summaryrefslogtreecommitdiff
path: root/src/logger/logger.hpp
blob: ff6a82b795fdf98b57c19fd95e5e21fa2f22ee27 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
#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 <iostream>
#include <fstream>

#define debug_lvl 0
#define info_lvl 1
#define warning_lvl 2
#define error_lvl 3

#include "biboumi.h"
#ifdef SYSTEMD_FOUND
# include <systemd/sd-daemon.h>
#else
# define SD_DEBUG    "[DEBUG]: "
# define SD_INFO     "[INFO]: "
# define SD_WARNING  "[WARNING]: "
# define SD_ERR      "[ERROR]: "
#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;

private:
  const int log_level;
  std::ofstream ofstream{};
  std::ostream stream;

  NullBuffer null_buffer;
  std::ostream null_stream;
};

#define WHERE __FILENAME__, ":", __LINE__, ":\t"

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 log_debug(U&&... args)
  {
    auto& os = Logger::instance()->get_stream(debug_lvl);
    os << SD_DEBUG;
    log(os, std::forward<U>(args)...);
  }

  template <typename... U>
  void log_info(U&&... args)
  {
    auto& os = Logger::instance()->get_stream(info_lvl);
    os << SD_INFO;
    log(os, std::forward<U>(args)...);
  }

  template <typename... U>
  void log_warning(U&&... args)
  {
    auto& os = Logger::instance()->get_stream(warning_lvl);
    os << SD_WARNING;
    log(os, std::forward<U>(args)...);
  }

  template <typename... U>
  void log_error(U&&... args)
  {
    auto& os = Logger::instance()->get_stream(error_lvl);
    os << SD_ERR;
    log(os, std::forward<U>(args)...);
  }
}

#define log_info(...) logging_details::log_info(WHERE, __VA_ARGS__)

#define log_warning(...) logging_details::log_warning(WHERE, __VA_ARGS__)

#define log_error(...) logging_details::log_error(WHERE, __VA_ARGS__)

#define log_debug(...) logging_details::log_debug(WHERE, __VA_ARGS__)