content: /*
   * Copyright (C) 2017 Facebook, 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.
   */
  package io.airlift.drift.protocol;
  
  import static java.lang.Math.max;
  
  public class TMemoryBuffer
          implements TTransport
  {
      private byte[] data;
      private int head;
      private int tail;
  
      public TMemoryBuffer(int initialSize)
      {
          data = new byte[max(initialSize, 16)];
      }
  
      @Override
      public void read(byte[] buf, int off, int len)
              throws TTransportException
      {
          if (head - tail < len) {
              throw new TTransportException("Too few bytes in buffer");
          }
          System.arraycopy(data, tail, buf, off, len);
          tail += len;
      }
  
      @Override
      public void write(byte[] buf, int off, int len)
      {
          int available = data.length - head;
          if (available < len) {
              int need = len - available - tail;
              byte[] temp = new byte[max(data.length * 2, need)];
              System.arraycopy(data, tail, temp, 0, head - tail);
              data = temp;
              head -= tail;
              tail = 0;
          }
          System.arraycopy(buf, off, data, head, len);
          head += len;
      }
  }
  