dynamictimeseriescollection.java

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/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by 
 * the Free Software Foundation; either version 2.1 of the License, or 
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License 
 * along with this library; if not, write to the Free Software Foundation, 
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * --------------------------------
 * DynamicTimeSeriesCollection.java
 * --------------------------------
 * (C) Copyright 2002-2005, by I. H. Thomae and Contributors.
 *
 * Original Author:  I. H. Thomae ([e-mail]);
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *
 * $Id: DynamicTimeSeriesCollection.java,v 1.11 2005/05/20 08:20:03 mungady Exp $
 *
 * Changes
 * -------
 * 22-Nov-2002 : Initial version completed
 *    Jan 2003 : Optimized advanceTime(), added implemnt'n of RangeInfo intfc
 *               (using cached values for min, max, and range); also added
 *               getOldestIndex() and getNewestIndex() ftns so client classes
 *               can use this class as the master "index authority".
 * 22-Jan-2003 : Made this class stand on its own, rather than extending
 *               class FastTimeSeriesCollection
 * 31-Jan-2003 : Changed TimePeriod --> RegularTimePeriod (DG);
 * 13-Mar-2003 : Moved to com.jrefinery.data.time package (DG);
 * 29-Apr-2003 : Added small change to appendData method, from Irv Thomae (DG);
 * 19-Sep-2003 : Added new appendData method, from Irv Thomae (DG);
 * 05-May-2004 : Now extends AbstractIntervalXYDataset.  This also required a
 *               change to the return type of the getY() method - I'm slightly
 *               unsure of the implications of this, so it might require some
 *               further amendment (DG);
 * 15-Jul-2004 : Switched getX() with getXValue() and getY() with 
 *               getYValue() (DG);
 * 11-Jan-2004 : Removed deprecated code in preparation for the 1.0.0 
 *               release (DG);
 * 
 */

package org.jfree.data.time;

import java.util.Calendar;
import java.util.TimeZone;

import org.jfree.data.DomainInfo;
import org.jfree.data.Range;
import org.jfree.data.RangeInfo;
import org.jfree.data.general.SeriesChangeEvent;
import org.jfree.data.xy.AbstractIntervalXYDataset;
import org.jfree.data.xy.IntervalXYDataset;

/**
 * A dynamic dataset.
 * <p>
 * Like FastTimeSeriesCollection, this class is a functional replacement
 * for JFreeChart's TimeSeriesCollection _and_ TimeSeries classes.
 * FastTimeSeriesCollection is appropriate for a fixed time range; for
 * real-time applications this subclass adds the ability to append new
 * data and discard the oldest.
 * In this class, the arrays used in FastTimeSeriesCollection become FIFO's.
 * NOTE:As presented here, all data is assumed >= 0, an assumption which is
 * embodied only in methods associated with interface RangeInfo.
 *
 * @author Irv Thomae.
 */
public class DynamicTimeSeriesCollection extends AbstractIntervalXYDataset
                                         implements IntervalXYDataset,
                                                    DomainInfo,
                                                    RangeInfo {

    /** 
     * Useful constant for controlling the x-value returned for a time 
     * period. 
     */
    public static final int START = 0;

    /** 
     * Useful constant for controlling the x-value returned for a time period. 
     */
    public static final int MIDDLE = 1;

    /** 
     * Useful constant for controlling the x-value returned for a time period. 
     */
    public static final int END = 2;

    /** The maximum number of items for each series (can be overridden). */
    private int maximumItemCount = 2000;  // an arbitrary safe default value

    /** The history count. */
    protected int historyCount;

    /** Storage for the series keys. */
    private Comparable[] seriesKeys;

    /** The time period class - barely used, and could be removed (DG). */
    private Class timePeriodClass = Minute.class;   // default value;

    /** Storage for the x-values. */
    protected RegularTimePeriod[] pointsInTime;

    /** The number of series. */
    private int seriesCount;

    /**
     * A wrapper for a fixed array of float values.
     */
    protected class ValueSequence {

        /** Storage for the float values. */
        float[] dataPoints;

        /**
         * Default constructor:
         */
        public ValueSequence() {
            this(DynamicTimeSeriesCollection.this.maximumItemCount);
        }

        /**
         * Creates a sequence with the specified length.
         *
         * @param length  the length.
         */
        public ValueSequence(int length) {
            this.dataPoints = new float[length];
            for (int i = 0; i < length; i++) {
                this.dataPoints[i] = 0.0f;
            }
        }

        /**
         * Enters data into the storage array.
         *
         * @param index  the index.
         * @param value  the value.
         */
        public void enterData(int index, float value) {
            this.dataPoints[index] = value;
        }

        /**
         * Returns a value from the storage array.
         *
         * @param index  the index.
         *
         * @return The value.
         */
        public float getData(int index) {
            return this.dataPoints[index];
        }
    }

