Room Statistics (#4338)

1 files changed, 325 insertions, 0 deletions

diff --git a/synapse/handlers/stats.py b/synapse/handlers/stats.py
new file mode 100644
index 0000000000..0e92b405ba
--- /dev/null
+++ b/synapse/handlers/stats.py
@@ -0,0 +1,325 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector 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.
+
+import logging
+
+from twisted.internet import defer
+
+from synapse.api.constants import EventTypes, JoinRules, Membership
+from synapse.handlers.state_deltas import StateDeltasHandler
+from synapse.metrics import event_processing_positions
+from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.types import UserID
+from synapse.util.metrics import Measure
+
+logger = logging.getLogger(__name__)
+
+
+class StatsHandler(StateDeltasHandler):
+    """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):
+        super(StatsHandler, self).__init__(hs)
+        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_bucket_size = hs.config.stats_bucket_size
+
+        # The current position in the current_state_delta stream
+        self.pos = None
+
+        # Guard to ensure we only process deltas one at a time
+        self._is_processing = False
+
+        if hs.config.stats_enabled:
+            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):
+        """Called when there may be more deltas to process
+        """
+        if not self.hs.config.stats_enabled:
+            return
+
+        if self._is_processing:
+            return
+
+        @defer.inlineCallbacks
+        def process():
+            try:
+                yield self._unsafe_process()
+            finally:
+                self._is_processing = False
+
+        self._is_processing = True
+        run_as_background_process("stats.notify_new_event", process)
+
+    @defer.inlineCallbacks
+    def _unsafe_process(self):
+        # If self.pos is None then means we haven't fetched it from DB
+        if self.pos is None:
+            self.pos = yield self.store.get_stats_stream_pos()
+
+        # If still None then the initial background update hasn't happened yet
+        if self.pos is None:
+            defer.returnValue(None)
+
+        # Loop round handling deltas until we're up to date
+        while True:
+            with Measure(self.clock, "stats_delta"):
+                deltas = yield self.store.get_current_state_deltas(self.pos)
+                if not deltas:
+                    return
+
+                logger.info("Handling %d state deltas", len(deltas))
+                yield self._handle_deltas(deltas)
+
+                self.pos = deltas[-1]["stream_id"]
+                yield self.store.update_stats_stream_pos(self.pos)
+
+                event_processing_positions.labels("stats").set(self.pos)
+
+    @defer.inlineCallbacks
+    def _handle_deltas(self, deltas):
+        """
+        Called with the state deltas to process
+        """
+        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, %s", typ, state_key, event_id)
+
+            token = yield self.store.get_earliest_token_for_room_stats(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:
+                # Errr...
+                continue
+
+            event_content = {}
+
+            if event_id is not None:
+                event_content = (yield self.store.get_event(event_id)).content or {}
+
+            # quantise time to the nearest bucket
+            now = yield self.store.get_received_ts(event_id)
+            now = (now // 1000 // self.stats_bucket_size) * self.stats_bucket_size
+
+            if typ == EventTypes.Member:
+                # we could use _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.
+                prev_event_content = {}
+                if prev_event_id is not None:
+                    prev_event_content = (
+                        yield self.store.get_event(prev_event_id)
+                    ).content
+
+                membership = event_content.get("membership", Membership.LEAVE)
+                prev_membership = prev_event_content.get("membership", Membership.LEAVE)
+
+                if prev_membership == membership:
+                    continue
+
+                if prev_membership == Membership.JOIN:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "joined_members", -1
+                    )
+                elif prev_membership == Membership.INVITE:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "invited_members", -1
+                    )
+                elif prev_membership == Membership.LEAVE:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "left_members", -1
+                    )
+                elif prev_membership == Membership.BAN:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "banned_members", -1
+                    )
+                else:
+                    err = "%s is not a valid prev_membership" % (repr(prev_membership),)
+                    logger.error(err)
+                    raise ValueError(err)
+
+                if membership == Membership.JOIN:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "joined_members", +1
+                    )
+                elif membership == Membership.INVITE:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "invited_members", +1
+                    )
+                elif membership == Membership.LEAVE:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "left_members", +1
+                    )
+                elif membership == Membership.BAN:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "banned_members", +1
+                    )
+                else:
+                    err = "%s is not a valid membership" % (repr(membership),)
+                    logger.error(err)
+                    raise ValueError(err)
+
+                user_id = state_key
+                if self.is_mine_id(user_id):
+                    # update user_stats as it's one of our users
+                    public = yield self._is_public_room(room_id)
+
+                    if membership == Membership.LEAVE:
+                        yield self.store.update_stats_delta(
+                            now,
+                            "user",
+                            user_id,
+                            "public_rooms" if public else "private_rooms",
+                            -1,
+                        )
+                    elif membership == Membership.JOIN:
+                        yield self.store.update_stats_delta(
+                            now,
+                            "user",
+                            user_id,
+                            "public_rooms" if public else "private_rooms",
+                            +1,
+                        )
+
+            elif typ == EventTypes.Create:
+                # Newly created room. Add it with all blank portions.
