Method AddRoot

agent/filefinder/engine.go:110–168

AddRoot adds a directory root to the engine.

(ctx context.Context, root string)

// AddRoot adds a directory root to the engine.
func (e *Engine) AddRoot(ctx context.Context, root string) error {
	absRoot, err := filepath.Abs(root)
	if err != nil {
		return xerrors.Errorf("resolve root: %w", err)
	}
	e.mu.Lock()
	if e.closed.Load() {
		e.mu.Unlock()
		return ErrClosed
	}
	if _, exists := e.roots[absRoot]; exists {
		e.mu.Unlock()
		return nil
	}
	e.mu.Unlock()

	// Walk and create the watcher outside the lock to avoid
	// blocking the event pipeline on filesystem I/O.
	idx, walkErr := walkRoot(absRoot)
	if walkErr != nil {
		return xerrors.Errorf("walk root: %w", walkErr)
	}
	wCtx, wCancel := context.WithCancel(context.Background())
	w, wErr := newFSWatcher(absRoot, e.logger)
	if wErr != nil {
		wCancel()
		return xerrors.Errorf("create watcher: %w", wErr)
	}

	e.mu.Lock()
	// Re-check after re-acquiring the lock: another goroutine
	// may have added this root or closed the engine while we
	// were walking.
	if e.closed.Load() {
		e.mu.Unlock()
		wCancel()
		_ = w.Close()
		return ErrClosed
	}
	if _, exists := e.roots[absRoot]; exists {
		e.mu.Unlock()
		wCancel()
		_ = w.Close()
		return nil
	}
	rs := &rootState{root: absRoot, index: idx, watcher: w, cancel: wCancel}
	e.roots[absRoot] = rs
	w.Start(wCtx)
	e.wg.Add(1)
	go e.forwardEvents(wCtx, absRoot, w)
	e.publishSnapshot()
	fileCount := idx.Len()
	e.mu.Unlock()
	e.logger.Info(ctx, "added root to engine",
		slog.F("root", absRoot),
		slog.F("files", fileCount),
	)
	return nil