StreamUtils.java

/*
** StreamUtils.java
**
** Copyright (c) 2011 Peter McQuillan
**
** All Rights Reserved.
**                       
** Distributed under the BSD Software License (see license.txt)  
**
*/

package com.beatofthedrum.alacdecoder;

class StreamUtils
{
    public static void stream_read(MyStream mystream, int size, int[] buf, int startPos) {
        byte[] byteBuf = new byte[size];
        int bytes_read = stream_read(mystream, size, byteBuf, 0);
        for(int i=0; i < bytes_read; i++) {
			buf[startPos + i] = byteBuf[i];
		}
    }

	public static int stream_read(MyStream mystream, int size, byte[] buf, int startPos)
	{
		int bytes_read = 0;

		try
		{
			bytes_read = mystream.stream.read(buf, startPos, size);
		}
		catch (Exception err)
		{
			System.err.println("stream_read: exception thrown: " + err);
		}
		mystream.currentPos = mystream.currentPos + bytes_read;
        return bytes_read;
	}

	public static int stream_read_uint32(MyStream mystream)
	{
		int v = 0;
		int tmp = 0;
		byte[] bytebuf = mystream.read_buf;
		int bytes_read = 0;

		try
		{
			bytes_read = mystream.stream.read(bytebuf, 0, 4);
			mystream.currentPos = mystream.currentPos + bytes_read;
			tmp =  (bytebuf[0] & 0xff);

			v = tmp << 24;
			tmp =  (bytebuf[1] & 0xff);

			v = v | (tmp << 16);
			tmp =  (bytebuf[2] & 0xff);

			v = v | (tmp << 8);

			tmp =  (bytebuf[3] & 0xff);
			v = v | tmp;

		}
		catch (Exception err)
		{
			System.err.println("stream_read_uint32: exception thrown: " + err);
		}
		
		return v;
	}

	public static int stream_read_int16(MyStream mystream)
	{
		int v = 0;
		try
		{
			v = mystream.stream.readShort();
			mystream.currentPos = mystream.currentPos + 2;
		}
		catch (Exception err)
		{
		}
		
		return v;
	}
	public static int stream_read_uint16(MyStream mystream)
	{
		int v = 0;
		int tmp = 0;
		byte[] bytebuf = mystream.read_buf;
		int bytes_read = 0;

		try
		{
			bytes_read = mystream.stream.read(bytebuf, 0, 2);
			mystream.currentPos = mystream.currentPos + bytes_read;
			tmp =  (bytebuf[0] & 0xff);
			v = tmp << 8;
			tmp =  (bytebuf[1] & 0xff);
			
			v = v | tmp;
		}
		catch (Exception e)
		{
		}

		return v;
	}

	public static int stream_read_uint8(MyStream mystream)
	{
		int v = 0;
		int bytes_read = 0;
		byte[] bytebuf = mystream.read_buf;
		
		try
		{
			bytes_read = mystream.stream.read(bytebuf, 0, 1);
			v =  (bytebuf[0] & 0xff);
			mystream.currentPos = mystream.currentPos + 1;
		}
		catch (Exception e)
		{
		}		
			
		return v;
	}

	public static void stream_skip(MyStream mystream, int skip)
	{
        int toskip = skip;
        int bytes_read = 0;

        if(toskip < 0)
		{
			System.err.println("stream_skip: request to seek backwards in stream - not supported, sorry");
			return;
		}

        try
        {
            bytes_read = mystream.stream.skipBytes(toskip);
            mystream.currentPos = mystream.currentPos + bytes_read;
        }
        catch (java.io.IOException ioe)
        {
        }
    }

	public static int stream_eof(MyStream mystream)
	{
		// TODO

		return 0;
	}

	public static int stream_tell(MyStream mystream)
	{
		return (mystream.currentPos);
	}
	public static int stream_setpos(MyStream mystream, int pos)
	{		
		return -1;
	}

}