diff --git a/mercurial/demandload.py b/mercurial/demandload.py deleted file mode 100644 --- a/mercurial/demandload.py +++ /dev/null @@ -1,135 +0,0 @@ -'''Demand load modules when used, not when imported.''' - -__author__ = '''Copyright 2006 Vadim Gelfer . -This software may be used and distributed according to the terms -of the GNU General Public License, incorporated herein by reference.''' - -# this is based on matt's original demandload module. it is a -# complete rewrite. some time, we may need to support syntax of -# "import foo as bar". - -class _importer(object): - '''import a module. it is not imported until needed, and is - imported at most once per scope.''' - - def __init__(self, scope, modname, fromlist): - '''scope is context (globals() or locals()) in which import - should be made. modname is name of module to import. - fromlist is list of modules for "from foo import ..." - emulation.''' - - self.scope = scope - self.modname = modname - self.fromlist = fromlist - self.mod = None - - def module(self): - '''import the module if needed, and return.''' - if self.mod is None: - self.mod = __import__(self.modname, self.scope, self.scope, - self.fromlist) - del self.modname, self.fromlist - return self.mod - -class _replacer(object): - '''placeholder for a demand loaded module. demandload puts this in - a target scope. when an attribute of this object is looked up, - this object is replaced in the target scope with the actual - module. - - we use __getattribute__ to avoid namespace clashes between - placeholder object and real module.''' - - def __init__(self, importer, target): - self.importer = importer - self.target = target - # consider case where we do this: - # demandload(globals(), 'foo.bar foo.quux') - # foo will already exist in target scope when we get to - # foo.quux. so we remember that we will need to demandload - # quux into foo's scope when we really load it. - self.later = [] - - def module(self): - return object.__getattribute__(self, 'importer').module() - - def __getattribute__(self, key): - '''look up an attribute in a module and return it. replace the - name of the module in the caller\'s dict with the actual - module.''' - - module = object.__getattribute__(self, 'module')() - target = object.__getattribute__(self, 'target') - importer = object.__getattribute__(self, 'importer') - later = object.__getattribute__(self, 'later') - - if later: - demandload(module.__dict__, ' '.join(later)) - - importer.scope[target] = module - - return getattr(module, key) - -class _replacer_from(_replacer): - '''placeholder for a demand loaded module. used for "from foo - import ..." emulation. semantics of this are different than - regular import, so different implementation needed.''' - - def module(self): - importer = object.__getattribute__(self, 'importer') - target = object.__getattribute__(self, 'target') - - return getattr(importer.module(), target) - - def __call__(self, *args, **kwargs): - target = object.__getattribute__(self, 'module')() - return target(*args, **kwargs) - -def demandload(scope, modules): - '''import modules into scope when each is first used. - - scope should be the value of globals() in the module calling this - function, or locals() in the calling function. - - modules is a string listing module names, separated by white - space. names are handled like this: - - foo import foo - foo bar import foo, bar - foo@bar import foo as bar - foo.bar import foo.bar - foo:bar from foo import bar - foo:bar,quux from foo import bar, quux - foo.bar:quux from foo.bar import quux''' - - for mod in modules.split(): - col = mod.find(':') - if col >= 0: - fromlist = mod[col+1:].split(',') - mod = mod[:col] - else: - fromlist = [] - as_ = None - if '@' in mod: - mod, as_ = mod.split("@") - importer = _importer(scope, mod, fromlist) - if fromlist: - for name in fromlist: - scope[name] = _replacer_from(importer, name) - else: - dot = mod.find('.') - if dot >= 0: - basemod = mod[:dot] - val = scope.get(basemod) - # if base module has already been demandload()ed, - # remember to load this submodule into its namespace - # when needed. - if isinstance(val, _replacer): - later = object.__getattribute__(val, 'later') - later.append(mod[dot+1:]) - continue - else: - basemod = mod - if not as_: - as_ = basemod - scope[as_] = _replacer(importer, as_)