feat: --tail-logs can track log rollovers and incoporates a sleep timer to minimize idle CPU cycles

src/utils/logs.rs

@@ -1,9 +1,11 @@
 use crate::config::paths;
 use colored::Colorize;
 use fancy_regex::Regex;
-use std::fs::File;
+use std::fs::{self, File};
 use std::io::{BufRead, BufReader, Seek, SeekFrom};
 use std::process;
+use std::time::Duration;
+use tokio::time::sleep;
 
 pub async fn tail_logs(no_color: bool) {
     let re = Regex::new(r"^(?P<timestamp>\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3})\s+<(?P<opid>[^\s>]+)>\s+\[(?P<level>[A-Z]+)\]\s+(?P<logger>[^:]+):(?P<line>\d+)\s+-\s+(?P<message>.*)$").unwrap();
@@ -16,20 +18,43 @@ pub async fn tail_logs(no_color: bool) {
         process::exit(1);
     };
 
-    let mut lines = reader.lines();
+    let mut line_buf = String::new();
 
     loop {
-        if let Some(Ok(line)) = lines.next() {
-            if no_color {
-                println!("{line}");
-            } else {
-                let colored_line = colorize_log_line(&line, &re);
-                println!("{colored_line}");
+        match reader.read_line(&mut line_buf) {
+            Ok(0) => {
+                if file_was_rotated(&file_path, &mut reader) {
+                    let file = File::open(&file_path).expect("Cannot open file");
+                    reader = BufReader::new(file);
+                }
+                sleep(Duration::from_millis(100)).await;
+            }
+            Ok(_) => {
+                let line = line_buf.trim_end();
+                if no_color {
+                    println!("{line}");
+                } else {
+                    let colored_line = colorize_log_line(line, &re);
+                    println!("{colored_line}");
+                }
+                line_buf.clear();
+            }
+            Err(_) => {
+                line_buf.clear();
+                sleep(Duration::from_millis(100)).await;
             }
         }
     }
 }
 
+fn file_was_rotated(path: &std::path::Path, reader: &mut BufReader<File>) -> bool {
+    let current_pos = reader.stream_position().unwrap_or(0);
+    match fs::metadata(path) {
+        Ok(metadata) => metadata.len() < current_pos,
+        Err(_) => true,
+    }
+}
+
 fn colorize_log_line(line: &str, re: &Regex) -> String {
     if let Some(caps) = re.captures(line).expect("Failed to capture log line") {
         let level = &caps["level"];