content: /*
   * Copyright 1999-2019 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
   *
   *      https://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.block.flow.param;
  
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  
  import com.alibaba.csp.sentinel.log.RecordLog;
  import com.alibaba.csp.sentinel.slotchain.ResourceWrapper;
  import com.alibaba.csp.sentinel.util.StringUtil;
  
  /**
   * @author Eric Zhao
   * @since 1.6.1
   */
  public final class ParameterMetricStorage {
  
      private static final Map<String, ParameterMetric> metricsMap = new ConcurrentHashMap<>();
  
      /**
       * Lock for a specific resource.
       */
      private static final Object LOCK = new Object();
  
      /**
       * Init the parameter metric and index map for given resource.
       * Package-private for test.
       *
       * @param resourceWrapper resource to init
       * @param rule            relevant rule
       */
      public static void initParamMetricsFor(ResourceWrapper resourceWrapper, /*@Valid*/ ParamFlowRule rule) {
          if (resourceWrapper == null || resourceWrapper.getName() == null) {
              return;
          }
          String resourceName = resourceWrapper.getName();
          ParameterMetric metric;
          // Assume that the resource is valid.
          if ((metric = metricsMap.get(resourceName)) == null) {
              synchronized (LOCK) {
                  if ((metric = metricsMap.get(resourceName)) == null) {
                      metric = new ParameterMetric();
                      metricsMap.put(resourceWrapper.getName(), metric);
                      RecordLog.info("[ParameterMetricStorage] Creating parameter metric for: {}", resourceWrapper.getName());
                  }
              }
          }
          metric.initialize(rule);
      }
  
      public static ParameterMetric getParamMetric(ResourceWrapper resourceWrapper) {
          if (resourceWrapper == null || resourceWrapper.getName() == null) {
              return null;
          }
          return metricsMap.get(resourceWrapper.getName());
      }
  
      public static ParameterMetric getParamMetricForResource(String resourceName) {
          if (resourceName == null) {
              return null;
          }
          return metricsMap.get(resourceName);
      }
  
      public static void clearParamMetricForResource(String resourceName) {
          if (StringUtil.isBlank(resourceName)) {
              return;
          }
          metricsMap.remove(resourceName);
          RecordLog.info("[ParameterMetricStorage] Clearing parameter metric for: {}", resourceName);
      }
  
      static Map<String, ParameterMetric> getMetricsMap() {
          return metricsMap;
      }
  
      private ParameterMetricStorage() {}
  }
  