web.py shared variables

Question

In web.py i need to create a shared variable, for which multiple threads(requests) can read or write to that variable.

What is the preferred way, for this kind of a situation.

thanks.

Perhaps give a little more detail on what you're trying to accomplish. — krs1
– krs1, Commented Apr 15, 2011 at 13:39
You should say what kind and size of data that variable will contain, how sensitive is the data, and how often you will write to it and read from it. — nosklo
– nosklo, Commented Apr 15, 2011 at 13:40
sorry for missing info. read and write is very often to the variable (hundreds in second). so database is not an option. think of an integer. — Ahmet Recep Navruz
– Ahmet Recep Navruz, Commented Apr 15, 2011 at 13:46
memcached is ok. but for my case, running memcached is not an option. — Ahmet Recep Navruz
– Ahmet Recep Navruz, Commented Apr 15, 2011 at 13:52

Ben Hoyt · Accepted Answer · 2011-04-15 14:22:09Z

2

I'm not sure this is really a web.py question, but we do this sort of thing all the time for process-wide caches (that is, dict caches that are shared by all request threads). We use web.py, but my example below should apply to any multi-threaded Python web server.

hotels.py:

cache = {}

def load_cache():
    """Load hotels into {id: data} dict cache."""
    rows = db.select('hotels')
    for row in rows:
        cache[row.id] = row

def get_hotel(hotel_id):
    """Get data for hotel with given ID, or return None if not found."""
    if not cache:
        raise Exception('hotels cache not loaded')
    return cache.get(hotel_id)

main.py:

import hotels

def main():
    hotels.load_cache()
    start_server()

answered Apr 15, 2011 at 14:22

Ben Hoyt

11.1k6 gold badges65 silver badges90 bronze badges

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

Comments

linbo · Accepted Answer · 2011-04-18 02:52:29Z

1

I find lots of code using this container: web.ctx

like

web.ctx.orm = scoped_session(sessionmaker(bind=engine))
web.ctx.session = web.config._session

u can init those in a function, then process them:

app.add_processor(web.loadhook(init_func))

Not sure it works or not for your scenario

answered Apr 18, 2011 at 2:52

linbo

2,4313 gold badges23 silver badges45 bronze badges

Collectives™ on Stack Overflow

web.py shared variables

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related