Function capMetricsLog

handoff/storage.go:222–252

(root string, maxLines int)

}

func capMetricsLog(root string, maxLines int) error {
	if maxLines <= 0 {
		return nil
	}

	path := MetricsPath(root)
	data, err := os.ReadFile(path)
	if err != nil {
		if os.IsNotExist(err) {
			return nil
		}
		return err
	}
	data = bytes.TrimSpace(data)
	if len(data) == 0 {
		return nil
	}

	lines := bytes.Split(data, []byte("\n"))
	if len(lines) <= maxLines {
		return nil
	}

	trimmed := bytes.Join(lines[len(lines)-maxLines:], []byte("\n"))
	trimmed = append(trimmed, '\n')
	tmpPath := path + ".tmp"
	if err := os.WriteFile(tmpPath, trimmed, 0644); err != nil {
		return err
	}
	return os.Rename(tmpPath, path)
}