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

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// Copyright (C) 2011 - Will Glozer.  All rights reserved.

package com.lambdaworks.redis.pubsub;

import com.lambdaworks.redis.codec.RedisCodec;
import com.lambdaworks.redis.protocol.*;
import io.netty.buffer.ByteBuf;
import io.netty.channel.*;

import java.util.concurrent.BlockingQueue;

/**
 * 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 RedisCodec codec;
    private PubSubOutput output;

    /**
     * Initialize a new instance.
     *
     * @param queue Command queue.
     * @param codec Codec.
     */
    public PubSubCommandHandler(BlockingQueue> queue, RedisCodec codec) {
        super(queue);
        this.codec  = codec;
        this.output = new PubSubOutput(codec);
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf buffer) throws InterruptedException {
        while (output.type() == null && !queue.isEmpty()) {
            CommandOutput output = queue.peek().getOutput();
            if (!rsm.decode(buffer, output)) {
                return;
            }
            queue.take().complete();
            if (output instanceof PubSubOutput && ((PubSubOutput) output).type() != null) {
                ctx.fireChannelRead(output);
            }
        }

        while (rsm.decode(buffer, output)) {
            ctx.fireChannelRead(output);
            output = new PubSubOutput(codec);
        }
    }

}