/*******************************************************************************
* Copyright (c) 2001-2005 Sasa Markovic and Ciaran Treanor.
* Copyright (c) 2011 The OpenNMS Group, Inc.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*******************************************************************************/
package org.jrobin.core.timespec;
import org.jrobin.core.RrdException;
import org.jrobin.core.Util;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
/**
* Simple class to represent time obtained by parsing at-style date specification (described
* in detail on the rrdfetch man page. See javadoc for {@link org.jrobin.core.timespec.TimeParser}
* for more information.
*/
public class TimeSpec {
static final int TYPE_ABSOLUTE = 0;
static final int TYPE_START = 1;
static final int TYPE_END = 2;
int type = TYPE_ABSOLUTE;
int year, month, day, hour, min, sec;
int wday;
int dyear, dmonth, dday, dhour, dmin, dsec;
String dateString;
TimeSpec context;
TimeSpec(String dateString) {
this.dateString = dateString;
}
void localtime(long timestamp) {
GregorianCalendar date = new GregorianCalendar();
date.setTime(new Date(timestamp * 1000L));
year = date.get(Calendar.YEAR) - 1900;
month = date.get(Calendar.MONTH);
day = date.get(Calendar.DAY_OF_MONTH);
hour = date.get(Calendar.HOUR_OF_DAY);
min = date.get(Calendar.MINUTE);
sec = date.get(Calendar.SECOND);
wday = date.get(Calendar.DAY_OF_WEEK) - Calendar.SUNDAY;
}
GregorianCalendar getTime() throws RrdException {
GregorianCalendar gc;
// absoulte time, this is easy
if (type == TYPE_ABSOLUTE) {
gc = new GregorianCalendar(year + 1900, month, day, hour, min, sec);
}
// relative time, we need a context to evaluate it
else if (context != null && context.type == TYPE_ABSOLUTE) {
gc = context.getTime();
}
// how would I guess what time it was?
else {
throw new RrdException("Relative times like '" +
dateString + "' require proper absolute context to be evaluated");
}
gc.add(Calendar.YEAR, dyear);
gc.add(Calendar.MONTH, dmonth);
gc.add(Calendar.DAY_OF_MONTH, dday);
gc.add(Calendar.HOUR_OF_DAY, dhour);
gc.add(Calendar.MINUTE, dmin);
gc.add(Calendar.SECOND, dsec);
return gc;
}
/**
* Returns the corresponding timestamp (seconds since Epoch). Example:<p>
* <pre>
* TimeParser p = new TimeParser("now-1day");
* TimeSpec ts = p.parse();
* System.out.println("Timestamp was: " + ts.getTimestamp();
* </pre>
*
* @return Timestamp (in seconds, no milliseconds)
* @throws RrdException Thrown if this TimeSpec object does not represent absolute time.
*/
public long getTimestamp() throws RrdException {
return Util.getTimestamp(getTime());
}
String dump() {
return (type == TYPE_ABSOLUTE ? "ABSTIME" : type == TYPE_START ? "START" : "END") +
": " + year + "/" + month + "/" + day +
"/" + hour + "/" + min + "/" + sec + " (" +
dyear + "/" + dmonth + "/" + dday +
"/" + dhour + "/" + dmin + "/" + dsec + ")";
}
/**
* Use this static method to resolve relative time references and obtain the corresponding
* Calendar objects. Example:<p>
* <pre>
* TimeParser pStart = new TimeParser("now-1month"); // starting time
* TimeParser pEnd = new TimeParser("start+1week"); // ending time
* TimeSpec specStart = pStart.parse();
* TimeSpec specEnd = pEnd.parse();
* GregorianCalendar[] gc = TimeSpec.getTimes(specStart, specEnd);
* </pre>
*
* @param spec1 Starting time specification
* @param spec2 Ending time specification
* @return Two element array containing Calendar objects
* @throws RrdException Thrown if relative time references cannot be resolved
*/
public static Calendar[] getTimes(TimeSpec spec1, TimeSpec spec2) throws RrdException {
if (spec1.type == TYPE_START || spec2.type == TYPE_END) {
throw new RrdException("Recursive time specifications not allowed");
}
spec1.context = spec2;
spec2.context = spec1;
return new Calendar[] {
spec1.getTime(),
spec2.getTime()
};
}
/**
* Use this static method to resolve relative time references and obtain the corresponding
* timestamps (seconds since epoch). Example:<p>
* <pre>
* TimeParser pStart = new TimeParser("now-1month"); // starting time
* TimeParser pEnd = new TimeParser("start+1week"); // ending time
* TimeSpec specStart = pStart.parse();
* TimeSpec specEnd = pEnd.parse();
* long[] ts = TimeSpec.getTimestamps(specStart, specEnd);
* </pre>
*
* @param spec1 Starting time specification
* @param spec2 Ending time specification
* @return array containing two timestamps (in seconds since epoch)
* @throws RrdException Thrown if relative time references cannot be resolved
*/
public static long[] getTimestamps(TimeSpec spec1, TimeSpec spec2) throws RrdException {
Calendar[] gcs = getTimes(spec1, spec2);
return new long[] {
Util.getTimestamp(gcs[0]), Util.getTimestamp(gcs[1])
};
}
}