[Web-SIG] Alternative to threading.local, based on the stack

[Donovan Preston]

On Jul 8, 2008, at 2:31 PM, Phillip J. Eby wrote:

> At 11:35 AM 7/8/2008 -0700, Donovan Preston wrote:
>> Obviously plenty of
>> people have a desire to have a place to store request-local data
>> without passing the environment everywhere. Using threading.local  
>> is a
>> good way to do that, unless the server is not using one thread per
>> request. Giving people an interface to write to that doesn't
>> specifically mention threads and is customizable by the wsgi server  
>> is
>> what I am suggesting.
>
> Er, and how do you propose people *access* that interface rather  
> than a specific implementation of it?  Wouldn't we need to pass it  
> in the environ, thereby rendering the whole thing even more  
> obviously moot?  :)

You're right. A standard specific implementation is what I am  
suggesting. Here, code should help:


## requestlocal.py

## use thread-local storage as the default
from threading import local

def set_local_implementation(imp):
     global local
     local = imp


If a wsgi server wants to implement request-local storage by using the  
environ, it would call set_local_implementation with an imp function  
that closes over the environ for each request.

Donovan