code: /*
   * Copyright (c) 2017-2018 The Regents of the University of California
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   *
   * 1. Redistributions of source code must retain the above copyright
   * notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package edu.berkeley.cs.jqf.fuzz.junit.quickcheck;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Optional;
  
  import com.pholser.junit.quickcheck.generator.GenerationStatus;
  import com.pholser.junit.quickcheck.internal.GeometricDistribution;
  import com.pholser.junit.quickcheck.random.SourceOfRandomness;
  
  /**
   * Provides a generation status that does not track the number of trials
   * generated so far. This is useful for guided fuzzing where the burden
   * of making choices is on the guidance system rather than on quickcheck.
   *
   * @author Rohan Padhye
   */
  public class NonTrackingGenerationStatus implements GenerationStatus {
  
      public static final int MEAN_SIZE = 10;
  
      private final SourceOfRandomness random;
      private final Map<Key<?>, Object> contextValues = new HashMap<>();
      private final GeometricDistribution geometric = new GeometricDistribution();
  
  
      public NonTrackingGenerationStatus(SourceOfRandomness random) {
          this.random = random;
      }
  
      @Override
      public int size() {
          return geometric.sampleWithMean(MEAN_SIZE, random);
      }
  
      @Override
      public int attempts() {
          throw new UnsupportedOperationException("attempts() and @ValueOf" +
                  " is not supported in guided mode.");
      }
  
      @Override
      public <T> GenerationStatus setValue(Key<T> key, T value) {
          contextValues.put(key, value);
          return this;
      }
  
      @Override
      public <T> Optional<T> valueOf(Key<T> key) {
          return Optional.ofNullable(key.cast(contextValues.get(key)));
      }
  }
  