content: package org.apache.cassandra.stress.settings;
  /*
   * 
   * 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.
   * 
   */
  
  
  import java.util.Arrays;
  import java.util.List;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import com.google.common.base.Function;
  
  import org.apache.cassandra.stress.generate.DistributionFactory;
  import org.apache.cassandra.stress.generate.RatioDistribution;
  import org.apache.cassandra.stress.generate.RatioDistributionFactory;
  
  /**
   * For selecting a mathematical distribution
   */
  public class OptionRatioDistribution extends Option
  {
  
      public static final Function<String, RatioDistributionFactory> BUILDER = new Function<String, RatioDistributionFactory>()
      {
          public RatioDistributionFactory apply(String s)
          {
              return get(s);
          }
      };
  
      private static final Pattern FULL = Pattern.compile("(.*)/([0-9]+[KMB]?)", Pattern.CASE_INSENSITIVE);
  
      final OptionDistribution delegate;
      private double divisor;
      final String defaultSpec;
  
      public OptionRatioDistribution(String prefix, String defaultSpec, String description)
      {
          this(prefix, defaultSpec, description, defaultSpec != null);
      }
  
      public OptionRatioDistribution(String prefix, String defaultSpec, String description, boolean required)
      {
          delegate = new OptionDistribution(prefix, null, description, required);
          this.defaultSpec = defaultSpec;
      }
  
      @Override
      public boolean accept(String param)
      {
          Matcher m = FULL.matcher(param);
          if (!m.matches() || !delegate.accept(m.group(1)))
              return false;
          divisor = OptionDistribution.parseLong(m.group(2));
          return true;
      }
  
      public static RatioDistributionFactory get(String spec)
      {
          OptionRatioDistribution opt = new OptionRatioDistribution("", "", "", true);
          if (!opt.accept(spec))
              throw new IllegalArgumentException("Invalid ratio definition: "+spec);
          return opt.get();
      }
  
      public RatioDistributionFactory get()
      {
          if (delegate.setByUser())
              return new DelegateFactory(delegate.get(), divisor);
          if (defaultSpec == null)
              return null;
          OptionRatioDistribution sub = new OptionRatioDistribution("", null, null, true);
          if (!sub.accept(defaultSpec))
              throw new IllegalStateException("Invalid default spec: " + defaultSpec);
          return sub.get();
      }
  
      @Override
      public boolean happy()
      {
          return delegate.happy();
      }
  
      public String longDisplay()
      {
          return delegate.longDisplay();
      }
  
      @Override
      public List<String> multiLineDisplay()
      {
          return Arrays.asList(
                  GroupedOptions.formatMultiLine("EXP(min..max)/divisor", "An exponential ratio distribution over the range [min..max]/divisor"),
                  GroupedOptions.formatMultiLine("EXTREME(min..max,shape)/divisor", "An extreme value (Weibull) ratio distribution over the range [min..max]/divisor"),
                  GroupedOptions.formatMultiLine("GAUSSIAN(min..max,stdvrng)/divisor", "A gaussian/normal ratio distribution, where mean=(min+max)/2, and stdev is ((mean-min)/stdvrng)/divisor"),
                  GroupedOptions.formatMultiLine("GAUSSIAN(min..max,mean,stdev)/divisor", "A gaussian/normal ratio distribution, with explicitly defined mean and stdev"),
                  GroupedOptions.formatMultiLine("UNIFORM(min..max)/divisor", "A uniform ratio distribution over the range [min, max]/divisor"),
                  GroupedOptions.formatMultiLine("FIXED(val)/divisor", "A fixed ratio distribution, always returning the same value"),
                  "Preceding the name with ~ will invert the distribution, e.g. ~exp(1..10)/10 will yield 0.1 least, instead of most, often",
                  "Aliases: extr, gauss, normal, norm, weibull"
          );
      }
  
      boolean setByUser()
      {
          return delegate.setByUser();
      }
  
      boolean present()
      {
          return delegate.present();
      }
  
      @Override
      public String shortDisplay()
      {
          return delegate.shortDisplay();
      }
      public String getOptionAsString()
      {
          return delegate.getOptionAsString();
      }
  
  
      // factories
  
      private static final class DelegateFactory implements RatioDistributionFactory
      {
          final DistributionFactory delegate;
          final double divisor;
  
          private DelegateFactory(DistributionFactory delegate, double divisor)
          {
              this.delegate = delegate;
              this.divisor = divisor;
          }
  
          @Override
          public RatioDistribution get()
          {
              return new RatioDistribution(delegate.get(), divisor);
          }
  
          @Override
          public String getConfigAsString(){return String.format("Ratio: divisor=%f;delegate=%s",divisor, delegate.getConfigAsString());};
  
      }
  
      @Override
      public int hashCode()
      {
          return delegate.hashCode();
      }
  
      @Override
      public boolean equals(Object that)
      {
          return super.equals(that) && ((OptionRatioDistribution) that).delegate.equals(this.delegate);
      }
  
  }
  