win32com.shell', # 'appdirs' tries to import win32com.shell '_winreg', # 2.7 mimetypes needs immediate ImportError 'pythoncom', # imported by tarfile, not available under Windows 'pwd', 'grp', # imported by profile, itself imported by hotshot.stats, # not available under Windows 'resource', # this trips up many extension authors 'gtk', # setuptools' pkg_resources.py expects "from __main__ import x" to # raise ImportError if x not defined '__main__', '_ssl', # conditional imports in the stdlib, issue1964 '_sre', # issue4920 'rfc822', 'mimetools', 'sqlalchemy.events', # has import-time side effects (issue5085) # setuptools 8 expects this module to explode early when not on windows 'distutils.msvc9compiler', '__builtin__', 'builtins', 'urwid.command_map', # for pudb } _pypy = '__pypy__' in sys.builtin_module_names if _pypy: # _ctypes.pointer is shadowed by "from ... import pointer" (PyPy 5) IGNORES.add('_ctypes.pointer') demandimport.init(IGNORES) # Re-export. isenabled = demandimport.isenabled disable = demandimport.disable deactivated = demandimport.deactivated def enable(): # chg pre-imports modules so do not enable demandimport for it if ('CHGINTERNALMARK' not in os.environ and os.environ.get('HGDEMANDIMPORT') != 'disable'): demandimport.enable()