/*******************************************************************************
* 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;
import java.io.IOException;
class RrdDouble extends RrdPrimitive {
private double cache;
private boolean cached = false;
RrdDouble(final RrdUpdater updater, final boolean isConstant) throws IOException {
super(updater, RrdDouble.RRD_DOUBLE, isConstant);
}
RrdDouble(final RrdUpdater updater) throws IOException {
super(updater, RrdDouble.RRD_DOUBLE, false);
}
void set(final double value) throws IOException {
if (!isCachingAllowed()) {
writeDouble(value);
}
// caching allowed
else if (!cached || !Util.equal(cache, value)) {
// update cache
writeDouble(cache = value);
cached = true;
}
}
double get() throws IOException {
return cached ? cache : readDouble();
}
}