code: /*
   * 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.datasketches.memory.internal;
  
  import java.nio.ByteOrder;
  
  import org.apache.datasketches.memory.MemoryRequestServer;
  import org.apache.datasketches.memory.WritableBuffer;
  
  /**
   * Implementation of {@link WritableBuffer} for heap-based, native byte order.
   *
   * @author Roman Leventov
   * @author Lee Rhodes
   */
  final class HeapWritableBufferImpl extends NativeWritableBufferImpl {
    private final Object unsafeObj;
  
    HeapWritableBufferImpl(
        final Object unsafeObj,
        final long offsetBytes,
        final long capacityBytes,
        final int typeId,
        final long cumOffsetBytes,
        final MemoryRequestServer memReqSvr) {
      super(capacityBytes);
      this.unsafeObj = unsafeObj;
      this.offsetBytes = offsetBytes;
      this.capacityBytes = capacityBytes;
      this.typeId = removeNnBuf(typeId) | HEAP | BUFFER | NATIVE;
      this.cumOffsetBytes = cumOffsetBytes;
      this.memReqSvr = memReqSvr; //in ResourceImpl
      if ((this.owner != null) && (this.owner != Thread.currentThread())) {
        throw new IllegalStateException(THREAD_EXCEPTION_TEXT);
      }
      this.owner = Thread.currentThread();
    }
  
    @Override
    BaseWritableBufferImpl toWritableRegion(
        final long regionOffsetBytes,
        final long capacityBytes,
        final boolean readOnly,
        final ByteOrder byteOrder) {
      final long newOffsetBytes = offsetBytes + regionOffsetBytes;
      final long newCumOffsetBytes = cumOffsetBytes + regionOffsetBytes;
      int typeIdOut = removeNnBuf(typeId) | BUFFER | REGION | (readOnly ? READONLY : 0);
  
      if (Util.isNativeByteOrder(byteOrder)) {
        typeIdOut |= NATIVE;
        return new HeapWritableBufferImpl(
            unsafeObj, newOffsetBytes, capacityBytes, typeIdOut, newCumOffsetBytes, memReqSvr);
      } else {
        typeIdOut |= NONNATIVE;
        return new HeapNonNativeWritableBufferImpl(
            unsafeObj, newOffsetBytes, capacityBytes, typeIdOut, newCumOffsetBytes, memReqSvr);
      }
    }
  
    @Override
    BaseWritableMemoryImpl toWritableMemory(final boolean readOnly, final ByteOrder byteOrder) {
      int typeIdOut = removeNnBuf(typeId) | MEMORY | (readOnly ? READONLY : 0);
  
      if (byteOrder == ByteOrder.nativeOrder()) {
        typeIdOut |= NATIVE;
        return new HeapWritableMemoryImpl(
            unsafeObj, offsetBytes, capacityBytes, typeIdOut, cumOffsetBytes, memReqSvr);
      } else {
        typeIdOut |= NONNATIVE;
        return new HeapNonNativeWritableMemoryImpl(
            unsafeObj, offsetBytes, capacityBytes, typeIdOut, cumOffsetBytes, memReqSvr);
      }
    }
  
    @Override
    BaseWritableBufferImpl toDuplicate(final boolean readOnly, final ByteOrder byteOrder) {
      int typeIdOut = removeNnBuf(typeId) | BUFFER | DUPLICATE | (readOnly ? READONLY : 0);
  
      if (byteOrder == ByteOrder.nativeOrder()) {
        typeIdOut |= NATIVE;
        return new HeapWritableBufferImpl(
            unsafeObj, offsetBytes, capacityBytes, typeIdOut, cumOffsetBytes, memReqSvr);
      } else {
        typeIdOut |= NONNATIVE;
        return new HeapNonNativeWritableBufferImpl(
            unsafeObj, offsetBytes, capacityBytes, typeIdOut, cumOffsetBytes, memReqSvr);
      }
    }
  
    @Override
    Object getUnsafeObject() {
      return unsafeObj;
    }
  
  }
  