diff options
Diffstat (limited to 'gi/importer.py')
| -rw-r--r-- | gi/importer.py | 133 |
1 files changed, 108 insertions, 25 deletions
diff --git a/gi/importer.py b/gi/importer.py index aa95cf6..73d0c5c 100644 --- a/gi/importer.py +++ b/gi/importer.py @@ -2,6 +2,7 @@ # 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. # @@ -20,18 +21,85 @@ # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 # USA -from __future__ import absolute_import -import logging import sys +import warnings +import importlib +from contextlib import contextmanager -from ._gi import Repository -from .module import DynamicModule +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. @@ -39,32 +107,47 @@ class DynamicImporter(object): def __init__(self, path): self.path = path - def find_module(self, fullname, path=None): + def _find_module_check(self, fullname): if not fullname.startswith(self.path): - return + return False path, namespace = fullname.rsplit('.', 1) - if path != self.path: - return - - if not repository.enumerate_versions(namespace): - logging.error('Could not find any typelib for %s', namespace) - return None - else: - return self + return path == self.path - def load_module(self, fullname): - if fullname in sys.modules: - return sys.modules[fullname] + def find_spec(self, fullname, path=None, target=None): + if self._find_module_check(fullname): + return importlib.util.spec_from_loader(fullname, self) - path, namespace = fullname.rsplit('.', 1) - dynamic_module = DynamicModule(namespace) - modules[namespace] = dynamic_module - - dynamic_module.__file__ = '<%s>' % fullname - dynamic_module.__loader__ = self + def find_module(self, fullname, path=None): + if self._find_module_check(fullname): + return self - sys.modules[fullname] = dynamic_module - dynamic_module._load() + def create_module(self, spec): + path, namespace = spec.name.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) return dynamic_module + + def exec_module(self, fullname): + # “exec” the module and consequently populate the module’s namespace + pass |