com.espertech.esper.epl.lookup.SubordIndexedTableLookupStrategyExprNW Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of esper Show documentation
Complex event processing and event series analysis component
There is a newer version: 7.1.0
/**************************************************************************************
 * Copyright (C) 2006-2015 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.expression.core.ExprNodeUtility;
import com.espertech.esper.epl.join.table.PropertyIndexedEventTable;
import com.espertech.esper.metrics.instrumentation.InstrumentationHelper;

import java.util.Collection;
import java.util.Set;

/**
 * Index lookup strategy for subqueries.
 */
public class SubordIndexedTableLookupStrategyExprNW implements SubordTableLookupStrategy
{
    /**
     * Index to look up in.
     */
    protected final PropertyIndexedEventTable index;

    protected final ExprEvaluator[] evaluators;

    protected final LookupStrategyDesc strategyDesc;

    /**
     * Ctor.
     * @param index is the table carrying the data to lookup into
     */
    public SubordIndexedTableLookupStrategyExprNW(ExprEvaluator[] evaluators, PropertyIndexedEventTable index, LookupStrategyDesc strategyDesc)
    {
        this.evaluators = evaluators;
        this.index = index;
        this.strategyDesc = strategyDesc;
    }

    /**
     * Returns index to look up in.
     * @return index to use
     */
    public PropertyIndexedEventTable getIndex()
    {
        return index;
    }

    public Collection lookup(EventBean[] eventsPerStream, ExprEvaluatorContext context)
    {
        if (InstrumentationHelper.ENABLED) { InstrumentationHelper.get().qIndexSubordLookup(this, index, null);}

        Object[] keys = getKeys(eventsPerStream, context);

        if (InstrumentationHelper.ENABLED) {
            Set result = index.lookup(keys);
            InstrumentationHelper.get().aIndexSubordLookup(result, keys);
            return result;
        }
        return index.lookup(keys);
    }

    /**
     * Get the index lookup keys.
     * @param eventsPerStream is the events for each stream
     * @return key object
     */
    protected Object[] getKeys(EventBean[] eventsPerStream, ExprEvaluatorContext context)
    {
        Object[] keyValues = new Object[evaluators.length];
        for (int i = 0; i < evaluators.length; i++)
        {
            keyValues[i] = evaluators[i].evaluate(eventsPerStream, true, context);
        }
        return keyValues;
    }

    public LookupStrategyDesc getStrategyDesc() {
        return strategyDesc;
    }

    public String toQueryPlan() {
        return this.getClass().getSimpleName() + " evaluators " + ExprNodeUtility.printEvaluators(evaluators);
    }
}