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.service.accord.txn;
  
  import java.nio.ByteBuffer;
  import java.util.Objects;
  import javax.annotation.Nonnull;
  import javax.annotation.Nullable;
  import javax.annotation.concurrent.NotThreadSafe;
  
  import accord.utils.Invariants;
  
  /**
   * Item that is serialized by default
   */
  @NotThreadSafe
  public abstract class AbstractSerialized<T>
  {
      protected @Nullable final ByteBuffer latestVersionBytes;
      protected transient @Nullable T memoized = null;
  
      public AbstractSerialized(@Nullable ByteBuffer latestVersionBytes)
      {
          this.latestVersionBytes = latestVersionBytes;
      }
  
      public abstract long estimatedSizeOnHeap();
  
      protected boolean isNull()
      {
          return latestVersionBytes == null;
      }
  
      public void unmemoize()
      {
          memoized = null;
      }
  
      @Nullable
      protected ByteBuffer unsafeBytes()
      {
          return latestVersionBytes;
      }
  
      @Nonnull
      protected ByteBuffer bytes()
      {
          Invariants.nonNull(latestVersionBytes);
          return latestVersionBytes;
      }
  
      @Override
      public boolean equals(Object o)
      {
          if (this == o) return true;
          if (o == null || (o.getClass() != getClass())) return false;
  
          AbstractSerialized<?> that = (AbstractSerialized<?>) o;
          return Objects.equals(latestVersionBytes, that.latestVersionBytes);
      }
  
      @Override
      public int hashCode()
      {
          return latestVersionBytes != null ? latestVersionBytes.hashCode() : 0;
      }
  }
  