/**************************************************************************************
* 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.core.start;
import com.espertech.esper.client.EventType;
import com.espertech.esper.core.service.EPServicesContext;
import com.espertech.esper.core.service.StatementContext;
import com.espertech.esper.epl.expression.ExprValidationException;
import com.espertech.esper.epl.spec.StatementSpecCompiled;
import com.espertech.esper.view.ViewProcessingException;
import com.espertech.esper.view.ZeroDepthStreamNoIterate;
import java.util.Collections;
/**
* Starts and provides the stop method for EPL statements.
*/
public class EPStatementStartMethodCreateExpression extends EPStatementStartMethodBase
{
public EPStatementStartMethodCreateExpression(StatementSpecCompiled statementSpec) {
super(statementSpec);
}
public EPStatementStartResult startInternal(final EPServicesContext services, StatementContext statementContext, boolean isNewStatement, boolean isRecoveringStatement, boolean isRecoveringResilient) throws ExprValidationException, ViewProcessingException {
String expressionName = services.getExprDeclaredService().addExpressionOrScript(statementSpec.getCreateExpressionDesc());
// define output event type
String typeName = "EventType_Expression_" + expressionName;
EventType resultType = services.getEventAdapterService().createAnonymousMapType(typeName, Collections.<String, Object>emptyMap());
EPStatementStopMethod stopMethod = new EPStatementStopMethod() {
public void stop() {
// no action
}
};
EPStatementDestroyMethod destroyMethod = new EPStatementDestroyMethod() {
public void destroy() {
services.getExprDeclaredService().destroyedExpression(statementSpec.getCreateExpressionDesc());
}
};
return new EPStatementStartResult(new ZeroDepthStreamNoIterate(resultType), stopMethod, destroyMethod);
}
}