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.slots.statistic.data;
  
  import java.util.Set;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import com.alibaba.csp.sentinel.slots.block.flow.param.RollingParamEvent;
  import com.alibaba.csp.sentinel.slots.statistic.cache.CacheMap;
  import com.alibaba.csp.sentinel.slots.statistic.cache.ConcurrentLinkedHashMapWrapper;
  import com.alibaba.csp.sentinel.util.AssertUtil;
  
  /**
   * Represents metric bucket of frequent parameters in a period of time window.
   *
   * @author Eric Zhao
   * @since 0.2.0
   */
  public class ParamMapBucket {
  
      private final CacheMap<Object, AtomicInteger>[] data;
  
      public ParamMapBucket() {
          this(DEFAULT_MAX_CAPACITY);
      }
  
      @SuppressWarnings("unchecked")
      public ParamMapBucket(int capacity) {
          AssertUtil.isTrue(capacity > 0, "capacity should be positive");
          RollingParamEvent[] events = RollingParamEvent.values();
          this.data = new CacheMap[events.length];
          for (RollingParamEvent event : events) {
              data[event.ordinal()] = new ConcurrentLinkedHashMapWrapper<Object, AtomicInteger>(capacity);
          }
      }
  
      public void reset() {
          for (RollingParamEvent event : RollingParamEvent.values()) {
              data[event.ordinal()].clear();
          }
      }
  
      public int get(RollingParamEvent event, Object value) {
          AtomicInteger counter = data[event.ordinal()].get(value);
          return counter == null ? 0 : counter.intValue();
      }
  
      public ParamMapBucket add(RollingParamEvent event, int count, Object value) {
          AtomicInteger counter = data[event.ordinal()].get(value);
          // Note: not strictly concise.
          if (counter == null) {
              AtomicInteger old = data[event.ordinal()].putIfAbsent(value, new AtomicInteger(count));
              if (old != null) {
                  old.addAndGet(count);
              }
          } else {
              counter.addAndGet(count);
          }
          return this;
      }
  
      public Set<Object> ascendingKeySet(RollingParamEvent type) {
          return data[type.ordinal()].keySet(true);
      }
  
      public Set<Object> descendingKeySet(RollingParamEvent type) {
          return data[type.ordinal()].keySet(false);
      }
  
      public static final int DEFAULT_MAX_CAPACITY = 200;
  }