Re: Patch: Make CGI handler obey rack spec for the greater good

[Max Cantor <max@maxcantor.net>]

On May 20, 10:09 am, James Tucker <jftuc...@gmail.com> wrote:
> On 12 May 2010, at 10:24, Max Cantor wrote:
>
> > The default CGI handler included in rack doesn't obey the rack spec;
> > its input stream is not rewindable, and thus generates Errno::ESPIPE
> > illegal seek errors.  You can see the Sinatra guys needed a workaround
> > for it here:https://sinatra.lighthouseapp.com/projects/9779/tickets/227-errnoespi...
>
> > This patch wraps the CGI handler's input stream in a rewindable input
> > object, which makes the handler adhere to the rack spec.
>
> Didn't we say this was optional in the spec?
>
> This could be a middleware, as has been discussed elsewhere on this ML in the last 6 months.


From the spec at http://rack.rubyforge.org/doc/SPEC.html:

> The input stream is an IO-like object which contains the raw HTTP POST data. When applicable, its external encoding must be “ASCII-8BIT” and it must be opened in binary mode, for Ruby 1.9 compatibility. The input stream must respond to gets, each, read and rewind.

> rewind must be called without arguments. It rewinds the input stream back to the beginning. It must not raise Errno::ESPIPE: that is, it may not be a pipe or a socket. Therefore, handler developers must buffer the input data into some rewindable object if the underlying input stream is not rewindable.

Perhaps it is out of date or I am interpreting it incorrectly, but I
took the "must" in those paragraphs to heart--my mistake if I'm
reading the wrong part of the spec or something.

Do you feel like there's a good reason to not make the CGI handler's
input stream rewindable?  Every time I update rack, I have to re-patch
it myself, because it never works.  It seems pretty unintuitive to
require adding middleware just to make the CGI handler work at all.

 - Max