/**************************************************************************************
* 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.expression;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.view.window.RandomAccessByIndex;
import com.espertech.esper.view.window.RandomAccessByIndexGetter;
import com.espertech.esper.view.window.RelativeAccessByEventNIndex;
import com.espertech.esper.view.window.RelativeAccessByEventNIndexMap;
import java.lang.reflect.Array;
import java.util.*;
public class ExprPreviousEvalStrategyWindow implements ExprPreviousEvalStrategy
{
private final int streamNumber;
private final ExprEvaluator evalNode;
private final Class componentType;
private final RandomAccessByIndexGetter randomAccessGetter;
private final RelativeAccessByEventNIndexMap relativeAccessGetter;
public ExprPreviousEvalStrategyWindow(int streamNumber, ExprEvaluator evalNode, Class componentType, RandomAccessByIndexGetter randomAccessGetter, RelativeAccessByEventNIndexMap relativeAccessGetter)
{
this.streamNumber = streamNumber;
this.evalNode = evalNode;
this.componentType = componentType;
this.randomAccessGetter = randomAccessGetter;
this.relativeAccessGetter = relativeAccessGetter;
}
public Object evaluate(EventBean[] eventsPerStream, ExprEvaluatorContext exprEvaluatorContext)
{
Iterator<EventBean> events;
int size;
if (randomAccessGetter != null)
{
RandomAccessByIndex randomAccess = randomAccessGetter.getAccessor();
events = randomAccess.getWindowIterator();
size = (int) randomAccess.getWindowCount();
}
else
{
EventBean evalEvent = eventsPerStream[streamNumber];
RelativeAccessByEventNIndex relativeAccess = relativeAccessGetter.getAccessor(evalEvent);
size = relativeAccess.getWindowToEventCount(evalEvent);
events = relativeAccess.getWindowToEvent(evalEvent);
}
if (size <= 0) {
return null;
}
EventBean originalEvent = eventsPerStream[streamNumber];
Object[] result = (Object[]) Array.newInstance(componentType, size);
for (int i = 0; i < size; i++) {
eventsPerStream[streamNumber] = events.next();
Object evalResult = evalNode.evaluate(eventsPerStream, true, exprEvaluatorContext);
result[i] = evalResult;
}
eventsPerStream[streamNumber] = originalEvent;
return result;
}
public Collection<EventBean> evaluateGetCollEvents(EventBean[] eventsPerStream, ExprEvaluatorContext context) {
Collection<EventBean> events;
if (randomAccessGetter != null)
{
RandomAccessByIndex randomAccess = randomAccessGetter.getAccessor();
events = randomAccess.getWindowCollectionReadOnly();
}
else
{
EventBean evalEvent = eventsPerStream[streamNumber];
RelativeAccessByEventNIndex relativeAccess = relativeAccessGetter.getAccessor(evalEvent);
events = relativeAccess.getWindowToEventCollReadOnly(evalEvent);
}
return events;
}
public Collection evaluateGetCollScalar(EventBean[] eventsPerStream, ExprEvaluatorContext context) {
Iterator<EventBean> events;
int size;
if (randomAccessGetter != null)
{
RandomAccessByIndex randomAccess = randomAccessGetter.getAccessor();
events = randomAccess.getWindowIterator();
size = (int) randomAccess.getWindowCount();
}
else
{
EventBean evalEvent = eventsPerStream[streamNumber];
RelativeAccessByEventNIndex relativeAccess = relativeAccessGetter.getAccessor(evalEvent);
size = relativeAccess.getWindowToEventCount(evalEvent);
events = relativeAccess.getWindowToEvent(evalEvent);
}
if (size <= 0) {
return Collections.emptyList();
}
EventBean originalEvent = eventsPerStream[streamNumber];
Deque deque = new ArrayDeque(size);
for (int i = 0; i < size; i++) {
eventsPerStream[streamNumber] = events.next();
Object evalResult = evalNode.evaluate(eventsPerStream, true, context);
deque.add(evalResult);
}
eventsPerStream[streamNumber] = originalEvent;
return deque;
}
public EventBean evaluateGetEventBean(EventBean[] eventsPerStream, ExprEvaluatorContext context) {
return null;
}
}