ResultSetProcessorRowPerGroupSpecial.java

/**************************************************************************************
 * 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.epl.core;

import com.espertech.esper.client.EventBean;
import com.espertech.esper.collection.UniformPair;
import com.espertech.esper.core.context.util.AgentInstanceContext;
import com.espertech.esper.epl.agg.service.AggregationRowRemovedCallback;
import com.espertech.esper.epl.agg.service.AggregationService;
import com.espertech.esper.view.Viewable;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;

public class ResultSetProcessorRowPerGroupSpecial extends ResultSetProcessorRowPerGroup implements AggregationRowRemovedCallback {
    private static final Log log = LogFactory.getLog(ResultSetProcessorRowPerGroupSpecial.class);

    protected final Map<Object, EventBean> groupReps = new LinkedHashMap<Object, EventBean>();

    public ResultSetProcessorRowPerGroupSpecial(ResultSetProcessorRowPerGroupFactory prototype, SelectExprProcessor selectExprProcessor, OrderByProcessor orderByProcessor, AggregationService aggregationService, AgentInstanceContext agentInstanceContext) {
        super(prototype, selectExprProcessor, orderByProcessor, aggregationService, agentInstanceContext);

        aggregationService.setRemovedCallback(this);
    }

    @Override
    public UniformPair<EventBean[]> processViewResult(EventBean[] newData, EventBean[] oldData, boolean isSynthesize)
    {
        // Generate group-by keys for all events, collect all keys in a set for later event generation
        Map<Object, EventBean> keysAndEvents = new HashMap<Object, EventBean>();
        Object[] newDataMultiKey = generateGroupKeys(newData, keysAndEvents, true);
        Object[] oldDataMultiKey = generateGroupKeys(oldData, keysAndEvents, false);

        EventBean[] selectOldEvents = null;
        if (prototype.isSelectRStream())
        {
            selectOldEvents = generateOutputEventsView(keysAndEvents, false, isSynthesize);
        }

        // update aggregates
        EventBean[] eventsPerStream = new EventBean[1];
        if (newData != null)
        {
            // apply new data to aggregates
            for (int i = 0; i < newData.length; i++)
            {
                eventsPerStream[0] = newData[i];
                groupReps.put(newDataMultiKey[i], eventsPerStream[0]);
                aggregationService.applyEnter(eventsPerStream, newDataMultiKey[i], agentInstanceContext);
            }
        }
        if (oldData != null)
        {
            // apply old data to aggregates
            for (int i = 0; i < oldData.length; i++)
            {
                eventsPerStream[0] = oldData[i];
                aggregationService.applyLeave(eventsPerStream, oldDataMultiKey[i], agentInstanceContext);
            }
        }

        // generate new events using select expressions
        EventBean[] selectNewEvents = generateOutputEventsView(keysAndEvents, true, isSynthesize);

        if ((selectNewEvents != null) || (selectOldEvents != null))
        {
            return new UniformPair<EventBean[]>(selectNewEvents, selectOldEvents);
        }
        return null;
    }

    @Override
    public Iterator<EventBean> getIterator(Viewable parent) {
        if (orderByProcessor == null)
        {
            Iterator<EventBean> it = groupReps.values().iterator();
            return new ResultSetRowPerGroupIterator(it, this, aggregationService, agentInstanceContext);
        }
        return getIteratorSorted(groupReps.values().iterator());
    }


    public void removed(Object optionalGroupKeyPerRow) {
        groupReps.remove(optionalGroupKeyPerRow);
    }
}