package org.apache.cassandra.stress.generate;
/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
import org.apache.commons.math3.distribution.AbstractRealDistribution;
public class DistributionOffsetApache extends Distribution
{
final AbstractRealDistribution delegate;
final long min, delta;
public DistributionOffsetApache(AbstractRealDistribution delegate, long min, long max)
{
this.delegate = delegate;
this.min = min;
this.delta = max - min;
}
public void setSeed(long seed)
{
delegate.reseedRandomGenerator(seed);
}
@Override
public long next()
{
return offset(min, delta, delegate.sample());
}
public double nextDouble()
{
return offsetDouble(min, delta, delegate.sample());
}
@Override
public long inverseCumProb(double cumProb)
{
return offset(min, delta, delegate.inverseCumulativeProbability(cumProb));
}
private long offset(long min, long delta, double val)
{
long r = (long) val;
if (r < 0)
r = 0;
if (r > delta)
r = delta;
return min + r;
}
private double offsetDouble(long min, long delta, double r)
{
if (r < 0)
r = 0;
if (r > delta)
r = delta;
return min + r;
}
}