/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.zeppelin.resource;

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


/**
 * InputStream from bytebuffer
 */
public class ByteBufferInputStream extends InputStream {

  ByteBuffer buf;

  public ByteBufferInputStream(ByteBuffer buf) {
    this.buf = buf;
  }

  public int read() throws IOException {
    if (!buf.hasRemaining()) {
      return -1;
    }
    return buf.get() & 0xFF;
  }

  public int read(byte[] bytes, int off, int len) throws IOException {
    if (!buf.hasRemaining()) {
      return -1;
    }
    len = Math.min(len, buf.remaining());
    buf.get(bytes, off, len);
    return len;
  }

  public static InputStream get(ByteBuffer buf) {
    if (buf.hasArray()) {
      return new ByteArrayInputStream(buf.array());
    } else {
      return new ByteBufferInputStream(buf);
    }
  }
}
