code: /*
   * Copyright 2012-2018 Chronicle Map Contributors
   *
   * Licensed 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 net.openhft.chronicle.hash.serialization;
  
  import net.openhft.chronicle.bytes.Bytes;
  import net.openhft.chronicle.hash.ChronicleHashBuilder;
  import net.openhft.chronicle.map.ChronicleMapBuilder;
  import net.openhft.chronicle.wire.Marshallable;
  import org.jetbrains.annotations.NotNull;
  import org.jetbrains.annotations.Nullable;
  
  /**
   * Deserializer of objects from bytes, pairing {@link BytesWriter}, without accepting additional
   * information about serialized objects.
   * <p>
   * <p>Read <a href="https://github.com/OpenHFT/Chronicle-Map/blob/ea/docs/CM_Tutorial_Bytes.adoc">{@code
   * BytesWriter} and {@code BytesReader}</a> and
   * <a href="https://github.com/OpenHFT/Chronicle-Map/blob/ea/docs/CM_Tutorial.adoc#custom-serialization-checklist">custom
   * serialization checklist</a> sections in the Chronicle Map tutorial for more information on this
   * interface, how to implement and use it properly.
   *
   * @param <T> type of objects deserialized
   * @see BytesWriter
   * @see ChronicleHashBuilder#keyMarshallers(BytesReader, BytesWriter)
   * @see ChronicleMapBuilder#valueMarshallers(BytesReader, BytesWriter)
   */
  public interface BytesReader<T> extends Marshallable {
  
      /**
       * Reads and returns the object from {@link Bytes#readPosition()} (i. e. the current position)
       * in the given {@code in}. Should attempt to reuse the given {@code using} object, i. e. to
       * read the deserialized data into the given object. If it is possible, this object then
       * returned from this method back. If it is impossible for any reason, a new object should be
       * created and returned. The given {@code using} object could be {@code null}, in this case this
       * method, of cause, should create a new object.
       * <p>
       * <p>This method should increment the position in the given {@code Bytes}, i. e. consume the
       * read bytes. {@code in} bytes shouldn't be written.
       *
       * @param in    the {@code Bytes} to read the object from
       * @param using the object to read the deserialized data into, could be {@code null}
       * @return the object read from the bytes, either reused or newly created
       */
      @NotNull
      T read(Bytes in, @Nullable T using);
  }
  