如何在 ASP.NET MVC 3 中从下载的文件优化内存中 zip 存档创建

我正在制作一个控制器，它应该返回从另一台服务器（位于同一数据中心）下载的文件的压缩列表

我为妈妈做了什么：

/// <summary>
/// Enables processing of the result of an action method by a custom type that inherits from the <see cref="T:System.Web.Mvc.ActionResult"/> class.
/// </summary>
/// <param name="context">The context in which the result is executed. The context information includes the controller, HTTP content, request context, and route data.</param>
public override void ExecuteResult(ControllerContext context)
{
    context.HttpContext.Response.ContentType = "application/zip";
    context.HttpContext.Response.CacheControl = "private";
    context.HttpContext.Response.Cache.SetCacheability(HttpCacheability.NoCache);
    context.HttpContext.Response.AddHeader("content-disposition", string.Format("attachment; filename='"{0}'"", this.ResultFileName));
    var buffer = new byte[BufferSize];
    using (var zippedUploadStream = new ZipOutputStream(context.HttpContext.Response.OutputStream))
    {
        zippedUploadStream.SetLevel(0);
        foreach (var url in this.Urls)
        {
            var request = WebRequest.Create(url);
            var response = request.GetResponse();
            var downloadStream = response.GetResponseStream();
            if (downloadStream != null)
            {
                var zipEntry = new ZipEntry(Path.GetFileName(response.ResponseUri.ToString()));
                zippedUploadStream.PutNextEntry(zipEntry);
                int read;
                while ((read = downloadStream.Read(buffer, 0, buffer.Length)) > 0)
                {
                    zippedUploadStream.Write(buffer, 0, read);
                    context.HttpContext.Response.Flush();
                }
            }
            if (!context.HttpContext.Response.IsClientConnected)
            {
                break;
            }
        }
        zippedUploadStream.Finish();
    }
    context.HttpContext.Response.Flush();
    context.HttpContext.Response.End();
}

让我害怕的是，所有操作都是同步的。

如果我离开这个实现，性能会受到多大的打击？

是否可以访问上下文。来自另一个线程的 HttpContext.Response 对象？

是否可以使用异步调用优化此代码？