daemon.py

import logging
import json

import redis

from .registrar import register_file


logger = logging.getLogger(__name__)


def run_daemon(config, replace, host, port, listen_queue, progress_set, failure_set, success_set):
    """ Run the registrar daemon, listening on a redis queue
        for files to be registered.
    """
    # initialize the queue client
    client = redis.Redis(
        host=host, port=port, charset="utf-8", decode_responses=True
    )
    logger.debug("waiting for redis queue '%s'..." % listen_queue)
    while True:
        # fetch an item from the queue to be registered
        _, value = client.brpop(listen_queue)
        client.sadd(progress_set, value)
        # start the registration on that file
        try:
            item = register_file(config, value, replace)
            client.sadd(success_set, item.identifier)
            client.srem(progress_set, value)
        except Exception as e:
            if 'is already registered' not in "%s" % e:
                # do not add to failure if skipped due to already registered
                client.sadd(failure_set, value)
            client.srem(progress_set, value)
            logger.exception(e)