package org.jacorb.util;
/*
* JacORB - a free Java ORB
*
* Copyright (C) 2002-2004 Gerald Brose
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
import org.jacorb.orb.CDRInputStream;
import org.jacorb.orb.CDROutputStream;
import org.omg.TimeBase.UtcT;
import org.omg.TimeBase.UtcTHelper;
/**
* Contains static methods to handle CORBA time values.
*
* @author Andre Spiegel <spiegel@gnu.org>
* @version $Id: Time.java,v 1.11 2008-11-14 08:55:37 nick.cross Exp $
*/
public class Time
{
private Time()
{
// utility class
super();
}
/**
* Difference between the CORBA Epoch and the Unix Epoch: the time
* from 1582/10/15 00:00 until 1970/01/01 00:00 in 100 ns units.
*/
public static final long UNIX_OFFSET = 122192928000000000L;
/**
* Returns the current time as a CORBA UtcT.
*/
public static UtcT corbaTime()
{
return corbaTime(System.currentTimeMillis());
}
/**
* Converts the given unixTime into a CORBA UtcT.
* @param unixTime the number of milliseconds since 1970/01/01 00:00 UTC.
*/
public static UtcT corbaTime(long unixTime)
{
UtcT result = new UtcT();
result.time = (unixTime * 10000) + UNIX_OFFSET;
// unixTime is always UTC.
// Therefore, no time zone offset.
result.tdf = 0;
// nothing reasonable to put here
result.inacchi = 0;
result.inacclo = 0;
return result;
}
/**
* Converts the given Java date into a CORBA UtcT.
*/
public static UtcT corbaTime(java.util.Date date)
{
return corbaTime(date.getTime());
}
/**
* Returns a CORBA UtcT that represents an instant that lies
* a given number of CORBA time units (100 ns) in the future.
* If the argument is negative, returns null.
*/
public static UtcT corbaFuture(long corbaUnits)
{
if (corbaUnits < 0)
{
return null;
}
UtcT result = corbaTime();
result.time = result.time + corbaUnits;
return result;
}
/**
* Returns the number of milliseconds between now and the given CORBA
* time. The value is positive if that time is in the future, and
* negative otherwise.
*/
public static long millisTo(UtcT time)
{
long unixTime = (time.time - UNIX_OFFSET) / 10000;
// if the time is not UTC, correct time zone
if (time.tdf != 0)
{
unixTime = unixTime - (time.tdf * 60000);
}
return unixTime - System.currentTimeMillis();
}
/**
* Returns true if the instant represented by the given UtcT is
* already in the past, false otherwise. As a special convenience,
* this method also returns false if the argument is null.
*/
public static boolean hasPassed(UtcT time)
{
if (time != null)
{
return millisTo(time) < 0;
}
return false;
}
/**
* Compares two UtcT time values and returns that which is earlier.
* Either argument can be null; this is considered as a time that
* lies indefinitely in the future. If both arguments are null,
* this method returns null itself.
*/
public static UtcT earliest(UtcT timeA, UtcT timeB)
{
if (timeA == null)
{
if (timeB == null)
{
return null;
}
return timeB;
}
if (timeB == null || timeA.time <= timeB.time)
{
return timeA;
}
return timeB;
}
/**
* Returns a CDR encapsulation of the given UtcT.
*/
public static byte[] toCDR(UtcT time)
{
// TODO: make this more efficient with mere bit shifting
byte[] buffer = new byte[25];
CDROutputStream out = new CDROutputStream(buffer);
out.beginEncapsulatedArray();
UtcTHelper.write(out, time);
return out.getBufferCopy();
}
/**
* Decodes a CDR encapsulation of a UtcT.
*/
public static UtcT fromCDR(byte[] buffer)
{
CDRInputStream in = new CDRInputStream(null, buffer);
in.openEncapsulatedArray();
return UtcTHelper.read(in);
}
/**
* This method blocks until the given time has been reached.
* If the time is null, or it has already passed,
* then this method returns immediately.
*/
public static void waitFor(UtcT time)
{
if (time != null)
{
long now = System.currentTimeMillis();
long delta = Time.millisTo(time);
long then = now + delta;
while(delta > 0)
{
try
{
Thread.sleep(delta);
}
catch (InterruptedException e)
{
// ignored
}
delta = then - System.currentTimeMillis();
}
}
}
}