package com.espertech.esper.epl.property;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventPropertyGetter;
import com.espertech.esper.client.FragmentEventType;
import com.espertech.esper.epl.expression.ExprEvaluator;
import com.espertech.esper.epl.expression.ExprEvaluatorContext;
import com.espertech.esper.epl.expression.ExprNodeUtility;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.ArrayDeque;
import java.util.Collection;
import java.util.List;
/**
* A property evaluator that returns a full row of events for each stream, i.e. flattened inner-join results for
* property-upon-property.
*/
public class PropertyEvaluatorAccumulative
{
private static final Log log = LogFactory.getLog(PropertyEvaluatorAccumulative.class);
private final EventPropertyGetter[] getter;
private final FragmentEventType[] fragmentEventType;
private final ExprEvaluator[] whereClauses;
private final EventBean[] eventsPerStream;
private final int lastLevel;
private final int levels;
private final List<String> propertyNames;
/**
* Ctor.
* @param getter property getters
* @param fragmentEventType property fragment types
* @param whereClauses filters, if any
* @param propertyNames the property names that are staggered
*/
public PropertyEvaluatorAccumulative(EventPropertyGetter[] getter, FragmentEventType[] fragmentEventType, ExprEvaluator[] whereClauses, List<String> propertyNames)
{
this.fragmentEventType = fragmentEventType;
this.getter = getter;
this.whereClauses = whereClauses;
lastLevel = fragmentEventType.length - 1;
levels = fragmentEventType.length + 1;
eventsPerStream = new EventBean[levels];
this.propertyNames = propertyNames;
}
/**
* Returns the accumulative events for the input event.
* @param event is the input event
* @param exprEvaluatorContext expression evaluation context
* @return events per stream for each row
*/
public ArrayDeque<EventBean[]> getAccumulative(EventBean event, ExprEvaluatorContext exprEvaluatorContext)
{
ArrayDeque<EventBean[]> resultEvents = new ArrayDeque<EventBean[]>();
eventsPerStream[0] = event;
populateEvents(event, 0, resultEvents, exprEvaluatorContext);
if (resultEvents.isEmpty())
{
return null;
}
return resultEvents;
}
private void populateEvents(EventBean branch, int level, Collection<EventBean[]> events, ExprEvaluatorContext exprEvaluatorContext)
{
try
{
Object result = getter[level].getFragment(branch);
if (fragmentEventType[level].isIndexed())
{
EventBean[] fragments = (EventBean[]) result;
if (level == lastLevel)
{
if (whereClauses[level] != null)
{
for (EventBean event : fragments)
{
eventsPerStream[level+1] = event;
if (ExprNodeUtility.applyFilterExpression(whereClauses[level], eventsPerStream, exprEvaluatorContext))
{
EventBean[] eventsPerRow = new EventBean[levels];
System.arraycopy(eventsPerStream, 0, eventsPerRow, 0, levels);
events.add(eventsPerRow);
}
}
}
else
{
for (EventBean event : fragments)
{
eventsPerStream[level+1] = event;
EventBean[] eventsPerRow = new EventBean[levels];
System.arraycopy(eventsPerStream, 0, eventsPerRow, 0, levels);
events.add(eventsPerRow);
}
}
}
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))
{
EventBean[] eventsPerRow = new EventBean[levels];
System.arraycopy(eventsPerStream, 0, eventsPerRow, 0, levels);
events.add(eventsPerRow);
}
}
else
{
eventsPerStream[level+1] = fragment;
EventBean[] eventsPerRow = new EventBean[levels];
System.arraycopy(eventsPerStream, 0, eventsPerRow, 0, levels);
events.add(eventsPerRow);
}
}
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 '" +
propertyNames.get(level + 1) + "': " + ex.getMessage(), ex);
}
}
}