CacheHelper.java

/**
 * 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 java.io.FileNotFoundException;
import java.io.PrintStream;
import java.time.Duration;
import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;

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

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

    private static DateTimeFormatter tsFormat = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.nnnnnnnnnZ");
    public static PrintStream ps = System.out;

    static {
        try {
            ps = new PrintStream("src/test/resources/logs.txt");
        } catch (FileNotFoundException e) {
        }
    }

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

    /**
     * Returns <code>true</code> if {@link TimeInterval} i1 contains
     * {@link TimeInterval} i2, <code>false</code> otherwise (<code>null</code>
     * 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 <code>true</code> if {@link TimeInterval} i1 intersects
     * {@link TimeInterval} i2, <code>false</code> otherwise (<code>null</code>
     * 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,
     * <code>null</code> if i1 does not intersects i2 (<code>null</code> 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);
        Instant 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());

        Instant 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(Instant t) {
        return tsFormat.format(ZonedDateTime.ofInstant(t, ZoneId.systemDefault()));
    }

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

    /** Returns a formated {@link String} from the specified {@link Duration}. */
    public static String format(Duration d) {
        double seconds = TimeDuration.toSecondsDouble(d);
        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);
    }

}