content: /*
   * Copyright (c) 2010-2018 Nathan Rajlich
   *
   *  Permission is hereby granted, free of charge, to any person
   *  obtaining a copy of this software and associated documentation
   *  files (the "Software"), to deal in the Software without
   *  restriction, including without limitation the rights to use,
   *  copy, modify, merge, publish, distribute, sublicense, and/or sell
   *  copies of the Software, and to permit persons to whom the
   *  Software is furnished to do so, subject to the following
   *  conditions:
   *
   *  The above copyright notice and this permission notice shall be
   *  included in all copies or substantial portions of the Software.
   *
   *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
   *  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
   *  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
   *  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
   *  OTHER DEALINGS IN THE SOFTWARE.
   */
  
  package com.alipay.api.java_websocket.util;
  
  import java.nio.ByteBuffer;
  
  /**
   * Utility class for ByteBuffers
   */
  public class ByteBufferUtils {
  
      /**
       * Private constructor for static class
       */
      private ByteBufferUtils() {
      }
  
      /**
       * Transfer from one ByteBuffer to another ByteBuffer
       *
       * @param source the ByteBuffer to copy from
       * @param dest   the ByteBuffer to copy to
       * @return the number of transferred bytes
       */
      public static int transferByteBuffer(ByteBuffer source, ByteBuffer dest) {
          if (source == null || dest == null) {
              throw new IllegalArgumentException();
          }
          int fremain = source.remaining();
          int toremain = dest.remaining();
          if (fremain > toremain) {
              int limit = Math.min(fremain, toremain);
              source.limit(limit);
              dest.put(source);
              return limit;
          } else {
              dest.put(source);
              return fremain;
          }
      }
  
      /**
       * Get a ByteBuffer with zero capacity
       *
       * @return empty ByteBuffer
       */
      public static ByteBuffer getEmptyByteBuffer() {
          return ByteBuffer.allocate(0);
      }
  }
  