Improve docstrings for methods related to sending EDUs to application services (#11138)

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Andrew Morgan 2021-10-21 17:42:25 +01:00 committed by GitHub
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7 changed files with 148 additions and 23 deletions

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changelog.d/11138.misc Normal file
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@ -0,0 +1 @@
Add docstrings and comments to the application service ephemeral event sending code.

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@ -185,19 +185,26 @@ class ApplicationServicesHandler:
new_token: Optional[int], new_token: Optional[int],
users: Optional[Collection[Union[str, UserID]]] = None, users: Optional[Collection[Union[str, UserID]]] = None,
) -> None: ) -> None:
"""This is called by the notifier in the background """
when a ephemeral event handled by the homeserver. This is called by the notifier in the background when an ephemeral event is handled
by the homeserver.
This will determine which appservices This will determine which appservices are interested in the event, and submit them.
are interested in the event, and submit them.
Events will only be pushed to appservices
that have opted into ephemeral events
Args: Args:
stream_key: The stream the event came from. stream_key: The stream the event came from.
new_token: The latest stream token
users: The user(s) involved with the event. `stream_key` can be "typing_key", "receipt_key" or "presence_key". Any other
value for `stream_key` will cause this function to return early.
Ephemeral events will only be pushed to appservices that have opted into
them.
Appservices will only receive ephemeral events that fall within their
registered user and room namespaces.
new_token: The latest stream token.
users: The users that should be informed of the new event, if any.
""" """
if not self.notify_appservices: if not self.notify_appservices:
return return
@ -232,21 +239,32 @@ class ApplicationServicesHandler:
for service in services: for service in services:
# Only handle typing if we have the latest token # Only handle typing if we have the latest token
if stream_key == "typing_key" and new_token is not None: if stream_key == "typing_key" and new_token is not None:
# Note that we don't persist the token (via set_type_stream_id_for_appservice)
# for typing_key due to performance reasons and due to their highly
# ephemeral nature.
#
# Instead we simply grab the latest typing updates in _handle_typing
# and, if they apply to this application service, send it off.
events = await self._handle_typing(service, new_token) events = await self._handle_typing(service, new_token)
if events: if events:
self.scheduler.submit_ephemeral_events_for_as(service, events) self.scheduler.submit_ephemeral_events_for_as(service, events)
# We don't persist the token for typing_key for performance reasons
elif stream_key == "receipt_key": elif stream_key == "receipt_key":
events = await self._handle_receipts(service) events = await self._handle_receipts(service)
if events: if events:
self.scheduler.submit_ephemeral_events_for_as(service, events) self.scheduler.submit_ephemeral_events_for_as(service, events)
# Persist the latest handled stream token for this appservice
await self.store.set_type_stream_id_for_appservice( await self.store.set_type_stream_id_for_appservice(
service, "read_receipt", new_token service, "read_receipt", new_token
) )
elif stream_key == "presence_key": elif stream_key == "presence_key":
events = await self._handle_presence(service, users) events = await self._handle_presence(service, users)
if events: if events:
self.scheduler.submit_ephemeral_events_for_as(service, events) self.scheduler.submit_ephemeral_events_for_as(service, events)
# Persist the latest handled stream token for this appservice
await self.store.set_type_stream_id_for_appservice( await self.store.set_type_stream_id_for_appservice(
service, "presence", new_token service, "presence", new_token
) )
@ -254,18 +272,54 @@ class ApplicationServicesHandler:
async def _handle_typing( async def _handle_typing(
self, service: ApplicationService, new_token: int self, service: ApplicationService, new_token: int
) -> List[JsonDict]: ) -> List[JsonDict]:
"""
Return the typing events since the given stream token that the given application
service should receive.
First fetch all typing events between the given typing stream token (non-inclusive)
and the latest typing event stream token (inclusive). Then return only those typing
events that the given application service may be interested in.
Args:
service: The application service to check for which events it should receive.
new_token: A typing event stream token.
Returns:
A list of JSON dictionaries containing data derived from the typing events that
should be sent to the given application service.
"""
typing_source = self.event_sources.sources.typing typing_source = self.event_sources.sources.typing
# Get the typing events from just before current # Get the typing events from just before current
typing, _ = await typing_source.get_new_events_as( typing, _ = await typing_source.get_new_events_as(
service=service, service=service,
# For performance reasons, we don't persist the previous # For performance reasons, we don't persist the previous
# token in the DB and instead fetch the latest typing information # token in the DB and instead fetch the latest typing event
# for appservices. # for appservices.
# TODO: It'd likely be more efficient to simply fetch the
# typing event with the given 'new_token' stream token and
# check if the given service was interested, rather than
# iterating over all typing events and only grabbing the
# latest few.
from_key=new_token - 1, from_key=new_token - 1,
) )
return typing return typing
async def _handle_receipts(self, service: ApplicationService) -> List[JsonDict]: async def _handle_receipts(self, service: ApplicationService) -> List[JsonDict]:
"""
Return the latest read receipts that the given application service should receive.
First fetch all read receipts between the last receipt stream token that this
application service should have previously received (non-inclusive) and the
latest read receipt stream token (inclusive). Then from that set, return only
those read receipts that the given application service may be interested in.
Args:
service: The application service to check for which events it should receive.
Returns:
A list of JSON dictionaries containing data derived from the read receipts that
should be sent to the given application service.
"""
from_key = await self.store.get_type_stream_id_for_appservice( from_key = await self.store.get_type_stream_id_for_appservice(
service, "read_receipt" service, "read_receipt"
) )
@ -278,6 +332,22 @@ class ApplicationServicesHandler:
async def _handle_presence( async def _handle_presence(
self, service: ApplicationService, users: Collection[Union[str, UserID]] self, service: ApplicationService, users: Collection[Union[str, UserID]]
) -> List[JsonDict]: ) -> List[JsonDict]:
"""
Return the latest presence updates that the given application service should receive.
First, filter the given users list to those that the application service is
interested in. Then retrieve the latest presence updates since the
the last-known previously received presence stream token for the given
application service. Return those presence updates.
Args:
service: The application service that ephemeral events are being sent to.
users: The users that should receive the presence update.
Returns:
A list of json dictionaries containing data derived from the presence events
that should be sent to the given application service.
"""
events: List[JsonDict] = [] events: List[JsonDict] = []
presence_source = self.event_sources.sources.presence presence_source = self.event_sources.sources.presence
from_key = await self.store.get_type_stream_id_for_appservice( from_key = await self.store.get_type_stream_id_for_appservice(
@ -290,9 +360,9 @@ class ApplicationServicesHandler:
interested = await service.is_interested_in_presence(user, self.store) interested = await service.is_interested_in_presence(user, self.store)
if not interested: if not interested:
continue continue
presence_events, _ = await presence_source.get_new_events( presence_events, _ = await presence_source.get_new_events(
user=user, user=user,
service=service,
from_key=from_key, from_key=from_key,
) )
time_now = self.clock.time_msec() time_now = self.clock.time_msec()

