update logging

local/utl/tracking/log_tailer.go

@@ -0,0 +1,78 @@
+package tracking
+
+import (
+	"bufio"
+	"os"
+	"time"
+)
+
+type LogTailer struct {
+	filePath    string
+	handleLine  func(string)
+	stopChan    chan struct{}
+	isRunning   bool
+}
+
+func NewLogTailer(filePath string, handleLine func(string)) *LogTailer {
+	return &LogTailer{
+		filePath:   filePath,
+		handleLine: handleLine,
+		stopChan:   make(chan struct{}),
+	}
+}
+
+func (t *LogTailer) Start() {
+	if t.isRunning {
+		return
+	}
+	t.isRunning = true
+
+	go func() {
+		var lastSize int64 = 0
+		for {
+			select {
+			case <-t.stopChan:
+				t.isRunning = false
+				return
+			default:
+				// Try to open and read the file
+				if file, err := os.Open(t.filePath); err == nil {
+					stat, err := file.Stat()
+					if err != nil {
+						file.Close()
+						time.Sleep(time.Second)
+						continue
+					}
+
+					// If file was truncated, start from beginning
+					if stat.Size() < lastSize {
+						lastSize = 0
+					}
+
+					// Seek to last read position
+					if lastSize > 0 {
+						file.Seek(lastSize, 0)
+					}
+
+					scanner := bufio.NewScanner(file)
+					for scanner.Scan() {
+						t.handleLine(scanner.Text())
+						lastSize, _ = file.Seek(0, 1) // Get current position
+					}
+
+					file.Close()
+				}
+
+				// Wait before next attempt
+				time.Sleep(time.Second)
+			}
+		}
+	}()
+}
+
+func (t *LogTailer) Stop() {
+	if !t.isRunning {
+		return
+	}
+	close(t.stopChan)
+}