Refactor metrics code.

common/src/main/java/com/alibaba/otter/canal/common/utils/SerializedLongAdder.java

@@ -1,31 +0,0 @@
-package com.alibaba.otter.canal.common.utils;
-
-/**
- * 用于dump记录counter
- * 这种场景下，
- * <strong>写操作>>读操作</strong>
- * dump线程为串行，读取counter时，并不严格要求最新值可见，使用普通long即可。
- *
- * @author Chuanyi Li
- */
-public class SerializedLongAdder {
-
-    private long value = 0;
-
-    public SerializedLongAdder(long initial) {
-        this.value = initial;
-    }
-
-    public void add(long x) {
-        value += x;
-    }
-
-    public void increment() {
-        value ++;
-    }
-
-    public long get() {
-        return value;
-    }
-
-}