def start(self, auto_process=False):
self.status = None
if not self.db:
assert self.frontend is not None
self.frontend.start_debconf()
self.db = self.frontend.db
self.ui_loop_level = 0
prep = self.prepare()
if prep is None:
self.run(None, None)
return
self.command = ['log-output', '-t', PACKAGE, '--pass-stdout']
if isinstance(prep[0], types.StringTypes):
self.command.append(prep[0])
else:
self.command.extend(prep[0])
question_patterns = prep[1]
if len(prep) > 2:
env = prep[2]
else:
env = {}
self.debug("Starting up '%s' for %s.%s", self.command,
self.__class__.__module__, self.__class__.__name__)
self.debug("Watching for question patterns %s",
', '.join(question_patterns))
widgets = {}
for pattern in question_patterns:
widgets[pattern] = self
self.dbfilter = DebconfFilter(self.db, widgets)
# TODO: Set as unseen all questions that we're going to ask.
if auto_process:
self.dbfilter.start(self.command, blocking=False, extra_env=env)
# Clearly, this isn't enough for full non-blocking operation.
# However, debconf itself is generally quick, and the confmodule
# will generally be listening for a reply when we try to send
# one; the slow bit is waiting for the confmodule to decide to
# send a command. Therefore, this is the only file descriptor we
# bother to watch, which greatly simplifies our life.
self.frontend.watch_debconf_fd(self.dbfilter.subout_fd,
self.process_input)
else:
self.dbfilter.start(self.command, blocking=True, extra_env=env)
