def notify_posts(shard, post_list, sequence_numbers=None):
"""Notifies logged-in users of a set of new posts.
Args:
shard: Shard ID to notify for.
post_list: When the post_list is a list of strings, then it's assumed
these are the IDs of Posts that must be fetched prior to
notification. Otherwise these should be Post entities.
sequence_numbers: When supplied, should be a list of sequence numbers
that correspond to each of the items in the post_list, in order.
This is used to tell the user what the sequence ID of each post is
within a particular shard.
"""
if not post_list:
return
if isinstance(post_list[0], basestring):
post_keys = [ndb.Key(models.Post._get_kind(), post_id)
for post_id in post_list]
post_list = yield ndb.get_multi_async(post_keys)
if not sequence_numbers:
sequence_numbers = [None] * len(post_list)
for post, sequence in zip(post_list, sequence_numbers):
post.sequence = sequence
posts_json = json.dumps({
'posts': marshal_posts(shard, post_list),
})
login_record_list = presence.get_present_users(shard)
rpc_list = []
for login_record in login_record_list:
logging.debug(
'Informing shard=%r, user=%r, nickname=%r about messages '
'with sequence_numbers=%r', shard, login_record.user_id,
login_record.nickname, sequence_numbers)
browser_token = presence.get_token(login_record.user_id)
rpc_list.append(send_message_async(browser_token, posts_json))
for rpc in rpc_list:
try:
yield rpc
except channel.Error, e:
# NOTE: When receiving an InvalidChannelKeyError the message may
# still be available the next time the user connects to the channel
# with that same application key due to buffering in the backends.
# The dev_appserver mimics this behavior, but it's not reliable in
# prod.
logging.warning('Could not send JSON message to user=%r with '
'browser_token=%r. %s: %s', login_record.user_id,
browser_token, e.__class__.__name__, str(e))
def list_topics(root_shard_id, user_id):
"""Lists topics for a root shard and associated read state for the user.
Args:
root_shard_id: Shard ID of the root with associated topics.
user_id: User ID that is requesting the list of topics and read states.
Returns:
Tuple (root_shard, shard_and_state_list) where:
root_shard: Shard entity for the root.
shard_and_state_list: List of pairs (Shard, ReadState) for
associated topics and read states for the given user_id. Will
be in order of update_time with most recently updated shards
first.
"""
# TODO(bslatkin): Remove the root_shard return value.
root_shard_future = models.Shard.get_by_id_async(
root_shard_id, use_cache=False, use_memcache=False)
oldest_update_time = (
datetime.datetime.now() -
datetime.timedelta(seconds=config.ephemeral_lifetime_seconds))
query = models.Shard.query()
query = query.filter(models.Shard.root_shard == root_shard_id)
query = query.filter(models.Shard.update_time > oldest_update_time)
query = query.order(-models.Shard.update_time)
shard_list = yield query.fetch_async(100)
# Include the root shard in the list of topics so the email digester
# will include updates to the root shard if no topics have ever been sent.
root_shard = yield root_shard_future
shard_list.append(root_shard)
# Get the current user's readstate for each shard that was found.
read_state_key_list = [
ndb.Key(models.LoginRecord._get_kind(), user_id,
models.ReadState._get_kind(), shard.shard_id)
for shard in shard_list]
read_state_list = yield ndb.get_multi_async(read_state_key_list)
shard_and_state_list = zip(shard_list, read_state_list)
raise ndb.Return((root_shard, shard_and_state_list))
