| # Copyright 2017 The Chromium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """Kludges to support legacy Autotest code. |
| |
| Autotest imports should be done by calling monkeypatch() first and then |
| calling load(). monkeypatch() should only be called once from a |
| script's main function. |
| """ |
| |
| from __future__ import absolute_import |
| from __future__ import division |
| from __future__ import print_function |
| |
| import imp |
| import importlib |
| import logging |
| import os |
| import site |
| import sys |
| |
| import autotest_lib |
| |
| _AUTOTEST_DIR = autotest_lib.__path__[0] |
| _SITEPKG_DIR = os.path.join(_AUTOTEST_DIR, 'site-packages') |
| |
| _setup_done = False |
| |
| logger = logging.getLogger(__name__) |
| |
| |
| def monkeypatch(): |
| """Do necessary Autotest monkeypatching. |
| |
| This should be called before any autotest_lib imports in the main |
| function in scripts. Thus, only the main function in scripts can |
| import autotest_lib. |
| |
| Library code should rely on dependency injection, falling back to |
| load(). |
| |
| This should be called no more than once. |
| |
| This adds Autotest's site-packages and modifies sys.meta_path so |
| that all common.py imports are no-ops. |
| """ |
| global _setup_done |
| assert not _setup_done |
| site.addsitedir(_SITEPKG_DIR) |
| sys.meta_path.insert(0, _CommonRemovingFinder()) |
| _setup_done = True |
| |
| |
| class _CommonRemovingFinder(object): |
| """Python import finder that neuters Autotest's common.py |
| |
| The common module is replaced with an empty module everywhere it is |
| imported. common.py should have only been imported for side |
| effects, so nothing should actually use the imported module. |
| |
| See also https://www.python.org/dev/peps/pep-0302/ |
| """ |
| |
| def find_module(self, fullname, path=None): |
| """Find module.""" |
| del path # unused |
| if not self._is_autotest_common(fullname): |
| return None |
| logger.debug('Dummying out %s import', fullname) |
| return self |
| |
| def _is_autotest_common(self, fullname): |
| return (fullname.partition('.')[0] == 'autotest_lib' |
| and fullname.rpartition('.')[-1] == 'common') |
| |
| def load_module(self, fullname): |
| """Load module.""" |
| if fullname in sys.modules: |
| return sys.modules[fullname] |
| mod = imp.new_module(fullname) |
| mod.__file__ = '<removed>' |
| mod.__loader__ = self |
| mod.__package__ = fullname.rpartition('.')[0] |
| sys.modules[fullname] = mod |
| return mod |
| |
| |
| def load(name): |
| """Import module from autotest. |
| |
| This enforces that monkeypatch() is called first. Otherwise, |
| autotest imports may or may not work. When they do work, they may |
| screw up global state. |
| |
| @param name: name of module as string, e.g., 'frontend.afe.models' |
| """ |
| if not _setup_done: |
| raise ImportError('cannot load Autotest modules before monkeypatching') |
| relpath = name.lstrip('.') |
| return importlib.import_module('.%s' % relpath, package='autotest_lib') |