subrepo: allow a representation of the working directory subrepo
Some code cannot handle a subrepo based on the working directory (e.g.
sub.dirty()), so the caller must opt in. This will be useful for archive, and
perhaps some other commands. The git and svn methods where this is used may
need to be fixed up on a case by case basis.
# 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
from contextlib import contextmanager
_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',
# setuptools 8 expects this module to explode early when not on windows
'distutils.msvc9compiler'
]
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
@contextmanager
def deactivated():
"context manager for disabling demandimport in 'with' blocks"
demandenabled = isenabled()
if demandenabled:
disable()
try:
yield
finally:
if demandenabled:
enable()