content: /*
   * 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 accord.burn.random;
  
  import accord.utils.Gen.LongGen;
  import accord.utils.RandomSource;
  
  public class RandomWalkRange implements LongGen
  {
      public final long min, max;
      private final long maxStepSize;
      long cur;
  
      public RandomWalkRange(RandomSource random, long min, long max)
      {
          this.min = min;
          this.max = max;
          this.maxStepSize = maxStepSize(random, min, max);
          this.cur = random.nextLong(min, max + 1);
      }
  
      @Override
      public long nextLong(RandomSource randomSource)
      {
          long step = randomSource.nextLong(-maxStepSize, maxStepSize + 1);
          long cur = this.cur;
          this.cur = step > 0 ? Math.min(max, cur + step)
                              : Math.max(min, cur + step);
          return cur;
      }
  
      private static long maxStepSize(RandomSource random, long min, long max)
      {
          switch (random.nextInt(3))
          {
              case 0:
                  return Math.max(1, (max/32) - (min/32));
              case 1:
                  return Math.max(1, (max/256) - (min/256));
              case 2:
                  return Math.max(1, (max/2048) - (min/2048));
              default:
                  return Math.max(1, (max/16384) - (min/16384));
          }
      }
  }
  