Christian Neukirchen wrote:
> * rack.input must be rewindable and support reading into a buffer,
>   wrap with Rack::RewindableInput if it isn't.

Nick Sieger pointed me to your implementation of RewindableInput, and I 
think you should know that Tempfile is a pretty slow API, especially if 
you're spinning up a tempfile for every incoming request. You'd probably 
be better off having the default RewindableInput buffer in memory, with 
a separate option to buffer to a tempfile or similar.

I'm also curious: why was this requirement was added at all? It means 
all servers will have to buffer request streams, which will often impact 
performance (since it will have to be buffered either in memory on on 
disk), and it doesn't seem typical when looking at other service APIs.

- Charlie