/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* 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.property;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.client.FragmentEventType;
import com.espertech.esper.epl.expression.core.ExprEvaluator;
import com.espertech.esper.epl.expression.core.ExprEvaluatorContext;
import com.espertech.esper.epl.expression.core.ExprNodeUtility;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Property evaluator that considers only level one and considers a where-clause,
* but does not consider a select clause or N-level.
*/
public class PropertyEvaluatorSimple implements PropertyEvaluator {
private static final Logger log = LoggerFactory.getLogger(PropertyEvaluatorSimple.class);
private final ContainedEventEval containedEventEval;
private final FragmentEventType fragmentEventType;
private final ExprEvaluator filter;
private final String expressionText;
/**
* Ctor.
*
* @param containedEventEval property getter or other evaluator
* @param fragmentEventType property event type
* @param filter optional where-clause expression
* @param expressionText the property name
*/
public PropertyEvaluatorSimple(ContainedEventEval containedEventEval, FragmentEventType fragmentEventType, ExprEvaluator filter, String expressionText) {
this.fragmentEventType = fragmentEventType;
this.containedEventEval = containedEventEval;
this.filter = filter;
this.expressionText = expressionText;
}
public EventBean[] getProperty(EventBean theEvent, ExprEvaluatorContext exprEvaluatorContext) {
try {
Object result = containedEventEval.getFragment(theEvent, new EventBean[]{theEvent}, exprEvaluatorContext);
EventBean[] rows;
if (fragmentEventType.isIndexed()) {
rows = (EventBean[]) result;
} else {
rows = new EventBean[]{(EventBean) result};
}
if (filter == null) {
return rows;
}
return ExprNodeUtility.applyFilterExpression(filter, theEvent, (EventBean[]) result, exprEvaluatorContext);
} catch (RuntimeException ex) {
log.error("Unexpected error evaluating property expression for event of type '" +
theEvent.getEventType().getName() +
"' and property '" +
expressionText + "': " + ex.getMessage(), ex);
}
return null;
}
public EventType getFragmentEventType() {
return fragmentEventType.getFragmentType();
}
/**
* Returns the property name.
*
* @return property name
*/
public String getExpressionText() {
return expressionText;
}
/**
* Returns the filter.
*
* @return filter
*/
public ExprEvaluator getFilter() {
return filter;
}
public boolean compareTo(PropertyEvaluator otherEval) {
if (!(otherEval instanceof PropertyEvaluatorSimple)) {
return false;
}
PropertyEvaluatorSimple other = (PropertyEvaluatorSimple) otherEval;
if (!other.getExpressionText().equals(this.getExpressionText())) {
return false;
}
if ((other.getFilter() == null) && (this.getFilter() == null)) {
return true;
}
return false;
}
}