Files
whipper-gui/morituri/common/task.py
Thomas Vander Stichele e5ad3bde58 * morituri/common/task.py:
* morituri/image/image.py:
	  Remove prints.  Describe tasks.
2009-05-07 11:11:22 +00:00

345 lines
9.3 KiB
Python

# -*- Mode: Python; test-case-name: morituri.test.test_common_task -*-
# vi:si:et:sw=4:sts=4:ts=4
# Morituri - for those about to RIP
# Copyright (C) 2009 Thomas Vander Stichele
# This file is part of morituri.
#
# morituri is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# morituri is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with morituri. If not, see <http://www.gnu.org/licenses/>.
import sys
import gobject
from morituri.common import log
class Task(object, log.Loggable):
"""
I wrap a task in an asynchronous interface.
I can be listened to for starting, stopping, and progress updates.
@ivar description: what am I doing
@ivar exception: set if an exception happened during the task
execution.
"""
description = 'I am doing something.'
progress = 0.0
increment = 0.01
running = False
runner = None
exception = None
_listeners = None
### subclass methods
def start(self, runner):
"""
Start the task.
Subclasses should chain up to me at the beginning.
"""
self.setProgress(self.progress)
self.running = True
self.runner = runner
self._notifyListeners('started')
def stop(self):
"""
Stop the task.
Subclasses should chain up to me at the end.
"""
self.debug('stopping')
self.running = False
self.runner = None
self._notifyListeners('stopped')
### base class methods
def setProgress(self, value):
"""
Notify about progress changes bigger than the increment.
Called by subclass implementations as the task progresses.
"""
if value - self.progress > self.increment or value >= 1.0 or value == 0.0:
self.progress = value
self._notifyListeners('progressed', value)
self.log('notifying progress: %r', value)
def setDescription(self, description):
if description != self.description:
self._notifyListeners('described', description)
self.description = description
def addListener(self, listener):
"""
Add a listener for task status changes.
Listeners should implement started, stopped, and progressed.
"""
if not self._listeners:
self._listeners = []
self._listeners.append(listener)
def _notifyListeners(self, methodName, *args, **kwargs):
if self._listeners:
for l in self._listeners:
getattr(l, methodName)(self, *args, **kwargs)
# this is a Dummy task that can be used if this works at all
class DummyTask(Task):
def start(self, runner):
Task.start(self, runner)
self.runner.schedule(1.0, self._wind)
def _wind(self):
self.setProgress(min(self.progress + 0.1, 1.0))
if self.progress >= 1.0:
self.stop()
return
self.runner.schedule(1.0, self._wind)
class BaseMultiTask(Task):
"""
I perform multiple tasks.
"""
description = 'Doing various tasks'
tasks = None
def __init__(self):
self.tasks = []
def addTask(self, task):
if self.tasks is None:
self.tasks = []
self.tasks.append(task)
def start(self, runner):
Task.start(self, runner)
# initialize task tracking
self._task = 0
self.__tasks = self.tasks[:]
self._generic = self.description
self.next()
def next(self):
# start next task
task = self.__tasks[0]
del self.__tasks[0]
self.debug('BaseMultiTask.next(): starting task %r', task)
self._task += 1
self.setDescription("%s (%d of %d) ..." % (
task.description, self._task, len(self.tasks)))
task.addListener(self)
task.start(self.runner)
### listener methods
def started(self, task):
pass
def progressed(self, task, value):
pass
def stopped(self, task):
if task.exception:
self.exception = task.exception
self.stop()
return
if not self.__tasks:
self.stop()
return
# pick another
self.next()
class MultiSeparateTask(BaseMultiTask):
"""
I perform multiple tasks.
I track progress of each individual task, going back to 0 for each task.
"""
description = 'Doing various tasks separately'
def start(self, runner):
self.debug('MultiSeparateTask.start()')
BaseMultiTask.start(self, runner)
def next(self):
self.debug('MultiSeparateTask.next()')
# start next task
self.progress = 0.0 # reset progress for each task
BaseMultiTask.next(self)
### listener methods
def progressed(self, task, value):
self.setProgress(value)
def described(self, description):
self.setDescription("%s (%d of %d) ..." % (
description, self._task, len(self.tasks)))
class MultiCombinedTask(BaseMultiTask):
"""
I perform multiple tasks.
I track progress as a combined progress on all tasks on task granularity.
"""
description = 'Doing various tasks combined'
_stopped = 0
### listener methods
def progressed(self, task, value):
self.setProgress(float(self._stopped + value) / len(self.tasks))
def stopped(self, task):
self._stopped += 1
self.setProgress(float(self._stopped) / len(self.tasks))
BaseMultiTask.stopped(self, task)
class TaskRunner(object):
"""
I am a base class for task runners.
Task runners should be reusable.
"""
def run(self, task):
"""
Run the given task.
@type task: Task
"""
raise NotImplementedError
### methods for tasks to call
def schedule(self, delta, callable, *args, **kwargs):
"""
Schedule a single future call.
Subclasses should implement this.
@type delta: float
@param delta: time in the future to schedule call for, in seconds.
"""
raise NotImplementedError
### listener callbacks
def progressed(self, task, value):
"""
Implement me to be informed about progress.
@type value: float
@param value: progress, from 0.0 to 1.0
"""
def described(self, task, description):
"""
Implement me to be informed about description changes.
@type description: str
@param description: description
"""
def started(self, task):
"""
Implement me to be informed about the task starting.
"""
def stopped(self, task):
"""
Implement me to be informed about the task starting.
"""
class SyncRunner(TaskRunner):
"""
I run the task synchronously in a gobject MainLoop.
"""
def __init__(self, verbose=True):
self._verbose = verbose
self._longest = 0 # longest string shown; for clearing
def run(self, task, verbose=None, skip=False):
self._task = task
self._verboseRun = self._verbose
if verbose is not None:
self._verboseRun = verbose
self._skip = skip
self._loop = gobject.MainLoop()
self._task.addListener(self)
# only start the task after going into the mainloop,
# otherwise the task might complete before we are in it
gobject.timeout_add(0L, self._task.start, self)
self._loop.run()
if self._task.exception:
raise self._task.exception
def schedule(self, delta, callable, *args, **kwargs):
def c():
callable(*args, **kwargs)
return False
gobject.timeout_add(int(delta * 1000L), c)
def progressed(self, task, value):
if not self._verboseRun:
return
self._report()
if value >= 1.0:
if self._skip:
self._output('%s %3d %%' % (
self._task.description, 100.0))
else:
# clear with whitespace
sys.stdout.write("%s\r" % (' ' * self._longest, ))
def _output(self, what, newline=False, ret=True):
sys.stdout.write(what)
sys.stdout.write(' ' * (self._longest - len(what)))
if ret:
sys.stdout.write('\r')
if newline:
sys.stdout.write('\n')
sys.stdout.flush()
if len(what) > self._longest:
#print; print 'setting longest', self._longest; print
self._longest = len(what)
def described(self, task, description):
if self._verboseRun:
self._report()
def stopped(self, task):
self.progressed(task, 1.0)
self._loop.quit()
def _report(self):
self._output('%s %3d %%' % (
self._task.description, self._task.progress * 100.0))
if __name__ == '__main__':
task = DummyTask()
runner = SyncRunner()
runner.run(task)