+ /**
+ * The applyState method will be called by the RaftActor when some data
+ * needs to be applied to the actor's state
+ *
+ * @param clientActor A reference to the client who sent this message. This
+ * is the same reference that was passed to persistData
+ * by the derived actor. clientActor may be null when
+ * the RaftActor is behaving as a follower or during
+ * recovery.
+ * @param identifier The identifier of the persisted data. This is also
+ * the same identifier that was passed to persistData by
+ * the derived actor. identifier may be null when
+ * the RaftActor is behaving as a follower or during
+ * recovery
+ * @param data A piece of data that was persisted by the persistData call.
+ * This should NEVER be null.
+ */
+ protected abstract void applyState(ActorRef clientActor, String identifier,
+ Object data);
+
+ /**
+ * This method will be called by the RaftActor when a snapshot needs to be
+ * created. The derived actor should respond with its current state.
+ * <p/>
+ * During recovery the state that is returned by the derived actor will
+ * be passed back to it by calling the applySnapshot method
+ *
+ * @return The current state of the actor
+ */
+ protected abstract Object createSnapshot();
+
+ /**
+ * This method will be called by the RaftActor during recovery to
+ * reconstruct the state of the actor.
+ * <p/>
+ * This method may also be called at any other point during normal
+ * operations when the derived actor is out of sync with it's peers
+ * and the only way to bring it in sync is by applying a snapshot
+ *
+ * @param snapshot A snapshot of the state of the actor
+ */
+ protected abstract void applySnapshot(Object snapshot);
+
+ private RaftActorBehavior switchBehavior(RaftState state) {
+ if (currentBehavior != null) {
+ if (currentBehavior.state() == state) {
+ return currentBehavior;
+ }
+ LOG.info("Switching from state " + currentBehavior.state() + " to "
+ + state);
+
+ try {
+ currentBehavior.close();
+ } catch (Exception e) {
+ LOG.error(e,
+ "Failed to close behavior : " + currentBehavior.state());
+ }
+
+ } else {
+ LOG.info("Switching behavior to " + state);
+ }
+ RaftActorBehavior behavior = null;
+ if (state == RaftState.Candidate) {
+ behavior = new Candidate(context);
+ } else if (state == RaftState.Follower) {
+ behavior = new Follower(context);
+ } else {
+ behavior = new Leader(context);
+ }
+ return behavior;
+ }
+
+ private void trimPersistentData(long sequenceNumber) {
+ // Trim snapshots
+ // FIXME : Not sure how exactly the SnapshotSelectionCriteria is applied
+ // For now guessing that it is ANDed.
+ deleteSnapshots(new SnapshotSelectionCriteria(
+ sequenceNumber - 100000, 43200000));
+
+ // Trim journal
+ deleteMessages(sequenceNumber);
+ }
+
Code Review / controller.git / commitdiff