/* This file is part of the db4o object database http://www.db4o.com

Copyright (C) 2004 - 2011  Versant Corporation http://www.versant.com

db4o is free software; you can redistribute it and/or modify it under
the terms of version 3 of the GNU General Public License as published
by the Free Software Foundation.

db4o 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.db4o.foundation;

import java.io.*;


public final class PrimitiveCodec {
	
	public static final int INT_LENGTH = 4;
	
	public static final int LONG_LENGTH = 8;
	
	
	public static final int readInt(byte[] buffer, int offset){
        offset += 3;
        return (buffer[offset] & 255) | (buffer[--offset] & 255)
            << 8 | (buffer[--offset] & 255)
            << 16 | buffer[--offset]
            << 24;
	}

	public static final int readInt(ByteArrayInputStream in){
		return (in.read() << 24) | ((in.read() & 255) << 16) | ((in.read() & 255) << 8) | (in.read() & 255);
	}

	public static final void writeInt(byte[] buffer, int offset, int val){
        offset += 3;
        buffer[offset] = (byte)val;
        buffer[--offset] = (byte) (val >>= 8);
        buffer[--offset] = (byte) (val >>= 8);
        buffer[--offset] = (byte) (val >> 8);
	}

	public static final void writeInt(ByteArrayOutputStream out, int val){
		out.write((byte)(val >> 24));
		out.write((byte)(val >> 16));
		out.write((byte)(val >> 8));
        out.write((byte)val);
	}

	public static final void writeLong(byte[] buffer, long val){
		writeLong(buffer, 0, val);
	}
	
	public static final void writeLong(byte[] buffer, int offset, long val){
		for (int i = 0; i < LONG_LENGTH; i++){
			buffer[offset++] = (byte) (val >> ((7 - i) * 8));
		}
	}

	public static final void writeLong(ByteArrayOutputStream out, long val){
		for (int i = 0; i < LONG_LENGTH; i++){
			out.write((byte) (val >> ((7 - i) * 8)));
		}
	}

	public static final long readLong(byte[] buffer, int offset){
		long ret = 0;
		for (int i = 0; i < LONG_LENGTH; i++){
			ret = (ret << 8) + (buffer[offset++] & 0xff);
		}
		return ret;
	}

	public static final long readLong(ByteArrayInputStream in){
		long ret = 0;
		for (int i = 0; i < LONG_LENGTH; i++){
			ret = (ret << 8) + ((byte)in.read() & 0xff);
		}
		return ret;
	}

}