473 lines
14 KiB
Python
473 lines
14 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 TaskException(Exception):
|
|
"""
|
|
I wrap an exception that happened during task execution.
|
|
"""
|
|
|
|
exception = None # original exception
|
|
|
|
def __init__(self, exception, message=None):
|
|
self.exception = exception
|
|
self.exceptionMessage = message
|
|
self.args = (exception, message, )
|
|
|
|
class Task(object, log.Loggable):
|
|
"""
|
|
I wrap a task in an asynchronous interface.
|
|
I can be listened to for starting, stopping, description changes
|
|
and progress updates.
|
|
|
|
I communicate an error by setting self.exception to an exception and
|
|
stopping myself from running.
|
|
The listener can then handle the Task.exception.
|
|
|
|
@ivar description: what am I doing
|
|
@ivar exception: set if an exception happened during the task
|
|
execution. Will be raised through run() at the end.
|
|
"""
|
|
logCategory = 'Task'
|
|
|
|
description = 'I am doing something.'
|
|
|
|
progress = 0.0
|
|
increment = 0.01
|
|
running = False
|
|
runner = None
|
|
exception = None
|
|
exceptionMessage = None
|
|
exceptionTraceback = None
|
|
|
|
_listeners = None
|
|
|
|
|
|
### subclass methods
|
|
def start(self, runner):
|
|
"""
|
|
Start the task.
|
|
|
|
Subclasses should chain up to me at the beginning.
|
|
"""
|
|
self.debug('starting')
|
|
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.
|
|
|
|
Listeners will get notified that the task is stopped,
|
|
whether successfully or with an exception.
|
|
"""
|
|
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
|
|
|
|
# FIXME: does not actually raise
|
|
def setAndRaiseException(self, exception):
|
|
"""
|
|
Call this to set a synthetically created exception (and not one
|
|
that was actually raised and caught)
|
|
"""
|
|
import traceback
|
|
|
|
stack = traceback.extract_stack()[:-1]
|
|
(filename, line, func, text) = stack[-1]
|
|
exc = exception.__class__.__name__
|
|
msg = ""
|
|
# a shortcut to extract a useful message out of most exceptions
|
|
# for now
|
|
if str(exception):
|
|
msg = ": %s" % str(exception)
|
|
line = "exception %(exc)s at %(filename)s:%(line)s: %(func)s()%(msg)s" \
|
|
% locals()
|
|
|
|
self.exception = exception
|
|
self.exceptionMessage = line
|
|
self.exceptionTraceback = traceback.format_exc()
|
|
self.debug('set exception, %r' % self.exceptionMessage)
|
|
|
|
def setException(self, exception):
|
|
import traceback
|
|
|
|
self.exception = exception
|
|
self.exceptionMessage = log.getExceptionMessage(exception)
|
|
self.exceptionTraceback = traceback.format_exc()
|
|
self.debug('set exception, %r' % self.exceptionMessage)
|
|
|
|
def addListener(self, listener):
|
|
"""
|
|
Add a listener for task status changes.
|
|
|
|
Listeners should implement started, stopped, and progressed.
|
|
"""
|
|
self.debug('Adding listener %r', listener)
|
|
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)
|
|
|
|
# FIXME: should this become a real interface, like in zope ?
|
|
class ITaskListener(object):
|
|
"""
|
|
I am an interface for objects listening to tasks.
|
|
"""
|
|
### 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 stopping.
|
|
If the task had an error, task.exception will be set.
|
|
"""
|
|
|
|
|
|
|
|
# this is a Dummy task that can be used to test 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, ITaskListener):
|
|
"""
|
|
I perform multiple tasks.
|
|
|
|
@ivar tasks: the tasks to run
|
|
@type tasks: list of L{Task}
|
|
"""
|
|
|
|
description = 'Doing various tasks'
|
|
tasks = None
|
|
|
|
def __init__(self):
|
|
self.tasks = []
|
|
self._task = 0
|
|
|
|
def addTask(self, task):
|
|
"""
|
|
Add a task.
