/*
 * 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.flink.runtime.operators.testutils;

import java.util.Random;

import org.apache.flink.runtime.operators.testutils.types.IntPair;
import org.apache.flink.util.MutableObjectIterator;

public class RandomIntPairGenerator implements MutableObjectIterator<IntPair>
{
	private final long seed;
	
	private final long numRecords;
	
	private Random rnd;
	
	private long count;
	
	
	public RandomIntPairGenerator(long seed) {
		this(seed, Long.MAX_VALUE);
	}
	
	public RandomIntPairGenerator(long seed, long numRecords) {
		this.seed = seed;
		this.numRecords = numRecords;
		this.rnd = new Random(seed);
	}

	
	@Override
	public IntPair next(IntPair reuse) {
		if (this.count++ < this.numRecords) {
			reuse.setKey(this.rnd.nextInt());
			reuse.setValue(this.rnd.nextInt());
			return reuse;
		} else {
			return null;
		}
	}

	@Override
	public IntPair next() {
		if (this.count++ < this.numRecords) {
			return new IntPair(this.rnd.nextInt(), this.rnd.nextInt());
		} else {
			return null;
		}
	}
	
	public void reset() {
		this.rnd = new Random(this.seed);
		this.count = 0;
	}
}