def poll(account_id, provider):
"""Query a remote contacts provider for updates and persist them to the
database.
Parameters
----------
account_id: int
ID for the account whose contacts should be queried.
db_session: sqlalchemy.orm.session.Session
Database session
provider: Interface to the remote contact data provider.
Must have a PROVIDER_NAME attribute and implement the get_contacts()
method.
"""
provider_name = provider.PROVIDER_NAME
with session_scope() as db_session:
account = db_session.query(Account).get(account_id)
# Contact data reflecting any local modifications since the last sync
# with the remote provider.
local_contacts = db_session.query(Contact).filter_by(
source='local', account=account,
provider_name=provider_name).all()
# Snapshot of contact data from immediately after last sync.
cached_contacts = db_session.query(Contact).filter_by(
source='remote', account=account,
provider_name=provider_name).all()
log.info('Query: have {0} contacts, {1} cached.'.format(
len(local_contacts), len(cached_contacts)))
cached_contact_dict = {contact.uid: contact for contact in
cached_contacts}
local_contact_dict = {contact.uid: contact for contact in
local_contacts}
change_counter = Counter()
last_sync = or_none(account.last_synced_contacts,
datetime.datetime.isoformat)
to_commit = []
for remote_contact in provider.get_contacts(last_sync):
remote_contact.account = account
assert remote_contact.uid is not None, \
'Got remote contact with null uid'
assert isinstance(remote_contact.uid, str)
cached_contact = cached_contact_dict.get(remote_contact.uid)
local_contact = local_contact_dict.get(remote_contact.uid)
# If the remote contact was deleted, purge the corresponding
# database entries.
if remote_contact.deleted:
if cached_contact is not None:
db_session.delete(cached_contact)
change_counter['deleted'] += 1
if local_contact is not None:
db_session.delete(local_contact)
continue
# Otherwise, update the database.
if cached_contact is not None:
# The provider gave an update to a contact we already have.
if local_contact is not None:
try:
# Attempt to merge remote updates into local_contact
merge(cached_contact, remote_contact, local_contact)
# And update cached_contact to reflect both local and
# remote updates
cached_contact.copy_from(local_contact)
except MergeError:
log.error('Conflicting local and remote updates to '
'contact.\nLocal: {0}\ncached: {1}\n '
'remote: {2}'.format(local_contact,
cached_contact,
remote_contact))
# TODO(emfree): Come up with a strategy for handling
# merge conflicts. For now, just don't update if there
# is a conflict.
continue
else:
log.warning('Contact {0} already present as remote but '
'not local contact'.format(cached_contact))
cached_contact.copy_from(remote_contact)
change_counter['updated'] += 1
else:
# This is a new contact, create both local and remote DB
# entries.
local_contact = Contact()
local_contact.copy_from(remote_contact)
local_contact.source = 'local'
to_commit.append(local_contact)
to_commit.append(remote_contact)
change_counter['added'] += 1
account.last_synced_contacts = datetime.datetime.now()
log.info('Added {0} contacts.'.format(change_counter['added']))
log.info('Updated {0} contacts.'.format(change_counter['updated']))
log.info('Deleted {0} contacts.'.format(change_counter['deleted']))
db_session.add_all(to_commit)
db_session.commit()
def poll(account_id, provider):
"""Query a remote contacts provider for updates and persist them to the
database.
Parameters
----------
account_id: int
ID for the account whose contacts should be queried.
db_session: sqlalchemy.orm.session.Session
Database session
provider: Interface to the remote contact data provider.
Must have a PROVIDER_NAME attribute and implement the get_contacts()
method.
"""
provider_name = provider.PROVIDER_NAME
with session_scope() as db_session:
account = db_session.query(Account).get(account_id)
change_counter = Counter()
last_sync = or_none(account.last_synced_contacts,
datetime.datetime.isoformat)
to_commit = []
for remote_contact in provider.get_contacts(last_sync):
remote_contact.account = account
assert remote_contact.uid is not None, \
'Got remote contact with null uid'
assert isinstance(remote_contact.uid, str)
matching_contacts = db_session.query(Contact).filter(
Contact.account == account,
Contact.provider_name == provider_name,
Contact.uid == remote_contact.uid)
# Snapshot of contact data from immediately after last sync:
cached_contact = matching_contacts. \
filter(Contact.source == 'remote').first()
# Contact data reflecting any local modifications since the last
# sync with the remote provider:
local_contact = matching_contacts. \
filter(Contact.source == 'local').first()
# If the remote contact was deleted, purge the corresponding
# database entries.
if remote_contact.deleted:
if cached_contact is not None:
db_session.delete(cached_contact)
change_counter['deleted'] += 1
if local_contact is not None:
db_session.delete(local_contact)
continue
# Otherwise, update the database.
if cached_contact is not None:
# The provider gave an update to a contact we already have.
if local_contact is not None:
try:
# Attempt to merge remote updates into local_contact
merge(cached_contact, remote_contact, local_contact)
# And update cached_contact to reflect both local and
# remote updates
cached_contact.copy_from(local_contact)
except MergeError:
log.error('Conflicting local and remote updates to '
'contact.\nLocal: {0}\ncached: {1}\n '
'remote: {2}'.format(local_contact,
cached_contact,
remote_contact))
# TODO(emfree): Come up with a strategy for handling
# merge conflicts. For now, just don't update if there
# is a conflict.
continue
else:
log.warning('Contact {0} already present as remote but '
'not local contact'.format(cached_contact))
cached_contact.copy_from(remote_contact)
change_counter['updated'] += 1
else:
# This is a new contact, create both local and remote DB
# entries.
local_contact = Contact()
local_contact.copy_from(remote_contact)
local_contact.source = 'local'
to_commit.append(local_contact)
to_commit.append(remote_contact)
change_counter['added'] += 1
account.last_synced_contacts = datetime.datetime.now()
log.info('Added {0} contacts.'.format(change_counter['added']))
log.info('Updated {0} contacts.'.format(change_counter['updated']))
log.info('Deleted {0} contacts.'.format(change_counter['deleted']))
db_session.add_all(to_commit)
db_session.commit()
