| /* |
| * |
| * 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. |
| * |
| */ |
| |
| package org.apache.cassandra.stress.generate; |
| |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| public class DistributionSequence extends Distribution |
| { |
| |
| private final long start; |
| private final long totalCount; |
| private final AtomicLong next = new AtomicLong(); |
| |
| public DistributionSequence(long start, long end) |
| { |
| if (start > end) |
| throw new IllegalStateException(); |
| this.start = start; |
| this.totalCount = 1 + end - start; |
| } |
| |
| private long nextWithWrap() |
| { |
| long next = this.next.getAndIncrement(); |
| return start + (next % totalCount); |
| } |
| |
| @Override |
| public long next() |
| { |
| return nextWithWrap(); |
| } |
| |
| @Override |
| public double nextDouble() |
| { |
| return nextWithWrap(); |
| } |
| |
| @Override |
| public long inverseCumProb(double cumProb) |
| { |
| return (long) (start + (totalCount-1) * cumProb); |
| } |
| |
| @Override |
| public void setSeed(long seed) |
| { |
| next.set(seed); |
| } |
| |
| } |
| |