Want an efficient ASP.NET Web API controller that

Question

I'd like to change the following code into an efficient Web API controller method that can return 30 to 50 JPEGs (for <20 simultaneous users) of average 3MB size.

    public async Task<HttpResponseMessage> Get(int imageid) {
        return await Task.Run(() => {
            var dzImage = _dataContext.DeepZoomImages.SingleOrDefault(_ => _.ImageID == imageid);
            if (dzImage == default(DeepZoomImage)) {
                throw new HttpResponseException(new HttpResponseMessage(HttpStatusCode.NotFound));
            }
            var response = new HttpResponseMessage(HttpStatusCode.OK);
            var bitmap = GetFullSizeBitmap(dzImage);
            var memoryStream = new MemoryStream();
            bitmap.Save(memoryStream, ImageFormat.Jpeg);
            response.Content = new ByteArrayContent(memoryStream.ToArray());
            var fileName = string.Format("{0}.jpg", dzImage.ImageName);
            response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") { FileName = fileName };
            response.Content.Headers.ContentType = new MediaTypeHeaderValue("image/jpeg");
            memoryStream.Flush();
            return response;
        });
    }

The foregoing method handles one image. How can I best pluralize it to handle multiple images efficiently for this usage/load scenario? Is it possible to return Task<HttpResponseMessage>[] or Task<HttpResponseMessage[]>?

Or would it be better generate all images and return them in one go?

Thanks for your help...

Answer 1

Based on our discussion the best approach here would be to create a ZIP file on the server and then download that one file to the user. As an alternative you could try this multi-file download approach.