Commit a1d07910 authored by Philipp Hörist's avatar Philipp Hörist
Browse files

Merge branch 'remove-demandimport' into 'master'

Remove demandimport, which is now unused

See merge request !20
parents 90a80fed 3fa2db7c
# - global demand-loading of modules for Mercurial
# Copyright 2006, 2007 Matt Mackall <>
# 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__
_origimport = __import__
nothing = object()
_origimport(__builtin__.__name__, {}, {}, None, -1)
except TypeError: # no level argument
def _import(name, globals, locals, fromlist, level):
"call _origimport with no level argument"
return _origimport(name, globals, locals, fromlist)
_import = _origimport
class _demandmod(object):
"""module demand-loader and proxy"""
def __init__(self, name, globals, locals):
if '.' in name:
head, rest = name.split('.', 1)
after = [rest]
head = name
after = []
object.__setattr__(self, "_data", (head, globals, locals, after))
object.__setattr__(self, "_module", None)
def _extend(self, name):
"""add to the list of submodules to load"""
def _load(self):
if not self._module:
head, globals, locals, after = self._data
mod = _origimport(head, globals, locals)
# 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)
return getattr(self._module, attr)
def __setattr__(self, attr, val):
setattr(self._module, attr, val)
def _demandimport(name, globals=None, locals=None, fromlist=None, level=-1):
if not locals or name in ignore or fromlist == ('*',):
# these cases we can't really delay
return _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):
return locals[base]
return _demandmod(name, globals, locals)
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 = _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 = [
'_winreg', # 2.7 mimetypes needs immediate ImportError
# imported by tarfile, not available under Windows
# imported by profile, itself imported by hotshot.stats,
# not available under Windows
# this trips up many extension authors
# setuptools' expects "from __main__ import x" to
# raise ImportError if x not defined
'_ssl', # conditional imports in the stdlib, issue1964
def enable():
"enable global demand-loading of modules"
__builtin__.__import__ = _demandimport
def disable():
"disable global demand-loading of modules"
__builtin__.__import__ = _origimport
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