from __future__ import absolute_import
import logging
def loop(rconn, keys, handler):
    failures = {}
    while True:
        key, value = rconn.blpop(keys)
        try:
            handler(rconn, value)
        except KeyboardInterrupt:
            raise
        except Exception as e:
            logging.error('%r (while handling %r)', e, value)
            fkey = hash(value)
            failures.setdefault(fkey, 0)
            failures[fkey] += 1
            if failures[fkey] > 3:
                logging.error('Dropping this value (too many errors)')
                failures.pop(fkey)
            else:
                logging.info('Saving this value for later')
                rconn.rpush(key, value)