Minor fixes, added some javadoc and corrected a method name typo

broker/src/main/java/org/dna/mqtt/moquette/messaging/spi/IStorageService.java

@@ -18,13 +18,25 @@ public interface IStorageService extends IPersistentSubscriptionStore {
      * */
     void initStore();
 
+    /**
+     * Persist the message. 
+     * If the message is empty then the topic is cleaned, else it's stored.
+     */
     void storeRetained(String topic, ByteBuffer message, AbstractMessage.QOSType qos);
 
+    /**
+     * Return a list of retained messages that satisfy the condition.
+     */
     Collection<StoredMessage> searchMatching(IMatchingCondition condition);
 
     void storePublishForFuture(PublishEvent evt);
 
-    List<PublishEvent> retrivePersistedPublishes(String clientID);
+    /**
+     * Return the list of persisted publishes for the given clientID.
+     * For QoS1 and QoS2 with clean session flag, this method return the list of 
+     * missed publish events while the client was disconnected.
+     */
+    List<PublishEvent> retrievePersistedPublishes(String clientID);
     
     void cleanPersistedPublishMessage(String clientID, int messageID);
 

broker/src/main/java/org/dna/mqtt/moquette/messaging/spi/impl/HawtDBStorageService.java

@@ -134,6 +134,7 @@ public class HawtDBStorageService implements IStorageService {
         m_qos2Store = (SortedIndex<String, StoredPublishEvent>) m_multiIndexFactory.openOrCreate("qos2Store", indexFactory);
     }
 
+    @Override
     public void storeRetained(String topic, ByteBuffer message, AbstractMessage.QOSType qos) {
         if (!message.hasRemaining()) {
             //clean the message from topic
@@ -146,6 +147,7 @@ public class HawtDBStorageService implements IStorageService {
         }
     }
 
+    @Override
     public Collection<StoredMessage> searchMatching(IMatchingCondition condition) {
         LOG.debug("searchMatching scanning all retained messages, presents are {}", m_retainedStore.size());
 
@@ -175,7 +177,8 @@ public class HawtDBStorageService implements IStorageService {
         LOG.debug("Stored published message for client <{}> on topic <{}>", clientID, evt.getTopic());
     }
 
-    public List<PublishEvent> retrivePersistedPublishes(String clientID) {
+    @Override
+    public List<PublishEvent> retrievePersistedPublishes(String clientID) {
         List<StoredPublishEvent> storedEvts = m_persistentMessageStore.get(clientID);
         if (storedEvts == null) {
             return null;
@@ -266,7 +269,7 @@ public class HawtDBStorageService implements IStorageService {
 
     /*-------- QoS 2  storage management --------------*/
     public void persistQoS2Message(String publishKey, PublishEvent evt) {
-        LOG.debug("persistQoS2Message store pubKey {}, evt {}", publishKey, evt);
+        LOG.debug("persistQoS2Message store pubKey: {}, evt: {}", publishKey, evt);
         m_qos2Store.put(publishKey, convertToStored(evt));
     }
 

broker/src/main/java/org/dna/mqtt/moquette/messaging/spi/impl/MemoryStorageService.java

@@ -74,7 +74,8 @@ public class MemoryStorageService implements IStorageService {
         m_persistentMessageStore.put(clientID, storedEvents);
     }
 
-    public List<PublishEvent> retrivePersistedPublishes(String clientID) {
+    @Override
+    public List<PublishEvent> retrievePersistedPublishes(String clientID) {
         return m_persistentMessageStore.get(clientID);
     }
     

broker/src/main/java/org/dna/mqtt/moquette/messaging/spi/impl/ProtocolProcessor.java

@@ -176,7 +176,7 @@ class ProtocolProcessor implements EventHandler<ValueEvent> {
     
     private void republishStored(String clientID) {
         LOG.trace("republishStored invoked");
-        List<PublishEvent> publishedEvents = m_storageService.retrivePersistedPublishes(clientID);
+        List<PublishEvent> publishedEvents = m_storageService.retrievePersistedPublishes(clientID);
         if (publishedEvents == null) {
             LOG.info("No stored messages for client <{}>", clientID);
             return;
@@ -224,7 +224,7 @@ class ProtocolProcessor implements EventHandler<ValueEvent> {
             sendPubRec(evt.getClientID(), evt.getMessageID());
         }
 
-        //NB publish 2 subscribers for QoS 2 happen upon PUBREL from publsher
+        //NB publish to subscribers for QoS 2 happen upon PUBREL from publisher
         if (qos != AbstractMessage.QOSType.EXACTLY_ONCE) {
             publish2Subscribers(topic, qos, message, retain, evt.getMessageID());
         }
@@ -294,7 +294,7 @@ class ProtocolProcessor implements EventHandler<ValueEvent> {
     }
     
     private void sendPublish(String clientId, String topic, AbstractMessage.QOSType qos, ByteBuffer message, boolean retained, int messageID) {
-        LOG.debug("sendPublish invoked clientId <{}> on topic <{}> QoS {} ratained {} messageID {}", clientId, topic, qos, retained, messageID);
+        LOG.debug("sendPublish invoked clientId <{}> on topic <{}> QoS {} retained {} messageID {}", clientId, topic, qos, retained, messageID);
         PublishMessage pubMessage = new PublishMessage();
         pubMessage.setRetainFlag(retained);
         pubMessage.setTopicName(topic);