SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package cc.squirreljme.emulator.terminal;

import cc.squirreljme.emulator.MLECallWouldFail;
import java.io.IOException;
import java.io.OutputStream;

/**
 * This is a terminal pipe which prints to a real output stream, it does still
 * prevent the target stream from being closed.
 *
 * @since 2020/07/06
 */
public final class RealTerminalPipe
    implements TerminalPipe
{
    /** The stream to write to. */
    protected final OutputStream out;
    
    /** Is this closed? */
    private boolean _closed;
    
    /**
     * Initializes the real pipe.
     * 
     * @param __out The real pipe to target.
     * @throws NullPointerException On null arguments.
     * @since 2020/07/06
     */
    public RealTerminalPipe(OutputStream __out)
        throws NullPointerException
    {
        if (__out == null)
            throw new NullPointerException("NARG");
        
        this.out = __out;
    }
    
    /**
     * {@inheritDoc}
     * @since 2020/07/06
     */
    @Override
    public final void close()
        throws IOException
    {
        synchronized (this)
        {
            // Have close go first so that the output is closed
            try
            {
                this.out.close();
            }
            
            // Always mark as closed regardless of failure or not
            finally
            {
                this._closed = true;
            }
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2020/07/06
     */
    @Override
    public final void flush()
        throws IOException
    {
        synchronized (this)
        {
            if (this._closed)
                throw new IOException("Real pipe closed.");
            
            this.out.flush();
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2020/07/06
     */
    @Override
    public final int read(byte[] __b, int __o, int __l)
        throws MLECallWouldFail
    {
        throw new MLECallWouldFail("Cannot read a real pipe.");
    }
    
    /**
     * {@inheritDoc}
     * @since 2020/07/06
     */
    @Override
    public final void write(int __b)
        throws IOException
    {
        synchronized (this)
        {
            if (this._closed)
                throw new IOException("Real pipe closed.");
            
            this.out.write(__b);
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2020/07/06
     */
    @Override
    public final void write(byte[] __b, int __o, int __l)
        throws IOException, MLECallWouldFail
    {
        if (__b == null || __o < 0 || __l < 0 || (__o + __l) > __b.length)
            throw new MLECallWouldFail("Null or out of bounds argument.");
        
        synchronized (this)
        {
            if (this._closed)
                throw new IOException("Real pipe closed.");
            
            this.out.write(__b, __o, __l);
        }
    }
}