// Copyright 2012 Citrix Systems, Inc. Licensed under the
// Apache License, Version 2.0 (the "License"); you may not use this
// file except in compliance with the License.  Citrix Systems, Inc.
// reserves all rights not expressly granted by 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.
// 
// Automatically generated by addcopyright.py at 04/03/2012
package com.cloud.utils.nio;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectionKey;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.spi.SelectorProvider;
import java.util.WeakHashMap;

import org.apache.log4j.Logger;

public class NioServer extends NioConnection {
    private final static Logger s_logger = Logger.getLogger(NioServer.class);
    
    protected InetSocketAddress _localAddr;
    
    protected WeakHashMap<InetSocketAddress, Link> _links;
    
    public NioServer(String name, int port, int workers, HandlerFactory factory) {
        super(name, port, workers, factory);
        _localAddr = null;
        _links = new WeakHashMap<InetSocketAddress, Link>(1024);
    }
    
    @Override
    protected void init() throws IOException {
        _selector = SelectorProvider.provider().openSelector();

        ServerSocketChannel ssc = ServerSocketChannel.open();
        ssc.configureBlocking(false);

        _localAddr = new InetSocketAddress(_port);
        ssc.socket().bind(_localAddr);

        ssc.register(_selector, SelectionKey.OP_ACCEPT, null);
        
        s_logger.info("NioConnection started and listening on " + _localAddr.toString());
    }
    
    @Override
    protected void registerLink(InetSocketAddress addr, Link link) {
        _links.put(addr, link);
    }

    @Override
    protected void unregisterLink(InetSocketAddress saddr) {
        _links.remove(saddr);
    }
    
    /**
     * Sends the data to the address specified.  If address is not already
     * connected, this does nothing and returns null.  If address is already
     * connected, then it returns the attached object so the caller can
     * prepare for any responses.
     * @param saddr
     * @param data
     * @return null if not sent.  attach object in link if sent.
     */
    public Object send(InetSocketAddress saddr, byte[] data) throws ClosedChannelException {
        Link link = _links.get(saddr);
        if (link == null) {
            return null;
        }
        link.send(data);
        return link.attachment();
    }
}