|
|
|
|
@type task: L{Task}
|
|
"""
|
|
if self.tasks is None:
|
|
self.tasks = []
|
|
self.tasks.append(task)
|
|
|
|
def start(self, runner):
|
|
"""
|
|
Start tasks.
|
|
|
|
Tasks can still be added while running. For example,
|
|
a first task can determine how many additional tasks to run.
|
|
"""
|
|
Task.start(self, runner)
|
|
|
|
# initialize task tracking
|
|
if not self.tasks:
|
|
self.warning('no tasks')
|
|
self._generic = self.description
|
|
|
|
self.next()
|
|
|
|
def next(self):
|
|
"""
|
|
Start the next task.
|
|
"""
|
|
try:
|
|
# start next task
|
|
task = self.tasks[self._task]
|
|
self._task += 1
|
|
self.debug('BaseMultiTask.next(): starting task %d of %d: %r',
|
|
self._task, len(self.tasks), task)
|
|
self.setDescription("%s (%d of %d) ..." % (
|
|
task.description, self._task, len(self.tasks)))
|
|
task.addListener(self)
|
|
task.start(self.runner)
|
|
except Exception, e:
|
|
self.setException(e)
|
|
self.debug('Got exception during next: %r', self.exceptionMessage)
|
|
self.stop()
|
|
return
|
|
|
|
### ITaskListener methods
|
|
def started(self, task):
|
|
pass
|
|
|
|
def progressed(self, task, value):
|
|
pass
|
|
|
|
def stopped(self, task):
|
|
"""
|
|
Subclasses should chain up to me at the end of their implementation.
|
|
They should fall through to chaining up if there is an exception.
|
|
"""
|
|
self.log('BaseMultiTask.stopped: task %r', task)
|
|
if task.exception:
|
|
self.log('BaseMultiTask.stopped: exception %r',
|
|
task.exceptionMessage)
|
|
self.exception = task.exception
|
|
self.exceptionMessage = task.exceptionMessage
|
|
self.stop()
|
|
return
|
|
|
|
if self._task == len(self.tasks):
|
|
self.log('BaseMultiTask.stopped: all tasks done')
|
|
self.stop()
|
|
return
|
|
|
|
# pick another
|
|
self.log('BaseMultiTask.stopped: pick next task')
|
|
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)
|
|
|
|
### ITaskListener 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
|
|
|
|
### ITaskListener 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, log.Loggable):
|
|
"""
|
|
I am a base class for task runners.
|
|
Task runners should be reusable.
|
|
"""
|
|
logCategory = 'TaskRunner'
|
|
|
|
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
|
|
|
|
|
|
class SyncRunner(TaskRunner, ITaskListener):
|
|
"""
|
|
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.debug('run task %r', task)
|
|
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._startWrap, self._task)
|
|
self.debug('run loop')
|
|
self._loop.run()
|
|
|
|
self.debug('done running task %r', task)
|
|
if task.exception:
|
|
# catch the exception message
|
|
# FIXME: this gave a traceback in the logging module
|
|
self.debug('raising TaskException for %r, %r' % (
|
|
task.exceptionMessage, task.exceptionTraceback))
|
|
msg = task.exceptionMessage
|
|
if task.exceptionTraceback:
|
|
msg += "\n" + task.exceptionTraceback
|
|
raise TaskException(task.exception, message=msg)
|
|
|
|
def _startWrap(self, task):
|
|
# wrap task start such that we can report any exceptions and
|
|
# never hang
|
|
try:
|
|
self.debug('start task %r' % task)
|
|
task.start(self)
|
|
except Exception, e:
|
|
# getExceptionMessage uses global exception state that doesn't
|
|
# hang around, so store the message
|
|
task.setException(e)
|
|
self.debug('exception during start: %r', task.exceptionMessage)
|
|
self.stopped(task)
|
|
|
|
|
|
def schedule(self, delta, callable, *args, **kwargs):
|
|
def c():
|
|
callable(*args, **kwargs)
|
|
return False
|
|
gobject.timeout_add(int(delta * 1000L), c)
|
|
|
|
### ITaskListener methods
|
|
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.debug('stopped task %r', 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)
|