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.runtime.gcf;

import java.io.IOException;
import java.io.InputStream;

/**
 * This is an input which tracks if it has been closed, if EOF is read from
 * a stream then it will automatically be closed.
 *
 * @since 2019/05/13
 */
public final class TrackedInputStream
    extends InputStream
{
    /** The tracker used. */
    protected final ConnectionStateTracker tracker;
    
    /** The wrapped stream. */
    protected final InputStream in;
    
    /**
     * Initializes the tracked stream.
     *
     * @param __t The tracker.
     * @param __in The input.
     * @throws NullPointerException On null arguments.
     * @since 2019/05/13
     */
    public TrackedInputStream(ConnectionStateTracker __t, InputStream __in)
        throws NullPointerException
    {
        if (__t == null || __in == null)
            throw new NullPointerException("NARG");
        
        this.tracker = __t;
        this.in = __in;
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/13
     */
    @Override
    public final int available()
        throws IOException
    {
        /* {@squirreljme.error EC0r The input has been closed.} */
        if (this.tracker._inclosed)
            throw new IOException("EC0r");
        
        return this.in.available();
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/13
     */
    @Override
    public final void close()
        throws IOException
    {
        // Always close the input
        this.in.close();
        
        // Set stream as closed
        this.tracker._inclosed = true;
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/13
     */
    @Override
    public final int read()
        throws IOException
    {
        /* {@squirreljme.error EC0s The input has been closed.} */
        if (this.tracker._inclosed)
            throw new IOException("EC0s");
        
        // Read data
        int rv = this.in.read();
        if (rv < 0)
            this.close();
        return rv;
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/13
     */
    @Override
    public final int read(byte[] __b)
        throws IOException
    {
        /* {@squirreljme.error EC0t The input has been closed.} */
        if (this.tracker._inclosed)
            throw new IOException("EC0t");
        
        // Read data
        int rv = this.in.read(__b);
        if (rv < 0)
            this.close();
        return rv;
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/13
     */
    @Override
    public final int read(byte[] __b, int __o, int __l)
        throws IOException
    {
        /* {@squirreljme.error EC0u The input has been closed.} */
        if (this.tracker._inclosed)
            throw new IOException("EC0u");
        
        // Read data
        int rv = this.in.read(__b, __o, __l);
        if (rv < 0)
            this.close();
        return rv;
    }
}