content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.alibaba.csp.sentinel.cluster.flow.statistic.metric;
  
  import java.util.concurrent.atomic.LongAdder;
  
  import com.alibaba.csp.sentinel.cluster.flow.statistic.data.ClusterFlowEvent;
  import com.alibaba.csp.sentinel.cluster.flow.statistic.data.ClusterMetricBucket;
  import com.alibaba.csp.sentinel.slots.statistic.base.LeapArray;
  import com.alibaba.csp.sentinel.slots.statistic.base.WindowWrap;
  
  /**
   * @author Eric Zhao
   * @since 1.4.0
   */
  public class ClusterMetricLeapArray extends LeapArray<ClusterMetricBucket> {
  
      private final LongAdder[] occupyCounter;
      private boolean hasOccupied = false;
  
      public ClusterMetricLeapArray(int sampleCount, int intervalInMs) {
          super(sampleCount, intervalInMs);
          ClusterFlowEvent[] events = ClusterFlowEvent.values();
          this.occupyCounter = new LongAdder[events.length];
          for (ClusterFlowEvent event : events) {
              occupyCounter[event.ordinal()] = new LongAdder();
          }
      }
  
      @Override
      public ClusterMetricBucket newEmptyBucket(long timeMillis) {
          return new ClusterMetricBucket();
      }
  
      @Override
      protected WindowWrap<ClusterMetricBucket> resetWindowTo(WindowWrap<ClusterMetricBucket> w, long startTime) {
          w.resetTo(startTime);
          w.value().reset();
          transferOccupyToBucket(w.value());
          return w;
      }
  
      private void transferOccupyToBucket(/*@Valid*/ ClusterMetricBucket bucket) {
          if (hasOccupied) {
              transferOccupiedCount(bucket, ClusterFlowEvent.PASS, ClusterFlowEvent.OCCUPIED_PASS);
              transferOccupiedThenReset(bucket, ClusterFlowEvent.PASS);
              transferOccupiedThenReset(bucket, ClusterFlowEvent.PASS_REQUEST);
              hasOccupied = false;
          }
      }
  
      private void transferOccupiedCount(ClusterMetricBucket bucket, ClusterFlowEvent source, ClusterFlowEvent target) {
          bucket.add(target, occupyCounter[source.ordinal()].sum());
      }
  
      private void transferOccupiedThenReset(ClusterMetricBucket bucket, ClusterFlowEvent event) {
          bucket.add(event, occupyCounter[event.ordinal()].sumThenReset());
      }
  
      public void addOccupyPass(int count) {
          occupyCounter[ClusterFlowEvent.PASS.ordinal()].add(count);
          occupyCounter[ClusterFlowEvent.PASS_REQUEST.ordinal()].add(1);
          this.hasOccupied = true;
      }
  
      public long getOccupiedCount(ClusterFlowEvent event) {
          return occupyCounter[event.ordinal()].sum();
      }
  
      public long getFirstCountOfWindow(ClusterFlowEvent event) {
          if (event == null) {
              return 0;
          }
          WindowWrap<ClusterMetricBucket> windowWrap = getValidHead();
          if (windowWrap == null) {
              return 0;
          }
          return windowWrap.value().get(event);
      }
  }
  