dupeguru/hscommon/jobprogress/performer.py

74 lines
2.2 KiB
Python

# Created By: Virgil Dupras
# Created On: 2010-11-19
# Copyright 2011 Hardcoded Software (http://www.hardcoded.net)
#
# This software is licensed under the "GPLv3" License as described in the "LICENSE" file,
# which should be included with this package. The terms are also available at
# http://www.gnu.org/licenses/gpl-3.0.html
from threading import Thread
import sys
from hscommon.jobprogress.job import Job, JobInProgressError, JobCancelled
class ThreadedJobPerformer:
"""Run threaded jobs and track progress.
To run a threaded job, first create a job with _create_job(), then call _run_threaded(), with
your work function as a parameter.
Example:
j = self._create_job()
self._run_threaded(self.some_work_func, (arg1, arg2, j))
"""
_job_running = False
last_error = None
# --- Protected
def create_job(self):
if self._job_running:
raise JobInProgressError()
self.last_progress = -1
self.last_desc = ""
self.job_cancelled = False
return Job(1, self._update_progress)
def _async_run(self, *args):
target = args[0]
args = tuple(args[1:])
self._job_running = True
self.last_error = None
try:
target(*args)
except JobCancelled:
pass
except Exception as e:
self.last_error = e
self.last_traceback = sys.exc_info()[2]
finally:
self._job_running = False
self.last_progress = None
def reraise_if_error(self):
"""Reraises the error that happened in the thread if any.
Call this after the caller of run_threaded detected that self._job_running returned to False
"""
if self.last_error is not None:
raise self.last_error.with_traceback(self.last_traceback)
def _update_progress(self, newprogress, newdesc=""):
self.last_progress = newprogress
if newdesc:
self.last_desc = newdesc
return not self.job_cancelled
def run_threaded(self, target, args=()):
if self._job_running:
raise JobInProgressError()
args = (target,) + args
Thread(target=self._async_run, args=args).start()