From: Austin Ziegler <austin@...>
Date: 2003-11-04T06:29:54+09:00
Subject: Re: CGI uses file size to distinguish between regular values and files

On Tue, 4 Nov 2003 04:37:19 +0900, Dmitry Borodaenko wrote:
> On Mon, Nov 03, 2003 at 11:40:48PM +0900, Austin Ziegler wrote:
[snip]
> You've missed the question in the beginning of this thread:
> 
>   For starters, how would one move a small file, treated as
>   StringIO, to another location? With Tempfile, you just do
>   Tempfile#local_path, and move away. But it's not so straight
>   forward with StringIO.
> 
> Obviously, asker _wants_ his own file handling.

I didn't miss that. What's wrong, though, is that the CGI library is
returning different values for parameters based on the total size of
the data. I'm sorry, but that's broken. Remember -- one of the
complaints was based on the size of the upload:

  If I upload just one file that brings the content_length above
  10240, ALL fields in the request is treated as Tempfiles. If I'm
  uploading a small file that keeps the content_length below 10240,
  all the fields -- including the file -- is treated as StringIOs.

The problem is that this means that access to the data is much
harder to deal with if you're dealing with a file upload. Like I
said; I don't like the Perl implementation, but it's *consistent*.
This appears to be highly inconsistent.

> Since I do that in Samizdat, I know at least one reason for that:
> I don't want to add two extra layers of indirection (Ruby and SQL)
> between Apache (or rsync or Gnutella) and a hundred-megabyte video
> file on disk.

I think you're misunderstanding. I *want* to be able to deal with
the data in either way. I'm looking at this from the perspective of
two different applications: Ruwiki and Bug Traction. Ruwiki may
support file uploads at some point. If this happens, there will be
multiple fields *plus* the file itself. The fields, I want to
accesss as pure data. The file, on the other hand, will be handled
either as a file (by the flatfiles backend) or as raw data (by a
putative database backend). Bug Traction, when I port it to Ruby, by
default has a database backend, so I *only* want to deal with the
data in a raw data mode.

Ideally, I should be able to do something like:

  cgi['file']     # => returns the data of the file
  cgi['file'].IO? # => +true+

I realize that this isn't really the best way, but maybe an
alternative means might be:

  cgi['file']           # => returns the data of the file
  cgi['file'].tempfile  # => returns -- or creates to return -- an
                        #    associated tempfile for the data

IMO, this would be much better than the current situation. I should
*not* have to make my program work differently based on whether I've
uploaded a large enough file or not -- or even if I'm uploading a
file or not.

-austin
--
austin ziegler    * austin@halostatue.ca * Toronto, ON, Canada
software designer * pragmatic programmer * 2003.11.03
                                         * 15.59.28