spdlog
Version 1.15.0
Pustaka logging C++ yang cepat
Salin folder include ke pohon build Anda dan gunakan kompiler C++11.
$ git clone https://github.com/gabime/spdlog.git
$ cd spdlog && mkdir build && cd build
$ cmake .. && cmake --build .lihat contoh CMakeLists.txt tentang cara menggunakan.
sudo apt install libspdlog-devbrew install spdlogsudo port install spdlogpkg install spdlogdnf install spdlogemerge dev-libs/spdlogpacman -S spdlogsudo zypper in spdlog-develvcpkg install spdlogconan install --requires=spdlog/[*]conda install -c conda-forge spdlogdepends: spdlog ^1.8.2 OutputDebugString(..) ).# include " spdlog/spdlog.h "
int main ()
{
spdlog::info ( " Welcome to spdlog! " );
spdlog::error ( " Some error message with arg: {} " , 1 );
spdlog::warn ( " Easy padding in numbers like {:08d} " , 12 );
spdlog::critical ( " Support for int: {0:d}; hex: {0:x}; oct: {0:o}; bin: {0:b} " , 42 );
spdlog::info ( " Support for floats {:03.2f} " , 1.23456 );
spdlog::info ( " Positional args are {1} {0}.. " , " too " , " supported " );
spdlog::info ( " {:<30} " , " left aligned " );
spdlog::set_level (spdlog::level::debug); // Set global log level to debug
spdlog::debug ( " This message should be displayed.. " );
// change log pattern
spdlog::set_pattern ( " [%H:%M:%S %z] [%n] [%^---%L---%$] [thread %t] %v " );
// Compile time log levels
// Note that this does not change the current log level, it will only
// remove (depending on SPDLOG_ACTIVE_LEVEL) the call on the release code.
SPDLOG_TRACE ( " Some trace message with param {} " , 42 );
SPDLOG_DEBUG ( " Some debug message " );
}
# include " spdlog/spdlog.h "
# include " spdlog/sinks/stdout_color_sinks.h "
void stdout_example ()
{
// create a color multi-threaded logger
auto console = spdlog::stdout_color_mt ( " console " );
auto err_logger = spdlog::stderr_color_mt ( " stderr " );
spdlog::get ( " console " )-> info ( " loggers can be retrieved from a global registry using the spdlog::get(logger_name) " );
}# include " spdlog/sinks/basic_file_sink.h "
void basic_logfile_example ()
{
try
{
auto logger = spdlog::basic_logger_mt ( " basic_logger " , " logs/basic-log.txt " );
}
catch ( const spdlog::spdlog_ex &ex)
{
std::cout << " Log init failed: " << ex. what () << std::endl;
}
}# include " spdlog/sinks/rotating_file_sink.h "
void rotating_example ()
{
// Create a file rotating logger with 5 MB size max and 3 rotated files
auto max_size = 1048576 * 5 ;
auto max_files = 3 ;
auto logger = spdlog::rotating_logger_mt ( " some_logger_name " , " logs/rotating.txt " , max_size, max_files);
}# include " spdlog/sinks/daily_file_sink.h "
void daily_example ()
{
// Create a daily logger - a new file is created every day at 2:30 am
auto logger = spdlog::daily_logger_mt ( " daily_logger " , " logs/daily.txt " , 2 , 30 );
}
// Debug messages can be stored in a ring buffer instead of being logged immediately.
// This is useful to display debug logs only when needed (e.g. when an error happens).
// When needed, call dump_backtrace() to dump them to your log.
spdlog::enable_backtrace ( 32 ); // Store the latest 32 messages in a buffer.
// or my_logger->enable_backtrace(32)..
for ( int i = 0 ; i < 100 ; i++)
{
spdlog::debug ( " Backtrace message {} " , i); // not logged yet..
