/*
 * Copyright 2008-present MongoDB, Inc.
 *
 * 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.
 *
 * Original Work: MIT License, Copyright (c) [2015-2020] all contributors
 * https://github.com/marianobarrios/tls-channel
 */

package com.mongodb.internal.connection.tlschannel;

import com.mongodb.internal.connection.tlschannel.util.DirectBufferDeallocator;

import java.nio.ByteBuffer;

Allocator that creates direct buffers. The free(ByteBuffer) method, if called, deallocates the buffer immediately, without having to wait for GC (and the finalizer) to run. Calling free(ByteBuffer) is actually optional, but should result in reduced memory consumption. 
Direct buffers are generally preferred for using with I/O, to avoid an extra user-space copy,
or to reduce garbage collection overhead.
/**
 * Allocator that creates direct buffers. The {@link #free(ByteBuffer)} method, if called,
 * deallocates the buffer immediately, without having to wait for GC (and the finalizer) to run.
 * Calling {@link #free(ByteBuffer)} is actually optional, but should result in reduced memory
 * consumption.
 *
 * <p>Direct buffers are generally preferred for using with I/O, to avoid an extra user-space copy,
 * or to reduce garbage collection overhead.
 */
public class DirectBufferAllocator implements BufferAllocator {

  private final DirectBufferDeallocator deallocator = new DirectBufferDeallocator();

  @Override
  public ByteBuffer allocate(int size) {
    return ByteBuffer.allocateDirect(size);
  }

  @Override
  public void free(ByteBuffer buffer) {
    // do not wait for GC (and finalizer) to run
    deallocator.deallocate(buffer);
  }
}