aggregationaverage.java

High performance DB query

/*
 * @(#)$Id: AggregationAverage.java,v 1.9 2005/04/13 20:17:44 huebsch Exp $
 *
 * Copyright (c) 2001-2004 Regents of the University of California.
 * All rights reserved.
 *
 * This file is distributed under the terms in the attached BERKELEY-LICENSE
 * file. If you do not find these files, copies can be found by writing to:
 * Computer Science Division, Database Group, Universite of California,
 * 617 Soda Hall #1776, Berkeley, CA 94720-1776. Attention: Berkeley License
 *
 * Copyright (c) 2003-2004 Intel Corporation. All rights reserved.
 *
 * This file is distributed under the terms in the attached INTEL-LICENSE file.
 * If you do not find these files, copies can be found by writing to:
 * Intel Research Berkeley, 2150 Shattuck Avenue, Suite 1300,
 * Berkeley, CA, 94704.  Attention:  Intel License Inquiry.
 */


package pier.helpers.aggregation;

import pier.data.DataTypes;
import services.network.Payload;
import util.network.serialization.GenericByteBuffer;
import util.network.serialization.SerializationManager;

/**
 * Class AggregationAverage
 *
 */
public class AggregationAverage implements AggregationOperator {

    public static long serialVersionUID =
        SerializationManager.getSerialUID(
            "pier.helpers.aggregation.AggregationAverage");
    private long count;
    private Object sum;

    /**
     * DeSerialize the object from the provided GenericByteBuffer.
     *
     * @param inputBuffer
     */

    /**
     * Constructor AggregationAverage
     *
     * @param inputBuffer
     */
    public AggregationAverage(GenericByteBuffer inputBuffer) {
        this.count = inputBuffer.getLong();
        this.sum = SerializationManager.deSerializeExtended(inputBuffer);
    }

    /**
     * Serialize the object into the provided GenericByteBuffer.
     *
     * @param outputBuffer
     * @return
     */

    /**
     * Method serialize
     *
     * @param outputBuffer
     * @return
     */
    public long serialize(
            util.network.serialization.GenericByteBuffer outputBuffer) {
        outputBuffer.putLong(count);
        SerializationManager.serializeExtended(outputBuffer, sum);

        return serialVersionUID;
    }

    /**
     * Constructor AggregationAverage
     */
    public AggregationAverage() {
        count = 0;
        sum = null;
    }

    /**
     * Method addBaseValue
     *
     * @param data
     * @return
     */
    public boolean addBaseValue(Object data) {
        count++;

        if (sum == null) {
            sum = DataTypes.getClone(data);
        } else {
            sum = DataTypes.add(sum, data);
        }

        return true;
    }

    /**
     * Method addPartialResult
     *
     * @param data
     * @return
     */
    public boolean addPartialResult(AggregationOperator data) {
        count += ((AggregationAverage) data).count;

        if (sum == null) {
            sum = ((AggregationAverage) data).sum;
        } else {
            sum = DataTypes.add(sum, ((AggregationAverage) data).sum);
        }

        return true;
    }

    /**
     * Method result
     * @return
     */
    public Object result() {
        if (count > 0) {
            return DataTypes.divide(sum, count);
        } else {
            return null;
        }
    }

    /**
     * Method getSize
     * @return
     */
    public int getSize() {
        return Payload.LONG_SIZE + DataTypes.getSize(sum);
    }

    /**
     * Method hashCode
     * @return
     */
    public int hashCode() {
        return sum.hashCode();
    }

    /**
     * Method equals
     *
     * @param other
     * @return
     */
    public boolean equals(Object other) {
        return ((sum.equals(((AggregationAverage) other).sum))
                && (count == ((AggregationAverage) other).count));
    }

    /**
     * Method compareTo
     *
     * @param o
     * @return
     */
    public int compareTo(Object o) {
        return DataTypes.compareTo(sum, ((AggregationAverage) o).sum);
    }

    /**
     * Method getClone
     * @return
     */
    public Object getClone() {
        AggregationAverage newObject = new AggregationAverage();

        newObject.sum = DataTypes.getClone(sum);
        newObject.count = count;

        return newObject;
    }

    /**
     * Method add
     *
     * @param other
     * @return
     */
    public Object add(Object other) {
        throw new RuntimeException(
            "DataTypes: Unsupported data type for adding: " + this.getClass()
            + " and " + other.getClass());
    }

    /**
     * Method divide
     *
     * @param denominator
     * @return
     */
    public Object divide(long denominator) {
        throw new RuntimeException(
            "DataTypes: Unsupported data type for division: "
            + this.getClass());
    }

    /**
     * Method toString
     * @return
     */
    public String toString() {
        return new String("AGG-AVG:" + sum + "/" + count);
    }
}