Add type hints for state. (#8140)

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Patrick Cloke 2020-08-24 14:25:27 -04:00 committed by GitHub
parent cbd8d83da7
commit 5758dcf30c
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10 changed files with 420 additions and 203 deletions

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@ -16,7 +16,21 @@
import heapq
import itertools
import logging
from typing import Dict, List, Optional
from typing import (
Any,
Callable,
Dict,
Generator,
Iterable,
List,
Optional,
Sequence,
Set,
Tuple,
overload,
)
from typing_extensions import Literal
import synapse.state
from synapse import event_auth
@ -40,10 +54,10 @@ async def resolve_events_with_store(
clock: Clock,
room_id: str,
room_version: str,
state_sets: List[StateMap[str]],
state_sets: Sequence[StateMap[str]],
event_map: Optional[Dict[str, EventBase]],
state_res_store: "synapse.state.StateResolutionStore",
):
) -> StateMap[str]:
"""Resolves the state using the v2 state resolution algorithm
Args:
@ -63,8 +77,7 @@ async def resolve_events_with_store(
state_res_store:
Returns:
Deferred[dict[(str, str), str]]:
a map from (type, state_key) to event_id.
A map from (type, state_key) to event_id.
"""
logger.debug("Computing conflicted state")
@ -171,18 +184,23 @@ async def resolve_events_with_store(
return resolved_state
async def _get_power_level_for_sender(room_id, event_id, event_map, state_res_store):
async def _get_power_level_for_sender(
room_id: str,
event_id: str,
event_map: Dict[str, EventBase],
state_res_store: "synapse.state.StateResolutionStore",
) -> int:
"""Return the power level of the sender of the given event according to
their auth events.
Args:
room_id (str)
event_id (str)
event_map (dict[str,FrozenEvent])
state_res_store (StateResolutionStore)
room_id
event_id
event_map
state_res_store
Returns:
Deferred[int]
The power level.
"""
event = await _get_event(room_id, event_id, event_map, state_res_store)
@ -217,17 +235,21 @@ async def _get_power_level_for_sender(room_id, event_id, event_map, state_res_st
return int(level)
async def _get_auth_chain_difference(state_sets, event_map, state_res_store):
async def _get_auth_chain_difference(
state_sets: Sequence[StateMap[str]],
event_map: Dict[str, EventBase],
state_res_store: "synapse.state.StateResolutionStore",
) -> Set[str]:
"""Compare the auth chains of each state set and return the set of events
that only appear in some but not all of the auth chains.
Args:
state_sets (list)
event_map (dict[str,FrozenEvent])
state_res_store (StateResolutionStore)
state_sets
event_map
state_res_store
Returns:
Deferred[set[str]]: Set of event IDs
Set of event IDs
"""
difference = await state_res_store.get_auth_chain_difference(
@ -237,17 +259,19 @@ async def _get_auth_chain_difference(state_sets, event_map, state_res_store):
return difference
def _seperate(state_sets):
def _seperate(
state_sets: Iterable[StateMap[str]],
) -> Tuple[StateMap[str], StateMap[Set[str]]]:
"""Return the unconflicted and conflicted state. This is different than in
the original algorithm, as this defines a key to be conflicted if one of
the state sets doesn't have that key.
Args:
state_sets (list)
state_sets
Returns:
tuple[dict, dict]: A tuple of unconflicted and conflicted state. The
conflicted state dict is a map from type/state_key to set of event IDs
A tuple of unconflicted and conflicted state. The conflicted state dict
is a map from type/state_key to set of event IDs
"""
unconflicted_state = {}
conflicted_state = {}
@ -260,18 +284,20 @@ def _seperate(state_sets):
event_ids.discard(None)
conflicted_state[key] = event_ids
return unconflicted_state, conflicted_state
# mypy doesn't understand that discarding None above means that conflicted
# state is StateMap[Set[str]], not StateMap[Set[Optional[Str]]].
return unconflicted_state, conflicted_state # type: ignore
def _is_power_event(event):
def _is_power_event(event: EventBase) -> bool:
"""Return whether or not the event is a "power event", as defined by the
v2 state resolution algorithm
Args:
event (FrozenEvent)
event
Returns:
boolean
True if the event is a power event.
