# Copyright 2014-2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import TYPE_CHECKING, Dict, Iterable, List, Tuple
from synapse.api.presence import PresenceState, UserPresenceState
from synapse.replication.tcp.streams import PresenceStream
from synapse.storage._base import SQLBaseStore, make_in_list_sql_clause
from synapse.storage.database import DatabasePool
from synapse.storage.engines import PostgresEngine
from synapse.storage.types import Connection
from synapse.storage.util.id_generators import MultiWriterIdGenerator, StreamIdGenerator
from synapse.util.caches.descriptors import cached, cachedList
from synapse.util.caches.stream_change_cache import StreamChangeCache
from synapse.util.iterutils import batch_iter
if TYPE_CHECKING:
from synapse.server import HomeServer
class PresenceBackgroundUpdateStore(SQLBaseStore):
def __init__(
self,
database: DatabasePool,
db_conn: Connection,
hs: "HomeServer",
):
super().__init__(database, db_conn, hs)
# Used by `PresenceStore._get_active_presence()`
self.db_pool.updates.register_background_index_update(
"presence_stream_not_offline_index",
index_name="presence_stream_state_not_offline_idx",
table="presence_stream",
columns=["state"],
where_clause="state != 'offline'",
)
class PresenceStore(PresenceBackgroundUpdateStore):
def __init__(
self,
database: DatabasePool,
db_conn: Connection,
hs: "HomeServer",
):
super().__init__(database, db_conn, hs)
self._can_persist_presence = (
hs.get_instance_name() in hs.config.worker.writers.presence
)
if isinstance(database.engine, PostgresEngine):
self._presence_id_gen = MultiWriterIdGenerator(
db_conn=db_conn,
db=database,
stream_name="presence_stream",
instance_name=self._instance_name,
tables=[("presence_stream", "instance_name", "stream_id")],
sequence_name="presence_stream_sequence",
writers=hs.config.worker.writers.presence,
)
else:
self._presence_id_gen = StreamIdGenerator(
db_conn, "presence_stream", "stream_id"
)
self.hs = hs
self._presence_on_startup = self._get_active_presence(db_conn)
presence_cache_prefill, min_presence_val = self.db_pool.get_cache_dict(
db_conn,
"presence_stream",
entity_column="user_id",
stream_column="stream_id",
max_value=self._presence_id_gen.get_current_token(),
)
self.presence_stream_cache = StreamChangeCache(
"PresenceStreamChangeCache",
min_presence_val,
prefilled_cache=presence_cache_prefill,
)
async def update_presence(self, presence_states):
assert self._can_persist_presence
stream_ordering_manager = self._presence_id_gen.get_next_mult(
len(presence_states)
)
async with stream_ordering_manager as stream_orderings:
await self.db_pool.runInteraction(
"update_presence",
self._update_presence_txn,
stream_orderings,
presence_states,
)
return stream_orderings[-1], self._presence_id_gen.get_current_token()
def _update_presence_txn(self, txn, stream_orderings, presence_states):
for stream_id, state in zip(stream_orderings, presence_states):
txn.call_after(
self.presence_stream_cache.entity_has_changed, state.user_id, stream_id
)
txn.call_after(self._get_presence_for_user.invalidate, (state.user_id,))
# Delete old rows to stop database from getting really big
sql = "DELETE FROM presence_stream WHERE stream_id < ? AND "
for states in batch_iter(presence_states, 50):
clause, args = make_in_list_sql_clause(
self.database_engine, "user_id", [s.user_id for s in states]
)
txn.execute(sql + clause, [stream_id] + list(args))
# Actually insert new rows
self.db_pool.simple_insert_many_txn(
txn,
table="presence_stream",
values=[
{
"stream_id": stream_id,
"user_id": state.user_id,
"state": state.state,
"last_active_ts": state.last_active_ts,
"last_federation_update_ts": state.last_federation_update_ts,
"last_user_sync_ts": state.last_user_sync_ts,
"status_msg": state.status_msg,
"currently_active": state.currently_active,
"instance_name": self._instance_name,
}
for stream_id, state in zip(stream_orderings, presence_states)
],
)
async def get_all_presence_updates(
self, instance_name: str, last_id: int, current_id: int, limit: int
) -> Tuple[List[Tuple[int, list]], int, bool]:
"""Get updates for presence replication stream.
Args:
instance_name: The writer we want to fetch updates from. Unused
here since there is only ever one writer.
last_id: The token to fetch updates from. Exclusive.
current_id: The token to fetch updates up to. Inclusive.
limit: The requested limit for the number of rows to return. The
function may return more or fewer rows.
Returns:
A tuple consisting of: the updates, a token to use to fetch
subsequent updates, and whether we returned fewer rows than exists
between the requested tokens due to the limit.
The token returned can be used in a subsequent call to this
function to get further updatees.
The updates are a list of 2-tuples of stream ID and the row data
"""
if last_id == current_id:
return [], current_id, False
def get_all_presence_updates_txn(txn):
sql = """
SELECT stream_id, user_id, state, last_active_ts,
last_federation_update_ts, last_user_sync_ts,
status_msg,
currently_active
FROM presence_stream
WHERE ? < stream_id AND stream_id <= ?
ORDER BY stream_id ASC
LIMIT ?
