[broker-23] rework splitTopic

Author: crazyrokr

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

@@ -12,6 +12,10 @@
 
 public class SharedSubscriber implements Subscriber {
 
+    private static @NotNull SingleSubscriber next(@NotNull Array<SingleSubscriber> subscribers, int current) {
+        return subscribers.get(current % subscribers.size());
+    }
+
     private final @NotNull SharedTopicFilter topicFilter;
     private final @NotNull ConcurrentArray<SingleSubscriber> subscribers;
     private final @NotNull AtomicInteger current;
@@ -40,10 +44,6 @@ public int size() {
         return subscribers.getInReadLock(Collection::size);
     }
 
-    private static @NotNull SingleSubscriber next(@NotNull Array<SingleSubscriber> subscribers, int current) {
-        return subscribers.get(current % subscribers.size());
-    }
-
     public @NotNull String getGroup() {
         return topicFilter.getGroup();
     }

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

@@ -3,12 +3,11 @@
 import static com.ss.mqtt.broker.util.TopicUtils.splitTopic;
 import static com.ss.rlib.common.util.StringUtils.EMPTY;
 import com.ss.mqtt.broker.util.DebugUtils;
+import com.ss.rlib.common.util.array.Array;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.List;
-
 @Getter
 @EqualsAndHashCode(of = "rawTopic")
 public abstract class AbstractTopic {
@@ -17,13 +16,13 @@ public abstract class AbstractTopic {
         DebugUtils.registerIncludedFields("rawTopic");
     }
 
-    private final @NotNull List<String> segments;
+    private final @NotNull Array<String> segments;
     private final @NotNull String rawTopic;
     private final int length;
 
     AbstractTopic() {
         length = 0;
-        segments = List.of();
+        segments = empty();
         rawTopic = EMPTY;
     }
 
@@ -41,6 +40,10 @@ int levelsCount() {
         return segments.size();
     }
 
+    String lastSegment() {
+        return segments.get(segments.size() - 1);
+    }
+
     @Override
     public @NotNull String toString() {
         return rawTopic;

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

@@ -1,13 +1,12 @@
 package com.ss.mqtt.broker.util;
 
-import static java.util.Collections.unmodifiableList;
+import static com.ss.rlib.common.util.array.ArrayFactory.newReadOnlyArray;
 import com.ss.mqtt.broker.model.topic.SharedTopicFilter;
 import com.ss.mqtt.broker.model.topic.TopicFilter;
 import com.ss.mqtt.broker.model.topic.TopicName;
+import com.ss.rlib.common.util.array.Array;
 import org.jetbrains.annotations.NotNull;
-
-import java.util.ArrayList;
-import java.util.List;
+import org.springframework.util.StringUtils;
 
 public class TopicUtils {
 
@@ -55,15 +54,16 @@ public static boolean hasWildcard(@NotNull TopicFilter topicFilter) {
         }
     }
 
-    public static @NotNull List<String> splitTopic(@NotNull String topic) {
-        var segments = new ArrayList<String>();
-        int pos = 0, end;
+    public static @NotNull Array<String> splitTopic(@NotNull String topic) {
+        int segmentCount = StringUtils.countOccurrencesOf(topic, DELIMITER) + 1;
+        var segments = new String[segmentCount];
+        int i = 0, pos = 0, end;
         while ((end = topic.indexOf(DELIMITER, pos)) >= 0) {
-            segments.add(topic.substring(pos, end));
+            segments[i++] = topic.substring(pos, end);
             pos = end + 1;
         }
-        segments.add(topic.substring(pos));
-        return unmodifiableList(segments);
+        segments[i] = topic.substring(pos);
+        return newReadOnlyArray(segments);
     }
 
     private static @NotNull TopicFilter newSharedTopicFilter(@NotNull String topicFilter) {