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.impl.stage.data.bytes;
  
  import net.openhft.chronicle.bytes.Bytes;
  import net.openhft.chronicle.bytes.RandomDataInput;
  import net.openhft.chronicle.hash.AbstractData;
  import net.openhft.chronicle.hash.impl.stage.entry.SegmentStages;
  import net.openhft.chronicle.hash.impl.stage.hash.CheckOnEachPublicOperation;
  import net.openhft.chronicle.map.impl.VanillaChronicleMapHolder;
  import net.openhft.chronicle.map.impl.stage.entry.MapEntryStages;
  import net.openhft.chronicle.map.impl.stage.map.ValueBytesInterop;
  import net.openhft.sg.Stage;
  import net.openhft.sg.StageRef;
  import net.openhft.sg.Staged;
  
  @Staged
  public class EntryValueBytesData<V> extends AbstractData<V> {
  
      @StageRef
      VanillaChronicleMapHolder<?, V, ?> mh;
      @StageRef
      ValueBytesInterop<V> vi;
      @StageRef
      SegmentStages s;
      @StageRef
      MapEntryStages<?, V> entry;
      @StageRef
      CheckOnEachPublicOperation checkOnEachPublicOperation;
  
      @Stage("CachedEntryValue")
      private V cachedEntryValue =
              mh.m().valueType() == CharSequence.class ? (V) new StringBuilder() : null;
      @Stage("CachedEntryValue")
      private boolean cachedEntryValueRead = false;
  
      private void initCachedEntryValue() {
          cachedEntryValue = innerGetUsing(cachedEntryValue);
          cachedEntryValueRead = true;
      }
  
      public boolean cachedEntryValueInit() {
          return cachedEntryValueRead;
      }
  
      public void closeCachedEntryValue() {
          cachedEntryValueRead = false;
      }
  
      @Override
      public RandomDataInput bytes() {
          checkOnEachPublicOperation.checkOnEachPublicOperation();
          return s.segmentBS;
      }
  
      @Override
      public long offset() {
          checkOnEachPublicOperation.checkOnEachPublicOperation();
          return entry.valueOffset;
      }
  
      @Override
      public long size() {
          checkOnEachPublicOperation.checkOnEachPublicOperation();
          return entry.valueSize;
      }
  
      @Override
      public V get() {
          checkOnEachPublicOperation.checkOnEachPublicOperation();
          return cachedEntryValue;
      }
  
      @Override
      public V getUsing(V using) {
          checkOnEachPublicOperation.checkOnEachPublicOperation();
          return innerGetUsing(using);
      }
  
      private V innerGetUsing(V usingValue) {
          Bytes segmentBytes = s.segmentBytesForRead();
          segmentBytes.readPosition(entry.valueOffset);
          return vi.valueReader.read(segmentBytes, size(), usingValue);
      }
  }
  