include/spdlog/logger.h

0001 // Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
0002 // Distributed under the MIT License (http://opensource.org/licenses/MIT)
0003
0004 #pragma once
0005
0006 // Thread safe logger (except for set_error_handler())
0007 // Has name, log level, vector of std::shared sink pointers and formatter
0008 // Upon each log write the logger:
0009 // 1. Checks if its log level is enough to log the message and if yes:
0010 // 2. Call the underlying sinks to do the job.
0011 // 3. Each sink use its own private copy of a formatter to format the message
0012 // and send to its destination.
0013 //
0014 // The use of private formatter per sink provides the opportunity to cache some
0015 // formatted data, and support for different format per sink.
0016
0017 #include <spdlog/common.h>
0018 #include <spdlog/details/backtracer.h>
0019 #include <spdlog/details/log_msg.h>
0020
0021 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
0022     #ifndef _WIN32
0023         #error SPDLOG_WCHAR_TO_UTF8_SUPPORT only supported on windows
0024     #endif
0025     #include <spdlog/details/os.h>
0026 #endif
0027
0028 #include <vector>
0029
0030 #ifndef SPDLOG_NO_EXCEPTIONS
0031     #define SPDLOG_LOGGER_CATCH(location)                                                 \
0032         catch (const std::exception &ex) {                                                \
0033             if (location.filename) {                                                      \
0034                 err_handler_(fmt_lib::format(SPDLOG_FMT_STRING("{} [{}({})]"), ex.what(), \
0035                                              location.filename, location.line));          \
0036             } else {                                                                      \
0037                 err_handler_(ex.what());                                                  \
0038             }                                                                             \
0039         }                                                                                 \
0040         catch (...) {                                                                     \
0041             err_handler_("Rethrowing unknown exception in logger");                       \
0042             throw;                                                                        \
0043         }
0044 #else
0045     #define SPDLOG_LOGGER_CATCH(location)
0046 #endif
0047
0048 namespace spdlog {
0049
0050 class SPDLOG_API logger {
0051 public:
0052     // Empty logger
0053     explicit logger(std::string name)
0054         : name_(std::move(name)),
0055           sinks_() {}
0056
0057     // Logger with range on sinks
0058     template <typename It>
0059     logger(std::string name, It begin, It end)
0060         : name_(std::move(name)),
0061           sinks_(begin, end) {}
0062
0063     // Logger with single sink
0064     logger(std::string name, sink_ptr single_sink)
0065         : logger(std::move(name), {std::move(single_sink)}) {}
0066
0067     // Logger with sinks init list
0068     logger(std::string name, sinks_init_list sinks)
0069         : logger(std::move(name), sinks.begin(), sinks.end()) {}
0070
0071     virtual ~logger() = default;
0072
0073     logger(const logger &other);
0074     logger(logger &&other) SPDLOG_NOEXCEPT;
0075     logger &operator=(logger other) SPDLOG_NOEXCEPT;
0076     void swap(spdlog::logger &other) SPDLOG_NOEXCEPT;
0077
0078     template <typename... Args>
0079     void log(source_loc loc, level::level_enum lvl, format_string_t<Args...> fmt, Args &&...args) {
0080         log_(loc, lvl, details::to_string_view(fmt), std::forward<Args>(args)...);
0081     }
0082
0083     template <typename... Args>
0084     void log(level::level_enum lvl, format_string_t<Args...> fmt, Args &&...args) {
0085         log(source_loc{}, lvl, fmt, std::forward<Args>(args)...);
0086     }
0087
0088     template <typename T>
0089     void log(level::level_enum lvl, const T &msg) {
0090         log(source_loc{}, lvl, msg);
0091     }
0092
0093     // T cannot be statically converted to format string (including string_view/wstring_view)
0094     template <class T,
0095               typename std::enable_if<!is_convertible_to_any_format_string<const T &>::value,
0096                                       int>::type = 0>
0097     void log(source_loc loc, level::level_enum lvl, const T &msg) {
0098         log(loc, lvl, "{}", msg);
0099     }
0100
0101     void log(log_clock::time_point log_time,
0102              source_loc loc,
0103              level::level_enum lvl,
0104              string_view_t msg) {
0105         bool log_enabled = should_log(lvl);
0106         bool traceback_enabled = tracer_.enabled();
0107         if (!log_enabled && !traceback_enabled) {
0108             return;
0109         }
0110
0111         details::log_msg log_msg(log_time, loc, name_, lvl, msg);
0112         log_it_(log_msg, log_enabled, traceback_enabled);
0113     }
0114
0115     void log(source_loc loc, level::level_enum lvl, string_view_t msg) {
0116         bool log_enabled = should_log(lvl);
0117         bool traceback_enabled = tracer_.enabled();
