Random.java
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Random.java
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	package org.softwareheritage.graph.benchmark.utils;

	import java.util.PrimitiveIterator;

	import org.softwareheritage.graph.Graph;
	import org.softwareheritage.graph.Node;

	/**
	* Random related utility class.
	*
	* @author The Software Heritage developers
	*/

	public class Random {
	/** Internal pseudorandom generator */
	java.util.Random random;

	/**
	* Constructor.
	*/
	public Random() {
	this.random = new java.util.Random();
	}

	/**
	* Constructor.
	*
	* @param seed random generator seed
	*/
	public Random(long seed) {
	this.random = new java.util.Random(seed);
	}

	/**
	* Generates random node ids.
	*
	* @param graph graph used to pick node ids
	* @param nbNodes number of node ids to generate
	* @return an array of random node ids
	*/
	public long[] generateNodeIds(Graph graph, int nbNodes) {
	return random.longs(nbNodes, 0, graph.numNodes()).toArray();
	}

	/**
	* Generates random node ids with a specific type.
	*
	* @param graph graph used to pick node ids
	* @param nbNodes number of node ids to generate
	* @param expectedType specific node type to pick
	* @return an array of random node ids
	*/
	public long[] generateNodeIdsOfType(Graph graph, int nbNodes, Node.Type expectedType) {
	PrimitiveIterator.OfLong nodes = random.longs(0, graph.numNodes()).iterator();
	long[] nodeIds = new long[nbNodes];

	long nextId;
	for (int i = 0; i < nbNodes; i++) {
	do {
	nextId = nodes.nextLong();
	} while (graph.getNodeType(nextId) != expectedType);
	nodeIds[i] = nextId;
	}

	return nodeIds;
	}
	}