spdlog

XLogger.h

#pragma once
#include "spdlog/async.h"
#include "spdlog/sinks/basic_file_sink.h"
#include "spdlog/sinks/rotating_file_sink.h"
#include "spdlog/sinks/stdout_color_sinks.h"// or "../stdout_sinks.h" if no color needed
#include "spdlog/spdlog.h"
#include <chrono>
#include <iostream>
#include <memory>
#include <string>
#include <time.h>

static inline int NowDateToInt() {
  time_t now;
  time(&now);

  // choose thread save version in each platform
  tm p;
#ifdef _WIN32
  localtime_s(&p, &now);
#else
  localtime_r(&now, &p);
#endif// _WIN32
  int now_date = (1900 + p.tm_year) * 10000 + (p.tm_mon + 1) * 100 + p.tm_mday;
  return now_date;
}

static inline int NowTimeToInt() {
  time_t now;
  time(&now);
  // choose thread save version in each platform
  tm p;
#ifdef _WIN32
  localtime_s(&p, &now);
#else
  localtime_r(&now, &p);
#endif// _WIN32

  int now_int = p.tm_hour * 10000 + p.tm_min * 100 + p.tm_sec;
  return now_int;
}

class XLogger {
 public:
  static XLogger *getInstance() {
    static XLogger xlogger;
    return &xlogger;
  }

  std::shared_ptr<spdlog::logger> getLogger() {
    return m_logger;
  }

 private:
  // make constructor private to avoid outside instance
  XLogger() {
    // hardcode log path
    const std::string log_dir = "./logs";// should create the folder if not exist
    const std::string logger_name_prefix = "VFConfigGen_";

    // decide print to console or log file
    bool console = true;

    // decide the log level
    std::string level = "trace";

    try {
      // logger name with timestamp
      int date = NowDateToInt();
      int time = NowTimeToInt();
      //const std::string logger_name = logger_name_prefix + std::to_string(date) + "_" + std::to_string(time);
      const std::string logger_name = logger_name_prefix + std::to_string(date);

      if (console) {
        auto console_sink = std::make_shared<spdlog::sinks::stdout_color_sink_mt>();
        auto file_sink = std::make_shared<spdlog::sinks::rotating_file_sink_mt>(log_dir + "/" + logger_name + ".log", 5 * 1024 * 1024, 7);// multi part log files, with every part 500M, max 1000 files
        spdlog::sinks_init_list sink_list = {console_sink, file_sink};
        m_logger = std::make_shared<spdlog::logger>("my_logger", sink_list);
        //m_logger = spdlog::stdout_color_st(logger_name); // single thread console output faster
      } else {
        //m_logger = spdlog::create_async<spdlog::sinks::basic_file_sink_mt>(logger_name, log_dir + "/" + logger_name + ".log"); // only one log file
        m_logger = spdlog::create_async<spdlog::sinks::rotating_file_sink_mt>(logger_name, log_dir + "/" + logger_name + ".log", 5 * 1024 * 1024, 7);// multi part log files, with every part 500M, max 1000 files
      }

      // custom format
      //      m_logger->set_pattern("[%Y-%m-%d %H:%M:%S.%f] [%P:%t] [%l] [%@] [%^%!%$] %v");// with timestamp, thread_id, filename and line number
      m_logger->set_pattern("[%Y-%m-%d %H:%M:%S.%f] [%P:%t] [%l] [%^%!%$] %v");// with timestamp, thread_id, filename and line number

      if (level == "trace") {
        m_logger->set_level(spdlog::level::trace);
        m_logger->flush_on(spdlog::level::trace);
      } else if (level == "debug") {
        m_logger->set_level(spdlog::level::debug);
        m_logger->flush_on(spdlog::level::debug);
      } else if (level == "info") {
        m_logger->set_level(spdlog::level::info);
        m_logger->flush_on(spdlog::level::info);
      } else if (level == "warn") {
        m_logger->set_level(spdlog::level::warn);
        m_logger->flush_on(spdlog::level::warn);
      } else if (level == "error") {
        m_logger->set_level(spdlog::level::err);
        m_logger->flush_on(spdlog::level::err);
      }
    } catch (const spdlog::spdlog_ex &ex) {
      std::cout << "Log initialization failed: " << ex.what() << std::endl;
    }
  }

  ~XLogger() {
    spdlog::drop_all();// must do this
  }

  void *operator new(size_t size) {}

  XLogger(const XLogger &) = delete;
  XLogger &operator=(const XLogger &) = delete;

 private:
  std::shared_ptr<spdlog::logger> m_logger;
};

// use embedded macro to support file and line number
#define XLOG_TRACE(...) SPDLOG_LOGGER_CALL(XLogger::getInstance()->getLogger().get(), spdlog::level::trace, __VA_ARGS__)
#define XLOG_DEBUG(...) SPDLOG_LOGGER_CALL(XLogger::getInstance()->getLogger().get(), spdlog::level::debug, __VA_ARGS__)
#define XLOG_INFO(...) SPDLOG_LOGGER_CALL(XLogger::getInstance()->getLogger().get(), spdlog::level::info, __VA_ARGS__)
#define XLOG_WARN(...) SPDLOG_LOGGER_CALL(XLogger::getInstance()->getLogger().get(), spdlog::level::warn, __VA_ARGS__)
#define XLOG_ERROR(...) SPDLOG_LOGGER_CALL(XLogger::getInstance()->getLogger().get(), spdlog::level::err, __VA_ARGS__)