0118         if (!log_enabled && !traceback_enabled) {
0119             return;
0120         }
0121
0122         details::log_msg log_msg(loc, name_, lvl, msg);
0123         log_it_(log_msg, log_enabled, traceback_enabled);
0124     }
0125
0126     void log(level::level_enum lvl, string_view_t msg) { log(source_loc{}, lvl, msg); }
0127
0128     template <typename... Args>
0129     void trace(format_string_t<Args...> fmt, Args &&...args) {
0130         log(level::trace, fmt, std::forward<Args>(args)...);
0131     }
0132
0133     template <typename... Args>
0134     void debug(format_string_t<Args...> fmt, Args &&...args) {
0135         log(level::debug, fmt, std::forward<Args>(args)...);
0136     }
0137
0138     template <typename... Args>
0139     void info(format_string_t<Args...> fmt, Args &&...args) {
0140         log(level::info, fmt, std::forward<Args>(args)...);
0141     }
0142
0143     template <typename... Args>
0144     void warn(format_string_t<Args...> fmt, Args &&...args) {
0145         log(level::warn, fmt, std::forward<Args>(args)...);
0146     }
0147
0148     template <typename... Args>
0149     void error(format_string_t<Args...> fmt, Args &&...args) {
0150         log(level::err, fmt, std::forward<Args>(args)...);
0151     }
0152
0153     template <typename... Args>
0154     void critical(format_string_t<Args...> fmt, Args &&...args) {
0155         log(level::critical, fmt, std::forward<Args>(args)...);
0156     }
0157
0158 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
0159     template <typename... Args>
0160     void log(source_loc loc, level::level_enum lvl, wformat_string_t<Args...> fmt, Args &&...args) {
0161         log_(loc, lvl, details::to_string_view(fmt), std::forward<Args>(args)...);
0162     }
0163
0164     template <typename... Args>
0165     void log(level::level_enum lvl, wformat_string_t<Args...> fmt, Args &&...args) {
0166         log(source_loc{}, lvl, fmt, std::forward<Args>(args)...);
0167     }
0168
0169     void log(log_clock::time_point log_time,
0170              source_loc loc,
0171              level::level_enum lvl,
0172              wstring_view_t msg) {
0173         bool log_enabled = should_log(lvl);
0174         bool traceback_enabled = tracer_.enabled();
0175         if (!log_enabled && !traceback_enabled) {
0176             return;
0177         }
0178
0179         memory_buf_t buf;
0180         details::os::wstr_to_utf8buf(wstring_view_t(msg.data(), msg.size()), buf);
0181         details::log_msg log_msg(log_time, loc, name_, lvl, string_view_t(buf.data(), buf.size()));
0182         log_it_(log_msg, log_enabled, traceback_enabled);
0183     }
0184
0185     void log(source_loc loc, level::level_enum lvl, wstring_view_t msg) {
0186         bool log_enabled = should_log(lvl);
0187         bool traceback_enabled = tracer_.enabled();
0188         if (!log_enabled && !traceback_enabled) {
0189             return;
0190         }
0191
0192         memory_buf_t buf;
0193         details::os::wstr_to_utf8buf(wstring_view_t(msg.data(), msg.size()), buf);
0194         details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
0195         log_it_(log_msg, log_enabled, traceback_enabled);
0196     }
0197
0198     void log(level::level_enum lvl, wstring_view_t msg) { log(source_loc{}, lvl, msg); }
0199
0200     template <typename... Args>
0201     void trace(wformat_string_t<Args...> fmt, Args &&...args) {
0202         log(level::trace, fmt, std::forward<Args>(args)...);
0203     }
0204
0205     template <typename... Args>
0206     void debug(wformat_string_t<Args...> fmt, Args &&...args) {
0207         log(level::debug, fmt, std::forward<Args>(args)...);
0208     }
0209
0210     template <typename... Args>
0211     void info(wformat_string_t<Args...> fmt, Args &&...args) {
0212         log(level::info, fmt, std::forward<Args>(args)...);
0213     }
0214
0215     template <typename... Args>
0216     void warn(wformat_string_t<Args...> fmt, Args &&...args) {
0217         log(level::warn, fmt, std::forward<Args>(args)...);
0218     }
0219
0220     template <typename... Args>
0221     void error(wformat_string_t<Args...> fmt, Args &&...args) {
0222         log(level::err, fmt, std::forward<Args>(args)...);
0223     }
0224
0225     template <typename... Args>
0226     void critical(wformat_string_t<Args...> fmt, Args &&...args) {
0227         log(level::critical, fmt, std::forward<Args>(args)...);
0228     }
0229 #endif
0230
0231     template <typename T>
0232     void trace(const T &msg) {
0233         log(level::trace, msg);
0234     }
0235
0236     template <typename T>
0237     void debug(const T &msg) {
0238         log(level::debug, msg);
0239     }
0240
0241     template <typename T>
0242     void info(const T &msg) {
0243         log(level::info, msg);
0244     }
0245
0246     template <typename T>
0247     void warn(const T &msg) {
0248         log(level::warn, msg);
0249     }
0250
0251     template <typename T>
0252     void error(const T &msg) {
0253         log(level::err, msg);
0254     }
0255
0256     template <typename T>
0257     void critical(const T &msg) {
0258         log(level::critical, msg);
0259     }
0260
0261     // return true logging is enabled for the given level.
