/**************************************************************************************
* 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.window;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.core.context.util.AgentInstanceViewFactoryChainContext;
import com.espertech.esper.core.service.EPStatementHandleCallback;
import com.espertech.esper.core.service.ExtensionServicesContext;
import com.espertech.esper.epl.expression.ExprTimePeriodEvalDeltaConst;
import com.espertech.esper.epl.expression.ExprTimePeriodEvalDeltaResult;
import com.espertech.esper.metrics.instrumentation.InstrumentationHelper;
import com.espertech.esper.schedule.ScheduleHandleCallback;
import com.espertech.esper.schedule.ScheduleSlot;
import com.espertech.esper.util.StopCallback;
import com.espertech.esper.view.*;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.Iterator;
import java.util.LinkedHashSet;
/**
* Same as the {@link TimeBatchView}, this view also supports fast-remove from the batch for remove stream events.
*/
public class TimeBatchViewRStream extends ViewSupport implements CloneableView, StoppableView, StopCallback, DataWindowView {
// View parameters
private final TimeBatchViewFactory timeBatchViewFactory;
protected final AgentInstanceViewFactoryChainContext agentInstanceContext;
protected final ExprTimePeriodEvalDeltaConst timeDeltaComputation;
private final Long initialReferencePoint;
protected final ScheduleSlot scheduleSlot;
private final boolean isForceOutput;
private final boolean isStartEager;
protected EPStatementHandleCallback handle;
// Current running parameters
protected Long currentReferencePoint;
protected LinkedHashSet<EventBean> lastBatch = null;
protected LinkedHashSet<EventBean> currentBatch = new LinkedHashSet<EventBean>();
protected boolean isCallbackScheduled;
/**
* Constructor.
* @param timeDeltaComputation is the number of milliseconds to batch events for
* @param referencePoint is the reference point onto which to base intervals, or null if
* there is no such reference point supplied
* @param timeBatchViewFactory fr copying this view in a group-by
* @param forceOutput is true if the batch should produce empty output if there is no value to output following time intervals
* @param isStartEager is true for start-eager
*/
public TimeBatchViewRStream(TimeBatchViewFactory timeBatchViewFactory,
AgentInstanceViewFactoryChainContext agentInstanceContext,
ExprTimePeriodEvalDeltaConst timeDeltaComputation,
Long referencePoint,
boolean forceOutput,
boolean isStartEager)
{
this.agentInstanceContext = agentInstanceContext;
this.timeBatchViewFactory = timeBatchViewFactory;
this.timeDeltaComputation = timeDeltaComputation;
this.initialReferencePoint = referencePoint;
this.isStartEager = isStartEager;
this.isForceOutput = forceOutput;
this.scheduleSlot = agentInstanceContext.getStatementContext().getScheduleBucket().allocateSlot();
// schedule the first callback
if (this.isStartEager)
{
currentReferencePoint = agentInstanceContext.getStatementContext().getSchedulingService().getTime();
scheduleCallback();
isCallbackScheduled = true;
}
agentInstanceContext.addTerminationCallback(this);
}
public View cloneView()
{
return timeBatchViewFactory.makeView(agentInstanceContext);
}
public ExprTimePeriodEvalDeltaConst getTimeDeltaComputation() {
return timeDeltaComputation;
}
/**
* Gets the reference point to use to anchor interval start and end dates to.
* @return is the millisecond reference point.
*/
public final Long getInitialReferencePoint()
{
return initialReferencePoint;
}
/**
* True for force-output.
* @return indicates force-output
*/
public boolean isForceOutput()
{
return isForceOutput;
}
/**
* True for start-eager.
* @return indicates start-eager
*/
public boolean isStartEager()
{
return isStartEager;
}
public final EventType getEventType()
{
return parent.getEventType();
}
public void update(EventBean[] newData, EventBean[] oldData)
{
if (InstrumentationHelper.ENABLED) { InstrumentationHelper.get().qViewProcessIRStream(this, timeBatchViewFactory.getViewName(), newData, oldData);}
if (oldData != null)
{
for (int i = 0; i < oldData.length; i++)
{
currentBatch.remove(oldData[i]);
internalHandleRemoved(oldData[i]);
}
}
// we don't care about removed data from a prior view
if ((newData == null) || (newData.length == 0))
{
if (InstrumentationHelper.ENABLED) { InstrumentationHelper.get().aViewProcessIRStream();}
return;
}
// If we have an empty window about to be filled for the first time, schedule a callback
if (currentBatch.isEmpty())
{
if (currentReferencePoint == null)
{
currentReferencePoint = initialReferencePoint;
if (currentReferencePoint == null)
{
currentReferencePoint = agentInstanceContext.getStatementContext().getSchedulingService().getTime();
}
}
// Schedule the next callback if there is none currently scheduled
if (!isCallbackScheduled)
{
scheduleCallback();
isCallbackScheduled = true;
}
}
// add data points to the timeWindow
for (EventBean newEvent : newData) {
currentBatch.add(newEvent);
}
// We do not update child views, since we batch the events.
