Bohr1005/flog

logger,high-performance,lightweight

flog

flog(flash logger) is a logging library I use in my high-frequency trading system, it's a lightweight and high-performance logging library that supports asynchronous logging to the console or files.I separated it from my high-frequency trading system and partially open-sourced

how to use

#include "logger.hpp"

int main(){
    flog::init(flog::level::INFO, 1024)  // asynchronous logging to console

    //flog::init(flog::level::INFO,"file", 1024) // asynchronous logging to ./log/file.log
    INFO("hello", "world");
}

The logger has two constructors:

explicit logger(flog::level, uint32_t = 1024);
logger(flog::level, std::string_view, uint32_t = 1024);

The first constructor outputs logs to the console, while the second constructor outputs logs to a specified file. 1024 represents the maximum number of logs that can be stored before the logs are refreshed.

why is the performance excellent?

• Using a lock-free circular queue to store logs, and ensuring that the elements in the queue are arranged continuously in memory.

• The size of each log is aligned with cache size.

• Each log is directly emplaced at the end of the queue in binary without copy or memory allocation.

run example

bazel run log_cout
[10:18:55.691850716 log_cout.cpp:8 INFO] hello world

benchmark

It performs significantly better than spdlog on device with Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz

write 1,000,000 items of size 50 bytes each to file

bazel run bm_logger --cxxopt="-O3"
benchmark file elapse:0.05896 avg:1.69607e+07/sec