UscExceptionHandler.java

/*
 * Copyright (c) 2015 Huawei, Inc and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.usc.plugin;

import io.netty.channel.Channel;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

import org.opendaylight.usc.manager.UscRouteBrokerService;
import org.opendaylight.usc.manager.cluster.UscRouteIdentifier;
import org.opendaylight.usc.plugin.exception.UscChannelException;
import org.opendaylight.usc.plugin.exception.UscConnectionException;
import org.opendaylight.usc.plugin.exception.UscException;
import org.opendaylight.usc.plugin.exception.UscSessionException;
import org.opendaylight.usc.plugin.model.UscChannelImpl;
import org.opendaylight.usc.plugin.model.UscSessionImpl;
import org.opendaylight.usc.util.UscServiceUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.util.concurrent.SettableFuture;

/**
 * This Netty handler is automatically installed in the client channel pipeline
 * to facilitate the throwing of any exceptions that are encountered in the USC
 * session into the client state.
 */
@Sharable
public class UscExceptionHandler extends SimpleChannelInboundHandler<UscException> {

    private static final Logger log = LoggerFactory.getLogger(UscExceptionHandler.class);
    private final UscPlugin plugin;
    private UscRouteBrokerService broker;

    public UscExceptionHandler(UscPlugin plugin) {
        this.plugin = plugin;
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, UscException ex) throws Exception {
        log.trace("UscExceptionHandler channelRead0" + ex);

        final Throwable t = ex.getCause();
        Channel channel = ctx.channel();
        UscRouteIdentifier routeId = ctx.channel().attr(UscPlugin.ROUTE_IDENTIFIER).get();
        if (routeId != null) {
            // this is a channel using remote channel
            if (broker == null) {
                broker = UscServiceUtils.getService(UscRouteBrokerService.class);
            }
            if (broker != null) {
                broker.removeLocalSession(routeId);
            } else {
                log.error(
                        "Broker service is null! Can't check if it is remote channel message, failed to proccess this exception {}.",
                        ex);
            }
            return;
        }
        SettableFuture<UscSessionImpl> tmp = channel.attr(UscPlugin.SESSION).get();
        if (tmp != null) {
            UscSessionImpl session = tmp.get();
            UscChannelImpl connection = session.getChannel();

            // connection is down
            if (t instanceof UscConnectionException) {
                plugin.getConnectionManager().removeConnection(connection);
            } else if (t instanceof UscChannelException) {
                // TODO
                ;
            } else if (t instanceof UscSessionException) {
                connection.removeSession(session.getSessionId());
            }
        }

        throw ex;
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        UscConnectionException ex = new UscConnectionException("The channel is closed.");
        UscRouteIdentifier routeId = ctx.channel().attr(UscPlugin.ROUTE_IDENTIFIER).get();
        if (routeId != null) {
            // this is a channel using remote channel
            if (broker == null) {
                broker = UscServiceUtils.getService(UscRouteBrokerService.class);
            }
            if (broker != null) {
                broker.removeLocalSession(routeId);
            } else {
                log.error(
                        "Broker service is null! Can't check if it is remote channel message, failed to proccess this exception {}.",
                        ex);
            }
            return;
        }
        throw ex;
    }

}