/*

 *   SONEWS News Server

 *   see AUTHORS for the list of contributors

 *

 *   This program is free software: you can redistribute it and/or modify

 *   it under the terms of the GNU General Public License as published by

 *   the Free Software Foundation, either version 3 of the License, or

 *   (at your option) any later version.

 *

 *   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, see <http://www.gnu.org/licenses/>.

 */

package org.sonews.daemon;

import org.sonews.util.Log;

import java.nio.ByteBuffer;

import java.nio.channels.SocketChannel;

import java.util.concurrent.ArrayBlockingQueue;

/**

 * Does most of the work: parsing input, talking to client and Database.

 * @author Christian Lins

 * @since sonews/0.5.0

 */

class ConnectionWorker extends AbstractDaemon

{

	// 256 pending events should be enough

	private static ArrayBlockingQueue<SocketChannel> pendingChannels = new ArrayBlockingQueue<SocketChannel>(256, true);

	/**

	 * Registers the given channel for further event processing.

	 * @param channel

	 */

	public static void addChannel(SocketChannel channel)

		throws InterruptedException

	{

		pendingChannels.put(channel);

	}

	/**

	 * Processing loop.

	 */

	@Override

	public void run()

	{

		while (isRunning()) {

			try {

				// Retrieve and remove if available, otherwise wait.

				SocketChannel channel = pendingChannels.take();

				if (channel != null) {

					// Connections.getInstance().get() MAY return null

					NNTPConnection conn = Connections.getInstance().get(channel);

					// Try to lock the connection object

					if (conn != null && conn.tryReadLock()) {

						ByteBuffer buf = conn.getBuffers().nextInputLine();

						while (buf != null) // Complete line was received

						{

							final byte[] line = new byte[buf.limit()];

							buf.get(line);

							ChannelLineBuffers.recycleBuffer(buf);

							// Here is the actual work done

							conn.lineReceived(line);

							// Read next line as we could have already received the next line

							buf = conn.getBuffers().nextInputLine();

						}

						conn.unlockReadLock();

					} else {

						addChannel(channel);

					}

				}

			} catch (InterruptedException ex) {

				Log.get().info("ConnectionWorker interrupted: " + ex);

			} catch (Exception ex) {

				Log.get().severe("Exception in ConnectionWorker: " + ex);

				ex.printStackTrace();

			}

		} // end while(isRunning())

	}

}