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

##Features

Very fast - performance is the primary goal (see becnhmarks below)
Headers only
No dependencies
Cross platform - Linux / Windows on 32/64 bits
Mult/Single threaded loggers
Rotating log files
Daily log files
Console logging
Optional async logging
Logging levels
Custom formatting with user defined patterns

Benchmarks

Here are some benchmarks comparing spdlog vs boost log(1.56.0) on Ubuntu 64 bits, Intel i7-4770 CPU @ 3.40GHz.

The bench writes 1,000,000 log lines to a rotating log file (using shared synchronous logger object):

spdlog vs. boost - single thread

library	log lines	threads	elapsed
boost	1,000,000	1	4.207s
spdlog	1,000,000	1	0.975s

spdlog vs. boost - 10 threads

library	log lines	threads	elapsed
boost	1,000,000	10	6.592s
spdlog	1,000,000	10	0.961s

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 i = 0; i < 100; ++i)
        {
            auto square = i*i;
            file_logger->info() << i << '*' << i << '=' << square << " (" << "0x" << std::hex << square << ")";
        }

        // 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;
}

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