JezK
Edit File: importer.py
# -*- Mode: Python; py-indent-offset: 4 -*- # vim: tabstop=4 shiftwidth=4 expandtab # # Copyright (C) 2005-2009 Johan Dahlin <johan@gnome.org> # 2015 Christoph Reiter # # importer.py: dynamic importer for introspected libraries. # # This library is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public # License as published by the Free Software Foundation; either # version 2.1 of the License, or (at your option) any later version. # # This library is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this library; if not, write to the Free Software # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 # USA import sys import warnings import importlib from contextlib import contextmanager import gi from ._gi import Repository, RepositoryError from ._gi import PyGIWarning from .module import get_introspection_module from .overrides import load_overrides repository = Repository.get_default() # only for backwards compatibility modules = {} @contextmanager def _check_require_version(namespace, stacklevel): """A context manager which tries to give helpful warnings about missing gi.require_version() which could potentially break code if only an older version than expected is installed or a new version gets introduced. :: with _check_require_version("Gtk", stacklevel): load_namespace_and_overrides() """ was_loaded = repository.is_registered(namespace) yield if was_loaded: # it was loaded before by another import which depended on this # namespace or by C code like libpeas return if namespace in ("GLib", "GObject", "Gio"): # part of glib (we have bigger problems if versions change there) return if gi.get_required_version(namespace) is not None: # the version was forced using require_version() return version = repository.get_version(namespace) warnings.warn( "%(namespace)s was imported without specifying a version first. " "Use gi.require_version('%(namespace)s', '%(version)s') before " "import to ensure that the right version gets loaded." % {"namespace": namespace, "version": version}, PyGIWarning, stacklevel=stacklevel) def get_import_stacklevel(import_hook): """Returns the stacklevel value for warnings.warn() for when the warning gets emitted by an imported module, but the warning should point at the code doing the import. Pass import_hook=True if the warning gets generated by an import hook (warn() gets called in load_module(), see PEP302) """ py_version = sys.version_info[:2] if py_version <= (3, 2): # 2.7 included return 4 if import_hook else 2 elif py_version == (3, 3): return 8 if import_hook else 10 elif py_version == (3, 4): return 10 if import_hook else 8 else: # fixed again in 3.5+, see https://bugs.python.org/issue24305 return 4 if import_hook else 2 class DynamicImporter(object): # Note: see PEP302 for the Importer Protocol implemented below. def __init__(self, path): self.path = path def _find_module_check(self, fullname): if not fullname.startswith(self.path): return False path, namespace = fullname.rsplit('.', 1) return path == self.path def find_spec(self, fullname, path=None, target=None): if self._find_module_check(fullname): return importlib.util.spec_from_loader(fullname, self) def find_module(self, fullname, path=None): if self._find_module_check(fullname): return self def load_module(self, fullname): if fullname in sys.modules: return sys.modules[fullname] path, namespace = fullname.rsplit('.', 1) # is_registered() is faster than enumerate_versions() and # in the common case of a namespace getting loaded before its # dependencies, is_registered() returns True for all dependencies. if not repository.is_registered(namespace) and not \ repository.enumerate_versions(namespace): raise ImportError('cannot import name %s, ' 'introspection typelib not found' % namespace) stacklevel = get_import_stacklevel(import_hook=True) with _check_require_version(namespace, stacklevel=stacklevel): try: introspection_module = get_introspection_module(namespace) except RepositoryError as e: raise ImportError(e) # Import all dependencies first so their init functions # (gdk_init, ..) in overrides get called. # https://bugzilla.gnome.org/show_bug.cgi?id=656314 for dep in repository.get_immediate_dependencies(namespace): importlib.import_module('gi.repository.' + dep.split("-")[0]) dynamic_module = load_overrides(introspection_module) dynamic_module.__file__ = '<%s>' % fullname dynamic_module.__loader__ = self sys.modules[fullname] = dynamic_module return dynamic_module