spdlog/README.md
2014-12-07 05:33:33 +02:00

3.3 KiB

spdlog

Very fast, header only, C++ logging library.

Install

Just copy the files to your build tree and use a C++11 compiler

Tested on:

  • gcc 4.8.1 and above
  • clang 3.5
  • visual studio 2013
  • mingw with g++ 4.9.x

##Features

  • Very fast - performance is the primary goal (see becnhmarks below).
  • Headers only.
  • No dependencies.
  • Cross platform - Linux / Windows on 32/64 bits.
  • new! Feature rich cppfromat call style using the excellent cppformat library:logger.info("Hello {} !!", "world");
  • ostream call style logger.info() << "Hello << "logger";
  • Mixed cppformat/ostream call style logger.info("{} + {} = ", 1, 2) << "?";
  • Custom formatting.
  • Multi/Single threaded loggers.
  • Various log targets:
    • Rotating log files.
    • Daily log files.
    • Console logging.
    • Linux syslog.
    • Easily extendable with custom log targets (just implement a single function in the sink interface).
  • Optional, (extremly fast!), async logging.
  • Log levels.

Benchmarks

Below are some benchmarks comparing the time needed to log 1,000,000 lines to file under Ubuntu 64 bit, Intel i7-4770 CPU @ 3.40GHz:

threads boost log glog g2log spdlog spdlog async mode
1 4.779s 1.109s 3.155s 0.947s 1.455s
10 15.151ss 3.546s 3.500s 1.549s 2.040s

Usage Example

#include <iostream>
#include "spdlog/spdlog.h"

int main(int, char* [])
{
    namespace spd = spdlog;

    try
    {
        std::string filename = "spdlog_example";
        auto console = spd::stdout_logger_mt("console");
        console->info("Welcome to spdlog!") ;
        console->info("Creating file {}..", filename);

        auto file_logger = spd::rotating_logger_mt("file_logger", filename, 1024 * 1024 * 5, 3);
        file_logger->info("Log file message number {}..", 1);

        for (int j = 1; j <= 10; ++j)
           for (int i = 1; i < 10; ++i)
             file_logger->info("{} * {} equals {}, i, j, i*j );
        
        console->info("Easy padding in numbers like {:08d}", 12);
        console->info("Support for int: {0:d};  hex: {0:x};  oct: {0:o}; bin: {0:b}", 42);
        console->infor("Supprot for floats {:03.2f}", 1.23456);
        console->info("Positional args are {1} {0}..", "too", "supported): 
        
        console->info("{:<30}", "left aligned");
        console->info("{:>30}", "right aligned");
        console->info("{:^30}", "centered");
        
        //see cppformat's full docs here:
        //http://cppformat.readthedocs.org/en/stable/syntax.html
        
        // Change log level to all loggers to warning and above
        spd::set_level(spd::level::WARN);
        console->info("This should not be displayed");
        console->warn("This should!");
        spd::set_level(spd::level::INFO);

        // Change format pattern to all loggers
        spd::set_pattern(" **** %Y-%m-%d %H:%M:%S.%e %l **** %v");
        spd::get("console")->info("This is another message with different format");
    }
    catch (const spd::spdlog_ex& ex)
    {
        std::cout << "Log failed: " << ex.what() << std::endl;
    }
    return 0;
}