+                yield self.store.update_room_state(
+                    room_id,
+                    {
+                        "join_rules": None,
+                        "history_visibility": None,
+                        "encryption": None,
+                        "name": None,
+                        "topic": None,
+                        "avatar": None,
+                        "canonical_alias": None,
+                    },
+                )
+
+            elif typ == EventTypes.JoinRules:
+                yield self.store.update_room_state(
+                    room_id, {"join_rules": event_content.get("join_rule")}
+                )
+
+                is_public = yield self._get_key_change(
+                    prev_event_id, event_id, "join_rule", JoinRules.PUBLIC
+                )
+                if is_public is not None:
+                    yield self.update_public_room_stats(now, room_id, is_public)
+
+            elif typ == EventTypes.RoomHistoryVisibility:
+                yield self.store.update_room_state(
+                    room_id,
+                    {"history_visibility": event_content.get("history_visibility")},
+                )
+
+                is_public = yield self._get_key_change(
+                    prev_event_id, event_id, "history_visibility", "world_readable"
+                )
+                if is_public is not None:
+                    yield self.update_public_room_stats(now, room_id, is_public)
+
+            elif typ == EventTypes.Encryption:
+                yield self.store.update_room_state(
+                    room_id, {"encryption": event_content.get("algorithm")}
+                )
+            elif typ == EventTypes.Name:
+                yield self.store.update_room_state(
+                    room_id, {"name": event_content.get("name")}
+                )
+            elif typ == EventTypes.Topic:
+                yield self.store.update_room_state(
+                    room_id, {"topic": event_content.get("topic")}
+                )
+            elif typ == EventTypes.RoomAvatar:
+                yield self.store.update_room_state(
+                    room_id, {"avatar": event_content.get("url")}
+                )
+            elif typ == EventTypes.CanonicalAlias:
+                yield self.store.update_room_state(
+                    room_id, {"canonical_alias": event_content.get("alias")}
+                )
+
+    @defer.inlineCallbacks
+    def update_public_room_stats(self, ts, room_id, is_public):
+        """
+        Increment/decrement a user's number of public rooms when a room they are
+        in changes to/from public visibility.
+
+        Args:
+            ts (int): Timestamp in seconds
+            room_id (str)
+            is_public (bool)
+        """
+        # For now, blindly iterate over all local users in the room so that
+        # we can handle the whole problem of copying buckets over as needed
+        user_ids = yield self.store.get_users_in_room(room_id)
+
+        for user_id in user_ids:
+            if self.hs.is_mine(UserID.from_string(user_id)):
+                yield self.store.update_stats_delta(
+                    ts, "user", user_id, "public_rooms", +1 if is_public else -1
+                )
+                yield self.store.update_stats_delta(
+                    ts, "user", user_id, "private_rooms", -1 if is_public else +1
+                )
+
+    @defer.inlineCallbacks
+    def _is_public_room(self, room_id):
+        join_rules = yield self.state.get_current_state(room_id, EventTypes.JoinRules)
+        history_visibility = yield self.state.get_current_state(
+            room_id, EventTypes.RoomHistoryVisibility
+        )
+
+        if (join_rules and join_rules.content.get("join_rule") == JoinRules.PUBLIC) or (
+            (
+                history_visibility
+                and history_visibility.content.get("history_visibility")
+                == "world_readable"
+            )
+        ):
+            defer.returnValue(True)
+        else:
+            defer.returnValue(False)