bigtop-master/bigtop-data-generators/bigtop-samplers/src/main/java/org/apache/bigtop/datagenerators/samplers/samplers/SequenceSampler.java
/**
 * 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.bigtop.datagenerators.samplers.samplers;

public class SequenceSampler implements Sampler<Integer>
{
	Integer start;
	Integer end;
	Integer step;
	Integer next;

	public SequenceSampler()
	{
		start = 0;
		end = null;
		step = 1;
		next = start;
	}

	public SequenceSampler(Integer start)
	{
		this.start = start;
		end = null;
		step = 1;
		next = start;
	}

	public SequenceSampler(Integer start, Integer end)
	{
		this.start = start;
		this.end = end;
		step = 1;
		next = start;
	}

	public SequenceSampler(Integer start, Integer end, Integer step)
	{
		this.start = start;
		this.end = end;
		this.step = step;
		next = start;
	}

	public Integer sample() throws Exception
	{
		if(end == null || next < end)
		{
			Integer current = next;
			next = current + step;
			return current;
		}

		throw new Exception("All values have been sampled");
	}


}
