Stream/FileStreamer.php
public function getStreamedResponse(ResourceInterface $resource, $bufferLength = 512)
    {
        $fs = $this->resourceManager->getFilesystem($resource);
        if (!$fs->has($resource->getPath())) {
            throw new NotFoundHttpException("File not found {$resource->getPath()} ({$resource::getType()})");
        }

        $originalFilename = $resource->getPath();
        if ($resource) {
            $originalFilename = $resource->getOriginalFileName();
        }

        $stream = $fs->readStream($resource->getPath());
        if (!$stream) {
            throw new \RuntimeException("Unable to open stream to resource {$resource->getPath()}");
        }

        $response = new StreamedResponse(
            function () use ($stream, $bufferLength) {
                while (!feof($stream)) {
                    echo fread($stream, $bufferLength);
                }
                fclose($stream);
            },
            200
        );

        $response->headers->set(
            'Content-Disposition',
            $response->headers->makeDisposition(
                'attachment',
                $originalFilename,
                FilenameTransliterator::transliterateFilename($originalFilename)
            )
        );
        $response->headers->set('Content-Type', $fs->getMimetype($resource->getPath()));

        return $response;
    }
public function getStreamedResponse(ResourceInterface $resource, $bufferLength = 512)
    {
        $fs = $this->resourceManager->getFilesystem($resource);
        if (!$fs->has($resource->getPath())) {
            throw new NotFoundHttpException("File not found {$resource->getPath()} ({$resource::getType()})");
        }

        $originalFilename = $resource->getPath();
        if ($resource) {
            $originalFilename = $resource->getOriginalFileName();
        }

        $stream = $fs->readStream($resource->getPath());
        if (!$stream) {
            throw new \RuntimeException("Unable to open stream to resource {$resource->getPath()}");
        }

        $response = new StreamedResponse(
            function () use ($stream, $bufferLength) {
                while (!feof($stream)) {
                    echo fread($stream, $bufferLength);
                }
                fclose($stream);
            },
            200
        );

        $response->headers->set(
            'Content-Disposition',
            $response->headers->makeDisposition(
                'attachment',
                $originalFilename,
                FilenameTransliterator::transliterateFilename($originalFilename)
            )
        );
        $response->headers->set('Content-Type', $fs->getMimetype($resource->getPath()));

        return $response;
    }
@param ResourceInterface $resource
@param int               $bufferLength

@throws \League\Flysystem\FileNotFoundException

@return StreamedResponse