chronicle

C++20 header-only library for low-latency asynchronous logging

Installation

Just place contents of include directory at your include path

Tests and benchmark

To build tests and benchmark:

cd chronicle
just test
just bench

Benchmark

Logging string, integer number and float number 100000 times with two threads.

Logger	Version	Date	Latency (ns)	Ratio
chronicle		01.09.2024	311	x1.0
NanoLog		08.03.2017	375	x1.2
spdlog	1.14.1	30.04.2024	1459	x4.7

m2 pro, clang 15.0.0

Usage

Opening single-threaded text logger

#include <iostream>
#include <system_error>
#include <chronicle/text_log.hpp>
#include <chronicle/sinks/file.hpp>

namespace cr = chronicle;
cr::unique_text_log log; // 'cr::shared_text_log' for multi-threaded

int main() {

    auto const opened = log.open(cr::sinks::file::open("test.log"));
    if(!opened) {
        std::cerr << opened.error().message() << '\n';
        return -1;
    }

    // Should be: "source", "message", {parameter}
    log.info("main", "Some message", "{ name1: ", 127, ", name2: ", "\"value2\" }");

    // Possible output:
    //    2020-05-09 16:57:02.343402 [main] Some message { name1: 127, name2: "value2" }

    return 0;
}

Opening multithreaded structured logger with daily rotation

#include <iostream>
#include <chronicle/structured_log.hpp>
#include <chronicle/sinks/daily_rotated_file.hpp>

namespace cr = chronicle;
cr::shared_structured_log log;

int main() {

    // Something like "test-2020_05_09.log" will be opened
    auto const opened = log.open(cr::sinks::daily_rotated_file::open("test.log", failed));
    if(!opened) {
        std::cerr << opened.error().message() << '\n';
        return -1;
    }

    // Should be: "source", "message", {"name", value}
    log.info("main", "Some message", "name1", 127, "name2", "value2");

    // Possible output:
    //    2020-05-09 16:57:02.343402 [14648] [main] Some message { name1: 127, name2: "value2" }

    return 0;
}

Using milliseconds instead of microseconds for single-threaded log

#include <chronicle/structured_log.hpp>
#include <chronicle/traits.hpp>
#include <ufmt/text.hpp>

namespace cr = chronicle;

using unique_log = cr::structured_log<cr::traits_unique_ms<ufmt::text>>;

Using only time (without date) for multithreaded log

#include <chronicle/structured_log.hpp>
#include <chronicle/traits.hpp>
#include <ufmt/text.hpp>

namespace cr = chronicle;

using shared_log = cr::structured_log<cr::traits_shared_time_only_us<ufmt::text>>;

Logging custom type

struct point {
  int x, y;
};

template<typename S> S&
operator << (S& stream, point const& p) {
    return s << "{ x: " << p.x << ", y: " << p.y << " }";
}

Dependencies

• hydra
• ufmt