countingoutputstream.java

JPC: x86 PC Hardware Emulator. 牛津大学开发的一个纯JAVA的x86系统结构硬件模拟器。

/*
    JPC: A x86 PC Hardware Emulator for a pure Java Virtual Machine
    Release Version 2.0

    A project from the Physics Dept, The University of Oxford

    Copyright (C) 2007 Isis Innovation Limited

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License version 2 as published by
    the Free Software Foundation.

    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, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
    Details (including contact information) can be found at: 

    www.physics.ox.ac.uk/jpc
*/

package org.jpc.emulator.memory.codeblock.fastcompiler;
    
import java.io.*;

public class CountingOutputStream extends OutputStream
{
    private final OutputStream backing;
    private int count;
    
    public CountingOutputStream(OutputStream wraps)
    {
	backing = wraps;
	count = 0;
    }
    
    public int position()
    {
	return count;
    }
    
    public void close() throws IOException { backing.close(); }
    public void flush() throws IOException { backing.flush(); }

    public void write(byte[] b) throws IOException
    {
	if ((count + b.length) > 0xffff)
	    throw new IllegalStateException("Oversize Method");

	backing.write(b); count += b.length;
    }
 
    public void write(byte[] b, int off, int len) throws IOException
    {
	if ((count + len) > 0xffff)
	    throw new IllegalStateException("Oversize Method");
	    
	backing.write(b, off, len); count += len;
    }

    public void write(int b) throws IOException				    
    {
	if ((count + 1) > 0xffff)
	    throw new IllegalStateException("Oversize Method");
	
	backing.write(b); count++;
    }
}