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# arch-tag: cb40743b-1a3d-4c56-9647-512721976ad2
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# Copyright (C) 2004 Canonical Ltd.
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# Author: David Allouche <david@canonical.com>
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program 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
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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"""Command-line back-end glue."""
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def default_backend():
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"""Default command-line backend.
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:rtype: `CommandLineBackend`
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return CommandLineBackend(
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spawning = DelayedGuessedSpawningStrategy,
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logger = logger.Logger())
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class CommandLineBackend(object):
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"""Facade for command-line back-end options."""
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def __init__(self, command, module, spawning, logger):
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self._command = command
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self._spawning = spawning
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def _get_command(self):
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def _set_command(self, command):
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self._command = command
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_get_command, _set_command, None,
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"""Name of the command line program.
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def _get_spawning(self):
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def _set_spawning(self, spawning):
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self._spawning = spawning
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spawning_strategy = property(
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_get_spawning, _set_spawning, None,
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"""`SpawningStrategy` factory used to create the spawner.
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:type: factory of `SpawningStrategy`""")
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def _get_logger(self):
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def _set_logger(self, logger):
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_get_logger, _set_logger, None,
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"""Command line logger.
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:type: `logger.Logger`""")
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def _get_spawner(self):
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if self._spawner is None:
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self._spawner = self._spawning(self._command, self._logger)
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_get_spawner, None, None,
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"""Command line program spawner. (read-only)
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:type: `SpawningStrategy`""")
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class SpawningStrategy(object):
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"""Abstract class for process spawning strategies."""
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def status_cmd(self, args, chdir, expected):
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raise NotImplementedError
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def status_text_cmd(self, args, chdir, expected):
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raise NotImplementedError
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def sequence_cmd(self, args, chdir=None, expected=(0,)):
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raise NotImplementedError
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class DelayedGuessedSpawningStrategy(SpawningStrategy):
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"""SpawningStrategy that uses Twisted if it is present in ``sys.modules``.
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This SpawningStrategy tries to do the right thing my looking at
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the contents of ``sys.modules``: if "twisted" or a module of that
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package is loaded when the first spawning method is run, it will
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use the Twisted spawning strategy. Otherwise, it will use a simple
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fork/exec spawning strategy which does not depend on Twisted.
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__pychecker__ = 'no-override'
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def __init__(self, *args, **kwargs):
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self._init_args = args
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self._init_kwargs = kwargs
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self._cached_guess = None
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if self._cached_guess is not None:
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return self._cached_guess
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for name in sys.modules:
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if name == 'twisted' or name.startswith('twisted.'):
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strategy = knotted.TwistedSpawningStrategy
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strategy = forkexec.PyArchSpawningStrategy
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self._cached_guess = strategy(*self._init_args, **self._init_kwargs)
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return self._cached_guess
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def sequence_cmd(self, *args, **kwargs):
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return self._guess().sequence_cmd(*args, **kwargs)
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def status_cmd(self, *args, **kwargs):
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return self._guess().status_cmd(*args, **kwargs)
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def status_text_cmd(self, *args, **kwargs):
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return self._guess().status_text_cmd(*args, **kwargs)
added
removed
fai/arch/backends/commandline.py
