Stream zip file MVC.NET start streaming

Question

I'm trying to create a method which continually streams a zip file as a user downloads it (so that there is no wasted streaming)

I added a thread.sleep to simulate latency

public override void ExecuteResult(ControllerContext context) {
    HttpResponseBase response = context.HttpContext.Response;

    response.Clear();
    response.ClearContent();
    response.ClearHeaders();
    response.Cookies.Clear();
    response.ContentType = ContentType;
    response.ContentEncoding = Encoding.Default;
    response.AddHeader("Content-Type", ContentType);
    context.HttpContext.Response.AddHeader("Content-Disposition", 
                            String.Format("attachment; filename={0}", 
                            this.DownloadName));
    int ind = 0;
    using (ZipOutputStream zipOStream = 
                new ZipOutputStream(context.HttpContext.Response.OutputStream))
    {
        foreach (var file in FilesToZip)
        {
            ZipEntry entry = new ZipEntry(FilesToZipNames[ind++]);
            zipOStream.PutNextEntry(entry);
            Thread.Sleep(1000);
            zipOStream.Write(file, 0, file.Length);
            zipOStream.Flush();
        }
        zipOStream.Finish();
    }    
    response.OutputStream.Flush();
}

It seems like the zip will not start streaming until all the files are files are zipped. Is there a way to stream continuously? Maybe with a different library?

Answer 1

Assuming the zip format is partial to streaming, your problem is that your response is being buffered by default. If you set HttpResponseBase.BufferOutput to false, it should start streaming immediately.

Answer 2

I think you might need to be flushing the outputstream rather than the zipostream to see any output to http. So response.OutputStream.Flush() would appear in your loop in that case. Not sure if it will actually solver your problem though.