1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.rng.simple.internal; 18 19 import org.apache.commons.rng.core.source64.SplitMix64; 20 21 /** 22 * Uses a {@code Long} value to seed a {@link SplitMix64} RNG and 23 * create a {@code long[]} with the requested number of random 24 * values. 25 * 26 * @since 1.0 27 */ 28 public class Long2LongArray implements Seed2ArrayConverter<Long, long[]> { 29 /** Size of the output array. */ 30 private final int size; 31 32 /** 33 * @param size Size of the output array. 34 */ 35 public Long2LongArray(int size) { 36 this.size = size; 37 } 38 39 40 /** {@inheritDoc} */ 41 @Override 42 public long[] convert(Long seed) { 43 return convertSeed(seed, size); 44 } 45 46 /** 47 * {@inheritDoc} 48 * 49 * @since 1.3 50 */ 51 @Override 52 public long[] convert(Long seed, int outputSize) { 53 return convertSeed(seed, outputSize); 54 } 55 56 /** 57 * Convert the seed. 58 * 59 * @param seed Input seed. 60 * @param size Output array size. 61 * @return the converted seed. 62 */ 63 private static long[] convertSeed(Long seed, int size) { 64 final long[] out = new long[size]; 65 final SplitMix64 rng = new SplitMix64(seed); 66 for (int i = 0; i < size; i++) { 67 out[i] = rng.nextLong(); 68 } 69 70 return out; 71 } 72 }