text: //
  // Copyright(c) 2015 Gabi Melman.
  // Distributed under the MIT License (http://opensource.org/licenses/MIT)
  //
  
  #pragma once
  //
  // base sink templated over a mutex (either dummy or real)
  // concrete implementation should override the sink_it_() and flush_()  methods.
  // locking is taken care of in this class - no locking needed by the
  // implementers..
  //
  
  #include "spdlog/common.h"
  #include "spdlog/details/log_msg.h"
  #include "spdlog/formatter.h"
  #include "spdlog/sinks/sink.h"
  
  namespace spdlog {
  namespace sinks {
  template<typename Mutex>
  class base_sink : public sink
  {
  public:
      base_sink() = default;
      base_sink(const base_sink &) = delete;
      base_sink &operator=(const base_sink &) = delete;
  
      #ifdef SPDLOG_SCOPED_ATTRIBUTES
      void log(const details::log_msg &msg, const std::vector<details::attribute>& attr) override
      {
      }
      #endif
  
      void log(const details::log_msg &msg) final
      {
          std::lock_guard<Mutex> lock(mutex_);
          sink_it_(msg);
      }
  
      void flush() final
      {
          std::lock_guard<Mutex> lock(mutex_);
          flush_();
      }
  
      void set_pattern(const std::string &pattern) final
      {
          std::lock_guard<Mutex> lock(mutex_);
          set_pattern_(pattern);
      }
  
      void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) final
      {
          std::lock_guard<Mutex> lock(mutex_);
          set_formatter_(std::move(sink_formatter));
      }
  
  protected:
      virtual void sink_it_(const details::log_msg &msg) = 0;
      virtual void flush_() = 0;
  
      virtual void set_pattern_(const std::string &pattern)
      {
          set_formatter_(details::make_unique<spdlog::pattern_formatter>(pattern));
      }
  
      virtual void set_formatter_(std::unique_ptr<spdlog::formatter> sink_formatter)
      {
          formatter_ = std::move(sink_formatter);
      }
      Mutex mutex_;
  };
  } // namespace sinks
  } // namespace spdlog
  