pulsar-client-cpp/lib/RoundRobinMessageRouter.cc

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */
#include "RoundRobinMessageRouter.h"
#include <boost/algorithm/string.hpp>

namespace pulsar {
    RoundRobinMessageRouter::RoundRobinMessageRouter(unsigned int numPartitions):prevPartition_(0), numPartitions_(numPartitions) {
    }

    RoundRobinMessageRouter::~RoundRobinMessageRouter() {
    }

    //override
    int RoundRobinMessageRouter::getPartition(const Message& msg) {
        //if message has a key, hash the key and return the partition
        if (msg.hasPartitionKey()) {
            static StringHash hash;
            return hash(msg.getPartitionKey()) % numPartitions_;
        } else {
            Lock lock(mutex_);
            //else pick the next partition
            return prevPartition_++ % numPartitions_;
        }
    }

}