cpp-logger/logger.hpp

//
//  logger.hpp
//  logger
//
//  Created by Sam Jaffe on 9/3/16.
//

#pragma once

//
//  Logger.hpp
//  DanmakuRPG
//
//  Created by Sam Jaffe on 7/18/15.
//  Copyright (c) 2015 Sam Jaffe. All rights reserved.
//

#pragma once

#include <cstdarg>
#include <cstdlib>
#include <cstring>
#include <memory>
#include <string>

#include "logger_fwd.hpp"
#include "format.hpp"

#define log_message( logger, level, ... ) logger.log( level, { __FILE__, __LINE__, STRING( FUNCTION ) }, __VA_ARGS__ )

namespace logging {
  class logger_impl;
  typedef logger_impl& (*_binding)(void);
  bool bind_logger_impl(_binding impl);
    
  const char* level_header(log_level);
  
  class logger {
  public:
    static logger& instance();
    static logger& instance(std::string const & key);
  public:
    template <typename... Args>
    inline void log(log_level ll,
                    std::string const & interp, Args && ...args) {
      log( ll, location_info{}, interp, std::forward<Args>(args)... );
    }
    
    template <typename... Args>
    inline void log(log_level ll, location_info info,
                    std::string const & interp, Args && ...args) {
      if ( should_log( ll ) ) {
        log( ll, info, format_msg( interp, std::forward<Args>(args)... ) );
      }
    }
    
    void flush();
    
    ~logger();
  private:
    bool should_log( log_level ) const;
    void log( log_level ll, location_info info, std::string const& );
    
    explicit logger(std::string const & name = "");
    logger(logger const&);
    logger& operator=(logger const&);
    
    log_level min_level_;
    std::string const logger_name_;
    logger_impl& impl_;
  };
  
  class logger_impl {
  public:
    bool should_log( log_level ll ) const;
    virtual void write( logpacket const & pkt ) = 0;
    virtual void flush() = 0;
    virtual ~logger_impl() = default;
  private:
    log_level min_log_level;
  };
}