[tor-commits] [ooni-probe/master] Outline the base class for tasks (#7852)

[isis at torproject.org]

commit cc4b5f2180c451faf173f23c5213a18413f204a7
Author: Arturo Filastò <art at fuffa.org>
Date:   Thu Jan 10 16:21:50 2013 +0100

    Outline the base class for tasks (#7852)
    
    Tasks are the jobs that get handled by the managers.
---
 ooni/tasks.py |   75 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 75 insertions(+), 0 deletions(-)

diff --git a/ooni/tasks.py b/ooni/tasks.py
new file mode 100644
index 0000000..361dccb
--- /dev/null
+++ b/ooni/tasks.py
@@ -0,0 +1,75 @@
+class BaseTask(object):
+    _timer = None
+
+    def __init__(self):
+        self.running = False
+        self.failures = 0
+
+    def _failed(self, failure):
+        self.failures += 1
+        self.failed(failure)
+        return
+
+    def _run(self):
+        d = self.run()
+        d.addErrback(self._failed)
+        d.addCallback(self._succeeded)
+        return d
+
+    def _succeeded(self, result):
+        self.succeeded(result)
+
+    def succeeded(self, result):
+        """
+        Place here the logic to handle a successful execution of the task.
+        """
+        pass
+
+    def failed(self, failure):
+        """
+        Place in here logic to handle failure.
+        """
+        pass
+
+    def run(self):
+        """
+        Override this with the logic of your task.
+        Must return a deferred.
+        """
+        pass
+
+class TaskTimedOut(Exception):
+    pass
+
+class TaskWithTimeout(BaseTask):
+    timeout = 5
+
+    def _timedOut(self):
+        """Internal method for handling timeout failure"""
+        self.timedOut()
+
+    def _cancelTimer(self):
+        if self._timer:
+            self._timer.cancel()
+
+    def _succeeded(self, result):
+        self._cancelTimer()
+        BaseTask._succeeded(self, result)
+
+    def _failed(self, failure):
+        self._cancelTimer()
+        BaseTask._failed(self, failure)
+
+    def _run(self):
+        d = BaseTask._run(self)
+        self._timer = reactor.callLater(self.timeout, self._timedOut)
+        return d
+
+    def timedOut(self):
+        """
+        Override this with the operations to happen when the task has timed
+        out.
+        """
+        pass
+
+