/**************************************************************************************
* 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.view.std;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.collection.SingleEventIterator;
import com.espertech.esper.core.StatementContext;
import com.espertech.esper.view.CloneableView;
import com.espertech.esper.view.View;
import com.espertech.esper.view.ViewFieldEnum;
import com.espertech.esper.view.ViewSupport;
import com.espertech.esper.view.stat.StatViewAdditionalProps;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
/**
* This view is a very simple view presenting the number of elements in a stream or view.
* The view computes a single long-typed count of the number of events passed through it similar
* to the base statistics COUNT column.
*/
public final class SizeView extends ViewSupport implements CloneableView
{
private final StatementContext statementContext;
private final EventType eventType;
private final StatViewAdditionalProps additionalProps;
private long size = 0;
private EventBean lastSizeEvent;
private Object[] lastValuesEventNew;
/**
* Ctor.
* @param statementContext is services
*/
public SizeView(StatementContext statementContext, EventType eventType, StatViewAdditionalProps additionalProps)
{
this.statementContext = statementContext;
this.eventType = eventType;
this.additionalProps = additionalProps;
}
public View cloneView(StatementContext statementContext)
{
return new SizeView(statementContext, eventType, additionalProps);
}
public final EventType getEventType()
{
return eventType;
}
public final void update(EventBean[] newData, EventBean[] oldData)
{
long priorSize = size;
// add data points to the window
if (newData != null)
{
size += newData.length;
if ((additionalProps != null) && (newData.length != 0)) {
if (lastValuesEventNew == null) {
lastValuesEventNew = new Object[additionalProps.getAdditionalExpr().length];
}
for (int val = 0; val < additionalProps.getAdditionalExpr().length; val++) {
lastValuesEventNew[val] = additionalProps.getAdditionalExpr()[val].evaluate(new EventBean[] {newData[newData.length - 1]}, true, statementContext);
}
}
}
if (oldData != null)
{
size -= oldData.length;
}
// If there are child views, fireStatementStopped update method
if ((this.hasViews()) && (priorSize != size))
{
Map<String, Object> postNewData = new HashMap<String, Object>();
postNewData.put(ViewFieldEnum.SIZE_VIEW__SIZE.getName(), size);
addProperties(postNewData);
EventBean newEvent = statementContext.getEventAdapterService().adaptorForTypedMap(postNewData, eventType);
if (lastSizeEvent != null)
{
updateChildren(new EventBean[] {newEvent}, new EventBean[] {lastSizeEvent});
}
else
{
Map<String, Object> postOldData = new HashMap<String, Object>();
postOldData.put(ViewFieldEnum.SIZE_VIEW__SIZE.getName(), priorSize);
EventBean oldEvent = statementContext.getEventAdapterService().adaptorForTypedMap(postOldData, eventType);
updateChildren(new EventBean[] {newEvent}, new EventBean[] {oldEvent});
}
lastSizeEvent = newEvent;
}
}
public final Iterator<EventBean> iterator()
{
HashMap<String, Object> current = new HashMap<String, Object>();
current.put(ViewFieldEnum.SIZE_VIEW__SIZE.getName(), size);
addProperties(current);
return new SingleEventIterator(statementContext.getEventAdapterService().adaptorForTypedMap(current, eventType));
}
public final String toString()
{
return this.getClass().getName();
}
/**
* Creates the event type for this view
* @param statementContext is the event adapter service
* @return event type for view
*/
public static EventType createEventType(StatementContext statementContext, StatViewAdditionalProps additionalProps)
{
Map<String, Object> schemaMap = new HashMap<String, Object>();
schemaMap.put(ViewFieldEnum.SIZE_VIEW__SIZE.getName(), long.class);
StatViewAdditionalProps.addCheckDupProperties(schemaMap, additionalProps, ViewFieldEnum.SIZE_VIEW__SIZE);
return statementContext.getEventAdapterService().createAnonymousMapType(schemaMap);
}
private void addProperties(Map<String, Object> newDataMap)
{
if (additionalProps == null) {
return;
}
additionalProps.addProperties(newDataMap, lastValuesEventNew);
}
}