func()

in pcap-cli/internal/transformer/translator_worker.go [542:614]

• 48 lines of code
• 10 McCabe index (conditional complexity)

func (w *pcapTranslatorWorker) Run(ctx context.Context) (buffer interface{}) {
	defer func() {
		if r := recover(); r != nil {
			transformerLogger.Printf("%s @translator | panic: %s\n%s\n",
				*w.loggerPrefix, r, string(debug.Stack()))
			buffer = nil
		}
	}()

	// fail open:
	//   - if there aren't any filters, continue with translation.
	// fail fast:
	//   - do not translate any layers before enforcing filters.
	if w.filters != nil && !w.shouldTranslate(ctx) {
		return nil
	}

	var _buffer fmt.Stringer = nil

	select {
	case <-ctx.Done():
		_buffer = nil
	default:
		_buffer = w.translator.next(ctx, w.iface, w.serial, w.packet)
	}

	if _buffer == nil {
		transformerLogger.Printf("%s @translator | failed", *w.loggerPrefix)
		buffer = nil
		return nil
	}

	translations := make(chan fmt.Stringer, packetLayerTranslatorsSize)
	var wg sync.WaitGroup

	// number of layers to be translated
	packetLayers := w.pkt(ctx).Layers()
	wg.Add(len(packetLayers))

	go func(wg *sync.WaitGroup) {
		wg.Wait()
		close(translations)
	}(&wg)

	// O(N); N is the number of layers available in the packet
	// this is a faster implementation as there is no layer discovery;
	// layers are translated on-demand based on the packet's contents.
	for i, l := range packetLayers {
		// translate layers concurrently:
		//   - layers must know nothing about each other
		go w.translate(ctx, i, l, translations, &wg)
	}

	for translation := range translations {
		// translations are `nil` if layer is not available
		if translation != nil {
			// see: https://github.com/Jeffail/gabs?tab=readme-ov-file#merge-two-containers
			_buffer, _ = w.translator.merge(ctx, _buffer, translation)
		}
	}

	select {
	case <-ctx.Done():
		// skip `finalize` deliver translation as-is
		transformerLogger.Printf("%s @translator | incomplete", *w.loggerPrefix)
	default:
		// `finalize` is the only method that is allowed to work across layers
		_buffer, _ = w.translator.finalize(ctx, w.ifaces, w.iface, w.serial, w.packet, w.conntrack, _buffer)
	}

	buffer = &_buffer
	return &_buffer
}