}
// e.g. if some error happened:
spdlog::dump_backtrace (); // log them now! show the last 32 messages
// or my_logger->dump_backtrace(32).. // periodically flush all *registered* loggers every 3 seconds:
// warning: only use if all your loggers are thread-safe ("_mt" loggers)
spdlog::flush_every (std::chrono::seconds( 3 ));
// Stopwatch support for spdlog
# include " spdlog/stopwatch.h "
void stopwatch_example ()
{
spdlog::stopwatch sw;
spdlog::debug ( " Elapsed {} " , sw);
spdlog::debug ( " Elapsed {:.3} " , sw);
}
// many types of std::container<char> types can be used.
// ranges are supported too.
// format flags:
// {:X} - print in uppercase.
// {:s} - don't separate each byte with space.
// {:p} - don't print the position on each line start.
// {:n} - don't split the output into lines.
// {:a} - show ASCII if :n is not set.
# include " spdlog/fmt/bin_to_hex.h "
void binary_example ()
{
auto console = spdlog::get ( " console " );
std::array< char , 80 > buf;
console-> info ( " Binary example: {} " , spdlog::to_hex (buf));
console-> info ( " Another binary example:{:n} " , spdlog::to_hex ( std::begin (buf), std::begin (buf) + 10 ));
// more examples:
// logger->info("uppercase: {:X}", spdlog::to_hex(buf));
// logger->info("uppercase, no delimiters: {:Xs}", spdlog::to_hex(buf));
// logger->info("uppercase, no delimiters, no position info: {:Xsp}", spdlog::to_hex(buf));
}
// create a logger with 2 targets, with different log levels and formats.
// The console will show only warnings or errors, while the file will log all.
void multi_sink_example ()
{
auto console_sink = std::make_shared<spdlog::sinks::stdout_color_sink_mt>();
console_sink-> set_level (spdlog::level::warn);
console_sink-> set_pattern ( " [multi_sink_example] [%^%l%$] %v " );
auto file_sink = std::make_shared<spdlog::sinks::basic_file_sink_mt>( " logs/multisink.txt " , true );
file_sink-> set_level (spdlog::level::trace);
spdlog::logger logger ( " multi_sink " , {console_sink, file_sink});
logger. set_level (spdlog::level::debug);
logger. warn ( " this should appear in both console and file " );
logger. info ( " this message should not appear in the console, only in the file " );
} // create a logger with a lambda function callback, the callback will be called
// each time something is logged to the logger
void callback_example ()
{
auto callback_sink = std::make_shared<spdlog::sinks::callback_sink_mt>([]( const spdlog::details::log_msg &msg) {
// for example you can be notified by sending an email to yourself
});
callback_sink-> set_level (spdlog::level::err);
auto console_sink = std::make_shared<spdlog::sinks::stdout_color_sink_mt>();
spdlog::logger logger ( " custom_callback_logger " , {console_sink, callback_sink});
logger. info ( " some info log " );
logger. error ( " critical issue " ); // will notify you
}# include " spdlog/async.h "
# include " spdlog/sinks/basic_file_sink.h "
void async_example ()
{
// default thread pool settings can be modified *before* creating the async logger:
// spdlog::init_thread_pool(8192, 1); // queue with 8k items and 1 backing thread.
