| # Copyright (c) 2012 The Chromium OS Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """Module that contains meta-logic related to Cros Commands. |
| |
| This module contains two important definitions used by all commands: |
| CrosCommand: The parent class of all cros commands. |
| CommandDecorator: Decorator that must be used to ensure that the command shows |
| up in _commands and is discoverable by cros. |
| |
| Commands can be either imported directly or looked up using this module's |
| ListCommands() function. |
| """ |
| |
| from __future__ import print_function |
| |
| import glob |
| import os |
| |
| from chromite.lib import brick_lib |
| from chromite.lib import cros_import |
| |
| |
| _commands = dict() |
| |
| |
| def _FindModules(subdir_path): |
| """Returns a list of all the relevant python modules in |sub_dir_path|""" |
| # We only load cros_[!unittest] modules. |
| modules = [] |
| for file_path in glob.glob(subdir_path + '/cros_*.py'): |
| if not file_path.endswith('_unittest.py'): |
| modules.append(file_path) |
| |
| return modules |
| |
| |
| def _ImportCommands(): |
| """Directly imports all cros_[!unittest] python modules. |
| |
| This method imports the cros_[!unittest] modules which may contain |
| commands. When these modules are loaded, declared commands (those that use |
| the cros.CommandDecorator) will automatically get added to _commands. |
| """ |
| subdir_path = os.path.join(os.path.dirname(__file__), 'cros') |
| for file_path in _FindModules(subdir_path): |
| file_name = os.path.basename(file_path) |
| mod_name = os.path.splitext(file_name)[0] |
| cros_import.ImportModule(('chromite', 'cli', 'cros', mod_name)) |
| |
| |
| def ListCommands(): |
| """Return a dictionary mapping command names to classes.""" |
| _ImportCommands() |
| return _commands.copy() |
| |
| |
| class InvalidCommandError(Exception): |
| """Error that occurs when command class fails sanity checks.""" |
| pass |
| |
| |
| def CommandDecorator(command_name): |
| """Decorator that sanity checks and adds class to list of usable commands.""" |
| |
| def InnerCommandDecorator(original_class): |
| """"Inner Decorator that actually wraps the class.""" |
| if not hasattr(original_class, '__doc__'): |
| raise InvalidCommandError('All handlers must have docstrings: %s' % |
| original_class) |
| |
| if not issubclass(original_class, CrosCommand): |
| raise InvalidCommandError('All Commands must derive from CrosCommand: ' |
| '%s' % original_class) |
| |
| _commands[command_name] = original_class |
| original_class.command_name = command_name |
| |
| return original_class |
| |
| return InnerCommandDecorator |
| |
| |
| class CrosCommand(object): |
| """All CrosCommands must derive from this class. |
| |
| This class provides the abstract interface for all Cros Commands. When |
| designing a new command, you must sub-class from this class and use the |
| CommandDecorator decorator. You must specify a class docstring as that will be |
| used as the usage for the sub-command. |
| |
| In addition your command should implement AddParser which is passed in a |
| parser that you can add your own custom arguments. See argparse for more |
| information. |
| """ |
| # Indicates whether command stats should be uploaded for this command. |
| # Override to enable command stats uploading. |
| upload_stats = False |
| # We set the default timeout to 1 second, to prevent overly long waits for |
| # commands to complete. From manual tests, stat uploads usually take |
| # between 0.35s-0.45s in MTV. |
| upload_stats_timeout = 1 |
| |
| # Indicates whether command uses cache related commandline options. |
| use_caching_options = False |
| |
| def __init__(self, options): |
| self.options = options |
| brick = brick_lib.FindBrickInPath() |
| self.curr_brick_locator = brick.brick_locator if brick else None |
| |
| @classmethod |
| def AddParser(cls, parser): |
| """Add arguments for this command to the parser.""" |
| parser.set_defaults(cros_class=cls) |
| |
| def Run(self): |
| """The command to run.""" |
| raise NotImplementedError() |