org.diirt.datasource.timecache.util.CacheHelper Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of datasource-timecache Show documentation
Local cache for time series gathered from multiple sources.
The newest version!
/**
 * Copyright (C) 2010-14 diirt developers. See COPYRIGHT.TXT
 * All rights reserved. Use is subject to license terms. See LICENSE.TXT
 */
package org.diirt.datasource.timecache.util;

import org.diirt.util.time.TimeDuration;
import org.diirt.util.time.TimeInterval;
import org.diirt.util.time.Timestamp;
import org.diirt.util.time.TimestampFormat;

/**
 * Cache helper.
 * @author Fred Arnaud (Sopra Group) - ITER
 */
public class CacheHelper {

	private static TimestampFormat tsFormat = new TimestampFormat("yyyy-MM-dd'T'HH:mm:ss.NNNNNNNNNZ");

	/** Returns the minimum between the two specified {@link Timestamp}. */
	public static Timestamp min(Timestamp t1, Timestamp t2) {
		if (t1 == null || t2 == null) return null;
		if (t1.compareTo(t2) <= 0) return t1;
		else return t2;
	}

	/** Returns the maximum between the two specified {@link Timestamp}. */
	public static Timestamp max(Timestamp t1, Timestamp t2) {
		if (t1 == null || t2 == null) return null;
		if (t1.compareTo(t2) >= 0) return t1;
		else return t2;
	}

	/**
	 * Returns true if {@link TimeInterval} i1 contains
	 * {@link TimeInterval} i2, false otherwise (null
	 * border means infinity).
	 */
	public static boolean contains(TimeInterval i1, TimeInterval i2) {
		if (i1 == null || i2 == null)
			return false;
		i1 = arrange(i1);
		i2 = arrange(i2);
		if (i2.getStart() == null && i2.getEnd() == null) return i1.getStart() == null && i1.getEnd() == null;
		else if (i2.getStart() != null && i2.getEnd() == null) return i1.contains(i2.getStart()) && i1.getEnd() == null;
		else if (i2.getStart() == null && i2.getEnd() != null) return i1.getStart() == null && i1.contains(i2.getEnd());
		else return i1.contains(i2.getStart()) && i1.contains(i2.getEnd());
	}

	/**
	 * Returns true if {@link TimeInterval} i1 intersects
	 * {@link TimeInterval} i2, false otherwise (null
	 * border means infinity).
	 */
	public static boolean intersects(TimeInterval i1, TimeInterval i2) {
		if (i1 == null || i2 == null)
			return false;
		i1 = arrange(i1);
		i2 = arrange(i2);
		if (i1.getStart() == null && i1.getEnd() == null) { return true;
		} else if (i1.getStart() != null && i1.getEnd() == null) {
			if (i2.getEnd() == null) return true;
			else if (i2.getStart() == null && i2.getEnd() != null) return i1.contains(i2.getEnd());
			else return i1.contains(i2.getEnd()) || i1.contains(i2.getStart());
		} else if (i1.getStart() == null && i1.getEnd() != null) {
			if (i2.getStart() == null) return true;
			else if (i2.getStart() != null && i2.getEnd() == null) return i1.contains(i2.getStart());
			else return i1.contains(i2.getEnd()) || i1.contains(i2.getStart());
		} else {
			if (i2.getStart() == null && i2.getEnd() == null) return true;
			else if (i2.getStart() == null || i2.getEnd() == null) return i2.contains(i1.getEnd()) || i2.contains(i1.getStart());
			else return i1.contains(i2.getStart()) || i1.contains(i2.getEnd())
						|| i2.contains(i1.getStart()) || i2.contains(i1.getEnd());
		}
	}

	/**
	 * Returns the result of {@link TimeInterval} i1 & i2 intersection,
	 * null if i1 does not intersects i2 (null border
	 * means infinity).
	 */
	public static TimeInterval intersection(TimeInterval i1, TimeInterval i2) {
		if (i1 == null || i2 == null)
			return null;
		if (!intersects(i1, i2))
			return null;
		i1 = arrange(i1);
		i2 = arrange(i2);
		Timestamp a = null;
		if (i1.getStart() == null && i2.getStart() == null) a = null;
		else if (i1.getStart() == null && i2.getStart() != null) a = i2.getStart();
		else if (i1.getStart() != null && i2.getStart() == null) a = i1.getStart();
		else a = max(i1.getStart(), i2.getStart());

		Timestamp b = null;
		if (i1.getEnd() == null && i2.getEnd() == null) b = null;
		else if (i1.getEnd() == null && i2.getEnd() != null) b = i2.getEnd();
		else if (i1.getEnd() != null && i2.getEnd() == null) b = i1.getEnd();
		else b = min(i1.getEnd(), i2.getEnd());

		return TimeInterval.between(a, b);
	}

	/** Returns a re-arranged {@link TimeInterval} if borders order is reversed. */
	public static TimeInterval arrange(TimeInterval i) {
		if (i.getStart() != null && i.getEnd() != null
				&& i.getStart().compareTo(i.getEnd()) > 0)
			return TimeInterval.between(i.getEnd(), i.getStart());
		return i;
	}

	/** Returns a formated {@link String} from the specified {@link Timestamp}. */
	public static String format(Timestamp t) {
		return tsFormat.format(t);
	}

	/** Returns a formated {@link String} from the specified {@link TimeInterval}. */
	public static String format(TimeInterval i) {
		return "[" + format(i.getStart()) + " - " + format(i.getEnd()) + "]";
	}

	/** Returns a formated {@link String} from the specified {@link TimeDuration}. */
	public static String format(TimeDuration d) {
		double seconds = d.toSeconds();
		long h = Math.round(seconds / 3600);
		long m = Math.round((seconds % 3600) / 60);
		long s = Math.round(seconds % 60);
		return String.format("%d:%02d:%02d", h, m, s);
	}

}