Add files from hscommon and qtlib

hscommon/jobprogress/performer.py

@@ -0,0 +1,72 @@
+# 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 .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()
+