# Copyright 2018-2021 The Matrix.org Foundation C.I.C.
# Copyright 2020 Sorunome
#
# 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.
import logging
from collections import Counter
from typing import TYPE_CHECKING, Any, Dict, Iterable, Optional, Tuple
from typing_extensions import Counter as CounterType
from synapse.api.constants import EventTypes, Membership
from synapse.metrics import event_processing_positions
from synapse.metrics.background_process_metrics import run_as_background_process
from synapse.types import JsonDict
if TYPE_CHECKING:
from synapse.server import HomeServer
logger = logging.getLogger(__name__)
class StatsHandler:
"""Handles keeping the *_stats tables updated with a simple time-series of
information about the users, rooms and media on the server, such that admins
have some idea of who is consuming their resources.
Heavily derived from UserDirectoryHandler
"""
def __init__(self, hs: "HomeServer"):
self.hs = hs
self.store = hs.get_datastore()
self.state = hs.get_state_handler()
self.server_name = hs.hostname
self.clock = hs.get_clock()
self.notifier = hs.get_notifier()
self.is_mine_id = hs.is_mine_id
self.stats_enabled = hs.config.stats_enabled
# The current position in the current_state_delta stream
self.pos: Optional[int] = None
# Guard to ensure we only process deltas one at a time
self._is_processing = False
if self.stats_enabled and hs.config.run_background_tasks:
self.notifier.add_replication_callback(self.notify_new_event)
# We kick this off so that we don't have to wait for a change before
# we start populating stats
self.clock.call_later(0, self.notify_new_event)
def notify_new_event(self) -> None:
"""Called when there may be more deltas to process"""
if not self.stats_enabled or self._is_processing:
return
self._is_processing = True
async def process():
try:
await self._unsafe_process()
finally:
self._is_processing = False
run_as_background_process("stats.notify_new_event", process)
async def _unsafe_process(self) -> None:
# If self.pos is None then means we haven't fetched it from DB
if self.pos is None:
self.pos = await self.store.get_stats_positions()
# Loop round handling deltas until we're up to date
while True:
# Be sure to read the max stream_ordering *before* checking if there are any outstanding
# deltas, since there is otherwise a chance that we could miss updates which arrive
# after we check the deltas.
room_max_stream_ordering = self.store.get_room_max_stream_ordering()
if self.pos == room_max_stream_ordering:
break
logger.debug(
"Processing room stats %s->%s", self.pos, room_max_stream_ordering
)
max_pos, deltas = await self.store.get_current_state_deltas(
self.pos, room_max_stream_ordering
)
if deltas:
logger.debug("Handling %d state deltas", len(deltas))
room_deltas, user_deltas = await self._handle_deltas(deltas)
else:
room_deltas = {}
user_deltas = {}
logger.debug("room_deltas: %s", room_deltas)
logger.debug("user_deltas: %s", user_deltas)
# Always call this so that we update the stats position.
await self.store.bulk_update_stats_delta(
self.clock.time_msec(),
updates={"room": room_deltas, "user": user_deltas},
stream_id=max_pos,
)
logger.debug("Handled room stats to %s -> %s", self.pos, max_pos)
event_processing_positions.labels("stats").set(max_pos)
self.pos = max_pos
async def _handle_deltas(
self, deltas: Iterable[JsonDict]
) -> Tuple[Dict[str, CounterType[str]], Dict[str, CounterType[str]]]:
"""Called with the state deltas to process
Returns:
Two dicts: the room deltas and the user deltas,
mapping from room/user ID to changes in the various fields.
"""
room_to_stats_deltas: Dict[str, CounterType[str]] = {}
user_to_stats_deltas: Dict[str, CounterType[str]] = {}
room_to_state_updates: Dict[str, Dict[str, Any]] = {}
for delta in deltas:
typ = delta["type"]
state_key = delta["state_key"]
room_id = delta["room_id"]
event_id = delta["event_id"]
stream_id = delta["stream_id"]
prev_event_id = delta["prev_event_id"]
logger.debug("Handling: %r, %r %r, %s", room_id, typ, state_key, event_id)
token = await self.store.get_earliest_token_for_stats("room", room_id)
