C/C++ librdkafka库消费者的实现

    /* * librdkafka - Apache Kafka C library
     * * Copyright (c) 2019, Magnus Edenhill
     * All rights reserved.
     * * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions are met:
     * * 1. Redistributions of source code must retain the above copyright notice,
     *    this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright notice,
     *    this list of conditions and the following disclaimer in the documentation