#pragma once
/**
* Singleton used in logger macros to write into files or stdout, with
* various levels of severity.
* Only the macros should be used.
* @class Logger
*/
#include <memory>
#include <string>
#include <iostream>
#include <fstream>
#include <sstream>
#define debug_lvl 0
#define info_lvl 1
#define warning_lvl 2
#define error_lvl 3
#include "biboumi.h"
#ifdef SYSTEMD_FOUND
#define SD_JOURNAL_SUPPRESS_LOCATION
# include <systemd/sd-daemon.h>
# include <systemd/sd-journal.h>
#else
# define SD_DEBUG "[DEBUG]: "
# define SD_INFO "[INFO]: "
# define SD_WARNING "[WARNING]: "
# define SD_ERR "[ERROR]: "
# define LOG_ERR 3
# define LOG_WARNING 4
# define LOG_INFO 6
# define LOG_DEBUG 7
#endif
// Macro defined to get the filename instead of the full path. But if it is
// not properly defined by the build system, we fallback to __FILE__
#ifndef __FILENAME__
# define __FILENAME__ __FILE__
#endif
/**
* A buffer, used to construct an ostream that does nothing
* when we output data in it
*/
class NullBuffer: public std::streambuf
{
public:
int overflow(int c) { return c; }
};
class Logger
{
public:
static std::unique_ptr<Logger>& instance();
std::ostream& get_stream(const int);
Logger(const int log_level, const std::string& log_file);
Logger(const int log_level);
Logger(const Logger&) = delete;
Logger& operator=(const Logger&) = delete;
Logger(Logger&&) = delete;
Logger& operator=(Logger&&) = delete;
#ifdef SYSTEMD_FOUND
bool use_stdout() const
{
return this->stream.rdbuf() == std::cout.rdbuf();
}
bool use_systemd{false};
#endif
private:
const int log_level;
std::ofstream ofstream{};
std::ostream stream;
NullBuffer null_buffer;
std::ostream null_stream;
};
namespace logging_details
{
template <typename T>
void log(std::ostream& os, const T& arg)
{
os << arg << std::endl;
}
template <typename T, typename... U>
void log(std::ostream& os, const T& first, U&&... rest)
{
os << first;
log(os, std::forward<U>(rest)...);
}
template <typename... U>
void do_logging(const int level, int syslog_level, const char* src_file, int line, U&&... args)
{
#ifdef SYSTEMD_FOUND
if (Logger::instance()->use_systemd)
{
(void)level;
std::ostringstream os;
log(os, std::forward<U>(args)...);
sd_journal_send("MESSAGE=%s", os.str().data(),
"PRIORITY=%i", syslog_level,
"CODE_FILE=%s", src_file,
"CODE_LINE=%i", line,
nullptr);
}
else
{
#endif
(void)syslog_level;
static const char* priority_names[] = {"DEBUG", "INFO", "WARNING", "ERROR"};
auto& os = Logger::instance()->get_stream(level);
os << '[' << priority_names[level] << "]: " << src_file << ':' << line << ":\t";
log(os, std::forward<U>(args)...);
#ifdef SYSTEMD_FOUND
}
#endif
}
}
#define log_debug(...) logging_details::do_logging(debug_lvl, LOG_DEBUG, __FILENAME__, __LINE__, __VA_ARGS__)
#define log_info(...) logging_details::do_logging(info_lvl, LOG_INFO, __FILENAME__, __LINE__, __VA_ARGS__)
#define log_warning(...) logging_details::do_logging(warning_lvl, LOG_WARNING, __FILENAME__, __LINE__, __VA_ARGS__)
#define log_error(...) logging_details::do_logging(error_lvl, LOG_ERR, __FILENAME__, __LINE__, __VA_ARGS__)