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@ -454,6 +454,10 @@ class DeviceHandler(DeviceWorkerHandler):
) -> None: ) -> None:
"""Notify that a user's device(s) has changed. Pokes the notifier, and """Notify that a user's device(s) has changed. Pokes the notifier, and
remote servers if the user is local. remote servers if the user is local.
Args:
user_id: The Matrix ID of the user who's device list has been updated.
device_ids: The device IDs that have changed.
""" """
if not device_ids: if not device_ids:
# No changes to notify about, so this is a no-op. # No changes to notify about, so this is a no-op.

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@ -52,7 +52,6 @@ import synapse.metrics
from synapse.api.constants import EventTypes, Membership, PresenceState from synapse.api.constants import EventTypes, Membership, PresenceState
from synapse.api.errors import SynapseError from synapse.api.errors import SynapseError
from synapse.api.presence import UserPresenceState from synapse.api.presence import UserPresenceState
from synapse.appservice import ApplicationService
from synapse.events.presence_router import PresenceRouter from synapse.events.presence_router import PresenceRouter
from synapse.logging.context import run_in_background from synapse.logging.context import run_in_background
from synapse.logging.utils import log_function from synapse.logging.utils import log_function
@ -1483,11 +1482,37 @@ def should_notify(old_state: UserPresenceState, new_state: UserPresenceState) ->
def format_user_presence_state( def format_user_presence_state(
state: UserPresenceState, now: int, include_user_id: bool = True state: UserPresenceState, now: int, include_user_id: bool = True
) -> JsonDict: ) -> JsonDict:
"""Convert UserPresenceState to a format that can be sent down to clients """Convert UserPresenceState to a JSON format that can be sent down to clients
and to other servers. and to other servers.
The "user_id" is optional so that this function can be used to format presence Args:
updates for client /sync responses and for federation /send requests. state: The user presence state to format.
now: The current timestamp since the epoch in ms.
include_user_id: Whether to include `user_id` in the returned dictionary.
As this function can be used both to format presence updates for client /sync
responses and for federation /send requests, only the latter needs the include
the `user_id` field.
Returns:
A JSON dictionary with the following keys:
* presence: The presence state as a str.
* user_id: Optional. Included if `include_user_id` is truthy. The canonical
Matrix ID of the user.
* last_active_ago: Optional. Included if `last_active_ts` is set on `state`.
The timestamp that the user was last active.
* status_msg: Optional. Included if `status_msg` is set on `state`. The user's
status.
* currently_active: Optional. Included only if `state.state` is "online".
Example:
{
"presence": "online",
"user_id": "@alice:example.com",
"last_active_ago": 16783813918,
"status_msg": "Hello world!",
"currently_active": True
}
""" """
content: JsonDict = {"presence": state.state} content: JsonDict = {"presence": state.state}
if include_user_id: if include_user_id:
@ -1526,7 +1551,6 @@ class PresenceEventSource(EventSource[int, UserPresenceState]):
is_guest: bool = False, is_guest: bool = False,
explicit_room_id: Optional[str] = None, explicit_room_id: Optional[str] = None,
include_offline: bool = True, include_offline: bool = True,
service: Optional[ApplicationService] = None,
) -> Tuple[List[UserPresenceState], int]: ) -> Tuple[List[UserPresenceState], int]:
# The process for getting presence events are: # The process for getting presence events are:
# 1. Get the rooms the user is in. # 1. Get the rooms the user is in.

