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.ChannelFutureListener;
12 import io.netty.channel.ChannelHandlerContext;
13 import io.netty.channel.ChannelInboundHandlerAdapter;
14 import io.netty.util.concurrent.Promise;
16 import org.slf4j.Logger;
17 import org.slf4j.LoggerFactory;
19 import com.google.common.base.Preconditions;
22 * Abstract base class for session negotiators. It implements the basic
23 * substrate to implement SessionNegotiator API specification, with subclasses
24 * needing to provide only
26 * @param <M> Protocol message type
27 * @param <S> Protocol session type, has to extend {@code 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 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 (ChannelFutureListener) f -> {
65 LOG.info("Failed to send message {}", msg, f.cause());
66 negotiationFailed(f.cause());
68 LOG.trace("Message {} sent to socket", msg);
74 public final void channelActive(final ChannelHandlerContext ctx) {
75 LOG.debug("Starting session negotiation on channel {}", channel);
78 } catch (final Exception e) {
79 LOG.warn("Unexpected negotiation failure", e);
85 @SuppressWarnings("unchecked")
86 public final void channelRead(final ChannelHandlerContext ctx, final Object msg) {
87 LOG.debug("Negotiation read invoked on channel {}", channel);
89 handleMessage((M)msg);
90 } catch (final Exception e) {
91 LOG.debug("Unexpected error while handling negotiation message {}", msg, e);
97 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
98 LOG.info("Unexpected error during negotiation", cause);
99 negotiationFailed(cause);