simplelog

simplelog a header only log library and aims to provide out-of-the-box log feature and simple API.
It is super tiny and the lines of the code is about 150 but still thread safe.
You just have to log in most scenarios,so why bother?

Application Scenarios

small projects or non-performance-sensitive projects,just include it and log,no further configuration need to set.

Quick Start

#include <simple_log.hpp>
namespace sl = simplelog;

int main(int argc, char** argv)
{
  sl::Log::Info("info message");
  sl::Log::Error("error message");
  sl::Log::Debug("debug message");
}

Log Name

By default,the log file name is your executable name.Assumes that your executable name is calculate,
then a file calculate.log will be created and logged to whenever any simple::Log function is called.
You could also define macro SIMPLE_LOG_FILENAME to custom your own log name instead of executable name.

#define SIMPLE_LOG_FILENAME "trivial.log"
#include <simple_log.hpp>

...

Console

By default,simplelog will also print log content to stdout.
You could define macro SIMPLPE_LOG_NO_PRINT to disable it.

#define SIMPLPE_LOG_NO_PRINT
#include <simple_log.hpp>

...

Design

The performance of a widely used C++ log library is normally decent,but it is also huge and perhaps hard to configure.
The library provides simple api and header file that make it easy for anyone to read or DIY.

Thread Safety

On Windows an one-time output stream operation is thread safe.

std::string s;
std::ostream os;
// it is thread safe on Windows.
os << s;

// not thread safe because it is a two-time
// output stream operation.
os << s << std::endl

So on windows,the library use system io to keep log content in sync.

But on Linux,an one-time output stream operation could be thread safe or not.
It is depends on Linux release version or kernel version.
So there's a mutex to keep log content in sync on Linux version.

Performance

This library is not designed for high performance scenarios.
But on a small project or a non-performance-sensitive project,this library is easy to use and fast to begin coding.
It is also strange when the size of a log library is larger than your own project.
You could create a thread pool and then call simplelog::Log function to improve speed because
it is thread safe.