https://github.com/linkdd/logfmtxx
Header only C++23 structured logging library using logfmt
https://github.com/linkdd/logfmtxx
cpp cpp23 logfmt logging logging-library structured-logging
Last synced: 9 months ago
JSON representation
Header only C++23 structured logging library using logfmt
- Host: GitHub
- URL: https://github.com/linkdd/logfmtxx
- Owner: linkdd
- License: 0bsd
- Created: 2024-04-04T01:24:13.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2025-04-03T21:40:34.000Z (9 months ago)
- Last Synced: 2025-04-03T22:30:34.104Z (9 months ago)
- Topics: cpp, cpp23, logfmt, logging, logging-library, structured-logging
- Language: C++
- Homepage:
- Size: 106 KB
- Stars: 71
- Watchers: 3
- Forks: 2
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE.txt
Awesome Lists containing this project
README
# logfmtxx
Header-only C++23 structured logging library using the
[logfmt](https://brandur.org/logfmt) format.
## Installation
Just copy the `include/logfmtxx.hpp` in your project.
Or with [Shipp](https://github.com/linkdd/shipp), add it to your dependencies:
```json
{
"name": "myproject",
"version": "0.1.0",
"dependencies": [
{
"name": "logfmtxx",
"url": "https://github.com/linkdd/logfmtxx.git",
"version": "v0.4.1"
}
]
}
```
## Usage
First, include the relevant headers:
```cpp
#include // if you wish to print logs with std::cout or std::cerr
#include
```
Then create a logger:
```cpp
auto logger = logfmtxx::logger{
[](const std::string& message) {
std::cout << message << std::endl;
}
};
```
Or with a functor to avoid allocations:
```cpp
struct printer {
void operator()(const std::string& message) {
std::cout << message << std::endl;
}
};
auto logger = logfmtxx::logger{printer{}};
```
Or with global fields:
```cpp
auto logger = logfmtxx::logger{
[](const std::string& message) {
std::cout << message << std::endl;
},
logfmtxx::field{"foo", 42},
logfmtxx::field{"bar", 3.14}
};
```
Then, call the `log()` method:
```cpp
logger.log(logfmtxx::level::info, "hello world");
// or
logger.info("hello world");
```
The result should be:
```
time=2001-01-01T00:00:00Z level=info message="hello world" foo=42 bar=3.14000
```
You can add extra fields as well:
```cpp
logger.log(
logfmtxx::level::error,
"internal server error",
logfmtxx::field{"http.method", "GET"},
logfmtxx::field{"http.path", "/"},
logfmtxx::field{"http.status", 500}
);
```
The result should be:
```
time=2001-01-01T00:00:00Z level=error message="internal server error" foo=42 bar=3.14000 http.method="GET" http.path="/" http.status=500
```
If your type implements `as_string()`, it can be used with a field:
```cpp
struct foo {
std::string as_string() const {
return "i am foo";
}
};
logger.log(logfmtxx::level::info, "example", logfmtxx::field{"foo", foo{}});
```
## Benchmark
**CPU:** 13th Gen Intel(R) Core(TM) i7-13700K 3.40 GHz
**Results:**
| ns/op | op/s | err% | total | benchmark
|--------------------:|--------------------:|--------:|----------:|:----------
| 7,326.07 | 136,498.88 | 1.1% | 0.09 | `logger.info with context (fast)`
| 7,169.35 | 139,482.70 | 0.7% | 0.09 | `logger.info without context (fast)`
| 9,707.22 | 103,016.06 | 1.3% | 0.03 | `logger.info with context (slow)`
| 9,448.67 | 105,835.01 | 0.7% | 0.03 | `logger.info without context (slow)`
## License
This software is released under the terms of the
[BSD 0-clause License](./LICENSE.txt).