content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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.alipay.remoting;
  
  import com.alipay.remoting.config.ConfigManager;
  import com.alipay.remoting.config.Configs;
  import com.alipay.remoting.log.BoltLoggerFactory;
  import com.alipay.remoting.util.FutureTaskUtil;
  import com.alipay.remoting.util.RemotingUtil;
  import com.alipay.remoting.util.RunStateRecordedFutureTask;
  import org.slf4j.Logger;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  import java.util.Random;
  import java.util.concurrent.ConcurrentHashMap;
  
  /**
   * An implemented strategy to monitor connections:
   *   <lu>
   *       <li>each time scheduled, filter connections with {@link Configs#CONN_SERVICE_STATUS_OFF} at first.</li>
   *       <li>then close connections.</li>
   *   </lu>
   *
   * @author tsui
   * @version $Id: ScheduledDisconnectStrategy.java, v 0.1 2017-02-21 14:14 tsui Exp $
   */
  public class ScheduledDisconnectStrategy implements ConnectionMonitorStrategy {
      private static final Logger logger = BoltLoggerFactory.getLogger("CommonDefault");
  
      private final int           connectionThreshold;
      private final Random        random;
  
      public ScheduledDisconnectStrategy() {
          this.connectionThreshold = ConfigManager.conn_threshold();
          this.random = new Random();
      }
  
      /**
       * This method only invoked in ScheduledDisconnectStrategy, so no need to be exposed.
       * This method will be remove in next version, do not use this method.
       *
       * The user cannot call ScheduledDisconnectStrategy#filter, so modifying the implementation of this method is safe.
       *
       * @param connections connections from a connection pool
       */
      @Deprecated
      @Override
      public Map<String, List<Connection>> filter(List<Connection> connections) {
          List<Connection> serviceOnConnections = new ArrayList<Connection>();
          List<Connection> serviceOffConnections = new ArrayList<Connection>();
          Map<String, List<Connection>> filteredConnections = new ConcurrentHashMap<String, List<Connection>>();
  
          for (Connection connection : connections) {
              if (isConnectionOn(connection)) {
                  serviceOnConnections.add(connection);
              } else {
                  serviceOffConnections.add(connection);
              }
          }
  
          filteredConnections.put(Configs.CONN_SERVICE_STATUS_ON, serviceOnConnections);
          filteredConnections.put(Configs.CONN_SERVICE_STATUS_OFF, serviceOffConnections);
          return filteredConnections;
      }
  
      @Override
      public void monitor(Map<String, RunStateRecordedFutureTask<ConnectionPool>> connPools) {
          try {
              if (connPools == null || connPools.size() == 0) {
                  return;
              }
  
              for (Map.Entry<String, RunStateRecordedFutureTask<ConnectionPool>> entry : connPools
                  .entrySet()) {
                  String poolKey = entry.getKey();
                  ConnectionPool pool = FutureTaskUtil.getFutureTaskResult(entry.getValue(), logger);
  
                  List<Connection> serviceOnConnections = new ArrayList<Connection>();
                  List<Connection> serviceOffConnections = new ArrayList<Connection>();
                  for (Connection connection : pool.getAll()) {
                      if (isConnectionOn(connection)) {
                          serviceOnConnections.add(connection);
                      } else {
                          serviceOffConnections.add(connection);
                      }
                  }
  
                  if (serviceOnConnections.size() > connectionThreshold) {
                      Connection freshSelectConnect = serviceOnConnections.get(random
                          .nextInt(serviceOnConnections.size()));
                      freshSelectConnect.setAttribute(Configs.CONN_SERVICE_STATUS,
                          Configs.CONN_SERVICE_STATUS_OFF);
                      serviceOffConnections.add(freshSelectConnect);
                  } else {
                      if (logger.isDebugEnabled()) {
                          logger.debug("serviceOnConnections({}) size[{}], CONNECTION_THRESHOLD[{}].",
                              poolKey, serviceOnConnections.size(), connectionThreshold);
                      }
                  }
  
                  for (Connection offConn : serviceOffConnections) {
                      if (offConn.isInvokeFutureMapFinish()) {
                          if (offConn.isFine()) {
                              offConn.close();
                          }
                      } else {
                          if (logger.isDebugEnabled()) {
                              logger.debug("Address={} won't close at this schedule turn",
                                  RemotingUtil.parseRemoteAddress(offConn.getChannel()));
                          }
                      }
                  }
              }
          } catch (Exception e) {
              logger.error("ScheduledDisconnectStrategy monitor error", e);
          }
      }
  
      private boolean isConnectionOn(Connection connection) {
          String serviceStatus = (String) connection.getAttribute(Configs.CONN_SERVICE_STATUS);
          return serviceStatus == null || Boolean.parseBoolean(serviceStatus);
      }
  }
  