001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.rng.core;
018
019import java.util.Arrays;
020
021import org.apache.commons.rng.RandomProviderState;
022
023/**
024 * Wraps the internal state of a generator instance.
025 * Its purpose is to store all the data needed to recover the same
026 * state in order to restart a sequence where it left off.
027 * External code should not try to modify the data contained in instances
028 * of this class.
029 *
030 * @since 1.0
031 */
032public class RandomProviderDefaultState implements RandomProviderState {
033    /** Internal state. */
034    private final byte[] state;
035
036    /**
037     * Initializes an instance.
038     * The contents of the {@code state} argument is unspecified, and is
039     * guaranteed to be valid only if it was generated by implementations
040     * provided by this library.
041     *
042     * @param state Mapping of all the data which an implementation of
043     * {@link org.apache.commons.rng.UniformRandomProvider} needs in order
044     * to reset its internal state.
045     */
046    public RandomProviderDefaultState(byte[] state) {
047        this.state = Arrays.copyOf(state, state.length);
048    }
049
050    /**
051     * @return the internal state.
052     */
053    public byte[] getState() {
054        return Arrays.copyOf(state, state.length);
055    }
056}