feat(kafka_skin.h): kafka log support (#2655)

* feat(kafka_skin.h): kafka log support

add kafka log support

* refactor(kafka_skin.h): remove producer_  check

remove producer_  check

include/spdlog/sinks/kafka_skin.h

@@ -0,0 +1,133 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+//
+// Custom sink for kafka
+// Building and using requires librdkafka library.
+// For building librdkafka library check the url below
+// https://github.com/confluentinc/librdkafka
+//
+
+#include <spdlog/common.h>
+#include "spdlog/details/log_msg.h"
+#include "spdlog/sinks/base_sink.h"
+#include "spdlog/details/synchronous_factory.h"
+#include "spdlog/details/null_mutex.h"
+#include "spdlog/async.h"
+#include <mutex>
+
+// kafka header
+#include <librdkafka/rdkafkacpp.h>
+
+namespace spdlog {
+namespace sinks {
+
+struct kafka_sink_config
+{
+    std::string server_addr;
+    std::string produce_topic;
+    int32_t     flush_timeout_ms = 1000;
+
+    kafka_sink_config(std::string addr, std::string topic, int flush_timeout_ms = 1000)
+            : server_addr{std::move(addr)}
+            ,produce_topic{std::move(topic)}
+            ,flush_timeout_ms(flush_timeout_ms)
+    {}
+};
+
+template<typename Mutex>
+class kafka_skin : public base_sink<Mutex>
+{
+public:
+    kafka_skin(kafka_sink_config config)
+            : config_{std::move(config)}
+      {
+        try
+        {
+            std::string errstr;
+            conf_.reset(RdKafka::Conf::create(RdKafka::Conf::CONF_GLOBAL));
+            RdKafka::Conf::ConfResult confRes = conf_->set("bootstrap.servers", config_.server_addr, errstr);
+            if (confRes != RdKafka::Conf::CONF_OK)
+            {
+                throw_spdlog_ex(fmt_lib::format("conf set bootstrap.servers failed err:{}", errstr));
+            }
+
+            tconf_.reset(RdKafka::Conf::create(RdKafka::Conf::CONF_TOPIC));
+            if (tconf_ == nullptr)
+            {
+                throw_spdlog_ex(fmt_lib::format("create topic config failed"));
+            }
+
+            producer_.reset(RdKafka::Producer::create(conf_.get(), errstr));
+            if (producer_ == nullptr)
+            {
+                throw_spdlog_ex(fmt_lib::format("create producer failed err:{}", errstr));
+            }
+            topic_.reset(RdKafka::Topic::create(producer_.get(), config_.produce_topic, tconf_.get(), errstr));
+            if (topic_ == nullptr)
+            {
+                throw_spdlog_ex(fmt_lib::format("create topic failed err:{}", errstr));
+            }
+        }
+        catch (const std::exception &e)
+        {
+            throw_spdlog_ex(fmt_lib::format("error create kafka instance: {}", e.what()));
+        }
+      }
+
+    ~kafka_skin()
+    {
+        producer_->flush(config_.flush_timeout_ms);
+    }
+
+protected:
+    void sink_it_(const details::log_msg &msg) override
+    {
+        producer_->produce(topic_.get(), 0, RdKafka::Producer::RK_MSG_COPY,  (void *)msg.payload.data(), msg.payload.size(), NULL, NULL);
+    }
+
+    void flush_() override
+    {
+        producer_->flush(config_.flush_timeout_ms);
+    }
+
+private:
+    kafka_sink_config config_;
+    std::unique_ptr<RdKafka::Producer> producer_ = nullptr;
+    std::unique_ptr<RdKafka::Conf> conf_ = nullptr;
+    std::unique_ptr<RdKafka::Conf> tconf_ = nullptr;
+    std::unique_ptr<RdKafka::Topic> topic_ = nullptr;
+};
+
+using kafka_sink_mt = kafka_skin<std::mutex>;
+using kafka_sink_st = kafka_skin<spdlog::details::null_mutex>;
+
+}  // namespace sinks
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> kafka_logger_mt(const std::string &logger_name, spdlog::sinks::kafka_sink_config config)
+{
+    return Factory::template create<sinks::kafka_sink_mt>(logger_name, config);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> kafka_logger_st(const std::string &logger_name, spdlog::sinks::kafka_sink_config config)
+{
+    return Factory::template create<sinks::kafka_sink_st>(logger_name, config);
+}
+
+template<typename Factory = spdlog::async_factory>
+inline std::shared_ptr<spdlog::logger> kafka_logger_async_mt(std::string logger_name, spdlog::sinks::kafka_sink_config config)
+{
+        return Factory::template create<sinks::kafka_sink_mt>(logger_name, config);
+}
+
+template<typename Factory = spdlog::async_factory>
+inline std::shared_ptr<spdlog::logger> kafka_logger_async_st(std::string logger_name, spdlog::sinks::kafka_sink_config config)
+{
+        return Factory::template create<sinks::kafka_sink_st>(logger_name, config);
+}
+
+}  // namespace spdlog