Bug 122666 Performance enhancement for RandomAccessFile
The readInt method for RandomAccessFile makes 4 calls to system, and the calls are not buffered.
core/org.eclipse.birt.core/src/org/eclipse/birt/core/archive/RAFileInputStream.java
{
	private RandomAccessFile parent;
	private long startPos; 	
	private long endPos;   	
	private long cur;		
	
	/**
	 * @param parentFile - underlying RandomAccess file
	 * @param startPos - the (global) position of the first character in parentFile 
	 * @param endPos - the (global) position of EOF mark (not a valid character in the file)
	 */
	public RAFileInputStream( RandomAccessFile parentFile, long startPos, long endPos )
	{	
		this.parent = parentFile;
		this.startPos = startPos;
		this.endPos = endPos;
		
		try 
		{
			seekParent( 0 );
		} 
		catch (IOException e) 
		{
			
			e.printStackTrace();
		}
	}
    /**
     * The same behavior as InputStream.read().<br>
     * Reads the next byte of data from the input stream. The value byte is