/*
***************************************************************************************
* 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;
import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
/**
* A property evaluator that considers nested properties and that considers where-clauses
* but does not consider select-clauses.
*/
public class PropertyEvaluatorNested implements PropertyEvaluator {
private static final Logger log = LoggerFactory.getLogger(PropertyEvaluatorNested.class);
private final ContainedEventEval[] containedEventEvals;
private final FragmentEventType[] fragmentEventType;
private final ExprEvaluator[] whereClauses;
private final EventBean[] eventsPerStream;
private final int lastLevel;
private final List<String> expressionTexts;
/**
* Ctor.
*
* @param containedEventEvals property getters or other evaluators
* @param fragmentEventType the fragments
* @param whereClauses the where clauses
* @param expressionTexts the property names that are staggered
*/
public PropertyEvaluatorNested(ContainedEventEval[] containedEventEvals, FragmentEventType[] fragmentEventType, ExprEvaluator[] whereClauses, List<String> expressionTexts) {
this.fragmentEventType = fragmentEventType;
this.containedEventEvals = containedEventEvals;
this.whereClauses = whereClauses;
lastLevel = fragmentEventType.length - 1;
eventsPerStream = new EventBean[fragmentEventType.length + 1];
this.expressionTexts = expressionTexts;
}
public EventBean[] getProperty(EventBean theEvent, ExprEvaluatorContext exprEvaluatorContext) {
ArrayDeque<EventBean> resultEvents = new ArrayDeque<EventBean>();
eventsPerStream[0] = theEvent;
populateEvents(theEvent, 0, resultEvents, exprEvaluatorContext);
if (resultEvents.isEmpty()) {
return null;
}
return resultEvents.toArray(new EventBean[resultEvents.size()]);
}
private void populateEvents(EventBean branch, int level, Collection<EventBean> events, ExprEvaluatorContext exprEvaluatorContext) {
try {
Object result = containedEventEvals[level].getFragment(branch, eventsPerStream, exprEvaluatorContext);
if (fragmentEventType[level].isIndexed()) {
EventBean[] fragments = (EventBean[]) result;
if (level == lastLevel) {
if (whereClauses[level] != null) {
for (EventBean theEvent : fragments) {
eventsPerStream[level + 1] = theEvent;
if (ExprNodeUtility.applyFilterExpression(whereClauses[level], eventsPerStream, exprEvaluatorContext)) {
events.add(theEvent);
}
}
} else {
events.addAll(Arrays.asList(fragments));
}
} else {
if (whereClauses[level] != null) {
for (EventBean next : fragments) {
eventsPerStream[level + 1] = next;
if (ExprNodeUtility.applyFilterExpression(whereClauses[level], eventsPerStream, exprEvaluatorContext)) {
populateEvents(next, level + 1, events, exprEvaluatorContext);
}
}
} else {
for (EventBean next : fragments) {
eventsPerStream[level + 1] = next;
populateEvents(next, level + 1, events, exprEvaluatorContext);
}
}
}
} else {
EventBean fragment = (EventBean) result;
if (level == lastLevel) {
if (whereClauses[level] != null) {
eventsPerStream[level + 1] = fragment;
if (ExprNodeUtility.applyFilterExpression(whereClauses[level], eventsPerStream, exprEvaluatorContext)) {
events.add(fragment);
}
} else {
events.add(fragment);
}
} else {
if (whereClauses[level] != null) {
eventsPerStream[level + 1] = fragment;
if (ExprNodeUtility.applyFilterExpression(whereClauses[level], eventsPerStream, exprEvaluatorContext)) {
populateEvents(fragment, level + 1, events, exprEvaluatorContext);
}
} else {
eventsPerStream[level + 1] = fragment;
populateEvents(fragment, level + 1, events, exprEvaluatorContext);
}
}
}
} catch (RuntimeException ex) {
log.error("Unexpected error evaluating property expression for event of type '" +
branch.getEventType().getName() +
"' and property '" +
expressionTexts.get(level + 1) + "': " + ex.getMessage(), ex);
}
}
public EventType getFragmentEventType() {
return fragmentEventType[lastLevel].getFragmentType();
}
public boolean compareTo(PropertyEvaluator otherEval) {
return false;
}
}