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.dashboard.repository.rule;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  
  import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.RuleEntity;
  import com.alibaba.csp.sentinel.dashboard.discovery.MachineInfo;
  import com.alibaba.csp.sentinel.util.AssertUtil;
  
  /**
   * @author leyou
   */
  public abstract class InMemoryRuleRepositoryAdapter<T extends RuleEntity> implements RuleRepository<T, Long> {
  
      /**
       * {@code <machine, <id, rule>>}
       */
      private Map<MachineInfo, Map<Long, T>> machineRules = new ConcurrentHashMap<>(16);
      private Map<Long, T> allRules = new ConcurrentHashMap<>(16);
  
      private Map<String, Map<Long, T>> appRules = new ConcurrentHashMap<>(16);
  
      private static final int MAX_RULES_SIZE = 10000;
  
      @Override
      public T save(T entity) {
          if (entity.getId() == null) {
              entity.setId(nextId());
          }
          T processedEntity = preProcess(entity);
          if (processedEntity != null) {
              allRules.put(processedEntity.getId(), processedEntity);
              machineRules.computeIfAbsent(MachineInfo.of(processedEntity.getApp(), processedEntity.getIp(),
                  processedEntity.getPort()), e -> new ConcurrentHashMap<>(32))
                  .put(processedEntity.getId(), processedEntity);
              appRules.computeIfAbsent(processedEntity.getApp(), v -> new ConcurrentHashMap<>(32))
                  .put(processedEntity.getId(), processedEntity);
          }
  
          return processedEntity;
      }
  
      @Override
      public List<T> saveAll(List<T> rules) {
          // TODO: check here.
          allRules.clear();
          machineRules.clear();
          appRules.clear();
  
          if (rules == null) {
              return null;
          }
          List<T> savedRules = new ArrayList<>(rules.size());
          for (T rule : rules) {
              savedRules.add(save(rule));
          }
          return savedRules;
      }
  
      @Override
      public T delete(Long id) {
          T entity = allRules.remove(id);
          if (entity != null) {
              if (appRules.get(entity.getApp()) != null) {
                  appRules.get(entity.getApp()).remove(id);
              }
              machineRules.get(MachineInfo.of(entity.getApp(), entity.getIp(), entity.getPort())).remove(id);
          }
          return entity;
      }
  
      @Override
      public T findById(Long id) {
          return allRules.get(id);
      }
  
      @Override
      public List<T> findAllByMachine(MachineInfo machineInfo) {
          Map<Long, T> entities = machineRules.get(machineInfo);
          if (entities == null) {
              return new ArrayList<>();
          }
          return new ArrayList<>(entities.values());
      }
  
      @Override
      public List<T> findAllByApp(String appName) {
          AssertUtil.notEmpty(appName, "appName cannot be empty");
          Map<Long, T> entities = appRules.get(appName);
          if (entities == null) {
              return new ArrayList<>();
          }
          return new ArrayList<>(entities.values());
      }
  
      public void clearAll() {
          allRules.clear();
          machineRules.clear();
          appRules.clear();
      }
  
      protected T preProcess(T entity) {
          return entity;
      }
  
      /**
       * Get next unused id.
       *
       * @return next unused id
       */
      abstract protected long nextId();
  }
  