Execute LocalMessage.appendMessage() & LocalMessage.setFlag() in the same transaction for small message storing in order to speed up DB update.

This is a per message basis optimization. More improved speed could be attained by batching several messages in the same transaction.

src/com/fsck/k9/controller/MessagingController.java

@@ -1783,13 +1783,14 @@ public class MessagingController implements Runnable
                     }
 
                     // Store the updated message locally
-                    localFolder.appendMessages(new Message[] { message });
+                    final Message localMessage = localFolder.storeSmallMessage(message, new Runnable()
-
+                    {
-                    Message localMessage = localFolder.getMessage(message.getUid());
+                        @Override
+                        public void run()
+                        {
                             progress.incrementAndGet();
-
+                        }
-                    // Set a flag indicating this message has now be fully downloaded
+                    });
-                    localMessage.setFlag(Flag.X_DOWNLOADED_FULL, true);
                     if (K9.DEBUG)
                         Log.v(K9.LOG_TAG, "About to notify listeners that we got a new small message "
                               + account + ":" + folder + ":" + message.getUid());

src/com/fsck/k9/mail/store/LocalStore.java

@@ -2842,6 +2842,39 @@ public class LocalStore extends Store implements Serializable, LocalStoreMigrati
 
         }
 
+        /**
+         * Convenience transaction wrapper for storing a message and set it as fully downloaded. Implemented mainly to speed up DB transaction commit.
+         * 
+         * @param message Message to store. Never <code>null</code>.
+         * @param runnable What to do before setting {@link Flag#X_DOWNLOADED_FULL}. Never <code>null</code>.
+         * @return The local version of the message. Never <code>null</code>.
+         * @throws MessagingException
+         */
+        public Message storeSmallMessage(final Message message, final Runnable runnable) throws MessagingException
+        {
+            return execute(true, new DbCallback<Message>()
+            {
+                @Override
+                public Message doDbWork(final SQLiteDatabase db) throws WrappedException, UnavailableStorageException
+                {
+                    try
+                    {
+                        appendMessages(new Message[] { message });
+                        final String uid = message.getUid();
+                        final Message result = getMessage(uid);
+                        runnable.run();
+                        // Set a flag indicating this message has now be fully downloaded
+                        result.setFlag(Flag.X_DOWNLOADED_FULL, true);
+                        return result;
+                    }
+                    catch (MessagingException e)
+                    {
+                        throw new WrappedException(e);
+                    }
+                }
+            });
+        }
+
         /**
          * The method differs slightly from the contract; If an incoming message already has a uid
          * assigned and it matches the uid of an existing message then this message will replace the