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.arrow.memory.netty;
  
  import io.netty.buffer.PooledByteBufAllocatorL;
  import io.netty.buffer.UnsafeDirectLittleEndian;
  import io.netty.util.internal.PlatformDependent;
  import org.apache.arrow.memory.AllocationManager;
  import org.apache.arrow.memory.ArrowBuf;
  import org.apache.arrow.memory.BufferAllocator;
  import org.apache.arrow.memory.ReferenceManager;
  
  /**
   * The default implementation of {@link AllocationManager}. The implementation is responsible for
   * managing when memory is allocated and returned to the Netty-based PooledByteBufAllocatorL.
   */
  public class NettyAllocationManager extends AllocationManager {
  
    public static final AllocationManager.Factory FACTORY =
        new AllocationManager.Factory() {
  
          @Override
          public AllocationManager create(BufferAllocator accountingAllocator, long size) {
            return new NettyAllocationManager(accountingAllocator, size);
          }
  
          @Override
          public ArrowBuf empty() {
            return EMPTY_BUFFER;
          }
        };
  
    /**
     * The default cut-off value for switching allocation strategies. If the request size is not
     * greater than the cut-off value, we will allocate memory by {@link PooledByteBufAllocatorL}
     * APIs, otherwise, we will use {@link PlatformDependent} APIs.
     */
    public static final int DEFAULT_ALLOCATION_CUTOFF_VALUE = Integer.MAX_VALUE;
  
    private static final PooledByteBufAllocatorL INNER_ALLOCATOR = new PooledByteBufAllocatorL();
    static final UnsafeDirectLittleEndian EMPTY = INNER_ALLOCATOR.empty;
    static final ArrowBuf EMPTY_BUFFER =
        new ArrowBuf(ReferenceManager.NO_OP, null, 0, NettyAllocationManager.EMPTY.memoryAddress());
    static final long CHUNK_SIZE = INNER_ALLOCATOR.getChunkSize();
  
    private final long allocatedSize;
    private final UnsafeDirectLittleEndian memoryChunk;
    private final long allocatedAddress;
  
    /** The cut-off value for switching allocation strategies. */
    NettyAllocationManager(
        BufferAllocator accountingAllocator, long requestedSize, int allocationCutOffValue) {
      super(accountingAllocator);
  
      if (requestedSize > allocationCutOffValue) {
        this.memoryChunk = null;
        this.allocatedAddress = PlatformDependent.allocateMemory(requestedSize);
        this.allocatedSize = requestedSize;
      } else {
        this.memoryChunk = INNER_ALLOCATOR.allocate(requestedSize);
        this.allocatedAddress = memoryChunk.memoryAddress();
        this.allocatedSize = memoryChunk.capacity();
      }
    }
  
    NettyAllocationManager(BufferAllocator accountingAllocator, long requestedSize) {
      this(accountingAllocator, requestedSize, DEFAULT_ALLOCATION_CUTOFF_VALUE);
    }
  
    /**
     * Get the underlying memory chunk managed by this AllocationManager.
     *
     * @return the underlying memory chunk if the request size is not greater than the cutoff value
     *     provided in the constructor , or null otherwise.
     * @deprecated this method will be removed in a future release.
     */
    @Deprecated
    UnsafeDirectLittleEndian getMemoryChunk() {
      return memoryChunk;
    }
  
    @Override
    protected long memoryAddress() {
      return allocatedAddress;
    }
  
    @Override
    protected void release0() {
      if (memoryChunk == null) {
        PlatformDependent.freeMemory(allocatedAddress);
      } else {
        memoryChunk.release();
      }
    }
  
    /**
     * Returns the underlying memory chunk size managed.
     *
     * <p>NettyAllocationManager rounds requested size up to the next power of two.
     */
    @Override
    public long getSize() {
      return allocatedSize;
    }
  }
  