refactor(session):优化负载计算逻辑

- 移除 AtomicInteger 依赖
- 使用两个整型变量分别记录 offer 和 poll 操作次数
- 调整负载值计算方式为差值绝对值
- 注释掉调试打印语句

Author: smthing

src/main/java/tech/smartboot/redisun/RedisSession.java

@@ -4,7 +4,6 @@
 
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentLinkedQueue;
-import java.util.concurrent.atomic.AtomicInteger;
 
 /**
  * Redis会话管理类
@@ -35,7 +34,8 @@ final class RedisSession {
      */
     private RESP decodingResponse;
 
-    private final AtomicInteger load = new AtomicInteger();
+    private int offerCount = 0;
+    private int pollCount = 0;
 
     /**
      * 感知变化量，无需保障原子性
@@ -69,17 +69,19 @@ void setDecodingResponse(RESP decodingResponse) {
     }
 
     public CompletableFuture<RESP> poll() {
-        load.decrementAndGet();
+        pollCount++;
         return pipeline.poll();
     }
 
     public void offer(CompletableFuture<RESP> future) {
-        load.incrementAndGet();
+        offerCount++;
         pipeline.offer(future);
     }
 
     int load() {
-        return load.get();
+        int size = offerCount - pollCount;
+//        System.out.println("load: " + size);
+        return size >= 0 ? size : -size;
     }
 
 }