auto async_file = spdlog::basic_logger_mt<spdlog::async_factory>( " async_file_logger " , " logs/async_log.txt " );
// alternatively:
// auto async_file = spdlog::create_async<spdlog::sinks::basic_file_sink_mt>("async_file_logger", "logs/async_log.txt");
}
# include " spdlog/async.h "
# include " spdlog/sinks/stdout_color_sinks.h "
# include " spdlog/sinks/rotating_file_sink.h "
void multi_sink_example2 ()
{
spdlog::init_thread_pool ( 8192 , 1 );
auto stdout_sink = std::make_shared<spdlog::sinks::stdout_color_sink_mt >();
auto rotating_sink = std::make_shared<spdlog::sinks::rotating_file_sink_mt>( " mylog.txt " , 1024 * 1024 * 10 , 3 );
std::vector<spdlog::sink_ptr> sinks {stdout_sink, rotating_sink};
auto logger = std::make_shared<spdlog::async_logger>( " loggername " , sinks. begin (), sinks. end (), spdlog::thread_pool (), spdlog::async_overflow_policy::block);
spdlog::register_logger (logger);
} template <>
struct fmt ::formatter<my_type> : fmt::formatter<std::string>
{
auto format (my_type my, format_context &ctx) const -> decltype(ctx.out())
{
return fmt::format_to (ctx. out (), " [my_type i={}] " , my. i );
}
};
void user_defined_example ()
{
spdlog::info ( " user defined type: {} " , my_type ( 14 ));
}
// Log patterns can contain custom flags.
// the following example will add new flag '%*' - which will be bound to a <my_formatter_flag> instance.
# include " spdlog/pattern_formatter.h "
class my_formatter_flag : public spdlog ::custom_flag_formatter
{
public:
void format ( const spdlog::details::log_msg &, const std:: tm &, spdlog:: memory_buf_t &dest) override
{
std::string some_txt = " custom-flag " ;
dest. append (some_txt. data (), some_txt. data () + some_txt. size ());
}
std::unique_ptr<custom_flag_formatter> clone () const override
{
return spdlog::details::make_unique<my_formatter_flag>();
}
};
void custom_flags_example ()
{
auto formatter = std::make_unique<spdlog::pattern_formatter>();
formatter-> add_flag <my_formatter_flag>( ' * ' ). set_pattern ( " [%n] [%*] [%^%l%$] %v " );
spdlog::set_formatter ( std::move (formatter));
}
void err_handler_example ()
{
// can be set globally or per logger(logger->set_error_handler(..))
spdlog::set_error_handler ([]( const std::string &msg) { spdlog::get ( " console " )-> error ( " *** LOGGER ERROR ***: {} " , msg); });
spdlog::get ( " console " )-> info ( " some invalid message to trigger an error {}{}{}{} " , 3 );
}
# include " spdlog/sinks/syslog_sink.h "
void syslog_example ()
{
std::string ident = " spdlog-example " ;
auto syslog_logger = spdlog::syslog_logger_mt ( " syslog " , ident, LOG_PID);
syslog_logger-> warn ( " This is warning that will end up in syslog. " );
}# include " spdlog/sinks/android_sink.h "
void android_example ()
{
std::string tag = " spdlog-android " ;
auto android_logger = spdlog::android_logger_mt ( " android " , tag);
android_logger-> critical ( " Use " adb shell logcat " to view this message. " );
}# include " spdlog/cfg/env.h "
int main ( int argc, char *argv[])
{
spdlog::cfg::load_env_levels ();
// or from the command line:
// ./example SPDLOG_LEVEL=info,mylogger=trace
// #include "spdlog/cfg/argv.h" // for loading levels from argv
// spdlog::cfg::load_argv_levels(argc, argv);
}Jadi Anda dapat:
$ export SPDLOG_LEVEL=info,mylogger=trace
$ ./example // You can get callbacks from spdlog before/after a log file has been opened or closed.
// This is useful for cleanup procedures or for adding something to the start/end of the log file.
