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.hash.impl.util;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.nio.channels.FileChannel;
  
  public final class FileIOUtils {
  
      private FileIOUtils() {
      }
  
      public static void readFully(FileChannel fileChannel, long filePosition, ByteBuffer buffer)
              throws IOException {
          int startBufferPosition = buffer.position();
          while (buffer.remaining() > 0 &&
                  buffer.position() < fileChannel.size()) {
              int bytesRead = fileChannel.read(buffer,
                      filePosition + buffer.position() - startBufferPosition);
              if (bytesRead == -1)
                  break;
          }
      }
  
      public static void writeFully(FileChannel fileChannel, long filePosition, ByteBuffer buffer)
              throws IOException {
          int startBufferPosition = buffer.position();
          while (buffer.remaining() > 0) {
              fileChannel.write(buffer, filePosition + buffer.position() - startBufferPosition);
          }
      }
  }
  