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.db.marshal;
  
  import java.nio.ByteBuffer;
  import java.util.Map;
  import java.util.List;
  import java.util.concurrent.ConcurrentHashMap;
  
  import org.apache.cassandra.cql3.CQL3Type;
  import org.apache.cassandra.cql3.terms.Term;
  import org.apache.cassandra.cql3.functions.ArgumentDeserializer;
  import org.apache.cassandra.exceptions.ConfigurationException;
  import org.apache.cassandra.serializers.MarshalException;
  import org.apache.cassandra.serializers.TypeSerializer;
  import org.apache.cassandra.transport.ProtocolVersion;
  import org.apache.cassandra.utils.bytecomparable.ByteComparable;
  import org.apache.cassandra.utils.bytecomparable.ByteSource;
  
  public class ReversedType<T> extends AbstractType<T>
  {
      // interning instances
      private static final Map<AbstractType<?>, ReversedType> instances = new ConcurrentHashMap<>();
  
      public final AbstractType<T> baseType;
  
      public static <T> ReversedType<T> getInstance(TypeParser parser)
      {
          List<AbstractType<?>> types = parser.getTypeParameters();
          if (types.size() != 1)
              throw new ConfigurationException("ReversedType takes exactly one argument, " + types.size() + " given");
          return getInstance((AbstractType<T>) types.get(0));
      }
  
      public static <T> ReversedType<T> getInstance(AbstractType<T> baseType)
      {
          ReversedType<T> t = instances.get(baseType);
          return null == t
               ? instances.computeIfAbsent(baseType, ReversedType::new)
               : t;
      }
  
      private ReversedType(AbstractType<T> baseType)
      {
          super(ComparisonType.CUSTOM);
          this.baseType = baseType;
      }
  
      public boolean isEmptyValueMeaningless()
      {
          return baseType.isEmptyValueMeaningless();
      }
  
      @Override
      public <V> ByteSource asComparableBytes(ValueAccessor<V> accessor, V data, ByteComparable.Version version)
      {
          ByteSource src = baseType.asComparableBytes(accessor, data, version);
          if (src == null)    // Note: this will only compare correctly if used within a sequence
              return null;
          // Invert all bytes.
          // The comparison requirements for the original type ensure that this encoding will compare correctly with
          // respect to the reversed comparator function (and, specifically, prefixes of escaped byte-ordered types will
          // compare as larger). Additionally, the weak prefix-freedom requirement ensures this encoding will also be
          // weakly prefix-free.
          return () ->
          {
              int v = src.next();
              if (v == ByteSource.END_OF_STREAM)
                  return v;
              return v ^ 0xFF;
          };
      }
  
      @Override
      public <V> V fromComparableBytes(ValueAccessor<V> accessor, ByteSource.Peekable comparableBytes, ByteComparable.Version version)
      {
          return baseType.fromComparableBytes(accessor, ReversedPeekableByteSource.of(comparableBytes), version);
      }
  
      public <VL, VR> int compareCustom(VL left, ValueAccessor<VL> accessorL, VR right, ValueAccessor<VR> accessorR)
      {
          return baseType.compare(right, accessorR, left, accessorL);
      }
  
      @Override
      public int compareForCQL(ByteBuffer v1, ByteBuffer v2)
      {
          return baseType.compare(v1, v2);
      }
  
      public <V> String getString(V value, ValueAccessor<V> accessor)
      {
          return baseType.getString(value, accessor);
      }
  
      public ByteBuffer fromString(String source)
      {
          return baseType.fromString(source);
      }
  
      @Override
      public Term fromJSONObject(Object parsed) throws MarshalException
      {
          return baseType.fromJSONObject(parsed);
      }
  
      @Override
      public String toJSONString(ByteBuffer buffer, ProtocolVersion protocolVersion)
      {
          return baseType.toJSONString(buffer, protocolVersion);
      }
  
      @Override
      public boolean isCompatibleWith(AbstractType<?> otherType)
      {
          if (!(otherType instanceof ReversedType))
              return false;
  
          return this.baseType.isCompatibleWith(((ReversedType) otherType).baseType);
      }
  
      @Override
      public CQL3Type asCQL3Type()
      {
          return baseType.asCQL3Type();
      }
  
      @Override
      public TypeSerializer<T> getSerializer()
      {
          return baseType.getSerializer();
      }
  
      @Override
      public ArgumentDeserializer getArgumentDeserializer()
      {
          return baseType.getArgumentDeserializer();
      }
  
      @Override
      public <V> boolean referencesUserType(V name, ValueAccessor<V> accessor)
      {
          return baseType.referencesUserType(name, accessor);
      }
  
      @Override
      public AbstractType<?> expandUserTypes()
      {
          return getInstance(baseType.expandUserTypes());
      }
  
      @Override
      public boolean referencesDuration()
      {
          return baseType.referencesDuration();
      }
  
      @Override
      public ReversedType<?> withUpdatedUserType(UserType udt)
      {
          if (!referencesUserType(udt.name))
              return this;
  
          instances.remove(baseType);
  
          return getInstance(baseType.withUpdatedUserType(udt));
      }
  
      @Override
      public int valueLengthIfFixed()
      {
          return baseType.valueLengthIfFixed();
      }
  
      @Override
      public boolean isReversed()
      {
          return true;
      }
  
      @Override
      public String toString()
      {
          return getClass().getName() + "(" + baseType + ")";
      }
  
      private static final class ReversedPeekableByteSource extends ByteSource.Peekable
      {
          private final ByteSource.Peekable original;
  
          static ByteSource.Peekable of(ByteSource.Peekable original)
          {
              return original != null ? new ReversedPeekableByteSource(original) : null;
          }
  
          private ReversedPeekableByteSource(ByteSource.Peekable original)
          {
              super(null);
              this.original = original;
          }
  
          @Override
          public int next()
          {
              int v = original.next();
              if (v != END_OF_STREAM)
                  return v ^ 0xFF;
              return END_OF_STREAM;
          }
  
          @Override
          public int peek()
          {
              int v = original.peek();
              if (v != END_OF_STREAM)
                  return v ^ 0xFF;
              return END_OF_STREAM;
          }
      }
  
      @Override
      public ByteBuffer getMaskedValue()
      {
          return baseType.getMaskedValue();
      }
  
      @Override
      public AbstractType<T> unwrap()
      {
          return baseType.unwrap();
      }
  
      @Override
      public boolean isConstrainable()
      {
          return unwrap().isConstrainable();
      }
  }
  