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