|
|
# 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, incorporated herein by reference.
|
|
|
|
|
|
'''
|
|
|
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)
|
|
|
'''
|
|
|
|
|
|
_origimport = __import__
|
|
|
|
|
|
class _demandmod(object):
|
|
|
"""module demand-loader and proxy"""
|
|
|
def __init__(self, name, globals, locals):
|
|
|
if '.' in name:
|
|
|
head, rest = name.split('.', 1)
|
|
|
after = [rest]
|
|
|
else:
|
|
|
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"""
|
|
|
self._data[3].append(name)
|
|
|
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 not hasattr(mod, h):
|
|
|
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("'unloaded module' object is not callable")
|
|
|
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):
|
|
|
if not locals or name in ignore or fromlist == ('*',):
|
|
|
# these cases we can't really delay
|
|
|
return _origimport(name, globals, locals, fromlist)
|
|
|
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 _origimport(name, globals, locals, fromlist)
|
|
|
# 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)
|
|
|
else:
|
|
|
# from a import b,c,d
|
|
|
mod = _origimport(name, globals, locals)
|
|
|
# recurse down the module chain
|
|
|
for comp in name.split('.')[1:]:
|
|
|
if not hasattr(mod, comp):
|
|
|
setattr(mod, comp, _demandmod(comp, mod.__dict__, mod.__dict__))
|
|
|
mod = getattr(mod, comp)
|
|
|
for x in fromlist:
|
|
|
# set requested submodules for demand load
|
|
|
if not(hasattr(mod, x)):
|
|
|
setattr(mod, x, _demandmod(x, mod.__dict__, locals))
|
|
|
return mod
|
|
|
|
|
|
ignore = ['_hashlib', '_xmlplus', 'fcntl', 'win32com.gen_py']
|
|
|
|
|
|
def enable():
|
|
|
"enable global demand-loading of modules"
|
|
|
__builtins__["__import__"] = _demandimport
|
|
|
|
|
|
def disable():
|
|
|
"disable global demand-loading of modules"
|
|
|
__builtins__["__import__"] = _origimport
|
|
|
|
|
|
|
