code: /*
   * Copyright © 2014-2017 EntIT Software LLC, a Micro Focus company (L.P.)
   *
   * 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 io.cloudslang.engine.queue.services;
  
  import io.cloudslang.engine.queue.entities.ExecStatus;
  import io.cloudslang.engine.queue.entities.ExecutionMessage;
  import io.cloudslang.engine.queue.repositories.ExecutionQueueRepository;
  import io.cloudslang.orchestrator.services.CancelExecutionService;
  import io.cloudslang.score.facade.execution.ExecutionActionResult;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.transaction.annotation.Transactional;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import static java.lang.Boolean.parseBoolean;
  import static java.lang.System.getProperty;
  import static java.util.Comparator.comparingInt;
  import static java.util.stream.Collectors.groupingBy;
  
  public final class LargeMessagesMonitorServiceImpl implements LargeMessagesMonitorService {
  
      private static Logger logger = LogManager.getLogger(LargeMessagesMonitorServiceImpl.class);
  
      @Autowired
      private CancelExecutionService cancelExecutionService;
  
      @Autowired
      private ExecutionQueueRepository executionQueueRepository;
  
      @Autowired
      private ExecutionQueueService execQueue;
  
      @Override
      @Transactional
      public void monitor() {
          if (!parseBoolean(getProperty("score.poll.use.large.message.query", "true"))) {
              return;
          }
  
          int noRetries = getNoRetries();
  
          long time = System.currentTimeMillis() - getMessageExpirationTime() * 1000;
  
          List<ExecutionMessage> messages = executionQueueRepository.findOldMessages(time);
  
          Map<Long, List<ExecutionMessage>> execStateMap = messages.stream().
                  collect(groupingBy(ExecutionMessage::getExecStateId));
  
          Set<Long> toCancel = new HashSet<>();
          List<ExecutionMessage> toRetry = new ArrayList<>();
  
          for (Map.Entry<Long, List<ExecutionMessage>> entry : execStateMap.entrySet()) {
  
              long execStateId = entry.getKey();
              List<ExecutionMessage> msgs = entry.getValue();
  
              Collections.sort(msgs, comparingInt(ExecutionMessage::getMsgSeqId).reversed());
  
              if (countRetries(msgs) >= noRetries) {
                  toCancel.add(execStateId);
              } else {
                  ExecutionMessage firstMsg = msgs.get(0);
                  firstMsg.setWorkerId(ExecutionMessage.EMPTY_WORKER);
                  firstMsg.setStatus(ExecStatus.PENDING);
                  toRetry.add(firstMsg);
              }
          }
  
          // retry
          if (toRetry.size() > 0) {
              logger.warn("Retrying " + toRetry.size() + " entries " + toRetry);
              execQueue.enqueue(toRetry);
          }
  
          // cancel
          if (toCancel.size() > 0) {
              Set<Long> execIds = executionQueueRepository.getExecutionIdsForExecutionStateIds(toCancel);
  
              logger.warn("Canceling execution with ids " + execIds);
  
              for (Long executionId : execIds) {
                  ExecutionActionResult result = cancelExecutionService.requestCancelExecution(executionId);
                  logger.warn("Requested cancel of execution id: " + executionId + ", result: " + result);
              }
          }
      }
  
      private int countRetries(List<ExecutionMessage> msgs) {
  
          if (msgs.size() == 0) {
              return 0;
          }
  
          int retries = 0;
          if (msgs.get(0).getStatus() == ExecStatus.ASSIGNED) {
              retries = 1;
          }
  
          int size = msgs.size();
          int i = 1;
          while (i < size) {
              ExecutionMessage crt = msgs.get(i);
              ExecutionMessage prev = msgs.get(i - 1);
              if (crt.getStatus() == ExecStatus.ASSIGNED && crt.getMsgSeqId() == prev.getMsgSeqId() - 1) {
                  retries++;
              } else {
                  break;
              }
  
              i++;
          }
  
          return retries;
      }
  }
  