From: Dmitry Borodaenko <d.borodaenko@...>
Date: 2003-11-06T01:45:14+09:00
Subject: Re: CGI uses file size to distinguish between regular values and files

On Wed, Nov 05, 2003 at 12:53:01AM +0900, Yukihiro Matsumoto wrote:
> How about
> 
>   require 'fileutils'
>   File.open(upload, 'w') {|f| FileUtils.copy_stream(file,f)}
> 
> ?  It's bit longer, but works now without any modifies.

That is better than my ftools-based solution, since it solves the
problem of differentiating between StringIO and Tempfile (although it
won't work with Ruby 1.6, if anyone still cares about that).

But I think the harder problem lies earlier in the execution path, when
application decides whether to handle the parameter value as a String or
as IO. I don't see any simple way of moving responsibility for this
decision from application to cgi.rb library without getting bitten by
the corner case of a large upload that wouldn't fit into memory.

That is, unless Ruby learns to automatically convert strings to
tempfiles as soon as they become too large, which would be quite a
feat... :)

In the absence of such feat, I think it would be nice to have

  def multipart?
    @multipart
  end

in class CGI in order to make detection of multipart data more obvious.

-- 
Dmitry Borodaenko