dogpile.cache

dog_reader.py

'''
Starting a reader while a few dog_writer.py processes are running in the background:

$ bin/python dog_reader.py
??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ???
??? ??? ??? ??? ??? ??? ??? ??? ??? ??? 190 172 159 ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? 732 ???
??? ??? ??? ??? ??? 190 ??? ??? ??? ??? 190 172 190 ??? ??? ??? 172 ??? ??? 732 ??? ??? ??? ??? ??? ??? ??? ??? 732 159
??? 172 ??? ??? 159 172 ??? ??? ??? ??? 190 172 190 ??? ??? ??? 172 159 ??? 732 ??? ??? ??? 172 732 ??? ??? 732 732 159
172 172 ??? ??? 159 172 ??? ??? 172 ??? 190 172 190 159 ??? ??? 172 159 ??? 732 ??? ??? ??? 732 732 ??? 172 732 732 159
172 732 ??? ??? 159 172 ??? ??? 172 ??? 190 172 190 159 159 ??? 172 732 ??? 732 ??? ??? ??? 190 732 732 172 732 732 159
172 190 ??? ??? 159 172 ??? ??? 172 ??? 190 172 190 732 190 ??? 159 732 ??? 732 ??? 159 159 190 172 732 172 732 732 159

...then kill the dog_writer.py processes and wait 30 seconds...

159 ??? ??? ??? 159 732 159 732 732 732 159 190 190 159 ??? 159 732 159 ??? ??? 172 172 732 159 159 172 172 172 159 172
159 ??? ??? ??? 159 732 159 732 732 732 159 190 190 159 ??? 159 732 159 ??? ??? 172 172 732 ??? 159 172 172 172 159 172
??? ??? ??? ??? 159 732 159 732 732 732 159 190 190 159 ??? 159 732 159 ??? ??? 172 ??? 732 ??? ??? 172 172 172 159 172
??? ??? ??? ??? ??? 732 159 ??? ??? 732 159 190 190 159 ??? 159 732 159 ??? ??? 172 ??? 732 ??? ??? 172 172 172 159 172
??? ??? ??? ??? ??? 732 159 ??? ??? 732 159 190 ??? 159 ??? 159 732 ??? ??? ??? ??? ??? 732 ??? ??? ??? 172 ??? 159 172
??? ??? ??? ??? ??? 732 159 ??? ??? 732 ??? 190 ??? ??? ??? 159 ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? 172
??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ???

Everything has expired!
'''

import time
from dogpile.cache import make_region
from dogpile.cache.api import NO_VALUE

r = make_region().configure(
    'dogpile.cache.dbm',
    expiration_time=30,
    arguments={'filename': '/tmp/blah.dbm'}
)

def display(v):
    if v is NO_VALUE:
        return "???"
    return v

if __name__ == "__main__":
    while True:
        for i in range(1,30):
            print display(r.get(str(i))),
        print ""
        time.sleep(1)

dog_writer.py

'''
Start a bunch of writers in parallel:

$ for i in {0..10}; do bin/python dog_writer.py & done;

Stop them:

$ pkill -f python.*dog_writer
'''

import time
import random
from dogpile.cache import make_region

from dog_reader import r

if __name__ == "__main__":
    uid = random.randint(100, 999)
    while True:
        args = (str(random.randint(1,30)), uid)
        print args
        r.set(*args)
        time.sleep(random.random())