2 * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.protocol.framework;
10 import io.netty.channel.Channel;
11 import io.netty.channel.ChannelFuture;
12 import io.netty.channel.ChannelFutureListener;
13 import io.netty.channel.ChannelHandlerContext;
14 import io.netty.channel.ChannelInboundHandlerAdapter;
15 import io.netty.util.concurrent.Promise;
17 import org.slf4j.Logger;
18 import org.slf4j.LoggerFactory;
20 import com.google.common.base.Preconditions;
23 * Abstract base class for session negotiators. It implements the basic
24 * substrate to implement SessionNegotiator API specification, with subclasses
25 * needing to provide only
27 * @param <M> Protocol message type
28 * @param <S> Protocol session type, has to extend ProtocolSession<M>
30 public abstract class AbstractSessionNegotiator<M, S extends AbstractProtocolSession<?>> extends ChannelInboundHandlerAdapter implements SessionNegotiator<S> {
31 private final Logger LOG = LoggerFactory.getLogger(AbstractSessionNegotiator.class);
32 private final Promise<S> promise;
33 protected final Channel channel;
35 public AbstractSessionNegotiator(final Promise<S> promise, final Channel channel) {
36 this.promise = Preconditions.checkNotNull(promise);
37 this.channel = Preconditions.checkNotNull(channel);
40 protected abstract void startNegotiation() throws Exception;
41 protected abstract void handleMessage(M msg) throws Exception;
43 protected final void negotiationSuccessful(final S session) {
44 LOG.debug("Negotiation on channel {} successful with session {}", channel, session);
45 channel.pipeline().replace(this, "session", session);
46 promise.setSuccess(session);
49 protected final void negotiationFailed(final Throwable cause) {
50 LOG.debug("Negotiation on channel {} failed", channel, cause);
52 promise.setFailure(cause);
56 * Send a message to peer and fail negotiation if it does not reach
59 * @param msg Message which should be sent.
61 protected final void sendMessage(final M msg) {
62 this.channel.writeAndFlush(msg).addListener(
63 new ChannelFutureListener() {
65 public void operationComplete(final ChannelFuture f) {
67 LOG.info("Failed to send message {}", msg, f.cause());
68 negotiationFailed(f.cause());
70 LOG.trace("Message {} sent to socket", msg);
77 public final void channelActive(final ChannelHandlerContext ctx) {
78 LOG.debug("Starting session negotiation on channel {}", channel);
81 } catch (Exception e) {
82 LOG.warn("Unexpected negotiation failure", e);
88 @SuppressWarnings("unchecked")
89 public final void channelRead(final ChannelHandlerContext ctx, final Object msg) {
90 LOG.debug("Negotiation read invoked on channel {}", channel);
92 handleMessage((M)msg);
93 } catch (Exception e) {
94 LOG.debug("Unexpected error while handling negotiation message {}", msg, e);
100 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
101 LOG.info("Unexpected error during negotiation", cause);
102 negotiationFailed(cause);