From 7c8c97e635811609c5a7ae4c0bb94e6573c30753 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 30 Oct 2019 15:12:49 +0000 Subject: [PATCH] Split purge API into events vs state --- synapse/handlers/pagination.py | 7 +- synapse/storage/__init__.py | 2 + synapse/storage/data_stores/main/events.py | 328 ++++++++++----------- synapse/storage/data_stores/main/state.py | 23 ++ synapse/storage/purge_events.py | 117 ++++++++ tests/storage/test_purge.py | 15 +- 6 files changed, 308 insertions(+), 184 deletions(-) create mode 100644 synapse/storage/purge_events.py diff --git a/synapse/handlers/pagination.py b/synapse/handlers/pagination.py index 5744f4579d..9088ba14cd 100644 --- a/synapse/handlers/pagination.py +++ b/synapse/handlers/pagination.py @@ -69,6 +69,7 @@ class PaginationHandler(object): self.hs = hs self.auth = hs.get_auth() self.store = hs.get_datastore() + self.storage = hs.get_storage() self.clock = hs.get_clock() self._server_name = hs.hostname @@ -125,7 +126,9 @@ class PaginationHandler(object): self._purges_in_progress_by_room.add(room_id) try: with (yield self.pagination_lock.write(room_id)): - yield self.store.purge_history(room_id, token, delete_local_events) + yield self.storage.purge_events.purge_history( + room_id, token, delete_local_events + ) logger.info("[purge] complete") self._purges_by_id[purge_id].status = PurgeStatus.STATUS_COMPLETE except Exception: @@ -168,7 +171,7 @@ class PaginationHandler(object): if joined: raise SynapseError(400, "Users are still joined to this room") - await self.store.purge_room(room_id) + await self.storage.purge_events.purge_room(room_id) @defer.inlineCallbacks def get_messages( diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py index a6429d17ed..3646ebd007 100644 --- a/synapse/storage/__init__.py +++ b/synapse/storage/__init__.py @@ -30,6 +30,7 @@ stored in `synapse.storage.schema`. from synapse.storage.data_stores import DataStores from synapse.storage.data_stores.main import DataStore from synapse.storage.persist_events import EventsPersistenceStorage +from synapse.storage.purge_events import PurgeEventsStorage __all__ = ["DataStores", "DataStore"] @@ -45,6 +46,7 @@ class Storage(object): self.main = stores.main self.persistence = EventsPersistenceStorage(hs, stores) + self.purge_events = PurgeEventsStorage(hs, stores) def are_all_users_on_domain(txn, database_engine, domain): diff --git a/synapse/storage/data_stores/main/events.py b/synapse/storage/data_stores/main/events.py index 7c3607f308..4eacba8058 100644 --- a/synapse/storage/data_stores/main/events.py +++ b/synapse/storage/data_stores/main/events.py @@ -1368,6 +1368,10 @@ class EventsStore( if True, we will delete local events as well as remote ones (instead of just marking them as outliers and deleting their state groups). + + Returns: + Deferred[set[int]]: The set of state groups that reference deleted + events. """ return self.runInteraction( @@ -1521,60 +1525,6 @@ class EventsStore( "[purge] found %i referenced state groups", len(referenced_state_groups) ) - logger.info("[purge] finding state groups that can be deleted") - - _ = self._find_unreferenced_groups_during_purge(txn, referenced_state_groups) - state_groups_to_delete, remaining_state_groups = _ - - logger.info( - "[purge] found %i state groups to delete", len(state_groups_to_delete) - ) - - logger.info( - "[purge] de-delta-ing %i remaining state groups", - len(remaining_state_groups), - ) - - # Now we turn the state groups that reference to-be-deleted state - # groups to non delta versions. - for sg in remaining_state_groups: - logger.info("[purge] de-delta-ing remaining state group %s", sg) - curr_state = self._get_state_groups_from_groups_txn(txn, [sg]) - curr_state = curr_state[sg] - - self._simple_delete_txn( - txn, table="state_groups_state", keyvalues={"state_group": sg} - ) - - self._simple_delete_txn( - txn, table="state_group_edges", keyvalues={"state_group": sg} - ) - - self._simple_insert_many_txn( - txn, - table="state_groups_state", - values=[ - { - "state_group": sg, - "room_id": room_id, - "type": key[0], - "state_key": key[1], - "event_id": state_id, - } - for key, state_id in iteritems(curr_state) - ], - ) - - logger.info("[purge] removing redundant state groups") - txn.executemany( - "DELETE FROM state_groups_state WHERE state_group = ?", - ((sg,) for sg in state_groups_to_delete), - ) - txn.executemany( - "DELETE FROM state_groups WHERE id = ?", - ((sg,) for sg