/* ****************************************************************************
  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.

  See NOTICE file for details.
**************************************************************************** */
package org.jpype.pickle;

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;

/**
 *
 * @author Karl Einar Nelson
 */
public class ByteBufferInputStream extends InputStream
{

  ByteBuffer bb = ByteBuffer.allocate(1024);
  int loaded = 0;

  public void put(byte[] bytes)
  {
    // If we have additional capacity, use it
    if (bytes.length < bb.remaining())
    {
      int p = bb.position();
      bb.position(loaded);
      bb.put(bytes);
      loaded = bb.position();
      bb.position(p);
      return;
    }

    // Okay we may need to allocate more
    ByteBuffer bb2 = bb;
    int r = loaded - bb.position();

    // If we don't have space, make a new buffer.
    if (r + bytes.length > bb.capacity())
      bb = ByteBuffer.allocate(r + bytes.length);

    // If we have remaining bytes, then keep them
    if (r > 0)
    {
      bb.put(bb2.array(), bb2.position(), r);
    }

    // Add the new data
    bb.put(bytes);
    loaded = bb.position();
    bb.position(0);
  }

  public int available()
  {
    int out = loaded - bb.position();
    return out;
  }

  @Override
  public int read() throws IOException
  {
    int r = loaded - bb.position();
    if (r > 0)
    {
      int p = bb.get();
      return p;
    }
    return -1;
  }

  @Override
  public int read(byte[] arg0) throws IOException
  {
    int r = loaded - bb.position();
    if (arg0.length <= r)
    {
      bb.get(arg0);
      return arg0.length;
    }

    bb.get(arg0, 0, r);
    return r;
  }

  @Override
  public int read(byte[] buffer, int offset, int len) throws IOException
  {
    int r = loaded - bb.position();
    if (r == 0)
      return -1;

    if (len > r)
    {
      len = r;
    }

    bb.get(buffer, offset, len);
    return len;
  }
}