Flush IMAP data to disk when stopping. Closes #5095.

4 files changed, 59 insertions, 6 deletions

diff --git a/mail/changes/feature_5095_flush-data-to-disk-when-stopping b/mail/changes/feature_5095_flush-data-to-disk-when-stopping
new file mode 100644
index 00000000..d7c1ce7e
--- /dev/null
+++ b/mail/changes/feature_5095_flush-data-to-disk-when-stopping
@@ -0,0 +1 @@
+  o Flush IMAP data to disk when stopping. Closes #5095.
diff --git a/mail/src/leap/mail/imap/memorystore.py b/mail/src/leap/mail/imap/memorystore.py
index 9c7973d4..3eba59a0 100644
--- a/mail/src/leap/mail/imap/memorystore.py
+++ b/mail/src/leap/mail/imap/memorystore.py
@@ -875,6 +875,15 @@ class MemoryStore(object):
             self.remove_message(mbox, uid)
         return mem_deleted
 
+    def stop_and_flush(self):
+        """
+        Stop the write loop and trigger a write to the producer.
+        """
+        self._stop_write_loop()
+        if self._permanent_store is not None:
+            self.write_messages(self._permanent_store)
+            self.producer.flush()
+
     def expunge(self, mbox, observer):
         """
         Remove all messages flagged \\Deleted, from the Memory Store
@@ -890,12 +899,9 @@ class MemoryStore(object):
         """
         soledad_store = self._permanent_store
         try:
-            # 1. Stop the writing call
-            self._stop_write_loop()
-            # 2. Enqueue a last write.
-            self.write_messages(soledad_store)
-            # 3. Wait on the writebacks to finish
-
+            # Stop and trigger last write
+            self.stop_and_flush()
+            # Wait on the writebacks to finish
             pending_deferreds = (self._new_deferreds.get(mbox, []) +
                                  self._dirty_deferreds.get(mbox, []))
             d1 = defer.gatherResults(pending_deferreds, consumeErrors=True)
@@ -962,6 +968,10 @@ class MemoryStore(object):
         # are done (gatherResults)
         return getattr(self, self.WRITING_FLAG)
 
+    @property
+    def permanent_store(self):
+        return self._permanent_store
+
     # Memory management.
 
     def get_size(self):
diff --git a/mail/src/leap/mail/imap/service/imap.py b/mail/src/leap/mail/imap/service/imap.py
index 5487cfc8..93df51d1 100644
--- a/mail/src/leap/mail/imap/service/imap.py
+++ b/mail/src/leap/mail/imap/service/imap.py
@@ -19,7 +19,9 @@ Imap service initialization
 """
 import logging
 import os
+import time
 
+from twisted.internet import defer, threads
 from twisted.internet.protocol import ServerFactory
 from twisted.internet.error import CannotListenError
 from twisted.mail import imap4
@@ -122,6 +124,35 @@ class LeapIMAPFactory(ServerFactory):
         imapProtocol.factory = self
         return imapProtocol
 
+    def doStop(self, cv):
+        """
+        Stops imap service (fetcher, factory and port).
+
+        :param cv: A condition variable to which we can signal when imap
+                   indeed stops.
+        :type cv: threading.Condition
+        :return: a Deferred that stops and flushes the in memory store data to
+                 disk in another thread.
+        :rtype: Deferred
+        """
+        ServerFactory.doStop(self)
+
+        def _stop_imap_cb():
+            logger.debug('Stopping in memory store.')
+            self._memstore.stop_and_flush()
+            while not self._memstore.producer.is_queue_empty():
+                logger.debug('Waiting for queue to be empty.')
+                # TODO use a gatherResults over the new/dirty deferred list,
+                # as in memorystore's expunge() method.
+                time.sleep(1)
+            # notify that service has stopped
+            logger.debug('Notifying that service has stopped.')
+            cv.acquire()
+            cv.notify()
+            cv.release()
+
+        return threads.deferToThread(_stop_imap_cb)
+
 
 def run_service(*args, **kwargs):
     """
diff --git a/mail/src/leap/mail/messageflow.py b/mail/src/leap/mail/messageflow.py
index b7fc0304..80121c85 100644
--- a/mail/src/leap/mail/messageflow.py
+++ b/mail/src/leap/mail/messageflow.py
@@ -64,6 +64,11 @@ class IMessageProducer(Interface):
         Stop producing items.
         """
 
+    def flush(self):
+        """
+        Flush queued messages to consumer.
+        """
+
 
 class DummyMsgConsumer(object):
 
@@ -162,6 +167,12 @@ class MessageProducer(object):
         if self._loop.running:
             self._loop.stop()
 
+    def flush(self):
+        """
+        Flush queued messages to consumer.
+        """
+        self._check_for_new()
+
 
 if __name__ == "__main__":
     from twisted.internet import reactor