in state_groups_to_delete), - ) - logger.info("[purge] removing events from event_to_state_groups") txn.execute( "DELETE FROM event_to_state_groups " @@ -1661,87 +1611,7 @@ class EventsStore( logger.info("[purge] done") - def _find_unreferenced_groups_during_purge(self, txn, state_groups): - """Used when purging history to figure out which state groups can be - deleted and which need to be de-delta'ed (due to one of its prev groups - being scheduled for deletion). - - Args: - txn - state_groups (set[int]): Set of state groups referenced by events - that are going to be deleted. - - Returns: - tuple[set[int], set[int]]: The set of state groups that can be - deleted and the set of state groups that need to be de-delta'ed - """ - # Graph of state group -> previous group - graph = {} - - # Set of events that we have found to be referenced by events - referenced_groups = set() - - # Set of state groups we've already seen - state_groups_seen = set(state_groups) - - # Set of state groups to handle next. - next_to_search = set(state_groups) - while next_to_search: - # We bound size of groups we're looking up at once, to stop the - # SQL query getting too big - if len(next_to_search) < 100: - current_search = next_to_search - next_to_search = set() - else: - current_search = set(itertools.islice(next_to_search, 100)) - next_to_search -= current_search - - # Check if state groups are referenced - sql = """ - SELECT DISTINCT state_group FROM event_to_state_groups - LEFT JOIN events_to_purge AS ep USING (event_id) - WHERE ep.event_id IS NULL AND - """ - clause, args = make_in_list_sql_clause( - txn.database_engine, "state_group", current_search - ) - txn.execute(sql + clause, list(args)) - - referenced = set(sg for sg, in txn) - referenced_groups |= referenced - - # We don't continue iterating up the state group graphs for state - # groups that are referenced. - current_search -= referenced - - rows = self._simple_select_many_txn( - txn, - table="state_group_edges", - column="prev_state_group", - iterable=current_search, - keyvalues={}, - retcols=("prev_state_group", "state_group"), - ) - - prevs = set(row["state_group"] for row in rows) - # We don't bother re-handling groups we've already seen - prevs -= state_groups_seen - next_to_search |= prevs - state_groups_seen |= prevs - - for row in rows: - # Note: Each state group can have at most one prev group - graph[row["state_group"]] = row["prev_state_group"] - - to_delete = state_groups_seen - referenced_groups - - to_dedelta = set() - for sg in referenced_groups: - prev_sg = graph.get(sg) - if prev_sg and prev_sg in to_delete: - to_dedelta.add(sg) - - return to_delete, to_dedelta + return referenced_state_groups def purge_room(self, room_id): """Deletes all record of a room @@ -1753,46 +1623,7 @@ class EventsStore( return self.runInteraction("purge_room", self._purge_room_txn, room_id) def _purge_room_txn(self, txn, room_id): - # first we have to delete the state groups states - logger.info("[purge] removing %s from state_groups_state", room_id) - - txn.execute( - """ - DELETE FROM state_groups_state WHERE state_group IN ( - SELECT state_group FROM events JOIN event_to_state_groups USING(event_id) - WHERE events.room_id=? - ) - """, - (room_id,), - ) - - # ... and the state group edges - logger.info("[purge] removing %s from state_group_edges", room_id) - - txn.execute( - """ - DELETE FROM state_group_edges WHERE state_group IN ( - SELECT state_group FROM events JOIN event_to_state_groups USING(event_id) - WHERE events.room_id=? - ) - """, - (room_id,), - ) - - # ... and the state groups - logger.info("[purge] removing %s from state_groups", room_id) - - txn.execute( - """ - DELETE FROM state_groups WHERE id IN ( - SELECT state_group FROM events JOIN event_to_state_groups USING(event_id) - WHERE events.room_id=? - ) - """, - (room_id,), - ) - - # and then tables which lack an index on room_id but have one on event_id + # First delete tables which lack an index on room_id but have one on event_id for table in ( "event_auth", "event_edges", @@ -1881,6 +1712,153 @@ class EventsStore( logger.info("[purge] done") + def purge_unreferenced_state_groups(self, room_id, state_groups_to_delete): + """Deletes no longer referenced state groups and de-deltas any state + groups that reference them. + """ + + return self.runInteraction( + "purge_unreferenced_state_groups", + self._purge_unreferenced_state_groups, + room_id, + state_groups_to_delete, + ) + + def _purge_unreferenced_state_groups(self, txn, room_id, state_groups_to_delete): + logger.info( + "[purge] found %i state groups to delete", len(state_groups_to_delete) + ) + + rows = self._simple_select_many_txn( + txn, + table="state_group_edges", + column="prev_state_group", + iterable=state_groups_to_delete, + keyvalues={}, + retcols=("state_group",), + ) + + remaining_state_groups = set( + row["state_group"] + for row in rows + if row["state_group"] not in state_groups_to_delete + ) + + logger.info( + "[purge] de-delta-ing %i remaining state groups", + len(remaining_state_groups), + ) + + # Now we turn the state groups that reference to-be-deleted state + # groups to non delta versions. + for sg in remaining_state_groups: + logger.info("[purge] de-delta-ing remaining state group %s", sg) + curr_state = self._get_state_groups_from_groups_txn(txn, [sg]) + curr_state = curr_state[sg] + + self._simple_delete_txn( + txn, table="state_groups_state", keyvalues={"state_group": sg} + ) + + self._simple_delete_txn( + txn, table="state_group_edges", keyvalues={"state_group": sg} + ) + + self._simple_insert_many_txn( + txn, + table="state_groups_state", + values=[ + { + "state_group": sg, + "room_id": room_id, + "type": key[0], + "state_key": key[1], + "event_id": state_id, + } + for key, state_id in iteritems(curr_state) + ], + ) + + logger.info("[purge] removing redundant state groups") + txn.executemany( + "DELETE FROM state_groups_state WHERE state_group = ?", + ((sg,) for sg in state_groups_to_delete), + ) + txn.executemany( + "DELETE FROM state_groups WHERE id = ?", + ((sg,) for sg in state_groups_to_delete), + ) + + @defer.inlineCallbacks + def get_previous_state_groups(self, state_groups): + """Fetch the previous groups of the given state groups. + + Args: + state_groups (Iterable[int]) + + Returns: + Deferred[dict[int, int]]: mapping from state group to previous + state group. + """ + + rows = yield self._simple_select_many_batch( + table="state_group_edges", + column="prev_state_group", + iterable=state_groups, + keyvalues={}, + retcols=("prev_state_group", "state_group"), + desc="get_previous_state_groups", + ) + + return {row["state_group"]: row["prev_state_group"] for row in rows} + + def purge_room_state(self, room_id): + """Deletes all record of a room from state tables + + Args: + room_id (str): + """ + + return self.runInteraction( + "purge_room_state", self._purge_room_state_txn, room_id + ) + + def _purge_room_state_txn(self, txn, room_id): + # first we have to delete the state groups states + logger.info("[purge] removing %s from state_groups_state", room_id) + + txn.execute( + """ + DELETE FROM state_groups_state + INNER JOIN state_groups USING (event_id) + WHEREE state_groups.room_id = ? + """, + (room_id,), + ) + + # ... and the state group edges + logger.info("[purge] removing %s from state_group_edges", room_id) + + txn.execute( + """ + DELETE FROM state_group_edges + INNER JOIN state_groups USING (event_id) + WHEREE state_groups.room_id = ? + ) + """, + (room_id,), + ) + + # ... and the state groups + logger.info("[purge] removing %s from state_groups", room_id) + + txn.execute( + """ + DELETE FROM state_groups WHEREE room_id = ? + """, + (room_id,), + ) + async def is_event_after(self, event_id1, event_id2): """Returns True if event_id1 is after event_id2 in the stream """ diff --git a/synapse/storage/data_stores/main/state.py b/synapse/storage/data_stores/main/state.py index 9b2207075b..36be8f0a9d 100644 --- a/synapse/storage/data_stores/main/state.py +++ b/synapse/storage/data_stores/main/state.py @@ -989,6 +989,29 @@ class StateGroupWorkerStore( return self.runInteraction("store_state_group", _store_state_group_txn) + @defer.inlineCallbacks + def get_referenced_state_groups(self, state_groups): + """Check if the state groups are referenced by events. + + Args: + state_groups (Iterable[int]) + + Returns: + Deferred[set[int]]: The subset of state groups that are + referenced. + """ + + rows = yield self._simple_select_many_batch( + table="event_to_state_groups", + column="state_group", + iterable=state_groups, + keyvalues={}, + retcols=("DISTINCT state_group",), + desc="get_referenced_state_groups", + ) + + return set(row["state_group"] for row in rows) + class StateBackgroundUpdateStore( StateGroupBackgroundUpdateStore, BackgroundUpdateStore diff --git a/synapse/storage/purge_events.py b/synapse/storage/purge_events.py new