"""
if (event.type, event.state_key) in (
(EventTypes.PowerLevels, ""),
@ -288,19 +314,23 @@ def _is_power_event(event):
async def _add_event_and_auth_chain_to_graph(
graph, room_id, event_id, event_map, state_res_store, auth_diff
):
graph: Dict[str, Set[str]],
room_id: str,
event_id: str,
event_map: Dict[str, EventBase],
state_res_store: "synapse.state.StateResolutionStore",
auth_diff: Set[str],
) -> None:
"""Helper function for _reverse_topological_power_sort that add the event
and its auth chain (that is in the auth diff) to the graph
Args:
graph (dict[str, set[str]]): A map from event ID to the events auth
event IDs
room_id (str): the room we are working in
event_id (str): Event to add to the graph
event_map (dict[str,FrozenEvent])
state_res_store (StateResolutionStore)
auth_diff (set[str]): Set of event IDs that are in the auth difference.
graph: A map from event ID to the events auth event IDs
room_id: the room we are working in
event_id: Event to add to the graph
event_map
state_res_store
auth_diff: Set of event IDs that are in the auth difference.
"""
state = [event_id]
@ -318,24 +348,29 @@ async def _add_event_and_auth_chain_to_graph(
async def _reverse_topological_power_sort(
clock, room_id, event_ids, event_map, state_res_store, auth_diff
):
clock: Clock,
room_id: str,
event_ids: Iterable[str],
event_map: Dict[str, EventBase],
state_res_store: "synapse.state.StateResolutionStore",
auth_diff: Set[str],
) -> List[str]:
"""Returns a list of the event_ids sorted by reverse topological ordering,
and then by power level and origin_server_ts
Args:
clock (Clock)
room_id (str): the room we are working in
event_ids (list[str]): The events to sort
event_map (dict[str,FrozenEvent])
state_res_store (StateResolutionStore)
auth_diff (set[str]): Set of event IDs that are in the auth difference.
clock
room_id: the room we are working in
event_ids: The events to sort
event_map
state_res_store
auth_diff: Set of event IDs that are in the auth difference.
Returns:
Deferred[list[str]]: The sorted list
The sorted list
"""
graph = {}
graph = {} # type: Dict[str, Set[str]]
for idx, event_id in enumerate(event_ids, start=1):
await _add_event_and_auth_chain_to_graph(
graph, room_id, event_id, event_map, state_res_store, auth_diff
@ -372,22 +407,28 @@ async def _reverse_topological_power_sort(
async def _iterative_auth_checks(
clock, room_id, room_version, event_ids, base_state, event_map, state_res_store
):
clock: Clock,
room_id: str,
room_version: str,
event_ids: List[str],
base_state: StateMap[str],
event_map: Dict[str, EventBase],
state_res_store: "synapse.state.StateResolutionStore",
) -> StateMap[str]:
"""Sequentially apply auth checks to each event in given list, updating the
state as it goes along.
Args:
clock (Clock)
room_id (str)
room_version (str)
event_ids (list[str]): Ordered list of events to apply auth checks to
base_state (StateMap[str]): The set of state to start with
event_map (dict[str,FrozenEvent])
state_res_store (StateResolutionStore)
clock
room_id
room_version
event_ids: Ordered list of events to apply auth checks to
base_state: The set of state to start with
event_map
state_res_store
Returns:
Deferred[StateMap[str]]: Returns the final updated state
Returns the final updated state
"""
resolved_state = base_state.copy()
room_version_obj = KNOWN_ROOM_VERSIONS[room_version]
@ -439,21 +480,26 @@ async def _iterative_auth_checks(
async def _mainline_sort(
clock, room_id, event_ids, resolved_power_event_id, event_map, state_res_store
):
clock: Clock,
room_id: str,
event_ids: List[str],
resolved_power_event_id: Optional[str],
event_map: Dict[str, EventBase],
state_res_store: "synapse.state.StateResolutionStore",
) -> List[str]:
"""Returns a sorted list of event_ids sorted by mainline ordering based on
the given event resolved_power_event_id
Args:
clock (Clock)
room_id (str): room we're working in
event_ids (list[str]): Events to sort
resolved_power_event_id (str): The final resolved power level event ID
event_map (dict[str,FrozenEvent])
state_res_store (StateResolutionStore)
clock
room_id: room we're working in
event_ids: Events to sort
resolved_power_event_id: The final resolved power level event ID
event_map
state_res_store
Returns:
Deferred[list[str]]: The sorted list
The sorted list
"""
if not event_ids:
# It's possible for there to be no event IDs here to sort, so we can
@ -505,59 +551,90 @@ async def _mainline_sort(
async def _get_mainline_depth_for_event(
event, mainline_map, event_map, state_res_store
):
event: EventBase,
mainline_map: Dict[str, int],
event_map: Dict[str, EventBase],
state_res_store: "synapse.state.StateResolutionStore",
) -> int:
"""Get the mainline depths for the given event based on the mainline map
Args:
event (FrozenEvent)
mainline_map (dict[str, int]): Map from event_id to mainline depth for
events in the mainline.