0262     bool should_log(level::level_enum msg_level) const {
0263         return msg_level >= level_.load(std::memory_order_relaxed);
0264     }
0265
0266     // return true if backtrace logging is enabled.
0267     bool should_backtrace() const { return tracer_.enabled(); }
0268
0269     void set_level(level::level_enum log_level);
0270
0271     level::level_enum level() const;
0272
0273     const std::string &name() const;
0274
0275     // set formatting for the sinks in this logger.
0276     // each sink will get a separate instance of the formatter object.
0277     void set_formatter(std::unique_ptr<formatter> f);
0278
0279     // set formatting for the sinks in this logger.
0280     // equivalent to
0281     //     set_formatter(make_unique<pattern_formatter>(pattern, time_type))
0282     // Note: each sink will get a new instance of a formatter object, replacing the old one.
0283     void set_pattern(std::string pattern, pattern_time_type time_type = pattern_time_type::local);
0284
0285     // backtrace support.
0286     // efficiently store all debug/trace messages in a circular buffer until needed for debugging.
0287     void enable_backtrace(size_t n_messages);
0288     void disable_backtrace();
0289     void dump_backtrace();
0290
0291     // flush functions
0292     void flush();
0293     void flush_on(level::level_enum log_level);
0294     level::level_enum flush_level() const;
0295
0296     // sinks
0297     const std::vector<sink_ptr> &sinks() const;
0298
0299     std::vector<sink_ptr> &sinks();
0300
0301     // error handler
0302     void set_error_handler(err_handler);
0303
0304     // create new logger with same sinks and configuration.
0305     virtual std::shared_ptr<logger> clone(std::string logger_name);
0306
0307 protected:
0308     std::string name_;
0309     std::vector<sink_ptr> sinks_;
0310     spdlog::level_t level_{level::info};
0311     spdlog::level_t flush_level_{level::off};
0312     err_handler custom_err_handler_{nullptr};
0313     details::backtracer tracer_;
0314
0315     // common implementation for after templated public api has been resolved
0316     template <typename... Args>
0317     void log_(source_loc loc, level::level_enum lvl, string_view_t fmt, Args &&...args) {
0318         bool log_enabled = should_log(lvl);
0319         bool traceback_enabled = tracer_.enabled();
0320         if (!log_enabled && !traceback_enabled) {
0321             return;
0322         }
0323         SPDLOG_TRY {
0324             memory_buf_t buf;
0325 #ifdef SPDLOG_USE_STD_FORMAT
0326             fmt_lib::vformat_to(std::back_inserter(buf), fmt, fmt_lib::make_format_args(args...));
0327 #else
0328             fmt::vformat_to(fmt::appender(buf), fmt, fmt::make_format_args(args...));
0329 #endif
0330
0331             details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
0332             log_it_(log_msg, log_enabled, traceback_enabled);
0333         }
0334         SPDLOG_LOGGER_CATCH(loc)
0335     }
0336
0337 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
0338     template <typename... Args>
0339     void log_(source_loc loc, level::level_enum lvl, wstring_view_t fmt, Args &&...args) {
0340         bool log_enabled = should_log(lvl);
0341         bool traceback_enabled = tracer_.enabled();
0342         if (!log_enabled && !traceback_enabled) {
0343             return;
0344         }
0345         SPDLOG_TRY {
0346             // format to wmemory_buffer and convert to utf8
0347             wmemory_buf_t wbuf;
0348             fmt_lib::vformat_to(std::back_inserter(wbuf), fmt,
0349                                 fmt_lib::make_format_args<fmt_lib::wformat_context>(args...));
0350
0351             memory_buf_t buf;
0352             details::os::wstr_to_utf8buf(wstring_view_t(wbuf.data(), wbuf.size()), buf);
0353             details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
0354             log_it_(log_msg, log_enabled, traceback_enabled);
0355         }
0356         SPDLOG_LOGGER_CATCH(loc)
0357     }
0358 #endif  // SPDLOG_WCHAR_TO_UTF8_SUPPORT
0359
0360     // log the given message (if the given log level is high enough),
0361     // and save backtrace (if backtrace is enabled).
0362     void log_it_(const details::log_msg &log_msg, bool log_enabled, bool traceback_enabled);
0363     virtual void sink_it_(const details::log_msg &msg);
0364     virtual void flush_();
0365     void dump_backtrace_();
0366     bool should_flush_(const details::log_msg &msg);
0367
0368     // handle errors during logging.
0369     // default handler prints the error to stderr at max rate of 1 message/sec.
0370     void err_handler_(const std::string &msg);
0371 };
0372
0373 void swap(logger &a, logger &b);
0374
0375 }  // namespace spdlog
0376
0377 #ifdef SPDLOG_HEADER_ONLY
0378     #include "logger-inl.h"
0379 #endif