Mercurial > hg > mercurial-crew-with-dirclash
view mercurial/demandimport.py @ 4661:a7e9b6b1adeb
Backed out changeset cfa477946181824f4c769580ebf59710090ba08a
Only printenv was changed, not the actual execution of hooks.
And not setting an empty value might cause problems on platforms
which can't always remove variables from the environment.
author | Thomas Arendsen Hein <thomas@intevation.de> |
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date | Thu, 21 Jun 2007 10:00:59 +0200 |
parents | 63b9d2deed48 |
children | b51d07ed1b18 |
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# 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