[Web-SIG] Request for Comments on upcoming WSGI Changes

[Massimo Di Pierro]

+1

On Sep 21, 2009, at 8:28 PM, Mark Nottingham wrote:

> +1. There is no one answer for these issues (e.g., URI->IRI conversion
> can lose information), so low-level infrastructure like WSGI shouldn't
> be making choices for people.
>
>
> On 22/09/2009, at 5:31 AM, P.J. Eby wrote:
>
>> At 11:23 AM 9/21/2009 -0700, Robert Brewer wrote:
>>> I still don't see why the environ should have multiple versions of
>>> anything. It's not as if the HTTP request gives us multiple Request-
>>> URI's. There's a single processing step that has to happen
>>> somewhere: decoding the bytes of the Request-URI to unicode. For
>>> the vast majority of apps, it should only happen once. Twice is
>>> acceptable to me for some apps. As I pointed out in the linked
>>> email, doing that as soon as possible (i.e. in the WSGI origin
>>> server) allows URI's to be compared as character strings more
>>> easily. If you deploy a piece of middleware that transcodes (based
>>> on more information than servers want to deal with), it had better
>>> be nearly first in the stack so routing works reliably.
>>
>> The problem with this whole approach is that it's not composable.
>> You can't stick in an application under a router that uses a
>> different method for grokking its subtree of the URI space, unless
>> it knows what's been done to the URI and can un-do it.
>>
>> Maybe I'm missing something here, but the only way I see to preserve
>> composability here is to use latin-1 or bytes.
>>
>> The fundamental problem is that, like it or not, HTTP headers are
>> actually byte strings.  The *only* reason we ever supported unicode
>> in WSGI was to handle platforms where there's no such thing as a non-
>> unicode string, and there we made it explicit that it's just a way
>> of manipulating *bytes*, not unicode.
>>
>> ISTM that very few (if any) of the proposals floating around for
>> modifying WSGI are taking this concept into account.  Most of them
>> sound to me like people saying, "yeah, but this particular hack will
>> work for *my* apps...  so everybody else must be doing something
>> stupid."
>>
>> But WSGI was built on the principle of *equally inconveniencing
>> everyone*, specifically to avoid an impossible attempt at consensus
>> between incompatible ways of doing things.  (E.g., nine million
>> request/response APIs.)
>>
>> So, if the only problem we're going to cause by using bytes
>> everywhere is to make everyone need to change their routing code on
>> Python 3, I vote +1000.  ;-)
>>
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>
>
> --
> Mark Nottingham     http://www.mnot.net/
>
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