# fast_log
[](https://github.com/rbatis/fast_log/releases)
<img style="width: 200px;height: 200px;" width="200" height="200" src="https://github.com/rbatis/rbatis/blob/master/logo.png?raw=true" />
A log implementation for extreme speed, using Crossbeam/channel ,once Batch write logs,fast log date, Appender architecture, appender per thread
* High performance,Low overhead, logs auto merge, Full APPEND mode file writing
* Built-in `ZIP`,`LZ4` compression
* Support use ```log::logger().flush()``` method wait to flush disk
* Support custom file(impl Trait)
* Support rolling log(`ByDate`,`BySize`,`ByDuration`)
* Support Keep log(`All`,`KeepTime`,`KeepNum`) Delete old logs,Prevent logs from occupying the disk
* uses `#![forbid(unsafe_code)]` 100% Safe Rust.
```
-----------------
log data-> | main channel(crossbeam) | ->
-----------------
---------------- ----------------------
-> |thread channel)| -> background thread | appender1 |
---------------- ----------------------
---------------- ----------------------
-> |thread channel)| -> background thread | appender2 |
---------------- ----------------------
---------------- ----------------------
-> |thread channel)| -> background thread | appender3 |
---------------- ----------------------
---------------- ----------------------
-> |thread channel)| -> background thread | appender4 |
---------------- ----------------------
```
* How fast is?
* no flush(chan_len=1000000) benches/log.rs
```
//MACOS(Apple M1MAX-32GB)
test bench_log ... bench: 85 ns/iter (+/- 1,800)
```
* all log flush into file(chan_len=1000000) example/bench_test_file.rs
```
//MACOS(Apple M1MAX-32GB)
test bench_log ... bench: 323 ns/iter (+/- 0)
```
* how to use?
```toml
log = "0.4"
fast_log = {version = "1.7"}
```
or enable zip/lz4/gzip Compression library
```toml
log = "0.4"
# "lz4","zip","gzip"
fast_log = {version = "1.7" , features = ["lz4","zip","gzip"]}
```
#### Performance optimization(important)
* use ```chan_len(Some(100000))``` Preallocating channel memory reduces the overhead of memory allocation，for example:
```rust
use log::{error, info, warn};
fn main(){
fast_log::init(Config::new().file("target/test.log").chan_len(Some(100000))).unwrap();
log::info!("Commencing yak shaving{}", 0);
}
```
#### Use Log(Console)
```rust
use log::{error, info, warn};
fn main(){
fast_log::init(Config::new().console().chan_len(Some(100000))).unwrap();
log::info!("Commencing yak shaving{}", 0);
}
```
#### Use Log(Console Print)
```rust
use log::{error, info, warn};
fn main(){
fast_log::init(Config::new().console().chan_len(Some(100000))).unwrap();
fast_log::print("Commencing print\n".into());
}
```
#### Use Log(File)
```rust
use fast_log::{init_log};
use log::{error, info, warn};
fn main(){
fast_log::init(Config::new().file("target/test.log").chan_len(Some(100000))).unwrap();
log::info!("Commencing yak shaving{}", 0);
info!("Commencing yak shaving");
}
```
#### Split Log(ByLogDate)
```rust
use fast_log::config::Config;
use fast_log::plugin::file_split::{RollingType, KeepType, DateType, Rolling};
use std::thread::sleep;
use std::time::Duration;
use fast_log::plugin::packer::LogPacker;
fn main() {
fast_log::init(Config::new().chan_len(Some(100000)).console().file_split(
"target/logs/",
Rolling::new(RollingType::ByDate(DateType::Day)),
KeepType::KeepNum(2),
LogPacker {},
))
.unwrap();
for _ in 0..60 {
sleep(Duration::from_secs(1));
log::info!("Commencing yak shaving");
}
log::logger().flush();
println!("you can see log files in path: {}", "target/logs/")
}
```
#### Split Log(ByLogSize)
```rust
use fast_log::config::Config;
use fast_log::consts::LogSize;
use fast_log::plugin::file_split::{RollingType, KeepType, Rolling};
use fast_log::plugin::packer::LogPacker;
fn main() {
fast_log::init(Config::new().chan_len(Some(100000)).console().file_split(
"target/logs/",
Rolling::new(RollingType::BySize(LogSize::KB(500))),
KeepType::KeepNum(2),
LogPacker {},
))
.unwrap();
for _ in 0..40000 {
log::info!("Commencing yak shaving");
}
log::logger().flush();
println!("you can see log files in path: {}", "target/logs/")
}
```
##### Custom Log(impl do_log method)
```rust
use fast_log::{LogAppender};
use log::{error, info, warn};
pub struct CustomLog{}
impl LogAppender for CustomLog{
fn do_log(&mut self, record: &FastLogRecord) {
print!("{}",record);
}
}
fn main(){
let wait = fast_log::init(Config::new().custom(CustomLog {}).chan_len(Some(100000))).unwrap();
info!("Commencing yak shaving");
log::logger().flush();
}
```