/**************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package com.espertech.esper.epl.variable;
import com.espertech.esper.collection.SingleEventIterator;
import com.espertech.esper.core.StatementResultService;
import com.espertech.esper.epl.expression.ExprValidationException;
import com.espertech.esper.epl.expression.ExprEvaluatorContext;
import com.espertech.esper.epl.spec.OnTriggerSetAssignment;
import com.espertech.esper.epl.spec.OnTriggerSetDesc;
import com.espertech.esper.event.EventAdapterService;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.util.ExecutionPathDebugLog;
import com.espertech.esper.view.ViewSupport;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
/**
* A view that handles the setting of variables upon receipt of a triggering event.
* <p>
* Variables are updated atomically and thus a separate commit actually updates the
* new variable values, or a rollback if an exception occured during validation.
*/
public class OnSetVariableView extends ViewSupport
{
private static final Log log = LogFactory.getLog(OnSetVariableView.class);
private final OnTriggerSetDesc desc;
private final EventAdapterService eventAdapterService;
private final VariableService variableService;
private final EventType eventType;
private final VariableReadWritePackage variableReadWritePackage;
private final EventBean[] eventsPerStream = new EventBean[1];
private final StatementResultService statementResultService;
private final ExprEvaluatorContext exprEvaluatorContext;
/**
* Ctor.
* @param desc specification for the on-set statement
* @param eventAdapterService for creating statements
* @param variableService for setting variables
* @param statementResultService for coordinating on whether insert and remove stream events should be posted
* @param exprEvaluatorContext context for expression evalauation
* @throws ExprValidationException if the assignment expressions are invalid
*/
public OnSetVariableView(OnTriggerSetDesc desc, EventAdapterService eventAdapterService, VariableService variableService, StatementResultService statementResultService, ExprEvaluatorContext exprEvaluatorContext)
throws ExprValidationException
{
this.desc = desc;
this.eventAdapterService = eventAdapterService;
this.variableService = variableService;
this.statementResultService = statementResultService;
this.exprEvaluatorContext = exprEvaluatorContext;
variableReadWritePackage = new VariableReadWritePackage(desc.getAssignments(), variableService, eventAdapterService);
eventType = eventAdapterService.createAnonymousMapType(variableReadWritePackage.getVariableTypes());
}
public void update(EventBean[] newData, EventBean[] oldData)
{
if ((newData == null) || (newData.length == 0))
{
return;
}
Map<String, Object> values = null;
boolean produceOutputEvents = (statementResultService.isMakeNatural() || statementResultService.isMakeSynthetic());
if (produceOutputEvents)
{
values = new HashMap<String, Object>();
}
eventsPerStream[0] = newData[newData.length - 1];
variableReadWritePackage.writeVariables(variableService, eventsPerStream, values, exprEvaluatorContext);
if (values != null)
{
EventBean newDataOut[] = new EventBean[1];
newDataOut[0] = eventAdapterService.adaptorForTypedMap(values, eventType);
this.updateChildren(newDataOut, null);
}
}
public EventType getEventType()
{
return eventType;
}
public Iterator<EventBean> iterator()
{
Map<String, Object> values = variableReadWritePackage.iterate();
EventBean event = eventAdapterService.adaptorForTypedMap(values, eventType);
return new SingleEventIterator(event);
}
}