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 java.io.Serializable;
public abstract class Distribution implements Serializable
{
public abstract long next();
public abstract double nextDouble();
public abstract long inverseCumProb(double cumProb);
public abstract void setSeed(long seed);
public long maxValue()
{
return inverseCumProb(1d);
}
public long minValue()
{
return inverseCumProb(0d);
}
// approximation of the average; slightly costly to calculate, so should not be invoked frequently
public long average()
{
double sum = 0;
int count = 0;
for (float d = 0 ; d <= 1.0d ; d += 0.02d)
{
sum += inverseCumProb(d);
count += 1;
}
return (long) (sum / count);
}
}