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.map;
  
  import net.openhft.chronicle.bytes.BytesStore;
  import net.openhft.chronicle.hash.ChronicleHash;
  import net.openhft.chronicle.hash.Data;
  import net.openhft.chronicle.set.SetContext;
  
  /**
   * Context, in which {@link MapEntry MapEntries} are accessed. {@code MapContext} allows to access
   * {@link MapEntryOperations}, configured for the accessed {@link ChronicleMap} via {@link
   * ChronicleMapBuilder#entryOperations(MapEntryOperations)}. {@code MapContext} implements {@code
   * MapEntryOperations} by delegation to the configured {@code entryOperations}. The same for
   * {@link DefaultValueProvider}: {@code MapContext} delegates to the {@code DefaultValueProvider}
   * configured for the accessed {@code ChronicleMap} via {@link
   * ChronicleMapBuilder#defaultValueProvider(DefaultValueProvider)}, or the default {@code
   * DefaultValueProvider} implementation.
   *
   * @param <K> the map key type
   * @param <V> the map value type
   * @param <R> the return type of {@link MapEntryOperations} specified for the queried map
   */
  public interface MapContext<K, V, R>
          extends SetContext<K, R>, MapEntryOperations<K, V, R>, DefaultValueProvider<K, V> {
      /**
       * Returns the accessed {@code ChronicleMap}. Synonym to {@link #map()}.
       */
      @Override
      ChronicleHash<K, ?, ?, ?> hash();
  
      /**
       * Returns the accessed {@code ChronicleMap}. Synonym to {@link #hash()}.
       */
      ChronicleMap<K, V> map();
  
      /**
       * Wraps the given value as a {@code Data}. Useful when you need to pass a value
       * to some method accepting {@code Data}, for example, {@link MapEntryOperations#replaceValue(
       *MapEntry, Data)}, without allocating new objects (i. e. garbage) and {@code ThreadLocals}.
       * <p>
       * <p>The returned {@code Data} object shouldn't outlive this {@code MapContext}.
       *
       * @param value the value object to wrap
       * @return the value as {@code Data}
       */
      Data<V> wrapValueAsData(V value);
  
      /**
       * Wraps the given value bytes as a {@code Data}. Useful when you need to pass a value
       * to some method accepting {@code Data}, for example, {@link MapEntryOperations#replaceValue(
       *MapEntry, Data)}, without allocating manual deserialization and {@code ThreadLocals}.
       * <p>
       * <p>The returned {@code Data} object shouldn't outlive this {@code MapContext}.
       *
       * @param valueBytes the value bytes to wrap
       * @param offset     offset within the given valueBytes, the actual value bytes start from
       * @param size       length of the value bytes sequence
       * @return the value bytes as {@code Data}
       */
      Data<V> wrapValueBytesAsData(BytesStore valueBytes, long offset, long size);
  }
  