# If the earliest token to begin from is larger than our current
# stream ID, skip processing this delta.
if token is not None and token >= stream_id:
logger.debug(
"Ignoring: %s as earlier than this room's initial ingestion event",
event_id,
)
continue
if event_id is None and prev_event_id is None:
logger.error(
"event ID is None and so is the previous event ID. stream_id: %s",
stream_id,
)
continue
event_content: JsonDict = {}
if event_id is not None:
event = await self.store.get_event(event_id, allow_none=True)
if event:
event_content = event.content or {}
# All the values in this dict are deltas (RELATIVE changes)
room_stats_delta = room_to_stats_deltas.setdefault(room_id, Counter())
room_state = room_to_state_updates.setdefault(room_id, {})
if prev_event_id is None:
# this state event doesn't overwrite another,
# so it is a new effective/current state event
room_stats_delta["current_state_events"] += 1
if typ == EventTypes.Member:
# we could use StateDeltasHandler._get_key_change here but it's
# a bit inefficient given we're not testing for a specific
# result; might as well just grab the prev_membership and
# membership strings and compare them.
# We take None rather than leave as a previous membership
# in the absence of a previous event because we do not want to
# reduce the leave count when a new-to-the-room user joins.
prev_membership = None
if prev_event_id is not None:
prev_event = await self.store.get_event(
prev_event_id, allow_none=True
)
if prev_event:
prev_event_content = prev_event.content
prev_membership = prev_event_content.get(
"membership", Membership.LEAVE
)
membership = event_content.get("membership", Membership.LEAVE)
if prev_membership is None:
logger.debug("No previous membership for this user.")
elif membership == prev_membership:
pass # noop
elif prev_membership == Membership.JOIN:
room_stats_delta["joined_members"] -= 1
elif prev_membership == Membership.INVITE:
room_stats_delta["invited_members"] -= 1
elif prev_membership == Membership.LEAVE:
room_stats_delta["left_members"] -= 1
elif prev_membership == Membership.BAN:
room_stats_delta["banned_members"] -= 1
elif prev_membership == Membership.KNOCK:
room_stats_delta["knocked_members"] -= 1
else:
raise ValueError(
"%r is not a valid prev_membership" % (prev_membership,)
)
if membership == prev_membership:
pass # noop
elif membership == Membership.JOIN:
room_stats_delta["joined_members"] += 1
elif membership == Membership.INVITE:
room_stats_delta["invited_members"] += 1
elif membership == Membership.LEAVE:
room_stats_delta["left_members"] += 1
elif membership == Membership.BAN:
room_stats_delta["banned_members"] += 1
elif membership == Membership.KNOCK:
room_stats_delta["knocked_members"] += 1
else:
raise ValueError("%r is not a valid membership" % (membership,))
user_id = state_key
if self.is_mine_id(user_id):
# this accounts for transitions like leave → ban and so on.
has_changed_joinedness = (prev_membership == Membership.JOIN) != (
membership == Membership.JOIN
)
if has_changed_joinedness:
membership_delta = +1 if membership == Membership.JOIN else -1
user_to_stats_deltas.setdefault(user_id, Counter())[
"joined_rooms"
] += membership_delta
room_stats_delta["local_users_in_room"] += membership_delta
elif typ == EventTypes.Create:
room_state["is_federatable"] = (
event_content.get("m.federate", True) is True
)
elif typ == EventTypes.JoinRules:
room_state["join_rules"] = event_content.get("join_rule")
elif typ == EventTypes.RoomHistoryVisibility:
room_state["history_visibility"] = event_content.get(
"history_visibility"
)
elif typ == EventTypes.RoomEncryption:
room_state["encryption"] = event_content.get("algorithm")
elif typ == EventTypes.Name:
room_state["name"] = event_content.get("name")
elif typ == EventTypes.Topic:
room_state["topic"] = event_content.get("topic")
elif typ == EventTypes.RoomAvatar:
room_state["avatar"] = event_content.get("url")
elif typ == EventTypes.CanonicalAlias:
room_state["canonical_alias"] = event_content.get("alias")
elif typ == EventTypes.GuestAccess:
room_state["guest_access"] = event_content.get("guest_access")
for room_id, state in room_to_state_updates.items():
logger.debug("Updating room_stats_state for %s: %s", room_id, state)
await self.store.update_room_state(room_id, state)
return room_to_stats_deltas, user_to_stats_deltas