com.lambdaworks.redis.pubsub.PubSubCommandHandler Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of lettuce Show documentation

Advanced and thread-safe Java Redis client for synchronous, asynchronous, and reactive usage. Supports Cluster, Sentinel, Pipelining, Auto-Reconnect, Codecs and much more.

The newest version!

/*
 * Copyright 2011-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with 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.
 */
package com.lambdaworks.redis.pubsub;

import com.lambdaworks.redis.codec.RedisCodec;
import com.lambdaworks.redis.output.CommandOutput;
import com.lambdaworks.redis.protocol.CommandHandler;
import com.lambdaworks.redis.resource.ClientResources;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;

/**
 * A netty {@link ChannelHandler} responsible for writing redis pub/sub commands and reading the response stream from the
 * server.
 * 
 * @param  Key type.
 * @param  Value type.
 * 
 * @author Will Glozer
 */
public class PubSubCommandHandler extends CommandHandler {

    private final PubSubEndpoint endpoint;
    private final RedisCodec codec;
    private PubSubOutput output;

    /**
     * Initialize a new instance.
     * 
     * @param clientResources client resources for this connection
     * @param codec Codec.
     * @param endpoint the Pub/Sub endpoint for Pub/Sub callback.
     */
    public PubSubCommandHandler(ClientResources clientResources, RedisCodec codec, PubSubEndpoint endpoint) {

        super(clientResources, endpoint);

        this.codec = codec;
        this.output = new PubSubOutput<>(codec);
        this.endpoint = endpoint;
    }

    @SuppressWarnings("unchecked")
    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf buffer) throws InterruptedException {

        while (output.type() == null && !getQueue().isEmpty()) {
            CommandOutput currentOutput = getQueue().peek().getOutput();

            if (!super.decode(buffer, currentOutput)) {
                return;
            }

            getQueue().poll().complete();

            buffer.discardReadBytes();

            if (currentOutput instanceof PubSubOutput) {
                endpoint.notifyMessage((PubSubOutput) currentOutput);
            }
        }

        while (super.decode(buffer, output)) {

            endpoint.notifyMessage(output);
            output = new PubSubOutput<>(codec);

            buffer.discardReadBytes();
        }
    }
}