Problem with web.py + mod_wsgi file upload

Question

I'm working on a web.py app for uploading files and im having real problems with my deployment. Basically I want to give the user a 'percentage uploaded' but this seems to be messing up severely when deployed on mod_wsgi. The main upload works like this:

out = open(path, 'wb', 1000)

    while (True):

        packet = fileU.file.read(1000)

        if not packet:

            break

        else:

            out.write(packet)
            sessions[code].progress += 1

    out.close()

'Session' is a global dictionary that contains objects that keep track of sessions. To get the current progress I get the current progress for a given session via a GET request from the client every second.

The problem at the moment is that this only works for small uploads. It seems that anything over around 100kb will just not increment the progress variable. The value is definitely incremented if placed outside of the loop (or before read() is ever called) or if the file is fairly small.

Is it possible that wsgi is opening new threads for bigger files and therefore making my global counter only local to the upload thread? Could it be something else.

d0nut · Accepted Answer · 2011-02-08 05:36:48Z

2

You can't just use a global dictionary for this. It is in fact very likely that the webserver is using a separate thread to serve the following requests, and there is no guarantee that the session dictionary is the same. Try using the session object which is part of web.py. It uses either a db or a file to store the data which can be accessed across different threads or processes.

web.py session example

answered Feb 8, 2011 at 5:36

d0nut

6205 silver badges5 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

seadowg Over a year ago

Is there anyway to store custom data in a session? And I can't seem to find how you retrieve a session in a request for a given user.

d0nut Over a year ago

A session object basically has a dict interface, and you should be able to store any data you like. For instance if you set session[<user>] for one request, you should be able to retrieve session[<user>] in another request. You can more or less think about it as a really global dictionary.

Collectives™ on Stack Overflow

Problem with web.py + mod_wsgi file upload

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related