    /** An array for storing the objects that represent each series. */
    protected ValueSequence[] valueHistory;

    /** A working calendar (to recycle) */
    protected Calendar workingCalendar;

    /** 
     * The position within a time period to return as the x-value (START, 
     * MIDDLE or END). 
     */
    private int position;

    /**
     * A flag that indicates that the domain is 'points in time'.  If this flag 
     * is true, only the x-value is used to determine the range of values in 
     * the domain, the start and end x-values are ignored.
     */
    private boolean domainIsPointsInTime;

    /** index for mapping: points to the oldest valid time & data. */
    private int oldestAt;  // as a class variable, initializes == 0

    /** Index of the newest data item. */
    private int newestAt;

    // cached values used for interface DomainInfo:

    /** the # of msec by which time advances. */
    private long deltaTime;

    /** Cached domain start (for use by DomainInfo). */
    private Long domainStart;

    /** Cached domain end (for use by DomainInfo). */
    private Long domainEnd;

    /** Cached domain range (for use by DomainInfo). */
    private Range domainRange;

    // Cached values used for interface RangeInfo: (note minValue pinned at 0)
    //   A single set of extrema covers the entire SeriesCollection

    /** The minimum value. */
    private Float minValue = new Float(0.0f);

    /** The maximum value. */
    private Float maxValue = null;

    /** The value range. */
    private Range valueRange;  // autoinit's to null.

    /**
     * Constructs a dataset with capacity for N series, tied to default 
     * timezone.
     *
     * @param nSeries the number of series to be accommodated.
     * @param nMoments the number of TimePeriods to be spanned.
     */
    public DynamicTimeSeriesCollection(int nSeries, int nMoments) {

        this(nSeries, nMoments, new Millisecond(), TimeZone.getDefault());
        this.newestAt = nMoments - 1;

    }

    /**
     * Constructs an empty dataset, tied to a specific timezone.
     *
     * @param nSeries the number of series to be accommodated
     * @param nMoments the number of TimePeriods to be spanned
     * @param zone the timezone.
     */
    public DynamicTimeSeriesCollection(int nSeries, int nMoments, 
                                       TimeZone zone) {
        this(nSeries, nMoments, new Millisecond(), zone);
        this.newestAt = nMoments - 1;
    }

    /**
     * Creates a new dataset.
     *
     * @param nSeries  the number of series.
     * @param nMoments  the number of items per series.
     * @param timeSample  a time period sample.
     */
    public DynamicTimeSeriesCollection(int nSeries,
                                       int nMoments,
                                       RegularTimePeriod timeSample) {
        this(nSeries, nMoments, timeSample, TimeZone.getDefault());
    }

    /**
     * Creates a new dataset.
     *
     * @param nSeries  the number of series.
     * @param nMoments  the number of items per series.
     * @param timeSample  a time period sample.
     * @param zone  the time zone.
     */
    public DynamicTimeSeriesCollection(int nSeries,
                                       int nMoments,
                                       RegularTimePeriod timeSample,
                                       TimeZone zone) {

        // the first initialization must precede creation of the ValueSet array:
        this.maximumItemCount = nMoments;  // establishes length of each array
        this.historyCount = nMoments;
        this.seriesKeys = new Comparable[nSeries];
        // initialize the members of "seriesNames" array so they won't be null:
        for (int i = 0; i < nSeries; i++) {
            this.seriesKeys[i] = "";
        }
        this.newestAt = nMoments - 1;
        this.valueHistory = new ValueSequence[nSeries];
        this.timePeriodClass = timeSample.getClass();

        /// Expand the following for all defined TimePeriods:
        if (this.timePeriodClass == Second.class) {
            this.pointsInTime = new Second[nMoments];
        }
        else if (this.timePeriodClass == Minute.class) {
            this.pointsInTime = new Minute[nMoments];
        }
        else if (this.timePeriodClass == Hour.class) {
            this.pointsInTime = new Hour[nMoments];
        }
        ///  .. etc....
        this.workingCalendar = Calendar.getInstance(zone);
        this.position = START;
        this.domainIsPointsInTime = true;
    }

    /**
     * Fill the pointsInTime with times using TimePeriod.next():
     * Will silently return if the time array was already populated.
     *
     * Also computes the data cached for later use by
     * methods implementing the DomainInfo interface:
     *
     * @param start  the start.
     *
     * @return ??.
     */
    public synchronized long setTimeBase(RegularTimePeriod start) {

        if (this.pointsInTime[0] == null) {
            this.pointsInTime[0] = start;
            for (int i = 1; i < this.historyCount; i++) {
                this.pointsInTime[i] = this.pointsInTime[i - 1].next();
            }
        }
        long oldestL = this.pointsInTime[0].getFirstMillisecond(