com.amazonaws.services.simpleworkflow.flow.worker.AsyncDecisionTaskHandler Maven / Gradle / Ivy

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/*
 * Copyright 2012-2014 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"). You may not
 * use this file except in compliance with the License. A copy of the License is
 * located at
 * 
 * http://aws.amazon.com/apache2.0
 * 
 * or in the "license" file accompanying this file. This file 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.amazonaws.services.simpleworkflow.flow.worker;

import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.amazonaws.services.simpleworkflow.flow.core.AsyncTaskInfo;
import com.amazonaws.services.simpleworkflow.flow.generic.WorkflowDefinition;
import com.amazonaws.services.simpleworkflow.flow.generic.WorkflowDefinitionFactory;
import com.amazonaws.services.simpleworkflow.flow.generic.WorkflowDefinitionFactoryFactory;
import com.amazonaws.services.simpleworkflow.model.Decision;
import com.amazonaws.services.simpleworkflow.model.DecisionTask;
import com.amazonaws.services.simpleworkflow.model.RespondDecisionTaskCompletedRequest;
import com.amazonaws.services.simpleworkflow.model.WorkflowType;

public class AsyncDecisionTaskHandler extends DecisionTaskHandler {

    private static final Log log = LogFactory.getLog(AsyncDecisionTaskHandler.class);

    private static final Log asyncThreadDumpLog = LogFactory.getLog(AsyncDecisionTaskHandler.class.getName()
            + ".waitingTasksStacks");

    private final WorkflowDefinitionFactoryFactory definitionFactoryFactory;

    public AsyncDecisionTaskHandler(WorkflowDefinitionFactoryFactory definitionFactoryFactory) {
        this.definitionFactoryFactory = definitionFactoryFactory;
    }

    @Override
    public RespondDecisionTaskCompletedRequest handleDecisionTask(Iterator decisionTaskIterator) throws Exception {
        HistoryHelper historyHelper = new HistoryHelper(decisionTaskIterator);
        AsyncDecider decider = createDecider(historyHelper);
        decider.decide();
        DecisionsHelper decisionsHelper = decider.getDecisionsHelper();
        Collection decisions = decisionsHelper.getDecisions();
        String context = decisionsHelper.getWorkflowContextDataToReturn();
        DecisionTask decisionTask = historyHelper.getDecisionTask();
        if (log.isDebugEnabled()) {
            log.debug("WorkflowTask taskId=" + decisionTask.getStartedEventId() + ", taskToken=" + decisionTask.getTaskToken()
                    + " completed with " + decisions.size() + " new decisions");
        }
        if (decisions.size() == 0 && asyncThreadDumpLog.isTraceEnabled()) {
            asyncThreadDumpLog.trace("Empty decision list with the following waiting tasks:\n"
                    + decider.getAsynchronousThreadDumpAsString());
        }
        RespondDecisionTaskCompletedRequest completedRequest = new RespondDecisionTaskCompletedRequest();
        completedRequest.setTaskToken(decisionTask.getTaskToken());
        completedRequest.setDecisions(decisions);
        completedRequest.setExecutionContext(context);
        return completedRequest;
    }

    @Override
    public WorkflowDefinition loadWorkflowThroughReplay(Iterator decisionTaskIterator) throws Exception {
        HistoryHelper historyHelper = new HistoryHelper(decisionTaskIterator);
        AsyncDecider decider = createDecider(historyHelper);
        decider.decide();
        DecisionsHelper decisionsHelper = decider.getDecisionsHelper();
        if (decisionsHelper.isWorkflowFailed()) {
            throw new IllegalStateException("Cannot load failed workflow", decisionsHelper.getWorkflowFailureCause());
        }
        return decider.getWorkflowDefinition();
    }

    @Override
    public List getAsynchronousThreadDump(Iterator decisionTaskIterator) throws Exception {
        HistoryHelper historyHelper = new HistoryHelper(decisionTaskIterator);
        AsyncDecider decider = createDecider(historyHelper);
        decider.decide();
        return decider.getAsynchronousThreadDump();
    }

    @Override
    public String getAsynchronousThreadDumpAsString(Iterator decisionTaskIterator) throws Exception {
        HistoryHelper historyHelper = new HistoryHelper(decisionTaskIterator);
        AsyncDecider decider = createDecider(historyHelper);
        decider.decide();
        return decider.getAsynchronousThreadDumpAsString();
    }

    private AsyncDecider createDecider(HistoryHelper historyHelper) throws Exception {
        DecisionTask decisionTask = historyHelper.getDecisionTask();
        WorkflowType workflowType = decisionTask.getWorkflowType();
        if (log.isDebugEnabled()) {
            log.debug("WorkflowTask received: taskId=" + decisionTask.getStartedEventId() + ", taskToken="
                    + decisionTask.getTaskToken() + ", workflowExecution=" + decisionTask.getWorkflowExecution());
        }
        WorkflowDefinitionFactory workflowDefinitionFactory = definitionFactoryFactory.getWorkflowDefinitionFactory(workflowType);
        if (workflowDefinitionFactory == null) {
            log.error("Received decision task for workflow type not configured with a worker: workflowType="
                    + decisionTask.getWorkflowType() + ", taskToken=" + decisionTask.getTaskToken() + ", workflowExecution="
                    + decisionTask.getWorkflowExecution());
            if (workflowDefinitionFactory == null) {
                throw new IllegalArgumentException("No implementation was found for " + decisionTask.getWorkflowType());
            }
        }
        DecisionsHelper decisionsHelper = new DecisionsHelper(decisionTask);
        AsyncDecider decider = new AsyncDecider(workflowDefinitionFactory, historyHelper, decisionsHelper);
        return decider;
    }
}