/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Sep 24, 2008
*/
package com.bigdata.relation.rule;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.math.BigInteger;
/**
* Default implementation.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class Slice implements ISlice, Externalizable {
/**
*
*/
private static final long serialVersionUID = 5396509164843609197L;
private long offset;
private long limit;
private long last;
/**
* A slice corresponding to all results (offset is zero, limit is
* {@link Long#MAX_VALUE}).
*/
public static final transient ISlice ALL = new Slice(0, Long.MAX_VALUE);
/**
*
* @param offset
* @param limit
*
* @throws IllegalArgumentException
* if offset is negative.
* @throws IllegalArgumentException
* if limit is non-positive.
*/
public Slice(final long offset, final long limit) {
if (offset < 0)
throw new IllegalArgumentException();
if (limit <= 0)
throw new IllegalArgumentException();
this.offset = offset;
this.limit = limit;
// @todo what is a cheaper way to do this?
this.last = BigInteger.valueOf(offset).add(BigInteger.valueOf(limit))
.min(BigInteger.valueOf(Long.MAX_VALUE)).longValue();
}
public long getOffset() {
return offset;
}
public long getLimit() {
return limit;
}
public long getLast() {
return last;
}
public String toString() {
return "Slice{offset="+offset+", limit="+limit+", last="+last+"}";
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
offset = in.readLong();
limit = in.readLong();
last = in.readLong();
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeLong(offset);
out.writeLong(limit);
out.writeLong(last);
}
}