def __init__(self):
self.logger = Logger(self.__class__.__name__)
self.updating_followers = set()
self.candidates = []
# Load candidates from db and create objects to access their elements
self.candidates = CandidateDAO().all()
ConcurrencyUtils().create_lock('candidate_for_update')
def get_necessary_data(cls):
""" Retrieve db data and create candidates list. """
candidate_index, candidate_group = CandidateDAO(
).get_required_candidates()
candidates_list = list(candidate_index.keys())
candidates_rt_cursor = RawTweetDAO().get_rt_to_candidates_cursor(
candidates_list)
return candidate_index, candidates_list, candidate_group, candidates_rt_cursor
def create_indexes():
""" Create all required collection indexes. """
CandidateDAO().create_indexes()
RawFollowerDAO().create_indexes()
# RawTweetDAO().create_indexes()
UserHashtagDAO().create_indexes()
CooccurrenceGraphDAO().create_indexes()
def add_candidate(self, screen_name, nickname=None):
""" Add a candidate with given screen name and nickname to the database and to the json file. """
try:
CandidateDAO().find(screen_name)
except NonExistentCandidateError:
self.logger.info(f'Adding candidate {screen_name} to database.')
candidate = Candidate(**{
'screen_name': screen_name,
'nickname': nickname
})
# Store in database
CandidateDAO().save(candidate)
# Update json resource
CandidateDAO().update_json_resource(candidate)
# Update current structure
self.candidates.append(candidate)
return
raise CandidateAlreadyExistsError(screen_name)
def finish_follower_updating(self, candidate):
""" Unlock user for follower updating and update last updating time. """
if candidate not in self.updating_followers:
raise CandidateCurrentlyAvailableForUpdateError(
candidate.screen_name)
# Update last updated followers date
self.logger.info(
f'Removing candidate {candidate.screen_name} from currently updating set.'
)
candidate.last_updated_followers = datetime.now()
CandidateDAO().overwrite(candidate)
# Remove from set to not be polled again
self.updating_followers.remove(candidate)
def initialize_context(cls):
""" Create instances of all environment services in a Spring-like fashion."""
cls.LOGGER.info('Instantiating context services and components.')
ConfigurationManager()
ConcurrencyUtils()
Scheduler()
CandidateDAO()
RawFollowerDAO()
CandidatesFollowersDAO()
CredentialService()
CandidateService()
FollowerUpdateService()
TweetUpdateService()
FollowersQueueService()
class CandidateService(metaclass=Singleton):
def __init__(self):
self.logger = Logger(self.__class__.__name__)
self.updating_followers = set()
self.candidates = []
# Load candidates from db and create objects to access their elements
self.candidates = CandidateDAO().all()
ConcurrencyUtils().create_lock('candidate_for_update')
def get_all(self):
""" Returns all candidates currently in the list. """
return self.candidates
def get_for_follower_updating(self):
""" Polls a candidate for updating its follower list. """
# Lock to avoid concurrency issues when retrieving candidates across threads
ConcurrencyUtils().acquire_lock('candidate_for_update')
for candidate in self.candidates:
# We will only return a candidate if it was not updated today and is not being currently updated
if candidate not in self.updating_followers and not DateUtils.is_today(
candidate.last_updated_followers):
self.logger.info(
f'Returning candidate {candidate.screen_name} for follower retrieval.'
)
self.updating_followers.add(candidate)
# Unlock
ConcurrencyUtils().release_lock('candidate_for_update')
return candidate
# Unlock
ConcurrencyUtils().release_lock('candidate_for_update')
raise FollowerUpdatingNotNecessaryError()
def finish_follower_updating(self, candidate):
""" Unlock user for follower updating and update last updating time. """
if candidate not in self.updating_followers:
raise CandidateCurrentlyAvailableForUpdateError(
candidate.screen_name)
# Update last updated followers date
self.logger.info(
f'Removing candidate {candidate.screen_name} from currently updating set.'
)
candidate.last_updated_followers = datetime.now()
CandidateDAO().overwrite(candidate)
# Remove from set to not be polled again
self.updating_followers.remove(candidate)
def add_candidate(self, screen_name, nickname=None):
""" Add a candidate with given screen name and nickname to the database and to the json file. """
try:
CandidateDAO().find(screen_name)
except NonExistentCandidateError:
self.logger.info(f'Adding candidate {screen_name} to database.')
candidate = Candidate(**{
'screen_name': screen_name,
'nickname': nickname
})
# Store in database
CandidateDAO().save(candidate)
# Update json resource
CandidateDAO().update_json_resource(candidate)
# Update current structure
self.candidates.append(candidate)
return
raise CandidateAlreadyExistsError(screen_name)
def create_base_entries():
""" Create all required entries. """
CandidateDAO().create_base_entries()