From d16910ca021320f0fa09c6cf82a802ee97e22a0c Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Thu, 30 May 2024 12:07:32 +0100 Subject: Replaces all usages of `StreamIdGenerator` with `MultiWriterIdGenerator` (#17229) Replaces all usages of `StreamIdGenerator` with `MultiWriterIdGenerator`, which is safer. --- synapse/_scripts/synapse_port_db.py | 71 +++++++-- synapse/storage/databases/main/devices.py | 54 +++---- synapse/storage/databases/main/end_to_end_keys.py | 19 ++- synapse/storage/databases/main/push_rule.py | 24 ++-- synapse/storage/databases/main/pusher.py | 42 +++--- .../schema/main/delta/85/02_add_instance_names.sql | 27 ++++ .../main/delta/85/03_new_sequences.sql.postgres | 54 +++++++ synapse/storage/util/id_generators.py | 158 --------------------- 8 files changed, 225 insertions(+), 224 deletions(-) create mode 100644 synapse/storage/schema/main/delta/85/02_add_instance_names.sql create mode 100644 synapse/storage/schema/main/delta/85/03_new_sequences.sql.postgres (limited to 'synapse') diff --git a/synapse/_scripts/synapse_port_db.py b/synapse/_scripts/synapse_port_db.py index 1e56f46911..3bb4a34938 100755 --- a/synapse/_scripts/synapse_port_db.py +++ b/synapse/_scripts/synapse_port_db.py @@ -777,22 +777,74 @@ class Porter: await self._setup_events_stream_seqs() await self._setup_sequence( "un_partial_stated_event_stream_sequence", - ("un_partial_stated_event_stream",), + [("un_partial_stated_event_stream", "stream_id")], ) await self._setup_sequence( - "device_inbox_sequence", ("device_inbox", "device_federation_outbox") + "device_inbox_sequence", + [ + ("device_inbox", "stream_id"), + ("device_federation_outbox", "stream_id"), + ], ) await self._setup_sequence( "account_data_sequence", - ("room_account_data", "room_tags_revisions", "account_data"), + [ + ("room_account_data", "stream_id"), + ("room_tags_revisions", "stream_id"), + ("account_data", "stream_id"), + ], + ) + await self._setup_sequence( + "receipts_sequence", + [ + ("receipts_linearized", "stream_id"), + ], + ) + await self._setup_sequence( + "presence_stream_sequence", + [ + ("presence_stream", "stream_id"), + ], ) - await self._setup_sequence("receipts_sequence", ("receipts_linearized",)) - await self._setup_sequence("presence_stream_sequence", ("presence_stream",)) await self._setup_auth_chain_sequence() await self._setup_sequence( "application_services_txn_id_seq", - ("application_services_txns",), - "txn_id", + [ + ( + "application_services_txns", + "txn_id", + ) + ], + ) + await self._setup_sequence( + "device_lists_sequence", + [ + ("device_lists_stream", "stream_id"), + ("user_signature_stream", "stream_id"), + ("device_lists_outbound_pokes", "stream_id"), + ("device_lists_changes_in_room", "stream_id"), + ("device_lists_remote_pending", "stream_id"), + ("device_lists_changes_converted_stream_position", "stream_id"), + ], + ) + await self._setup_sequence( + "e2e_cross_signing_keys_sequence", + [ + ("e2e_cross_signing_keys", "stream_id"), + ], + ) + await self._setup_sequence( + "push_rules_stream_sequence", + [ + ("push_rules_stream", "stream_id"), + ], + ) + await self._setup_sequence( + "pushers_sequence", + [ + ("pushers", "id"), + ("deleted_pushers", "stream_id"), + ], ) # Step 3. Get tables. @@ -1101,12 +1153,11 @@ class Porter: async def _setup_sequence( self, sequence_name: str, - stream_id_tables: Iterable[str], - column_name: str = "stream_id", + stream_id_tables: Iterable[Tuple[str, str]], ) -> None: """Set a sequence to the correct value.""" current_stream_ids = [] - for stream_id_table in stream_id_tables: + for stream_id_table, column_name in stream_id_tables: max_stream_id = cast( int, await self.sqlite_store.db_pool.simple_select_one_onecol( diff --git a/synapse/storage/databases/main/devices.py b/synapse/storage/databases/main/devices.py index 48384e238c..1c771e48f7 100644 --- a/synapse/storage/databases/main/devices.py +++ b/synapse/storage/databases/main/devices.py @@ -57,10 +57,7 @@ from synapse.storage.database import ( from synapse.storage.databases.main.end_to_end_keys