send_file_headers! should get higher visibility or a public wrapper

Hello,
this is my use case.

We store files on a remote location (say Amazon S3).
When a user wants to stream a file we just redirect to the Amazon S3 file URL and that's fine.

However Safari/Mac is kinda broken in this regard:
http://stackoverflow.com/questions/1995589/html5-audio-safari-live-...
due to faulty range headers.

So my idea was to craft custom headers in our stream action and stream the file directly from our action.

In order to do that I need to call send_file_headers! with custom headers because send_data and send_file actually requires a file that resides on local filesystem and I want to avoid that.

The problem is that Ruby 1.9 doesn't allow to call private methods with send anymore.

I think publicizing up send_file_headers! or writing a public caller method would greatly increase the customization of the action if the developer know what he's doing.

  send_file_headers!(
    :length => S3Object.about(<s3 object>, <s3 bucket>)["content-length"],
    :filename=><the filename>
  )
  render :status => 200, :text => Proc.new { |response, output|
    S3Object.stream(<s3 object>, <s3 bucket>) do |chunk|
      output.write chunk
    end
  }

Also, in Rails 3 this method is considerably different, we may have to take care of that, for example :length is not used anymore.