1// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
2// Distributed under the MIT License (http://opensource.org/licenses/MIT)
3
4#pragma once
5
6#include <spdlog/sinks/base_sink.h>
7#include <spdlog/details/null_mutex.h>
8#include <spdlog/details/synchronous_factory.h>
9
10#include <array>
11#include <string>
12#include <syslog.h>
13
14namespace spdlog {
15namespace sinks {
16/**
17 * Sink that write to syslog using the `syscall()` library call.
18 */
19template<typename Mutex>
20class syslog_sink : public base_sink<Mutex>
21{
22
23public:
24 syslog_sink(std::string ident, int syslog_option, int syslog_facility, bool enable_formatting)
25 : enable_formatting_{enable_formatting}
26 , syslog_levels_{{/* spdlog::level::trace */ LOG_DEBUG,
27 /* spdlog::level::debug */ LOG_DEBUG,
28 /* spdlog::level::info */ LOG_INFO,
29 /* spdlog::level::warn */ LOG_WARNING,
30 /* spdlog::level::err */ LOG_ERR,
31 /* spdlog::level::critical */ LOG_CRIT,
32 /* spdlog::level::off */ LOG_INFO}}
33 , ident_{std::move(ident)}
34 {
35 // set ident to be program name if empty
36 ::openlog(ident_.empty() ? nullptr : ident_.c_str(), syslog_option, syslog_facility);
37 }
38
39 ~syslog_sink() override
40 {
41 ::closelog();
42 }
43
44 syslog_sink(const syslog_sink &) = delete;
45 syslog_sink &operator=(const syslog_sink &) = delete;
46
47protected:
48 void sink_it_(const details::log_msg &msg) override
49 {
50 string_view_t payload;
51 memory_buf_t formatted;
52 if (enable_formatting_)
53 {
54 base_sink<Mutex>::formatter_->format(msg, formatted);
55 payload = string_view_t(formatted.data(), formatted.size());
56 }
57 else
58 {
59 payload = msg.payload;
60 }
61
62 size_t length = payload.size();
63 // limit to max int
64 if (length > static_cast<size_t>(std::numeric_limits<int>::max()))
65 {
66 length = static_cast<size_t>(std::numeric_limits<int>::max());
67 }
68
69 ::syslog(syslog_prio_from_level(msg), "%.*s", static_cast<int>(length), payload.data());
70 }
71
72 void flush_() override {}
73 bool enable_formatting_ = false;
74
75private:
76 using levels_array = std::array<int, 7>;
77 levels_array syslog_levels_;
78 // must store the ident because the man says openlog might use the pointer as
79 // is and not a string copy
80 const std::string ident_;
81
82 //
83 // Simply maps spdlog's log level to syslog priority level.
84 //
85 int syslog_prio_from_level(const details::log_msg &msg) const
86 {
87 return syslog_levels_.at(static_cast<levels_array::size_type>(msg.level));
88 }
89};
90
91using syslog_sink_mt = syslog_sink<std::mutex>;
92using syslog_sink_st = syslog_sink<details::null_mutex>;
93} // namespace sinks
94
95// Create and register a syslog logger
96template<typename Factory = spdlog::synchronous_factory>
97inline std::shared_ptr<logger> syslog_logger_mt(const std::string &logger_name, const std::string &syslog_ident = "", int syslog_option = 0,
98 int syslog_facility = LOG_USER, bool enable_formatting = false)
99{
100 return Factory::template create<sinks::syslog_sink_mt>(logger_name, syslog_ident, syslog_option, syslog_facility, enable_formatting);
101}
102
103template<typename Factory = spdlog::synchronous_factory>
104inline std::shared_ptr<logger> syslog_logger_st(const std::string &logger_name, const std::string &syslog_ident = "", int syslog_option = 0,
105 int syslog_facility = LOG_USER, bool enable_formatting = false)
106{
107 return Factory::template create<sinks::syslog_sink_st>(logger_name, syslog_ident, syslog_option, syslog_facility, enable_formatting);
108}
109} // namespace spdlog
110