Rotate file if exceeds max file size config (#3)

README.md

@@ -40,6 +40,7 @@ You can set the following configuration options:
 
 - `.datetime_format("%Y-%m-%d %H:%M:%S.3f")` to set the datetime format
 - `.timezone(ftail::Tz::UTC)` to set the timezone [requires feature `timezone`]
+- `.max_file_size(100)` to set the maximum file size in MB (will move older logs to .old{N})
 
 ## Drivers
 

examples/single_file/src/main.rs

@@ -6,6 +6,7 @@ use log::LevelFilter;
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     Ftail::new()
         .single_file("logs/demo.log", true, LevelFilter::Trace)
+        .max_file_size(10)
         .init()?;
 
     log::trace!("This is a trace message");

src/drivers/daily_file.rs

@@ -2,18 +2,21 @@ use log::Log;
 use std::{
     fs::File,
     io::{LineWriter, Write},
+    path::PathBuf,
     sync::Mutex,
 };
 
 use crate::{
     error::FtailError,
     formatters::{default::DefaultFormatter, Formatter},
+    helpers::rotate_if_exceeds_max_file_size,
     Config,
 };
 
 /// A logger that logs messages to a daily log file.
 pub struct DailyFileLogger {
     file: Mutex<LineWriter<File>>,
+    file_path: PathBuf,
     dir: String,
     current_date: Mutex<String>,
     config: Config,
@@ -27,7 +30,7 @@ impl DailyFileLogger {
         let file = std::fs::OpenOptions::new()
             .create(true)
             .append(true)
-            .open(path)
+            .open(&path)
             .map_err(FtailError::IoError)?;
 
         let md = std::fs::metadata(dir).map_err(FtailError::IoError)?;
@@ -38,13 +41,14 @@ impl DailyFileLogger {
 
         Ok(DailyFileLogger {
             file: Mutex::new(LineWriter::new(file)),
+            file_path: PathBuf::from(path),
             dir: dir.to_string(),
             current_date: Mutex::new(today),
             config,
         })
     }
 
-    fn rotate_file_if_needed(&self) {
+    fn rotate_daily_file(&self) {
         let today = chrono::Local::now().format("%Y-%m-%d").to_string();
         let mut current_date = self.current_date.lock().unwrap();
 
@@ -71,7 +75,8 @@ impl Log for DailyFileLogger {
     }
 
     fn log(&self, record: &log::Record) {
-        self.rotate_file_if_needed();
+        rotate_if_exceeds_max_file_size(&self.file, self.file_path.clone(), &self.config);
+        self.rotate_daily_file();
 
         let formatter = DefaultFormatter::new(record, &self.config);
 

src/drivers/single_file.rs

@@ -2,18 +2,21 @@ use log::Log;
 use std::{
     fs::File,
     io::{LineWriter, Write},
+    path::PathBuf,
     sync::Mutex,
 };
 
 use crate::{
     error::FtailError,
     formatters::{default::DefaultFormatter, Formatter},
+    helpers::rotate_if_exceeds_max_file_size,
     Config,
 };
 
 /// A logger that logs messages to a single log file.
 pub struct SingleFileLogger {
     file: Mutex<LineWriter<File>>,
+    file_path: PathBuf,
     config: Config,
 }
 
@@ -34,6 +37,7 @@ impl SingleFileLogger {
 
         Ok(SingleFileLogger {
             file: Mutex::new(LineWriter::new(file)),
+            file_path: PathBuf::from(path),
             config,
         })
     }
@@ -45,6 +49,8 @@ impl Log for SingleFileLogger {
     }
 
     fn log(&self, record: &log::Record) {
+        rotate_if_exceeds_max_file_size(&self.file, self.file_path.clone(), &self.config);
+
         let formatter = DefaultFormatter::new(record, &self.config);
 
         let mut file = self.file.lock().unwrap();

src/formatters/mod.rs

@@ -13,6 +13,7 @@ impl Config {
             datetime_format: "%Y-%m-%d %H:%M:%S".to_string(),
             #[cfg(feature = "timezone")]
             timezone: chrono_tz::Tz::UTC,
+            max_file_size: None,
         }
     }
 }

src/helpers.rs

@@ -0,0 +1,34 @@
+use std::{fs::File, io::LineWriter, path::PathBuf, sync::Mutex};
+
+use crate::Config;
+
+pub(crate) fn rotate_if_exceeds_max_file_size(
+    file: &Mutex<LineWriter<File>>,
+    file_path: PathBuf,
+    config: &Config,
+) {
+    if config.max_file_size.is_none() {
+        return;
+    }
+
+    let mut file = file.lock().unwrap();
+
+    let md = file.get_ref().metadata().unwrap();
+
+    if md.len() > config.max_file_size.unwrap() {
+        let path = file_path.to_str().unwrap();
+
+        let mut new_path = format!("{}.old", path);
+
+        let mut counter = 1;
+        while std::fs::metadata(&new_path).is_ok() {
+            new_path = format!("{}.old{}", path, counter);
+            counter += 1;
+        }
+
+        std::fs::rename(path, &new_path).unwrap();
+
+        let new_file = std::fs::File::create(path).unwrap();
+        *file = LineWriter::new(new_file);
+    }
+}

src/lib.rs

@@ -40,6 +40,7 @@
 //!
 //! - `.datetime_format("%Y-%m-%d %H:%M:%S.3f")` to set the datetime format
 //! - `.timezone(ftail::Tz::UTC)` to set the timezone [requires feature `timezone`]
+//! - `.max_file_size(100)` to set the maximum file size in MB (will move older logs to .old{N})
 //!
 //! ## Drivers
 //!
@@ -191,6 +192,7 @@ pub mod drivers;
 /// Module containing the error type.
 pub mod error;
 mod formatters;
+mod helpers;
 mod writer;
 
 /// The main struct for configuring the logger.
@@ -219,6 +221,7 @@ pub struct Config {
     pub datetime_format: String,
     #[cfg(feature = "timezone")]
     pub timezone: chrono_tz::Tz,
+    pub max_file_size: Option<u64>,
 }
 
 impl Ftail {
@@ -246,6 +249,13 @@ impl Ftail {
         self
     }
 
+    /// Set the maximum file size for the logger.
+    pub fn max_file_size(mut self, max_file_size_in_mb: u64) -> Self {
+        self.config.max_file_size = Some(max_file_size_in_mb * 1024 * 1024);
+
+        self
+    }
+
     fn add_driver<F>(mut self, constructor: F, level: log::LevelFilter) -> Self
     where
         F: Fn(Config) -> Box<dyn Log + Send + Sync> + 'static,