apt-get install libspdlog-dev
brew install spdlog
cd /usr/ports/devel/spdlog/ && make install clean
yum install spdlog
pacman -S spdlog-git
vcpkg install spdlog
OutputDebugString(..)
)Below are some benchmarks comparing popular log libraries under Ubuntu 64 bit, Intel i7-4770 CPU @ 3.40GHz
Time needed to log 1,000,000 lines in synchronous mode (in seconds, the best of 3 runs):
threads | boost log 1.54 | glog | easylogging | spdlog |
---|---|---|---|---|
1 | 4.169s | 1.066s | 0.975s | 0.302s |
10 | 6.180s | 3.032s | 2.857s | 0.968s |
100 | 5.981s | 1.139s | 4.512s | 0.497s |
Time needed to log 1,000,000 lines in asynchronous mode, i.e. the time it takes to put them in the async queue (in seconds, the best of 3 runs):
threads | g2log async logger | spdlog async mode |
---|---|---|
1 | 1.850s | 0.216s |
10 | 0.943s | 0.173s |
100 | 0.959s | 0.202s |
#include "spdlog/spdlog.h" #include <iostream> #include <memory> void async_example(); void syslog_example(); void user_defined_example(); void err_handler_example(); namespace spd = spdlog; int main(int, char*[]) { try { // Console logger with color auto console = spd::stdout_color_mt("console"); console->info("Welcome to spdlog!"); console->error("Some error message with arg{}..", 1); // Conditional logging example auto i = 2; console->warn_if(i != 0, "an important message"); // Formatting examples console->warn("Easy padding in numbers like {:08d}", 12); console->critical("Support for int: {0:d}; hex: {0:x}; oct: {0:o}; bin: {0:b}", 42); console->info("Support for floats {:03.2f}", 1.23456); console->info("Positional args are {1} {0}..", "too", "supported"); console->info("{:<30}", "left aligned"); spd::get("console")->info("loggers can be retrieved from a global registry using the spdlog::get(logger_name) function"); // Create basic file logger (not rotated) auto my_logger = spd::basic_logger_mt("basic_logger", "logs/basic.txt"); my_logger->info("Some log message"); // Create a file rotating logger with 5mb size max and 3 rotated files auto rotating_logger = spd::rotating_logger_mt("some_logger_name", "logs/mylogfile", 1048576 * 5, 3); for (int i = 0; i < 10; ++i) rotating_logger->info("{} * {} equals {:>10}", i, i, i*i); // Create a daily logger - a new file is created every day on 2:30am auto daily_logger = spd::daily_logger_mt("daily_logger", "logs/daily", 2, 30); // trigger flush if the log severity is error or higher daily_logger->flush_on(spd::level::err); daily_logger->info(123.44); // Customize msg format for all messages spd::set_pattern("*** [%H:%M:%S %z] [thread %t] %v ***"); rotating_logger->info("This is another message with custom format"); // Runtime log levels spd::set_level(spd::level::info); //Set global log level to info console->debug("This message shold not be displayed!"); console->set_level(spd::level::debug); // Set specific logger's log level console->debug("This message shold be displayed.."); // Compile time log levels // define SPDLOG_DEBUG_ON or SPDLOG_TRACE_ON SPDLOG_TRACE(console, "Enabled only #ifdef SPDLOG_TRACE_ON..{} ,{}", 1, 3.23); SPDLOG_DEBUG(console, "Enabled only #ifdef SPDLOG_DEBUG_ON.. {} ,{}", 1, 3.23); // Asynchronous logging is very fast.. // Just call spdlog::set_async_mode(q_size) and all created loggers from now on will be asynchronous.. async_example(); // syslog example. linux/osx only syslog_example(); // android example. compile with NDK android_example(); // Log user-defined types example user_defined_example(); // Change default log error handler err_handler_example(); // Apply a function on all registered loggers spd::apply_all([&](std::shared_ptr<spd::logger> l) { l->info("End of example."); }); // Release and close all loggers spd::drop_all(); } // Exceptions will only be thrown upon failed logger or sink construction (not during logging) catch (const spd::spdlog_ex& ex) { std::cout << "Log init failed: " << ex.what() << std::endl; return 1; } } void async_example() { size_t q_size = 4096; //queue size must be power of 2 spd::set_async_mode(q_size); auto async_file = spd::daily_logger_st("async_file_logger", "logs/async_log.txt"); for (int i = 0; i < 100; ++i) async_file->info("Async message #{}", i); } //syslog example void syslog_example() { #ifdef SPDLOG_ENABLE_SYSLOG std::string ident = "spdlog-example"; auto syslog_logger = spd::syslog_logger("syslog", ident, LOG_PID); syslog_logger->warn("This is warning that will end up in syslog.."); #endif } // user defined types logging by implementing operator<< struct my_type { int i; template<typename OStream> friend OStream& operator<<(OStream& os, const my_type &c) { return os << "[my_type i="<<c.i << "]"; } }; #include <spdlog/fmt/ostr.h> // must be included void user_defined_example() { spd::get("console")->info("user defined type: {}", my_type { 14 }); } // //custom error handler // void err_handler_example() { spd::set_error_handler([](const std::string& msg) { std::cerr << "my err handler: " << msg << std::endl; }); // (or logger->set_error_handler(..) to set for specific logger) }
Documentation can be found in the wiki pages.