"""
txn.execute(sql, (last_id, current_id, limit))
updates = [(row[0], row[1:]) for row in txn]
upper_bound = current_id
limited = False
if len(updates) >= limit:
upper_bound = updates[-1][0]
limited = True
return updates, upper_bound, limited
return await self.db_pool.runInteraction(
"get_all_presence_updates", get_all_presence_updates_txn
)
@cached()
def _get_presence_for_user(self, user_id):
raise NotImplementedError()
@cachedList(
cached_method_name="_get_presence_for_user",
list_name="user_ids",
num_args=1,
)
async def get_presence_for_users(self, user_ids):
rows = await self.db_pool.simple_select_many_batch(
table="presence_stream",
column="user_id",
iterable=user_ids,
keyvalues={},
retcols=(
"user_id",
"state",
"last_active_ts",
"last_federation_update_ts",
"last_user_sync_ts",
"status_msg",
"currently_active",
),
desc="get_presence_for_users",
)
for row in rows:
row["currently_active"] = bool(row["currently_active"])
return {row["user_id"]: UserPresenceState(**row) for row in rows}
async def should_user_receive_full_presence_with_token(
self,
user_id: str,
from_token: int,
) -> bool:
"""Check whether the given user should receive full presence using the stream token
they're updating from.
Args:
user_id: The ID of the user to check.
from_token: The stream token included in their /sync token.
Returns:
True if the user should have full presence sent to them, False otherwise.
"""
def _should_user_receive_full_presence_with_token_txn(txn):
sql = """
SELECT 1 FROM users_to_send_full_presence_to
WHERE user_id = ?
AND presence_stream_id >= ?
"""
txn.execute(sql, (user_id, from_token))
return bool(txn.fetchone())
return await self.db_pool.runInteraction(
"should_user_receive_full_presence_with_token",
_should_user_receive_full_presence_with_token_txn,
)
async def add_users_to_send_full_presence_to(self, user_ids: Iterable[str]):
"""Adds to the list of users who should receive a full snapshot of presence
upon their next sync.
Args:
user_ids: An iterable of user IDs.
"""
# Add user entries to the table, updating the presence_stream_id column if the user already
# exists in the table.
await self.db_pool.simple_upsert_many(
table="users_to_send_full_presence_to",
key_names=("user_id",),
key_values=[(user_id,) for user_id in user_ids],
value_names=("presence_stream_id",),
# We save the current presence stream ID token along with the user ID entry so
# that when a user /sync's, even if they syncing multiple times across separate
# devices at different times, each device will receive full presence once - when
# the presence stream ID in their sync token is less than the one in the table
# for their user ID.
value_values=(
(self._presence_id_gen.get_current_token(),) for _ in user_ids
),
desc="add_users_to_send_full_presence_to",
)
async def get_presence_for_all_users(
self,
include_offline: bool = True,
) -> Dict[str, UserPresenceState]:
"""Retrieve the current presence state for all users.
Note that the presence_stream table is culled frequently, so it should only
contain the latest presence state for each user.
Args:
include_offline: Whether to include offline presence states
Returns:
A dict of user IDs to their current UserPresenceState.
"""
users_to_state = {}
exclude_keyvalues = None
if not include_offline:
# Exclude offline presence state
exclude_keyvalues = {"state": "offline"}
# This may be a very heavy database query.
# We paginate in order to not block a database connection.
limit = 100
offset = 0
while True:
rows = await self.db_pool.runInteraction(
"get_presence_for_all_users",
self.db_pool.simple_select_list_paginate_txn,
"presence_stream",
orderby="stream_id",
start=offset,
limit=limit,
exclude_keyvalues=exclude_keyvalues,
retcols=(
"user_id",
"state",
"last_active_ts",
"last_federation_update_ts",
"last_user_sync_ts",
"status_msg",
"currently_active",
),
order_direction="ASC",
)
for row in rows:
users_to_state[row["user_id"]] = UserPresenceState(**row)
# We've run out of updates to query
if len(rows) < limit:
break
offset += limit
return users_to_state
def get_current_presence_token(self):
return self._presence_id_gen.get_current_token()
def _get_active_presence(self, db_conn: Connection):
"""Fetch non-offline presence from the database so that we can register
the appropriate time outs.
"""
# The `presence_stream_state_not_offline_idx` index should be used for this
# query.
sql = (
"SELECT user_id, state, last_active_ts, last_federation_update_ts,"
" last_user_sync_ts, status_msg, currently_active FROM presence_stream"
" WHERE state != ?"
)
txn = db_conn.cursor()
txn.execute(sql, (PresenceState.OFFLINE,))
rows = self.db_pool.cursor_to_dict(txn)
txn.close()
for row in rows:
row["currently_active"] = bool(row["currently_active"])
return [UserPresenceState(**row) for row in rows]
def take_presence_startup_info(self):
active_on_startup = self._presence_on_startup
self._presence_on_startup = None
return active_on_startup
def process_replication_rows(self, stream_name, instance_name, token, rows):
if stream_name == PresenceStream.NAME:
self._presence_id_gen.advance(instance_name, token)
for row in rows:
self.presence_stream_cache.entity_has_changed(row.user_id, token)
self._get_presence_for_user.invalidate((row.user_id,))
return super().process_replication_rows(stream_name, instance_name, token, rows)