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@ -241,12 +241,18 @@ class ReceiptEventSource(EventSource[int, JsonDict]):
async def get_new_events_as( async def get_new_events_as(
self, from_key: int, service: ApplicationService self, from_key: int, service: ApplicationService
) -> Tuple[List[JsonDict], int]: ) -> Tuple[List[JsonDict], int]:
"""Returns a set of new receipt events that an appservice """Returns a set of new read receipt events that an appservice
may be interested in. may be interested in.
Args: Args:
from_key: the stream position at which events should be fetched from from_key: the stream position at which events should be fetched from
service: The appservice which may be interested service: The appservice which may be interested
Returns:
A two-tuple containing the following:
* A list of json dictionaries derived from read receipts that the
appservice may be interested in.
* The current read receipt stream token.
""" """
from_key = int(from_key) from_key = int(from_key)
to_key = self.get_current_key() to_key = self.get_current_key()

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@ -465,17 +465,23 @@ class TypingNotificationEventSource(EventSource[int, JsonDict]):
may be interested in. may be interested in.
Args: Args:
from_key: the stream position at which events should be fetched from from_key: the stream position at which events should be fetched from.
service: The appservice which may be interested service: The appservice which may be interested.
Returns:
A two-tuple containing the following:
* A list of json dictionaries derived from typing events that the
appservice may be interested in.
* The latest known room serial.
""" """
with Measure(self.clock, "typing.get_new_events_as"): with Measure(self.clock, "typing.get_new_events_as"):
from_key = int(from_key)
handler = self.get_typing_handler() handler = self.get_typing_handler()
events = [] events = []
for room_id in handler._room_serials.keys(): for room_id in handler._room_serials.keys():
if handler._room_serials[room_id] <= from_key: if handler._room_serials[room_id] <= from_key:
continue continue
if not await service.matches_user_in_member_list( if not await service.matches_user_in_member_list(
room_id, handler.store room_id, handler.store
): ):

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@ -379,7 +379,14 @@ class Notifier:
stream_key: str, stream_key: str,
new_token: Union[int, RoomStreamToken], new_token: Union[int, RoomStreamToken],
users: Optional[Collection[Union[str, UserID]]] = None, users: Optional[Collection[Union[str, UserID]]] = None,
): ) -> None:
"""Notify application services of ephemeral event activity.
Args:
stream_key: The stream the event came from.
new_token: The value of the new stream token.
users: The users that should be informed of the new event, if any.
"""
try: try:
stream_token = None stream_token = None
if isinstance(new_token, int): if isinstance(new_token, int):
@ -402,10 +409,17 @@ class Notifier:
new_token: Union[int, RoomStreamToken], new_token: Union[int, RoomStreamToken],
users: Optional[Collection[Union[str, UserID]]] = None, users: Optional[Collection[Union[str, UserID]]] = None,
rooms: Optional[Collection[str]] = None, rooms: Optional[Collection[str]] = None,
): ) -> None:
"""Used to inform listeners that something has happened event wise. """Used to inform listeners that something has happened event wise.
Will wake up all listeners for the given users and rooms. Will wake up all listeners for the given users and rooms.
Args:
stream_key: The stream the event came from.
new_token: The value of the new stream token.
users: The users that should be informed of the new event.
rooms: A collection of room IDs for which each joined member will be
informed of the new event.
""" """
users = users or [] users = users or []
rooms = rooms or [] rooms = rooms or []