import EndToEndKeyWorkerStore from synapse.storage.databases.main.roommember import RoomMemberWorkerStore from synapse.storage.types import Cursor -from synapse.storage.util.id_generators import ( - AbstractStreamIdGenerator, - StreamIdGenerator, -) +from synapse.storage.util.id_generators import MultiWriterIdGenerator from synapse.types import ( JsonDict, JsonMapping, @@ -99,19 +96,21 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore): # In the worker store this is an ID tracker which we overwrite in the non-worker # class below that is used on the main process. - self._device_list_id_gen = StreamIdGenerator( - db_conn, - hs.get_replication_notifier(), - "device_lists_stream", - "stream_id", - extra_tables=[ - ("user_signature_stream", "stream_id"), - ("device_lists_outbound_pokes", "stream_id"), - ("device_lists_changes_in_room", "stream_id"), - ("device_lists_remote_pending", "stream_id"), - ("device_lists_changes_converted_stream_position", "stream_id"), + self._device_list_id_gen = MultiWriterIdGenerator( + db_conn=db_conn, + db=database, + notifier=hs.get_replication_notifier(), + stream_name="device_lists_stream", + instance_name=self._instance_name, + tables=[ + ("device_lists_stream", "instance_name", "stream_id"), + ("user_signature_stream", "instance_name", "stream_id"), + ("device_lists_outbound_pokes", "instance_name", "stream_id"), + ("device_lists_changes_in_room", "instance_name", "stream_id"), + ("device_lists_remote_pending", "instance_name", "stream_id"), ], - is_writer=hs.config.worker.worker_app is None, + sequence_name="device_lists_sequence", + writers=["master"], ) device_list_max = self._device_list_id_gen.get_current_token() @@ -762,6 +761,7 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore): "stream_id": stream_id, "from_user_id": from_user_id, "user_ids": json_encoder.encode(user_ids), + "instance_name": self._instance_name, }, ) @@ -1582,6 +1582,8 @@ class DeviceBackgroundUpdateStore(SQLBaseStore): ): super().__init__(database, db_conn, hs) + self._instance_name = hs.get_instance_name() + self.db_pool.updates.register_background_index_update( "device_lists_stream_idx", index_name="device_lists_stream_user_id", @@ -1694,6 +1696,7 @@ class DeviceBackgroundUpdateStore(SQLBaseStore): "device_lists_outbound_pokes", { "stream_id": stream_id, + "instance_name": self._instance_name, "destination": destination, "user_id": user_id, "device_id": device_id, @@ -1730,10 +1733,6 @@ class DeviceBackgroundUpdateStore(SQLBaseStore): class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore): - # Because we have write access, this will be a StreamIdGenerator - # (see DeviceWorkerStore.__init__) - _device_list_id_gen: AbstractStreamIdGenerator - def __init__( self, database: DatabasePool, @@ -2092,9 +2091,9 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore): self.db_pool.simple_insert_many_txn( txn, table="device_lists_stream", - keys=("stream_id", "user_id", "device_id"), + keys=("instance_name", "stream_id", "user_id", "device_id"), values=[ - (stream_id, user_id, device_id) + (self._instance_name, stream_id, user_id, device_id) for stream_id, device_id in zip(stream_ids, device_ids) ], ) @@ -2124,6 +2123,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore): values = [ ( destination, + self._instance_name, next(stream_id_iterator), user_id, device_id, @@ -2139,6 +2139,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore): table="device_lists_outbound_pokes", keys=( "destination", + "instance_name", "stream_id", "user_id", "device_id", @@ -2157,7 +2158,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore): device_id, { stream_id: destination - for (destination, stream_id, _, _, _, _, _) in values + for (destination, _, stream_id, _, _, _, _, _) in values }, ) @@ -2210,6 +2211,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore): "device_id", "room_id", "stream_id", + "instance_name", "converted_to_destinations", "opentracing_context", ), @@ -2219,6 +2221,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore): device_id, room_id, stream_id, + self._instance_name, # We only need to calculate outbound pokes for local users not self.hs.is_mine_id(user_id), encoded_context, @@ -2338,7 +2341,10 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore): "user_id": user_id, "device_id": device_id, }, - values={"stream_id": stream_id}, + values={ + "stream_id": stream_id, + "instance_name": self._instance_name, + }, desc="add_remote_device_list_to_pending", ) diff --git a/synapse/storage/databases/main/end_to_end_keys.py b/synapse/storage/databases/main/end_to_end_keys.py index b219ea70ee..38d8785faa 100644 --- a/synapse/storage/databases/main/end_to_end_keys.py +++ b/synapse/storage/databases/main/end_to_end_keys.py @@ -58,7 +58,7 @@ from synapse.storage.database import ( ) from synapse.storage.databases.main.cache import CacheInvalidationWorkerStore from synapse.storage.engines import PostgresEngine -from synapse.storage.util.id_generators import StreamIdGenerator +from synapse.storage.util.id_generators import MultiWriterIdGenerator from synapse.types import JsonDict, JsonMapping from synapse.util import json_decoder, json_encoder from synapse.util.caches.descriptors import cached, cachedList @@ -1448,11 +1448,17 @@ class EndToEndKeyStore(EndToEndKeyWorkerStore, SQLBaseStore): ): super().__init__(database, db_conn, hs) - self._cross_signing_id_gen = StreamIdGenerator( - db_conn, - hs.get_replication_notifier(), - "e2e_cross_signing_keys", - "stream_id", + self._cross_signing_id_gen = MultiWriterIdGenerator( + db_conn=db_conn, + db=database, + notifier=hs.get_replication_notifier(), + stream_name="e2e_cross_signing_keys", + instance_name=self._instance_name, + tables=[ + ("e2e_cross_signing_keys", "instance_name", "stream_id"), + ], + sequence_name="e2e_cross_signing_keys_sequence", + writers=["master"], ) async def set_e2e_device_keys( @@ -1627,6 +1633,7 @@ class EndToEndKeyStore(EndToEndKeyWorkerStore, SQLBaseStore): "keytype": key_type, "keydata": json_encoder.encode(key), "stream_id": stream_id, + "instance_name": self._instance_name, }, ) diff --git a/synapse/storage/databases/main/push_rule.py b/synapse/storage/databases/main/push_rule.py index 660c834518..2a39dc9f90 100644 --- a/synapse/storage/databases/main/push_rule.py +++ b/synapse/storage/databases/main/push_rule.py @@ -53,7 +53,7 @@ from synapse.storage.databases.main.receipts import ReceiptsWorkerStore from synapse.storage.databases.main.roommember import RoomMemberWorkerStore from synapse.storage.engines import PostgresEngine, Sqlite3Engine from synapse.storage.push_rule import InconsistentRuleException, RuleNotFoundException -from synapse.storage.util.id_generators import IdGenerator, StreamIdGenerator +from synapse.storage.util.id_generators import IdGenerator, MultiWriterIdGenerator from synapse.synapse_rust.push import FilteredPushRules, PushRule, PushRules from synapse.types import JsonDict from synapse.util import json_encoder, unwrapFirstError @@ -126,7 +126,7 @@ class PushRulesWorkerStore( `get_max_push_rules_stream_id` which can be called in the initializer. """ - _push_rules_stream_id_gen: StreamIdGenerator + _push_rules_stream_id_gen: MultiWriterIdGenerator def __init__( self, @@ -140,14 +140,17 @@ class PushRulesWorkerStore( hs.get_instance_name() in hs.config.worker.writers.push_rules ) - # In the worker store this is an ID tracker which we overwrite in the non-worker - # class below that is used on the main process. - self._push_rules_stream_id_gen = StreamIdGenerator( - db_conn, - hs.get_replication_notifier(), - "push_rules_stream", - "stream_id", - is_writer=self._is_push_writer, + self._push_rules_stream_id_gen = MultiWriterIdGenerator( + db_conn=db_conn, + db=database, + notifier=hs.get_replication_notifier(), + stream_name="push_rules_stream", + instance_name=self._instance_name, + tables=[ + ("push_rules_stream", "instance_name", "stream_id"), + ], + sequence_name="push_rules_stream_sequence", + writers=hs.config.worker.writers.push_rules, ) push_rules_prefill, push_rules_id = self.db_pool.get_cache_dict( @@ -880,6 +883,7 @@ class PushRulesWorkerStore( raise Exception("Not a push writer") values = { + "instance_name": self._instance_name, "stream_id": stream_id, "event_stream_ordering": event_stream_ordering, "user_id": user_id, diff --git a/synapse/storage/databases/main/pusher.py b/synapse/storage/databases/main/pusher.py index 39e22d3b43..a8a37b6c85 100644 --- a/synapse/storage/databases/main/pusher.py +++ b/synapse/storage/databases/main/pusher.py @@ -40,10 +40,7 @@ from synapse.storage.database import ( LoggingDatabaseConnection, LoggingTransaction, ) -from synapse.storage.util.id_generators import ( - AbstractStreamIdGenerator, - StreamIdGenerator, -) +from synapse.storage.util.id_generators import MultiWriterIdGenerator from synapse.types import JsonDict from synapse.util import json_encoder from synapse.util.caches.descriptors import cached @@ -84,15 +81,20 @@ class PusherWorkerStore(SQLBaseStore): ): super().__init__(database, db_conn, hs) - # In the worker store this is an ID tracker which we overwrite in the non-worker - # class below that is used on the main process. - self._pushers_id_gen = StreamIdGenerator( - db_conn, - hs.get_replication_notifier(), - "pushers", - "id", - extra_tables=[("deleted_pushers", "stream_id")], - is_writer=hs.config.worker.worker_app is None, + self._instance_name = hs.get_instance_name() + + self._pushers_id_gen = MultiWriterIdGenerator( + db_conn=db_conn, + db=database, + notifier=hs.get_replication_notifier(), + stream_name="pushers", + instance_name=self._instance_name, + tables=[ + ("pushers", "instance_name", "id"), + ("deleted_pushers", "instance_name", "stream_id"), + ], + sequence_name="pushers_sequence", + writers=["master"], ) self.db_pool.updates.register_background_update_handler( @@ -655,7 +657,7 @@ class PusherBackgroundUpdatesStore(SQLBaseStore): class PusherStore(PusherWorkerStore, PusherBackgroundUpdatesStore): # Because we have write access, this will be a StreamIdGenerator # (see PusherWorkerStore.__init__) - _pushers_id_gen: AbstractStreamIdGenerator + _pushers_id_gen: MultiWriterIdGenerator async def add_pusher( self, @@ -688,6 +690,7 @@ class PusherStore(PusherWorkerStore, PusherBackgroundUpdatesStore): "last_stream_ordering": last_stream_ordering, "profile_tag": profile_tag, "id": stream_id, + "instance_name": self._instance_name, "enabled": enabled, "device_id": device_id, # XXX(quenting): We're only really persisting the access token ID @@ -735,6 +738,7 @@ class PusherStore(PusherWorkerStore, PusherBackgroundUpdatesStore): table="deleted_pushers", values={ "stream_id": stream_id, + "instance_name": self._instance_name, "app_id": app_id, "pushkey": pushkey, "user_id": user_id, @@ -773,9 +777,15 @@ class PusherStore(PusherWorkerStore, PusherBackgroundUpdatesStore): self.db_pool.simple_insert_many_txn( txn, table="deleted_pushers", - keys=("stream_id", "app_id", "pushkey", "user_id"), + keys=("stream_id", "instance_name", "app_id", "pushkey", "user_id"), values=[ - (stream_id, pusher.app_id, pusher.pushkey, user_id) + ( + stream_id, + self._instance_name, + pusher.app_id, + pusher.pushkey, + user_id, + ) for stream_id, pusher in zip(stream_ids, pushers) ], ) diff --git a/synapse/storage/schema/main/delta/85/02_add_instance_names.sql b/synapse/storage/schema/main/delta/85/02_add_instance_names.sql new file mode 100644 index 0000000000..d604595f73 --- /dev/null +++ b/synapse/storage/schema/main/delta/85/02_add_instance_names.sql @@ -0,0 +1,27 @@ +-- +-- This file is licensed under the Affero General Public License (AGPL) version 3. +-- +-- Copyright (C) 2024 New Vector, Ltd +-- +-- This program is free software: you can redistribute it and/or modify +-- it under the terms of the GNU Affero General Public License as +-- published by the Free Software Foundation, either version 3 of the +-- License, or (at your option) any later version. +-- +-- See the GNU Affero General Public License for more details: +-- . + +-- Add `instance_name` columns to stream tables to allow them to be used with +-- `MultiWriterIdGenerator` +ALTER TABLE device_lists_stream ADD COLUMN instance_name TEXT; +ALTER TABLE user_signature_stream ADD COLUMN instance_name TEXT; +ALTER TABLE device_lists_outbound_pokes ADD COLUMN instance_name TEXT; +ALTER TABLE device_lists_changes_in_room ADD COLUMN instance_name TEXT; +ALTER TABLE device_lists_remote_pending ADD COLUMN instance_name TEXT; + +ALTER TABLE e2e_cross_signing_keys ADD COLUMN instance_name TEXT; + +ALTER TABLE push_rules_stream ADD COLUMN instance_name TEXT; + +ALTER TABLE pushers ADD COLUMN instance_name TEXT; +ALTER TABLE deleted_pushers ADD COLUMN instance_name TEXT; diff --git a/synapse/storage/schema/main/delta/85/03_new_sequences.sql.postgres b/synapse/storage/schema/main/delta/85/03_new_sequences.sql.postgres new file mode 100644 index 0000000000..9d34066bf5 --- /dev/null +++ b/synapse/storage/schema/main/delta/85/03_new_sequences.sql.postgres @@ -0,0 +1,54 @@ +-- +-- This file is licensed under the Affero General Public License (AGPL) version 3. +-- +-- Copyright (C) 2024 New Vector, Ltd +-- +-- This program is free software: you can redistribute it and/or modify +-- it under the terms of the GNU Affero General Public License as +-- published by the Free Software Foundation, either version 3 of the +-- License, or (at your option) any later version. +-- +-- See the GNU Affero General Public License for more details: +-- . + +-- Add squences for stream tables to allow them to be used with +-- `MultiWriterIdGenerator` +CREATE SEQUENCE IF NOT EXISTS device_lists_sequence; + +-- We need to take the max across all the device lists tables as they share the +-- ID generator +SELECT setval('device_lists_sequence', ( + SELECT GREATEST( + (SELECT COALESCE(MAX(stream_id), 1) FROM device_lists_stream), + (SELECT COALESCE(MAX(stream_id), 1) FROM user_signature_stream), + (SELECT COALESCE(MAX(stream_id), 1) FROM device_lists_outbound_pokes), + (SELECT COALESCE(MAX(stream_id), 1) FROM device_lists_changes_in_room), + (SELECT COALESCE(MAX(stream_id), 1) FROM device_lists_remote_pending), + (SELECT COALESCE(MAX(stream_id), 1) FROM device_lists_changes_converted_stream_position) + ) +)); + +CREATE SEQUENCE IF NOT EXISTS e2e_cross_signing_keys_sequence; + +SELECT setval('e2e_cross_signing_keys_sequence', ( + SELECT COALESCE(MAX(stream_id), 1) FROM e2e_cross_signing_keys +)); + + +CREATE SEQUENCE IF NOT EXISTS push_rules_stream_sequence; + +SELECT setval('push_rules_stream_sequence', ( + SELECT COALESCE(MAX(stream_id), 1) FROM push_rules_stream +)); + + +CREATE SEQUENCE IF NOT EXISTS pushers_sequence; + +-- We need to take the max across all the pusher tables as they share the +-- ID generator +SELECT setval('pushers_sequence', ( + SELECT GREATEST( + (SELECT COALESCE(MAX(id), 1) FROM pushers), + (SELECT COALESCE(MAX(stream_id), 1) FROM deleted_pushers) + ) +)); diff --git a/synapse/storage/util/id_generators.py b/synapse/storage/util/id_generators.py index 0cf5851ad7..59c8e05c39 100644 --- a/synapse/storage/util/id_generators.py +++ b/synapse/storage/util/id_generators.py @@ -23,15 +23,12 @@ import abc import heapq import logging import threading -from collections import OrderedDict -from contextlib import contextmanager from types import TracebackType from typing import ( TYPE_CHECKING, AsyncContextManager, ContextManager, Dict, - Generator, Generic, Iterable, List, @@ -179,161 +176,6 @@ class AbstractStreamIdGenerator(metaclass=abc.ABCMeta): raise NotImplementedError() -class StreamIdGenerator(AbstractStreamIdGenerator): - """Generates and tracks stream IDs for a stream with a single writer. - - This class must only be used when the current Synapse process is the sole - writer for a stream. - - Args: - db_conn(connection): A database connection to use to fetch the - initial value of the generator from. - table(str): A database table to read the initial value of the id - generator from. - column(str): The column of the database table to read the initial - value from the id generator from. - extra_tables(list): List of pairs of database tables and