event_map (dict[str,FrozenEvent])
state_res_store (StateResolutionStore)
event
mainline_map: Map from event_id to mainline depth for events in the mainline.
event_map
state_res_store
Returns:
Deferred[int]
The mainline depth
"""
room_id = event.room_id
tmp_event = event # type: Optional[EventBase]
# We do an iterative search, replacing `event with the power level in its
# auth events (if any)
while event:
while tmp_event:
depth = mainline_map.get(event.event_id)
if depth is not None:
return depth
auth_events = event.auth_event_ids()
event = None
auth_events = tmp_event.auth_event_ids()
tmp_event = None
for aid in auth_events:
aev = await _get_event(
room_id, aid, event_map, state_res_store, allow_none=True
)
if aev and (aev.type, aev.state_key) == (EventTypes.PowerLevels, ""):
event = aev
tmp_event = aev
break
# Didn't find a power level auth event, so we just return 0
return 0
async def _get_event(room_id, event_id, event_map, state_res_store, allow_none=False):
@overload
async def _get_event(
room_id: str,
event_id: str,
event_map: Dict[str, EventBase],
state_res_store: "synapse.state.StateResolutionStore",
allow_none: Literal[False] = False,
) -> EventBase:
...
@overload
async def _get_event(
room_id: str,
event_id: str,
event_map: Dict[str, EventBase],
state_res_store: "synapse.state.StateResolutionStore",
allow_none: Literal[True],
) -> Optional[EventBase]:
...
async def _get_event(
room_id: str,
event_id: str,
event_map: Dict[str, EventBase],
state_res_store: "synapse.state.StateResolutionStore",
allow_none: bool = False,
) -> Optional[EventBase]:
"""Helper function to look up event in event_map, falling back to looking
it up in the store
Args:
room_id (str)
event_id (str)
event_map (dict[str,FrozenEvent])
state_res_store (StateResolutionStore)
allow_none (bool): if the event is not found, return None rather than raising
room_id
event_id
event_map
state_res_store
allow_none: if the event is not found, return None rather than raising
an exception
Returns:
Deferred[Optional[FrozenEvent]]
The event, or none if the event does not exist (and allow_none is True).
"""
if event_id not in event_map:
events = await state_res_store.get_events([event_id], allow_rejected=True)
@ -577,7 +654,9 @@ async def _get_event(room_id, event_id, event_map, state_res_store, allow_none=F
return event
def lexicographical_topological_sort(graph, key):
def lexicographical_topological_sort(
graph: Dict[str, Set[str]], key: Callable[[str], Any]
) -> Generator[str, None, None]:
"""Performs a lexicographic reverse topological sort on the graph.
This returns a reverse topological sort (i.e. if node A references B then B
@ -587,20 +666,20 @@ def lexicographical_topological_sort(graph, key):
NOTE: `graph` is modified during the sort.
Args:
graph (dict[str, set[str]]): A representation of the graph where each
node is a key in the dict and its value are the nodes edges.
key (func): A function that takes a node and returns a value that is
comparable and used to order nodes
graph: A representation of the graph where each node is a key in the
dict and its value are the nodes edges.
key: A function that takes a node and returns a value that is comparable
and used to order nodes
Yields:
str: The next node in the topological sort
The next node in the topological sort
"""
# Note, this is basically Kahn's algorithm except we look at nodes with no
# outgoing edges, c.f.
# https://en.wikipedia.org/wiki/Topological_sorting#Kahn's_algorithm
outdegree_map = graph
reverse_graph = {}
reverse_graph = {} # type: Dict[str, Set[str]]
# Lists of nodes with zero out degree. Is actually a tuple of
# `(key(node), node)` so that sorting does the right thing