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Object Automation library
There is a newer version: 3.7.10
/*  Copyright 1999 Vince Via [email protected]
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/
package com.viaoa.comm.multiplexer.io;

import java.net.*;
import java.io.*;

/**
 * A "virtual" socket connection to an MultiplexerServerSocket through a multiplexed connection. A
 * MultiplexerSocket is created and managed by MultiplexerSocketController, so that the input and output
 * streams are able to share the real socket.
 * 
 * @author vvia
 */
public abstract class VirtualSocket extends Socket {

    /**
     * Real socket connection id (assigned on server)
     */
    protected final int _connectionId;
    /**
     * unique identifer (assigned by MultiplexerSocketController)
     */
    protected final int _id;

    /**
     * Name of server socket.
     */
    protected String _serverSocketName;

    /**
     * the internal stream returned by getInputStream. All reads will be share the real socket.
     */
    private InputStream _inputStream;

    /**
     * the internal stream returned by getOutputStream. All writes will share the real socket.
     */
    private OutputStream _outputStream;

    /**
     * Lock used when waiting to perform a read on the real socket.
     */
    protected final Object _lockObject = new Object();

    // timeout used when waiting to read
    private int timeoutSeconds; 
    
    
    /**
     * Called by MultiplexerSocketController when creating a new socket or receiving a command to create
     * a new virtual socket.
     * 
     * @param id
     *            seq number assigned by MultiplexerSocketController.
     */
    protected VirtualSocket(int connectionId, int id, String serverSocketName) {
        if (id < 0) {
            throw new IllegalArgumentException("id can not be less then 0");
        }
        this._connectionId = connectionId;
        this._id = id;
        this._serverSocketName = serverSocketName;
        createInputStream();
        createOutputStream();
    }

    /**
     * Implement an inputStream that will use/share/multiplex the "real" socket.
     */
    protected synchronized void createInputStream() {
        if (_inputStream != null) return;

        _inputStream = new InputStream() {
            @Override
            public int read() throws IOException {
                int value = VirtualSocket.this.read();
                return value;
            }

            @Override
            public int read(byte[] bs) throws IOException {
                return this.read(bs, 0, bs.length);
            }

            @Override
            public int read(byte[] bs, int off, int len) throws IOException {
                if (bs == null || len < 1) return 0;
                int x = VirtualSocket.this.read(bs, off, len);
                return x;
            }
        };
    }

    @Override
    public InputStream getInputStream() throws IOException {
        if (isClosed()) {
            throw new SocketException("Socket is closed");
        }

        if (_inputStream != null) {
            createInputStream();
        }
        return _inputStream;
    }

    /**
     * Implement an outputStream that will use/share/multiplex the "real" socket.
     */
    protected synchronized void createOutputStream() {
        if (_outputStream != null) return;

        _outputStream = new OutputStream() {
            @Override
            public void write(int b) throws IOException {
                VirtualSocket.this.write(b);
            }

            @Override
            public void write(byte[] bs) throws IOException {
                write(bs, 0, bs.length);
            }

            @Override
            public void write(byte[] bs, int off, int len) throws IOException {
                if (bs == null || len < 1) return;
                VirtualSocket.this.write(bs, off, len);
            }
        };
    }

    @Override
    public OutputStream getOutputStream() throws IOException {
        if (isClosed()) {
            throw new SocketException("Socket is closed");
        }

        if (_outputStream == null) {
            createOutputStream();
        }
        return _outputStream;
    }

    /**
     * The ID that is assigned on the server to the real socket connection.
     */
    public int getConnectionId() {
        return _connectionId;
    }

    /**
     * The ID that is assigned by MultiplexerSocketController. This is assigned during the constructor,
     * and is a sequential number.
     */
    public int getId() {
        return _id;
    }

    public String getServerSocketName() {
        return this._serverSocketName;
    }

    /**
     * Used so that the real socket is used for the vsocket read. MultiplexerSocketController will
     * implement these methods and then manage access to the "real" socket.
     */
    public abstract int read(byte[] bs, int off, int len) throws IOException;

    public abstract int read() throws IOException;

    /**
     * Used so that the real socket is used for the vsocket write. MultiplexerSocketController will
     * implement these methods and then manage access to the "real" socket.
     */
    public abstract void write(byte[] bs, int off, int len) throws IOException;

    public abstract void write(int b) throws IOException;

    public abstract void close(boolean bSendCommand) throws IOException;
    
    public void setTimeoutSeconds(int x) {
        this.timeoutSeconds = x;
    }
    public int getTimeoutSeconds() {
        return this.timeoutSeconds;
    }
    
}