Simplified if-conditions

moquette-io · Nov 7, 2020 · d3ccb21 · d3ccb21
1 parent bf4347a
commit d3ccb21
Showing 1 changed file with 36 additions and 37 deletions.
diff --git a/broker/src/main/java/io/moquette/broker/SessionRegistry.java b/broker/src/main/java/io/moquette/broker/SessionRegistry.java
@@ -56,13 +56,11 @@ static final class PubRelMarker extends EnqueuedMessage {
     }
 
     public enum CreationModeEnum {
-        NOT_CREATED, CREATED_CLEAN_NEW, REOPEN_EXISTING, DROP_EXISTING;
+        CREATED_CLEAN_NEW, REOPEN_EXISTING, DROP_EXISTING;
     }
 
     public static class SessionCreationResult {
 
-        final static SessionCreationResult NONE = new SessionCreationResult(null, CreationModeEnum.NOT_CREATED, false);
-
         final Session session;
         final CreationModeEnum mode;
         final boolean alreadyStored;
@@ -117,48 +115,49 @@ private SessionCreationResult reopenExistingSession(MqttConnectMessage msg, Stri
                                                         Session newSession, String username) {
         final boolean newIsClean = msg.variableHeader().isCleanSession();
         final Session oldSession = pool.get(clientId);
-        SessionCreationResult creationResult = SessionCreationResult.NONE;
-        if (newIsClean && oldSession.disconnected()) {
-            // case 2
-            dropQueuesForClient(clientId);
-            unsubscribe(oldSession);
-
-            // publish new session
-            boolean result = oldSession.assignState(SessionStatus.DISCONNECTED, SessionStatus.CONNECTING);
-            if (!result) {
-                throw new SessionCorruptedException("old session was already changed state");
-            }
-            copySessionConfig(msg, oldSession);
-            LOG.trace("case 2, oldSession with same CId {} disconnected", clientId);
-            creationResult = new SessionCreationResult(oldSession, CreationModeEnum.CREATED_CLEAN_NEW, true);
-        } else if (!newIsClean && oldSession.disconnected()) {
-            final boolean connecting = oldSession.assignState(SessionStatus.DISCONNECTED, SessionStatus.CONNECTING);
-            if (!connecting) {
-                throw new SessionCorruptedException("old session moved in connected state by other thread");
+        final SessionCreationResult creationResult;
+        if (oldSession.disconnected()) {
+            if (newIsClean) {
+                boolean result = oldSession.assignState(SessionStatus.DISCONNECTED, SessionStatus.CONNECTING);
+                if (!result) {
+                    throw new SessionCorruptedException("old session was already changed state");
+                }
+
+                // case 2
+                // publish new session
+                dropQueuesForClient(clientId);
+                unsubscribe(oldSession);
+                copySessionConfig(msg, oldSession);
+
+                LOG.trace("case 2, oldSession with same CId {} disconnected", clientId);
+                creationResult = new SessionCreationResult(oldSession, CreationModeEnum.CREATED_CLEAN_NEW, true);
+            } else {
+                final boolean connecting = oldSession.assignState(SessionStatus.DISCONNECTED, SessionStatus.CONNECTING);
+                if (!connecting) {
+                    throw new SessionCorruptedException("old session moved in connected state by other thread");
+                }
+                // case 3
+                reactivateSubscriptions(oldSession, username);
+
+                LOG.trace("case 3, oldSession with same CId {} disconnected", clientId);
+                creationResult = new SessionCreationResult(oldSession, CreationModeEnum.REOPEN_EXISTING, true);
             }
-            // case 3
-            reactivateSubscriptions(oldSession, username);
-
-            LOG.trace("case 3, oldSession with same CId {} disconnected", clientId);
-            creationResult = new SessionCreationResult(oldSession, CreationModeEnum.REOPEN_EXISTING, true);
-        } else if (oldSession.connected()) {
+        } else {
             // case 4
             LOG.trace("case 4, oldSession with same CId {} still connected, force to close", clientId);
             oldSession.closeImmediately();
             //remove(clientId);
             creationResult = new SessionCreationResult(newSession, CreationModeEnum.DROP_EXISTING, true);
         }
 
-        if (creationResult != SessionCreationResult.NONE) {
-            final boolean published;
-            if (creationResult.mode == CreationModeEnum.DROP_EXISTING) {
-                published = pool.replace(clientId, oldSession, newSession);
-            } else {
-                published = pool.replace(clientId, oldSession, oldSession);
-            }
-            if (!published) {
-                throw new SessionCorruptedException("old session was already removed");
-            }
+        final boolean published;
+        if (creationResult.mode == CreationModeEnum.DROP_EXISTING) {
+            published = pool.replace(clientId, oldSession, newSession);
+        } else {
+            published = pool.replace(clientId, oldSession, oldSession);
+        }
+        if (!published) {
+            throw new SessionCorruptedException("old session was already removed");
         }
 
         // case not covered new session is clean true/false and old session not in CONNECTED/DISCONNECTED