[broker-23] small refactoring

Author: crazyrokr

src/main/java/com/ss/mqtt/broker/model/SingleSubscriber.java

@@ -3,21 +3,18 @@
 import com.ss.mqtt.broker.network.client.MqttClient;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 import org.jetbrains.annotations.NotNull;
 
 @ToString
 @EqualsAndHashCode(of = "mqttClient")
+@RequiredArgsConstructor
 public class SingleSubscriber implements Subscriber {
 
     private final @Getter @NotNull MqttClient mqttClient;
     private final @NotNull SubscribeTopicFilter subscribe;
 
-    public SingleSubscriber(@NotNull MqttClient mqttClient, @NotNull SubscribeTopicFilter subscribe) {
-        this.mqttClient = mqttClient;
-        this.subscribe = subscribe;
-    }
-
     public @NotNull QoS getQos() {
         return subscribe.getQos();
     }

src/main/java/com/ss/mqtt/broker/model/topic/TopicSubscribers.java

@@ -16,6 +16,8 @@
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.Optional;
+
 public class TopicSubscribers {
 
     private final static NotNullSupplier<TopicSubscribers> TOPIC_SUBSCRIBER_SUPPLIER = TopicSubscribers::new;
@@ -49,7 +51,7 @@ private static void addSharedSubscriber(
 
         var sharedSubscriber = (SharedSubscriber) subscribers.findAny(
             group,
-            SubscriberUtils::sharedSubscriberWithGroup
+            SubscriberUtils::isSharedSubscriberWithGroup
         );
 
         if (sharedSubscriber == null) {
@@ -91,7 +93,7 @@ private static boolean removeSharedSubscriber(
         boolean removed = false;
         var sharedSubscriber = (SharedSubscriber) subscribers.findAny(
             group,
-            SubscriberUtils::sharedSubscriberWithGroup
+            SubscriberUtils::isSharedSubscriberWithGroup
         );
 
         if (sharedSubscriber != null) {
@@ -213,17 +215,9 @@ private boolean searchSubscriberToRemove(int level, @NotNull TopicFilter topicFi
     }
 
     private boolean tryToRemoveSubscriber(@NotNull TopicFilter topicFilter, @NotNull MqttClient mqttClient) {
-        var removed = false;
-        var subscribers = getSubscribers();
-        if (subscribers != null) {
-            //noinspection ConstantConditions
-            removed = subscribers.getInWriteLock(
-                topicFilter,
-                mqttClient,
-                TopicSubscribers::removeSubscriber
-            );
-        }
-        return removed;
+        return Optional.ofNullable(getSubscribers())
+            .map(subscribers -> subscribers.getInWriteLock(topicFilter, mqttClient, TopicSubscribers::removeSubscriber))
+            .orElse(false);
     }
 
     public @NotNull Array<SingleSubscriber> matches(@NotNull TopicName topicName) {

src/main/java/com/ss/mqtt/broker/util/SubscriberUtils.java

@@ -17,7 +17,7 @@ private static boolean isSingleSubscriber(@NotNull Subscriber subscriber) {
         return subscriber instanceof SingleSubscriber;
     }
 
-    public static boolean sharedSubscriberWithGroup(@NotNull String group, @NotNull Subscriber subscriber) {
+    public static boolean isSharedSubscriberWithGroup(@NotNull String group, @NotNull Subscriber subscriber) {
         return isSharedSubscriber(subscriber) && group.equals(((SharedSubscriber) subscriber).getGroup());
     }