/*
***************************************************************************************
* 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.lookup;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.epl.expression.core.ExprEvaluator;
import com.espertech.esper.epl.expression.core.ExprEvaluatorContext;
import com.espertech.esper.epl.join.table.PropertyIndexedEventTableSingle;
import com.espertech.esper.metrics.instrumentation.InstrumentationHelper;
import java.util.Collection;
import java.util.Set;
/**
* Index lookup strategy for subqueries.
*/
public class SubordIndexedTableLookupStrategySingleExprNW implements SubordTableLookupStrategy {
/**
* Stream numbers to get key values from.
*/
protected final ExprEvaluator evaluator;
/**
* Index to look up in.
*/
protected final PropertyIndexedEventTableSingle index;
protected final LookupStrategyDesc strategyDesc;
public SubordIndexedTableLookupStrategySingleExprNW(ExprEvaluator evaluator, PropertyIndexedEventTableSingle index, LookupStrategyDesc strategyDesc) {
this.evaluator = evaluator;
this.index = index;
this.strategyDesc = strategyDesc;
}
/**
* Returns index to look up in.
*
* @return index to use
*/
public PropertyIndexedEventTableSingle getIndex() {
return index;
}
public Collection<EventBean> lookup(EventBean[] eventsPerStream, ExprEvaluatorContext context) {
if (InstrumentationHelper.ENABLED) {
InstrumentationHelper.get().qIndexSubordLookup(this, index, null);
}
Object key = getKey(eventsPerStream, context);
if (InstrumentationHelper.ENABLED) {
Set<EventBean> result = index.lookup(key);
InstrumentationHelper.get().aIndexSubordLookup(result, key);
return result;
}
return index.lookup(key);
}
/**
* Get the index lookup keys.
*
* @param eventsPerStream is the events for each stream
* @param context context
* @return key object
*/
protected Object getKey(EventBean[] eventsPerStream, ExprEvaluatorContext context) {
return evaluator.evaluate(eventsPerStream, true, context);
}
public LookupStrategyDesc getStrategyDesc() {
return strategyDesc;
}
public String toQueryPlan() {
return this.getClass().getSimpleName() + " evaluator " + evaluator.getClass().getSimpleName();
}
}