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 org.apache.cassandra.harry.gen;
  
  import java.util.Comparator;
  import java.util.Set;
  
  import com.google.common.base.Preconditions;
  import com.google.common.collect.BiMap;
  import com.google.common.collect.HashBiMap;
  
  import org.apache.cassandra.harry.MagicConstants;
  
  public class BijectionCache<T> implements Bijections.Bijection<T>
  {
      private final BiMap<T, Long> valueToDescriptor = HashBiMap.create();
      private final Comparator<? super T> comparator;
      private long counter = 0;
  
      public BijectionCache(Comparator<? super T> comparator)
      {
          this.comparator = comparator;
      }
  
      @Override
      public T inflate(long descriptor)
      {
          if (MagicConstants.NIL_DESCR == descriptor)
              throw new IllegalArgumentException("Asked for NIL_DESCR");
          T value = valueToDescriptor.inverse().get(descriptor);
          if (value == null)
              throw new IllegalArgumentException(String.format("Attempted to inflate %d, but it is undefined", descriptor));
          return value;
      }
  
      @Override
      public long deflate(T value)
      {
          Preconditions.checkNotNull(value, "Attempted to deflate 'null'");
          if (valueToDescriptor.containsKey(value))
              return valueToDescriptor.get(value);
          long d = counter++;
          valueToDescriptor.put(value, d);
          return d;
      }
  
      public long deflateOrUndefined(T value)
      {
          return valueToDescriptor.containsKey(value) ? valueToDescriptor.get(value) : MagicConstants.UNSET_DESCR;
      }
  
      public Set<Long> descriptors()
      {
          return valueToDescriptor.inverse().keySet();
      }
  
      public Set<T> values()
      {
          return valueToDescriptor.keySet();
      }
  
      @Override
      public int population()
      {
          throw new UnsupportedOperationException();
      }
  
      @Override
      public long adjustEntropyDomain(long descriptor)
      {
          throw new UnsupportedOperationException();
      }
  
      @Override
      public long minValue()
      {
          throw new UnsupportedOperationException();
      }
  
      @Override
      public long maxValue()
      {
          throw new UnsupportedOperationException();
      }
  
      @Override
      public boolean unsigned()
      {
          throw new UnsupportedOperationException();
      }
  
      @Override
      public Comparator<Long> descriptorsComparator()
      {
          return (a, b) -> comparator.compare(inflate(a), inflate(b));
      }
  
      @Override
      public String toString(long pd)
      {
          throw new UnsupportedOperationException();
      }
  
      @Override
      public int byteSize()
      {
          throw new UnsupportedOperationException();
      }
  
      @Override
      public int compare(long l, long r)
      {
          T lhs = inflate(l);
          T rhs = inflate(r);
          return comparator.compare(lhs, rhs);
      }
  }
  