if (InstrumentationHelper.ENABLED) { InstrumentationHelper.get().aViewProcessIRStream();}
}
/**
* This method updates child views and clears the batch of events.
* We schedule a new callback at this time if there were events in the batch.
*/
protected void sendBatch()
{
isCallbackScheduled = false;
// If there are child views and the batch was filled, fireStatementStopped update method
if (this.hasViews())
{
// Convert to object arrays
EventBean[] newData = null;
EventBean[] oldData = null;
if (!currentBatch.isEmpty())
{
newData = currentBatch.toArray(new EventBean[currentBatch.size()]);
}
if ((lastBatch != null) && (!lastBatch.isEmpty()))
{
oldData = lastBatch.toArray(new EventBean[lastBatch.size()]);
}
if ((newData != null) || (oldData != null) || (isForceOutput))
{
if (InstrumentationHelper.ENABLED) { InstrumentationHelper.get().qViewIndicate(this, timeBatchViewFactory.getViewName(), newData, oldData);}
updateChildren(newData, oldData);
if (InstrumentationHelper.ENABLED) { InstrumentationHelper.get().aViewIndicate();}
}
}
// Only if forceOutput is enabled or
// there have been any events in this or the last interval do we schedule a callback,
// such as to not waste resources when no events arrive.
if ((!currentBatch.isEmpty()) || ((lastBatch != null) && (!lastBatch.isEmpty()))
||
(isForceOutput))
{
scheduleCallback();
isCallbackScheduled = true;
}
lastBatch = currentBatch;
currentBatch = new LinkedHashSet<EventBean>();
}
/**
* Returns true if the window is empty, or false if not empty.
* @return true if empty
*/
public boolean isEmpty()
{
if (lastBatch != null)
{
if (!lastBatch.isEmpty())
{
return false;
}
}
return currentBatch.isEmpty();
}
public final Iterator<EventBean> iterator()
{
return currentBatch.iterator();
}
public final String toString()
{
return this.getClass().getName() +
" initialReferencePoint=" + initialReferencePoint;
}
protected void scheduleCallback()
{
long current = agentInstanceContext.getStatementContext().getSchedulingService().getTime();
ExprTimePeriodEvalDeltaResult deltaWReference = timeDeltaComputation.deltaMillisecondsAddWReference(current, currentReferencePoint);
long afterMSec = deltaWReference.getDelta();
currentReferencePoint = deltaWReference.getLastReference();
ScheduleHandleCallback callback = new ScheduleHandleCallback() {
public void scheduledTrigger(ExtensionServicesContext extensionServicesContext)
{
if (InstrumentationHelper.ENABLED) { InstrumentationHelper.get().qViewScheduledEval(TimeBatchViewRStream.this, timeBatchViewFactory.getViewName());}
TimeBatchViewRStream.this.sendBatch();
if (InstrumentationHelper.ENABLED) { InstrumentationHelper.get().aViewScheduledEval();}
}
};
handle = new EPStatementHandleCallback(agentInstanceContext.getEpStatementAgentInstanceHandle(), callback);
agentInstanceContext.getStatementContext().getSchedulingService().add(afterMSec, handle, scheduleSlot);
}
public void stopView() {
stopSchedule();
agentInstanceContext.removeTerminationCallback(this);
}
public void stop() {
stopSchedule();
}
public void stopSchedule() {
if (handle != null) {
agentInstanceContext.getStatementContext().getSchedulingService().remove(handle, scheduleSlot);
}
}
public void internalHandleRemoved(EventBean eventBean) {
// no action required
}
public void visitView(ViewDataVisitor viewDataVisitor) {
viewDataVisitor.visitPrimary(currentBatch, true, timeBatchViewFactory.getViewName(), null);
viewDataVisitor.visitPrimary(lastBatch, true, timeBatchViewFactory.getViewName(), null);
}
private static final Log log = LogFactory.getLog(TimeBatchViewRStream.class);
}