file mode 100644 index 0000000000..dd45df0c88 --- /dev/null +++ b/synapse/storage/purge_events.py @@ -0,0 +1,117 @@ +# -*- coding: utf-8 -*- +# Copyright 2019 The Matrix.org Foundation C.I.C. +# +# 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 itertools +import logging + +from twisted.internet import defer + +logger = logging.getLogger(__name__) + + +class PurgeEventsStorage(object): + """High level interface for purging rooms and event history. + """ + + def __init__(self, hs, stores): + self.stores = stores + + @defer.inlineCallbacks + def purge_room(self, room_id: str): + """Deletes all record of a room + """ + + yield self.stores.main.purge_room(room_id) + yield self.stores.main.purge_room_state(room_id) + + @defer.inlineCallbacks + def purge_history(self, room_id, token, delete_local_events): + """Deletes room history before a certain point + + Args: + room_id (str): + + token (str): A topological token to delete events before + + delete_local_events (bool): + if True, we will delete local events as well as remote ones + (instead of just marking them as outliers and deleting their + state groups). + """ + state_groups = yield self.stores.main.purge_history( + room_id, token, delete_local_events + ) + + logger.info("[purge] finding state groups that can be deleted") + + sg_to_delete = yield self._find_unreferenced_groups(state_groups) + + yield self.stores.main.purge_unreferenced_state_groups(room_id, sg_to_delete) + + @defer.inlineCallbacks + def _find_unreferenced_groups(self, state_groups): + """Used when purging history to figure out which state groups can be + deleted. + + Args: + state_groups (set[int]): Set of state groups referenced by events + that are going to be deleted. + + Returns: + Deferred[set[int]] The set of state groups that can be deleted. + """ + # Graph of state group -> previous group + graph = {} + + # Set of events that we have found to be referenced by events + referenced_groups = set() + + # Set of state groups we've already seen + state_groups_seen = set(state_groups) + + # Set of state groups to handle next. + next_to_search = set(state_groups) + while next_to_search: + # We bound size of groups we're looking up at once, to stop the + # SQL query getting too big + if len(next_to_search) < 100: + current_search = next_to_search + next_to_search = set() + else: + current_search = set(itertools.islice(next_to_search, 100)) + next_to_search -= current_search + + referenced = yield self.stores.main.get_referenced_state_groups( + current_search + ) + referenced_groups |= referenced + + # We don't continue iterating up the state group graphs for state + # groups that are referenced. + current_search -= referenced + + edges = yield self.stores.main.get_previous_state_groups(current_search) + + prevs = set(edges.values()) + # We don't bother re-handling groups we've already seen + prevs -= state_groups_seen + next_to_search |= prevs + state_groups_seen |= prevs + + graph.update(edges) + + to_delete = state_groups_seen - referenced_groups + + return to_delete diff --git a/tests/storage/test_purge.py b/tests/storage/test_purge.py index f671599cb8..b9fafaa1a6 100644 --- a/tests/storage/test_purge.py +++ b/tests/storage/test_purge.py @@ -40,23 +40,24 @@ class PurgeTests(HomeserverTestCase): third = self.helper.send(self.room_id, body="test3") last = self.helper.send(self.room_id, body="test4") - storage = self.hs.get_datastore() + store = self.hs.get_datastore() + storage = self.hs.get_storage() # Get the topological token - event = storage.get_topological_token_for_event(last["event_id"]) + event = store.get_topological_token_for_event(last["event_id"]) self.pump() event = self.successResultOf(event) # Purge everything before this topological token - purge = storage.purge_history(self.room_id, event, True) + purge = storage.purge_events.purge_history(self.room_id, event, True) self.pump() self.assertEqual(self.successResultOf(purge), None) # Try and get the events - get_first = storage.get_event(first["event_id"]) - get_second = storage.get_event(second["event_id"]) - get_third = storage.get_event(third["event_id"]) - get_last = storage.get_event(last["event_id"]) + get_first = store.get_event(first["event_id"]) + get_second = store.get_event(second["event_id"]) + get_third = store.get_event(third["event_id"]) + get_last = store.get_event(last["event_id"]) self.pump() # 1-3 should fail and last will succeed, meaning that 1-3 are deleted