Reintroduce #14376, with bugfix for monoliths (#14468)

* Add tests for StreamIdGenerator

* Drive-by: annotate all defs

* Revert "Revert "Remove slaved id tracker (#14376)" (#14463)"

This reverts commit d63814fd736fed5d3d45ff3af5e6d3bfae50c439, which in
turn reverted 36097e88c4da51fce6556a58c49bd675f4cf20ab. This restores
the latter.

* Fix StreamIdGenerator not handling unpersisted IDs

Spotted by @erikjohnston.

Closes #14456.

* Changelog

Co-authored-by: Nick Mills-Barrett <nick@fizzadar.com>
Co-authored-by: Erik Johnston <erik@matrix.org>

3 files changed, 0 insertions, 76 deletions

diff --git a/synapse/replication/slave/__init__.py b/synapse/replication/slave/__init__.py
deleted file mode 100644
index f43a360a80..0000000000
--- a/synapse/replication/slave/__init__.py
+++ /dev/null
@@ -1,13 +0,0 @@
-# Copyright 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.
diff --git a/synapse/replication/slave/storage/__init__.py b/synapse/replication/slave/storage/__init__.py
deleted file mode 100644
index f43a360a80..0000000000
--- a/synapse/replication/slave/storage/__init__.py
+++ /dev/null
@@ -1,13 +0,0 @@
-# Copyright 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.
diff --git a/synapse/replication/slave/storage/_slaved_id_tracker.py b/synapse/replication/slave/storage/_slaved_id_tracker.py
deleted file mode 100644
index 8f3f953ed4..0000000000
--- a/synapse/replication/slave/storage/_slaved_id_tracker.py
+++ /dev/null
@@ -1,50 +0,0 @@
-# Copyright 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 List, Optional, Tuple
-
-from synapse.storage.database import LoggingDatabaseConnection
-from synapse.storage.util.id_generators import AbstractStreamIdTracker, _load_current_id
-
-
-class SlavedIdTracker(AbstractStreamIdTracker):
-    """Tracks the "current" stream ID of a stream with a single writer.
-
-    See `AbstractStreamIdTracker` for more details.
-
-    Note that this class does not work correctly when there are multiple
-    writers.
-    """
-
-    def __init__(
-        self,
-        db_conn: LoggingDatabaseConnection,
-        table: str,
-        column: str,
-        extra_tables: Optional[List[Tuple[str, str]]] = None,
-        step: int = 1,
-    ):
-        self.step = step
-        self._current = _load_current_id(db_conn, table, column, step)
-        if extra_tables:
-            for table, column in extra_tables:
-                self.advance(None, _load_current_id(db_conn, table, column))
-
-    def advance(self, instance_name: Optional[str], new_id: int) -> None:
-        self._current = (max if self.step > 0 else min)(self._current, new_id)
-
-    def get_current_token(self) -> int:
-        return self._current
-
-    def get_current_token_for_writer(self, instance_name: str) -> int:
-        return self.get_current_token()