columns to - use to source the initial value of the generator from. The value - with the largest magnitude is used. - step(int): which direction the stream ids grow in. +1 to grow - upwards, -1 to grow downwards. - - Usage: - async with stream_id_gen.get_next() as stream_id: - # ... persist event ... - """ - - def __init__( - self, - db_conn: LoggingDatabaseConnection, - notifier: "ReplicationNotifier", - table: str, - column: str, - extra_tables: Iterable[Tuple[str, str]] = (), - step: int = 1, - is_writer: bool = True, - ) -> None: - assert step != 0 - self._lock = threading.Lock() - self._step: int = step - self._current: int = _load_current_id(db_conn, table, column, step) - self._is_writer = is_writer - for table, column in extra_tables: - self._current = (max if step > 0 else min)( - self._current, _load_current_id(db_conn, table, column, step) - ) - - # We use this as an ordered set, as we want to efficiently append items, - # remove items and get the first item. Since we insert IDs in order, the - # insertion ordering will ensure its in the correct ordering. - # - # The key and values are the same, but we never look at the values. - self._unfinished_ids: OrderedDict[int, int] = OrderedDict() - - self._notifier = notifier - - def advance(self, instance_name: str, new_id: int) -> None: - # Advance should never be called on a writer instance, only over replication - if self._is_writer: - raise Exception("Replication is not supported by writer StreamIdGenerator") - - self._current = (max if self._step > 0 else min)(self._current, new_id) - - def get_next(self) -> AsyncContextManager[int]: - with self._lock: - self._current += self._step - next_id = self._current - - self._unfinished_ids[next_id] = next_id - - @contextmanager - def manager() -> Generator[int, None, None]: - try: - yield next_id - finally: - with self._lock: - self._unfinished_ids.pop(next_id) - - self._notifier.notify_replication() - - return _AsyncCtxManagerWrapper(manager()) - - def get_next_mult(self, n: int) -> AsyncContextManager[Sequence[int]]: - with self._lock: - next_ids = range( - self._current + self._step, - self._current + self._step * (n + 1), - self._step, - ) - self._current += n * self._step - - for next_id in next_ids: - self._unfinished_ids[next_id] = next_id - - @contextmanager - def manager() -> Generator[Sequence[int], None, None]: - try: - yield next_ids - finally: - with self._lock: - for next_id in next_ids: - self._unfinished_ids.pop(next_id) - - self._notifier.notify_replication() - - return _AsyncCtxManagerWrapper(manager()) - - def get_next_txn(self, txn: LoggingTransaction) -> int: - """ - Retrieve the next stream ID from within a database transaction. - - Clean-up functions will be called when the transaction finishes. - - Args: - txn: The database transaction object. - - Returns: - The next stream ID. - """ - if not self._is_writer: - raise Exception("Tried to allocate stream ID on non-writer") - - # Get the next stream ID. - with self._lock: - self._current += self._step - next_id = self._current - - self._unfinished_ids[next_id] = next_id - - def clear_unfinished_id(id_to_clear: int) -> None: - """A function to mark processing this ID as finished""" - with self._lock: - self._unfinished_ids.pop(id_to_clear) - - # Mark this ID as finished once the database transaction itself finishes. - txn.call_after(clear_unfinished_id, next_id) - txn.call_on_exception(clear_unfinished_id, next_id) - - # Return the new ID. - return next_id - - def get_current_token(self) -> int: - if not self._is_writer: - return self._current - - with self._lock: - if self._unfinished_ids: - return next(iter(self._unfinished_ids)) - self._step - - return self._current - - def get_current_token_for_writer(self, instance_name: str) -> int: - return self.get_current_token() - - def get_minimal_local_current_token(self) -> int: - return self.get_current_token() - - class MultiWriterIdGenerator(AbstractStreamIdGenerator): """Generates and tracks stream IDs for a stream with multiple writers. -- cgit 1.4.1