LittleEndianDataInputStream.java

/**
 * Copyright (C) 2013 Gundog Studios LLC.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.gundogstudios.models.md2;

import java.io.DataInput;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * Taken from http://www.peterfranza.com/2008/09/26/little-endian-input-stream/
 */
public class LittleEndianDataInputStream extends InputStream implements DataInput {

	private DataInputStream d; // to get at high level readFully methods of DataInputStream
	private InputStream in; // to get at the low-level read methods of InputStream
	private byte w[]; // work array for buffering input

	public LittleEndianDataInputStream(InputStream in) {
		this.in = in;
		this.d = new DataInputStream(in);
		w = new byte[8];
	}

	public int available() throws IOException {
		return d.available();
	}

	public final short readShort() throws IOException {
		d.readFully(w, 0, 2);
		return (short) ((w[1] & 0xff) << 8 | (w[0] & 0xff));
	}

	public String readString(int length) throws IOException {
		if (length == 0) {
			return null;
		}

		byte[] b = new byte[length];
		d.readFully(b);

		return new String(b, "US-ASCII");
	}

	/**
	 * Note, returns int even though it reads a short.
	 */
	public final int readUnsignedShort() throws IOException {
		d.readFully(w, 0, 2);
		return ((w[1] & 0xff) << 8 | (w[0] & 0xff));
	}

	/**
	 * like DataInputStream.readChar except little endian.
	 */
	public final char readChar() throws IOException {
		d.readFully(w, 0, 2);
		return (char) ((w[1] & 0xff) << 8 | (w[0] & 0xff));
	}

	/**
	 * like DataInputStream.readInt except little endian.
	 */
	public final int readInt() throws IOException {
		d.readFully(w, 0, 4);
		return (w[3]) << 24 | (w[2] & 0xff) << 16 | (w[1] & 0xff) << 8 | (w[0] & 0xff);
	}

	/**
	 * like DataInputStream.readLong except little endian.
	 */
	public final long readLong() throws IOException {
		d.readFully(w, 0, 8);
		return (long) (w[7]) << 56 | (long) (w[6] & 0xff) << 48 | (long) (w[5] & 0xff) << 40
				| (long) (w[4] & 0xff) << 32 | (long) (w[3] & 0xff) << 24 | (long) (w[2] & 0xff) << 16
				| (long) (w[1] & 0xff) << 8 | (long) (w[0] & 0xff);
	}

	public final float readFloat() throws IOException {
		return Float.intBitsToFloat(readInt());
	}

	public final double readDouble() throws IOException {
		return Double.longBitsToDouble(readLong());
	}

	public final int read(byte b[], int off, int len) throws IOException {
		return in.read(b, off, len);
	}

	public final void readFully(byte b[]) throws IOException {
		d.readFully(b, 0, b.length);
	}

	public final void readFully(byte b[], int off, int len) throws IOException {
		d.readFully(b, off, len);
	}

	public final int skipBytes(int n) throws IOException {
		return d.skipBytes(n);
	}

	public final boolean readBoolean() throws IOException {
		return d.readBoolean();
	}

	public final byte readByte() throws IOException {
		return d.readByte();
	}

	public int read() throws IOException {
		return in.read();
	}

	public final int readUnsignedByte() throws IOException {
		return d.readUnsignedByte();
	}

	public final String readUTF() throws IOException {
		return d.readUTF();
	}

	public final void close() throws IOException {
		d.close();
	}

	@Deprecated
	public String readLine() throws IOException {
		return d.readLine();
	}
}