bpmn/MSOCommonBPMN/src/main/java/org/onap/so/bpmn/common/workflow/context/WorkflowContextHolder.java

   1 package org.onap.so.bpmn.common.workflow.context;
   2 /*-
   3  * ============LICENSE_START=======================================================
   4  * ONAP - SO
   5  * ================================================================================
   6  * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
   7  * ================================================================================
   8  * Modifications Copyright (c) 2019 Samsung
   9  * ================================================================================
  10  * Licensed under the Apache License, Version 2.0 (the "License");
  11  * you may not use this file except in compliance with the License.
  12  * You may obtain a copy of the License at
  13  *
  14  *      http://www.apache.org/licenses/LICENSE-2.0
  15  *
  16  * Unless required by applicable law or agreed to in writing, software
  17  * distributed under the License is distributed on an "AS IS" BASIS,
  18  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  19  * See the License for the specific language governing permissions and
  20  * limitations under the License.
  21  * ============LICENSE_END=========================================================
  22  */
  23
  24
  25
  26 import java.util.concurrent.DelayQueue;
  27 import java.util.concurrent.TimeUnit;
  28
  29 import org.onap.so.logger.ErrorCode;
  30 import org.onap.so.logger.MessageEnum;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33 import org.springframework.stereotype.Component;
  34
  35 /**
  36  * Workflow Context Holder instance which can be accessed elsewhere either in groovy scripts or Java
  37  * @version 1.0
  38  *
  39  */
  40
  41 @Component
  42 public class WorkflowContextHolder {
  43
  44         private static Logger logger = LoggerFactory.getLogger(WorkflowContextHolder.class);
  45         private static final String logMarker = "[WORKFLOW-CONTEXT-HOLDER]";
  46         private static WorkflowContextHolder instance = null;
  47
  48
  49         private long defaultContextTimeout=60000;
  50
  51         /**
  52          * Delay Queue which holds workflow context holder objects
  53          */
  54         private final DelayQueue<WorkflowContext> responseQueue = new DelayQueue<>();
  55         private final TimeoutThread timeoutThread = new TimeoutThread();
  56
  57         private WorkflowContextHolder() {
  58                 timeoutThread.start();
  59         }
  60
  61         /**
  62          * Singleton holder which eliminates hot lock
  63          * Since the JVM synchronizes static method there is no synchronization needed for this method
  64          * @return
  65          */
  66         public static synchronized WorkflowContextHolder getInstance() {
  67                 if (instance == null) {
  68                         instance = new WorkflowContextHolder();
  69                 }
  70                 return instance;
  71         }
  72
  73         public void put(WorkflowContext context) {
  74                 logger.debug("{} Adding context to the queue: {}", logMarker, context.getRequestId());
  75                 responseQueue.put(context);
  76         }
  77
  78         public void remove(WorkflowContext context) {
  79                 logger.debug("{} Removing context from the queue: {}", logMarker, context.getRequestId());
  80                 responseQueue.remove(context);
  81         }
  82
  83         public WorkflowContext getWorkflowContext(String requestId) {
  84                 // Note: DelayQueue interator is threadsafe
  85                 for (WorkflowContext context : responseQueue) {
  86                         if (requestId.equals(context.getRequestId())) {
  87                                 return context;
  88                         }
  89                 }
  90                 return null;
  91         }
  92
  93         /**
  94          * Builds the callback response object to respond to client
  95          * @param processKey
  96          * @param processInstanceId
  97          * @param requestId
  98          * @param callbackResponse
  99          * @return
 100          */
 101         public void processCallback(String processKey, String processInstanceId,
 102                         String requestId, WorkflowCallbackResponse callbackResponse) {
 103                 WorkflowResponse workflowResponse = new WorkflowResponse();
 104                 workflowResponse.setResponse(callbackResponse.getResponse());
 105                 workflowResponse.setProcessInstanceID(processInstanceId);
 106                 workflowResponse.setMessageCode(callbackResponse.getStatusCode());
 107                 workflowResponse.setMessage(callbackResponse.getMessage());
 108                 WorkflowContext context = new WorkflowContext(processKey, requestId, defaultContextTimeout,workflowResponse);
 109                 put(context);
 110         }
 111
 112
 113         /**
 114          * Timeout thread which monitors the delay queue for expired context and send timeout response
 115          * to client
 116          *
 117          * */
 118         private class TimeoutThread extends Thread {
 119                 @Override
 120                 public void run() {
 121                         while (!isInterrupted()) {
 122                                 try {
 123                                         WorkflowContext requestObject = responseQueue.take();
 124                                         logger.debug("Time remaining for request id: {}:{}", requestObject.getRequestId(), requestObject
 125                                                 .getDelay
 126                                                 (TimeUnit.MILLISECONDS));
 127                                         logger.debug("Preparing timeout response for {}:{}", requestObject.getProcessKey(), requestObject
 128                                                 .getRequestId());
 129                                 } catch (InterruptedException e) {
 130                                         Thread.currentThread().interrupt();
 131                                 } catch (Exception e) {
 132                                         logger.debug("WorkflowContextHolder timeout thread caught exception: ", e);
 133                                         logger.error("{} {} {} {}", MessageEnum.BPMN_GENERAL_EXCEPTION.toString(), "BPMN",
 134                                                         ErrorCode.UnknownError.getValue(), "Error in WorkflowContextHolder timeout thread");
 135                                 }
 136                         }
 137                         logger.debug("WorkflowContextHolder timeout thread interrupted, quitting");
 138                 }
 139         }
 140 }