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.adapter.gateway.common.slot;
  
  import java.util.List;
  
  import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayRuleManager;
  import com.alibaba.csp.sentinel.context.Context;
  import com.alibaba.csp.sentinel.node.DefaultNode;
  import com.alibaba.csp.sentinel.slotchain.AbstractLinkedProcessorSlot;
  import com.alibaba.csp.sentinel.slotchain.ResourceWrapper;
  import com.alibaba.csp.sentinel.slots.block.BlockException;
  import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowChecker;
  import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowException;
  import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowRule;
  import com.alibaba.csp.sentinel.slots.block.flow.param.ParameterMetricStorage;
  import com.alibaba.csp.sentinel.spi.Spi;
  
  /**
   * @author Eric Zhao
   * @since 1.6.1
   */
  @Spi(order = -4000)
  public class GatewayFlowSlot extends AbstractLinkedProcessorSlot<DefaultNode> {
  
      @Override
      public void entry(Context context, ResourceWrapper resource, DefaultNode node, int count,
                        boolean prioritized, Object... args) throws Throwable {
          checkGatewayParamFlow(resource, count, args);
  
          fireEntry(context, resource, node, count, prioritized, args);
      }
  
      private void checkGatewayParamFlow(ResourceWrapper resourceWrapper, int count, Object... args)
          throws BlockException {
          if (args == null) {
              return;
          }
  
          List<ParamFlowRule> rules = GatewayRuleManager.getConvertedParamRules(resourceWrapper.getName());
          if (rules == null || rules.isEmpty()) {
              return;
          }
  
          for (ParamFlowRule rule : rules) {
              // Initialize the parameter metrics.
              ParameterMetricStorage.initParamMetricsFor(resourceWrapper, rule);
  
              if (!ParamFlowChecker.passCheck(resourceWrapper, rule, count, args)) {
                  String triggeredParam = "";
                  if (args.length > rule.getParamIdx()) {
                      Object value = args[rule.getParamIdx()];
                      triggeredParam = String.valueOf(value);
                  }
                  throw new ParamFlowException(resourceWrapper.getName(), triggeredParam, rule);
              }
          }
      }
  
      @Override
      public void exit(Context context, ResourceWrapper resourceWrapper, int count, Object... args) {
          fireExit(context, resourceWrapper, count, args);
      }
  }
  