/*
    * Copyright (C) 2012, Google Inc. and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  
  package org.eclipse.jgit.internal.storage.file;
  
  import java.io.DataInput;
  import java.io.IOException;
  import java.io.InputStream;
  
  import org.eclipse.jgit.util.IO;
  import org.eclipse.jgit.util.NB;
  
  /**
   * An implementation of DataInput that only handles readInt() and readLong()
   * using the Git conversion utilities for network byte order handling. This is
   * needed to read {@link com.googlecode.javaewah.EWAHCompressedBitmap}s.
   */
  class SimpleDataInput implements DataInput {
  	private final InputStream fd;
  
  	private final byte[] buf = new byte[8];
  
  	SimpleDataInput(InputStream fd) {
  		this.fd = fd;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public int readInt() throws IOException {
  		readFully(buf, 0, 4);
  		return NB.decodeInt32(buf, 0);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public long readLong() throws IOException {
  		readFully(buf, 0, 8);
  		return NB.decodeInt64(buf, 0);
  	}
  
  	/**
  	 * Read unsigned int
  	 *
  	 * @return a long.
  	 * @throws java.io.IOException
  	 *             if any.
  	 */
  	public long readUnsignedInt() throws IOException {
  		readFully(buf, 0, 4);
  		return NB.decodeUInt32(buf, 0);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public void readFully(byte[] b) throws IOException {
  		readFully(b, 0, b.length);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public void readFully(byte[] b, int off, int len) throws IOException {
  		IO.readFully(fd, b, off, len);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public int skipBytes(int n) throws IOException {
  		throw new UnsupportedOperationException();
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public boolean readBoolean() throws IOException {
  		throw new UnsupportedOperationException();
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public byte readByte() throws IOException {
  		throw new UnsupportedOperationException();
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public int readUnsignedByte() throws IOException {
  		throw new UnsupportedOperationException();
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public short readShort() throws IOException {
  		throw new UnsupportedOperationException();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public int readUnsignedShort() throws IOException {
 		throw new UnsupportedOperationException();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public char readChar() throws IOException {
 		throw new UnsupportedOperationException();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public float readFloat() throws IOException {
 		throw new UnsupportedOperationException();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public double readDouble() throws IOException {
 		throw new UnsupportedOperationException();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public String readLine() throws IOException {
 		throw new UnsupportedOperationException();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public String readUTF() throws IOException {
 		throw new UnsupportedOperationException();
 	}
 }