Speed up MultiWriterIdGenerator when lots of IDs are in flight.

changelog.d/10755.misc

@@ -0,0 +1 @@
+Minor speed ups when joining large rooms over federation.

stubs/sortedcontainers/__init__.pyi

@@ -1,5 +1,6 @@
 from .sorteddict import SortedDict, SortedItemsView, SortedKeysView, SortedValuesView
 from .sortedlist import SortedKeyList, SortedList, SortedListWithKey
+from .sortedset import SortedSet
 
 __all__ = [
     "SortedDict",
@@ -9,4 +10,5 @@ __all__ = [
     "SortedKeyList",
     "SortedList",
     "SortedListWithKey",
+    "SortedSet",
 ]

stubs/sortedcontainers/sortedset.pyi

@@ -0,0 +1,118 @@
+# stub for SortedDict. This is a lightly edited copy of
+# https://github.com/grantjenks/python-sortedcontainers/blob/d0a225d7fd0fb4c54532b8798af3cbeebf97e2d5/sortedcontainers/sortedset.pyi
+# (from https://github.com/grantjenks/python-sortedcontainers/pull/107)
+
+from typing import (
+    AbstractSet,
+    Any,
+    Callable,
+    Generic,
+    Hashable,
+    Iterable,
+    Iterator,
+    List,
+    MutableSet,
+    Optional,
+    Sequence,
+    Set,
+    Tuple,
+    Type,
+    TypeVar,
+    Union,
+    overload,
+)
+
+# --- Global
+
+_T = TypeVar("_T", bound=Hashable)
+_S = TypeVar("_S", bound=Hashable)
+_SS = TypeVar("_SS", bound=SortedSet)
+_Key = Callable[[_T], Any]
+
+class SortedSet(MutableSet[_T], Sequence[_T]):
+    def __init__(
+        self,
+        iterable: Optional[Iterable[_T]] = ...,
+        key: Optional[_Key[_T]] = ...,
+    ) -> None: ...
+    @classmethod
+    def _fromset(
+        cls, values: Set[_T], key: Optional[_Key[_T]] = ...
+    ) -> SortedSet[_T]: ...
+    @property
+    def key(self) -> Optional[_Key[_T]]: ...
+    def __contains__(self, value: Any) -> bool: ...
+    @overload
+    def __getitem__(self, index: int) -> _T: ...
+    @overload
+    def __getitem__(self, index: slice) -> List[_T]: ...
+    def __delitem__(self, index: Union[int, slice]) -> None: ...
+    def __eq__(self, other: Any) -> bool: ...
+    def __ne__(self, other: Any) -> bool: ...
+    def __lt__(self, other: Iterable[_T]) -> bool: ...
+    def __gt__(self, other: Iterable[_T]) -> bool: ...
+    def __le__(self, other: Iterable[_T]) -> bool: ...
+    def __ge__(self, other: Iterable[_T]) -> bool: ...
+    def __len__(self) -> int: ...
+    def __iter__(self) -> Iterator[_T]: ...
+    def __reversed__(self) -> Iterator[_T]: ...
+    def add(self, value: _T) -> None: ...
+    def _add(self, value: _T) -> None: ...
+    def clear(self) -> None: ...
+    def copy(self: _SS) -> _SS: ...
+    def __copy__(self: _SS) -> _SS: ...
+    def count(self, value: _T) -> int: ...
+    def discard(self, value: _T) -> None: ...
+    def _discard(self, value: _T) -> None: ...
+    def pop(self, index: int = ...) -> _T: ...
+    def remove(self, value: _T) -> None: ...
+    def difference(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def __sub__(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def difference_update(
+        self, *iterables: Iterable[_S]
+    ) -> SortedSet[Union[_T, _S]]: ...
+    def __isub__(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def intersection(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def __and__(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def __rand__(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def intersection_update(
+        self, *iterables: Iterable[_S]
+    ) -> SortedSet[Union[_T, _S]]: ...
+    def __iand__(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def symmetric_difference(self, other: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def __xor__(self, other: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def __rxor__(self, other: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def symmetric_difference_update(
+        self, other: Iterable[_S]
+    ) -> SortedSet[Union[_T, _S]]: ...
+    def __ixor__(self, other: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def union(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def __or__(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def __ror__(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def update(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def __ior__(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def _update(self, *iterables: Iterable[_S]) -> SortedSet[Union[_T, _S]]: ...
+    def __reduce__(
+        self,
+    ) -> Tuple[Type[SortedSet[_T]], Set[_T], Callable[[_T], Any]]: ...
+    def __repr__(self) -> str: ...
+    def _check(self) -> None: ...
+    def bisect_left(self, value: _T) -> int: ...
+    def bisect_right(self, value: _T) -> int: ...
+    def islice(
+        self,
+        start: Optional[int] = ...,
+        stop: Optional[int] = ...,
+        reverse=bool,
+    ) -> Iterator[_T]: ...
+    def irange(
+        self,
+        minimum: Optional[_T] = ...,
+        maximum: Optional[_T] = ...,
+        inclusive: Tuple[bool, bool] = ...,
+        reverse: bool = ...,
+    ) -> Iterator[_T]: ...
+    def index(
+        self, value: _T, start: Optional[int] = ..., stop: Optional[int] = ...
+    ) -> int: ...
+    def _reset(self, load: int) -> None: ...

synapse/storage/util/id_generators.py

@@ -19,6 +19,7 @@
 from typing import Dict, Iterable, List, Optional, Set, Tuple, Union
 
 import attr
+from sortedcontainers import SortedSet
 
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.storage.database import DatabasePool, LoggingTransaction
@@ -240,7 +241,7 @@ def __init__(
 
         # Set of local IDs that we're still processing. The current position
         # should be less than the minimum of this set (if not empty).
-        self._unfinished_ids: Set[int] = set()
+        self._unfinished_ids: SortedSet[int] = SortedSet()
 
         # Set of local IDs that we've processed that are larger than the current
         # position, due to there being smaller unpersisted IDs.
@@ -473,7 +474,7 @@ def _mark_id_as_finished(self, next_id: int):
 
                 finished = set()
 
-                min_unfinshed = min(self._unfinished_ids)
+                min_unfinshed = self._unfinished_ids[0]
                 for s in self._finished_ids:
                     if s < min_unfinshed:
                         if new_cur is None or new_cur < s: