/*
    * 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.giraph.writable.kryo;
  
  import java.io.DataInput;
  import java.io.EOFException;
  import java.io.IOException;
  import java.io.InputStream;
  
  /**
   * Thin wrapper around DataInput so it can be used as an
   * {@link java.io.InputStream}
   *
   * For use with {@link com.esotericsoftware.kryo.io.Input}
   */
  public class DataInputWrapperStream extends InputStream {
    /** Wrapped DataInput object */
    private DataInput in;
  
    public void setDataInput(DataInput in) {
      this.in = in;
    }
  
    @Override
    public int read() throws IOException {
      try {
        return in.readByte() & 0xFF;
      } catch (EOFException e) {
        throw new RuntimeException(
            "Chunked input should never read more than chunked output wrote", e);
      }
    }
  
    @Override
    public int read(byte[] b, int off, int len) throws IOException {
      try {
        in.readFully(b, off, len);
        return len;
      } catch (EOFException e) {
        throw new RuntimeException(
            "Chunked input should never read more than chunked output wrote", e);
      }
    }
  }