void file_events_example ()
{
// pass the spdlog::file_event_handlers to file sinks for open/close log file notifications
spdlog::file_event_handlers handlers;
handlers. before_open = [](spdlog:: filename_t filename) { spdlog::info ( " Before opening {} " , filename); };
handlers. after_open = [](spdlog:: filename_t filename, std::FILE *fstream) { fputs ( " After opening n " , fstream); };
handlers. before_close = [](spdlog:: filename_t filename, std::FILE *fstream) { fputs ( " Before closing n " , fstream); };
handlers. after_close = [](spdlog:: filename_t filename) { spdlog::info ( " After closing {} " , filename); };
auto my_logger = spdlog::basic_logger_st ( " some_logger " , " logs/events-sample.txt " , true , handlers);
} void replace_default_logger_example ()
{
auto new_logger = spdlog::basic_logger_mt ( " new_default_logger " , " logs/new-default-log.txt " , true );
spdlog::set_default_logger (new_logger);
spdlog::info ( " new logger log message " );
}# include " spdlog/spdlog.h "
# include " spdlog/sinks/qt_sinks.h "
MainWindow::MainWindow (QWidget *parent) : QMainWindow(parent)
{
setMinimumSize ( 640 , 480 );
auto log_widget = new QTextEdit ( this );
setCentralWidget (log_widget);
int max_lines = 500 ; // keep the text widget to max 500 lines. remove old lines if needed.
auto logger = spdlog::qt_color_logger_mt ( " qt_logger " , log_widget, max_lines);
logger-> info ( " Some info message " );
} // Mapped Diagnostic Context (MDC) is a map that stores key-value pairs (string values) in thread local storage.
// Each thread maintains its own MDC, which loggers use to append diagnostic information to log outputs.
// Note: it is not supported in asynchronous mode due to its reliance on thread-local storage.
# include " spdlog/mdc.h "
void mdc_example ()
{
spdlog::mdc::put ( " key1 " , " value1 " );
spdlog::mdc::put ( " key2 " , " value2 " );
// if not using the default format, use the %& formatter to print mdc data
// spdlog::set_pattern("[%H:%M:%S %z] [%^%L%$] [%&] %v");
}Di bawah ini adalah beberapa benchmark yang dilakukan di Ubuntu 64 bit, CPU Intel i7-4770 @ 3.40GHz
[info] **************************************************************
[info] Single thread, 1,000,000 iterations
[info] **************************************************************
[info] basic_st Elapsed: 0.17 secs 5,777,626/sec
[info] rotating_st Elapsed: 0.18 secs 5,475,894/sec
[info] daily_st Elapsed: 0.20 secs 5,062,659/sec
[info] empty_logger Elapsed: 0.07 secs 14,127,300/sec
[info] **************************************************************
[info] C-string (400 bytes). Single thread, 1,000,000 iterations
[info] **************************************************************
[info] basic_st Elapsed: 0.41 secs 2,412,483/sec
[info] rotating_st Elapsed: 0.72 secs 1,389,196/sec
[info] daily_st Elapsed: 0.42 secs 2,393,298/sec
[info] null_st Elapsed: 0.04 secs 27,446,957/sec
[info] **************************************************************
[info] 10 threads, competing over the same logger object, 1,000,000 iterations
[info] **************************************************************
[info] basic_mt Elapsed: 0.60 secs 1,659,613/sec
[info] rotating_mt Elapsed: 0.62 secs 1,612,493/sec
[info] daily_mt Elapsed: 0.61 secs 1,638,305/sec
[info] null_mt Elapsed: 0.16 secs 6,272,758/sec
[info] -------------------------------------------------
[info] Messages : 1,000,000
[info] Threads : 10
[info] Queue : 8,192 slots
[info] Queue memory : 8,192 x 272 = 2,176 KB
[info] -------------------------------------------------
[info]
[info] *********************************
[info] Queue Overflow Policy: block
[info] *********************************
[info] Elapsed: 1.70784 secs 585,535/sec
[info] Elapsed: 1.69805 secs 588,910/sec
[info] Elapsed: 1.7026 secs 587,337/sec
[info]
[info] *********************************
[info] Queue Overflow Policy: overrun
[info] *********************************
[info] Elapsed: 0.372816 secs 2,682,285/sec
[info] Elapsed: 0.379758 secs 2,633,255/sec
[info] Elapsed: 0.373532 secs 2,677,147/sec
Dokumentasi dapat ditemukan di halaman wiki.
Terima kasih kepada JetBrains karena telah menyumbangkan lisensi produk untuk membantu mengembangkan spdlog
