/**
* MicroDate
* Copyright 2008 by Michael Peter Christen
* First released 3.7.2008 at http://yacy.net
*
* 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 program in the file lgpl21.txt
* If not, see <http://www.gnu.org/licenses/>.
*/
package net.yacy.cora.date;
import java.util.Date;
import net.yacy.cora.order.Base64Order;
public class MicroDate {
private static final long hour = 3600000L; // milliseconds of a hour
private static final long day = 86400000L; // milliseconds of a day
public static int microDateDays(final Date modified) {
return microDateDays(modified.getTime());
}
public static int microDateDays(final long modified) {
// this calculates a virtual age from a given date
// the purpose is to have an age in days of a given modified date
// from a fixed standpoint in the past
// one day has 60*60*24 seconds = 86400 seconds
// we take mod 64**3 = 262144, this is the mask of the storage
return (int) ((modified / day) % 262144L);
}
public static int microDateHoursInt(final long time) {
return (int) ((time / hour) % 262144L);
}
public static int microDateHoursAge(final String mdhs) {
return microDateHoursInt(System.currentTimeMillis()) - (int) Base64Order.enhancedCoder.decodeLong(mdhs);
}
public static long reverseMicroDateDays(final long microDateDays) {
return Math.min(System.currentTimeMillis(), microDateDays * day);
}
public static void main(final String[] args) {
}
}