revset: optimize baseset.__sub__ (issue4313)
dd716807fd23 regressed performance of baseset.__sub__ by introducing
a lazyset. This patch restores that lost performance by eagerly
evaluating baseset.__sub__ if the other set is a baseset.
revsetbenchmark.py results impacted by this change:
revset #6: roots(0::tip)
0) wall 2.923473 comb 2.920000 user 2.920000 sys 0.000000 (best of 4)
1) wall 0.077614 comb 0.080000 user 0.080000 sys 0.000000 (best of 100)
revset #23: roots((0:tip)::)
0) wall 2.875178 comb 2.880000 user 2.880000 sys 0.000000 (best of 4)
1) wall 0.154519 comb 0.150000 user 0.150000 sys 0.000000 (best of 61)
On the author's machine, this slowdown manifested during evaluation of
'roots(%ln::)' in phases.retractboundary after unbundling the Firefox
repository. Using `time hg unbundle firefox.hg` as a benchmark:
Before: 8:00
After: 4:28
Delta: -3:32
For reference, the subset and cs baseset instances impacted by this
change were of lengths 193634 and 193627, respectively.
Explicit test coverage of roots(%ln::), while similar to the existing
roots(0::tip) benchmark, has been added.
# demandimport.py - global demand-loading of modules for Mercurial
#
# Copyright 2006, 2007 Matt Mackall <mpm@selenic.com>
#
# 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 demandloading of modules
To enable this module, do:
import demandimport; demandimport.enable()
Imports of the following forms will be demand-loaded:
import a, b.c
import a.b as c
from a import b,c # a will be loaded immediately
These imports will not be delayed:
from a import *
b = __import__(a)
'''
import __builtin__, os, sys
_origimport = __import__
nothing = object()
try:
# Python 3 doesn't have relative imports nor level -1.
level = -1
if sys.version_info[0] >= 3:
level = 0
_origimport(__builtin__.__name__, {}, {}, None, level)
except TypeError: # no level argument
def _import(name, globals, locals, fromlist, level):
"call _origimport with no level argument"
return _origimport(name, globals, locals, fromlist)
else:
_import = _origimport
def _hgextimport(importfunc, name, globals, *args):
try:
return importfunc(name, globals, *args)
except ImportError:
if not globals:
raise
# extensions are loaded with "hgext_" prefix
hgextname = 'hgext_%s' % name
nameroot = hgextname.split('.', 1)[0]
contextroot = globals.get('__name__', '').split('.', 1)[0]
if nameroot != contextroot:
raise
# retry to import with "hgext_" prefix
return importfunc(hgextname, globals, *args)
class _demandmod(object):
"""module demand-loader and proxy"""
def __init__(self, name, globals, locals, level=level):
if '.' in name:
head, rest = name.split('.', 1)
after = [rest]
else:
head = name
after = []
object.__setattr__(self, "_data",
(head, globals, locals, after, level))
object.__setattr__(self, "_module", None)
def _extend(self, name):
"""add to the list of submodules to load"""
self._data[3].append(name)
def _load(self):
if not self._module:
head, globals, locals, after, level = self._data
mod = _hgextimport(_import, head, globals, locals, None, level)
# load submodules
def subload(mod, p):
h, t = p, None
if '.' in p:
h, t = p.split('.', 1)
if getattr(mod, h, nothing) is nothing:
setattr(mod, h, _demandmod(p, mod.__dict__, mod.__dict__))
elif t:
subload(getattr(mod, h), t)
for x in after:
subload(mod, x)
# are we in the locals dictionary still?
if locals and locals.get(head) == self:
locals[head] = mod
object.__setattr__(self, "_module", mod)
def __repr__(self):
if self._module:
return "<proxied module '%s'>" % self._data[0]
return "<unloaded module '%s'>" % self._data[0]
def __call__(self, *args, **kwargs):
raise TypeError("%s object is not callable" % repr(self))
def __getattribute__(self, attr):
if attr in ('_data', '_extend', '_load', '_module'):
return object.__getattribute__(self, attr)
self._load()
return getattr(self._module, attr)
def __setattr__(self, attr, val):
self._load()
setattr(self._module, attr, val)
def _demandimport(name, globals=None, locals=None, fromlist=None, level=level):
if not locals or name in ignore or fromlist == ('*',):
# these cases we can't really delay
return _hgextimport(_import, name, globals, locals, fromlist, level)
elif not fromlist:
# import a [as b]
if '.' in name: # a.b
base, rest = name.split('.', 1)
# email.__init__ loading email.mime
if globals and globals.get('__name__', None) == base:
return _import(name, globals, locals, fromlist, level)
# if a is already demand-loaded, add b to its submodule list
if base in locals:
if isinstance(locals[base], _demandmod):
locals[base]._extend(rest)
return locals[base]
return _demandmod(name, globals, locals, level)
else:
if level != -1:
# from . import b,c,d or from .a import b,c,d
return _origimport(name, globals, locals, fromlist, level)
# from a import b,c,d
mod = _hgextimport(_origimport, name, globals, locals)
# recurse down the module chain
for comp in name.split('.')[1:]:
if getattr(mod, comp, nothing) is nothing:
setattr(mod, comp, _demandmod(comp, mod.__dict__, mod.__dict__))
mod = getattr(mod, comp)
for x in fromlist:
# set requested submodules for demand load
if getattr(mod, x, nothing) is nothing:
setattr(mod, x, _demandmod(x, mod.__dict__, locals))
return mod
ignore = [
'_hashlib',
'_xmlplus',
'fcntl',
'win32com.gen_py',
'_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
'rfc822',
'mimetools',
]
def isenabled():
return __builtin__.__import__ == _demandimport
def enable():
"enable global demand-loading of modules"
if os.environ.get('HGDEMANDIMPORT') != 'disable':
__builtin__.__import__ = _demandimport
def disable():
"disable global demand-loading of modules"
__builtin__.__import__ = _origimport