Federation API for Space summary (#9652)

Builds on the work done in #9643 to add a federation API for space summaries.

There's a bit of refactoring of the existing client-server code first, to avoid too much duplication.
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Richard van der Hoff 2021-03-23 11:51:12 +00:00 committed by GitHub
parent b7748d3c00
commit 4ecba9bd5c
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3 changed files with 200 additions and 57 deletions

1
changelog.d/9652.feature Normal file
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@ -0,0 +1 @@
Add initial experimental support for a "space summary" API.

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@ -18,7 +18,7 @@
import functools
import logging
import re
from typing import Optional, Tuple, Type
from typing import Container, Mapping, Optional, Sequence, Tuple, Type
import synapse
from synapse.api.constants import MAX_GROUP_CATEGORYID_LENGTH, MAX_GROUP_ROLEID_LENGTH
@ -29,7 +29,7 @@ from synapse.api.urls import (
FEDERATION_V1_PREFIX,
FEDERATION_V2_PREFIX,
)
from synapse.http.server import JsonResource
from synapse.http.server import HttpServer, JsonResource
from synapse.http.servlet import (
parse_boolean_from_args,
parse_integer_from_args,
@ -44,7 +44,8 @@ from synapse.logging.opentracing import (
whitelisted_homeserver,
)
from synapse.server import HomeServer
from synapse.types import ThirdPartyInstanceID, get_domain_from_id
from synapse.types import JsonDict, ThirdPartyInstanceID, get_domain_from_id
from synapse.util.ratelimitutils import FederationRateLimiter
from synapse.util.stringutils import parse_and_validate_server_name
from synapse.util.versionstring import get_version_string
@ -1376,6 +1377,40 @@ class FederationGroupsSettingJoinPolicyServlet(BaseFederationServlet):
return 200, new_content
class FederationSpaceSummaryServlet(BaseFederationServlet):
PREFIX = FEDERATION_UNSTABLE_PREFIX + "/org.matrix.msc2946"
PATH = "/spaces/(?P<room_id>[^/]*)"
async def on_POST(
self,
origin: str,
content: JsonDict,
query: Mapping[bytes, Sequence[bytes]],
room_id: str,
) -> Tuple[int, JsonDict]:
suggested_only = content.get("suggested_only", False)
if not isinstance(suggested_only, bool):
raise SynapseError(
400, "'suggested_only' must be a boolean", Codes.BAD_JSON
)
exclude_rooms = content.get("exclude_rooms", [])
if not isinstance(exclude_rooms, list) or any(
not isinstance(x, str) for x in exclude_rooms
):
raise SynapseError(400, "bad value for 'exclude_rooms'", Codes.BAD_JSON)
max_rooms_per_space = content.get("max_rooms_per_space")
if max_rooms_per_space is not None and not isinstance(max_rooms_per_space, int):
raise SynapseError(
400, "bad value for 'max_rooms_per_space'", Codes.BAD_JSON
)
return 200, await self.handler.federation_space_summary(
room_id, suggested_only, max_rooms_per_space, exclude_rooms
)
class RoomComplexityServlet(BaseFederationServlet):
"""
Indicates to other servers how complex (and therefore likely
@ -1474,18 +1509,24 @@ DEFAULT_SERVLET_GROUPS = (
)
def register_servlets(hs, resource, authenticator, ratelimiter, servlet_groups=None):
def register_servlets(
hs: HomeServer,
resource: HttpServer,
authenticator: Authenticator,
ratelimiter: FederationRateLimiter,
servlet_groups: Optional[Container[str]] = None,
):
"""Initialize and register servlet classes.
Will by default register all servlets. For custom behaviour, pass in
a list of servlet_groups to register.
Args:
hs (synapse.server.HomeServer): homeserver
resource (JsonResource): resource class to register to
authenticator (Authenticator): authenticator to use
ratelimiter (util.ratelimitutils.FederationRateLimiter): ratelimiter to use
servlet_groups (list[str], optional): List of servlet groups to register.
hs: homeserver
resource: resource class to register to
authenticator: authenticator to use
ratelimiter: ratelimiter to use
servlet_groups: List of servlet groups to register.
Defaults to ``DEFAULT_SERVLET_GROUPS``.
"""
if not servlet_groups:
@ -1500,6 +1541,14 @@ def register_servlets(hs, resource, authenticator, ratelimiter, servlet_groups=N
server_name=hs.hostname,
).register(resource)
if hs.config.experimental.spaces_enabled:
FederationSpaceSummaryServlet(
handler=hs.get_space_summary_handler(),
authenticator=authenticator,
ratelimiter=ratelimiter,
server_name=hs.hostname,
).register(resource)
if "openid" in servlet_groups:
for servletclass in OPENID_SERVLET_CLASSES:
servletclass(

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@ -16,7 +16,9 @@
import itertools
import logging
from collections import deque
from typing import TYPE_CHECKING, Iterable, List, Optional, Set
from typing import TYPE_CHECKING, Iterable, List, Optional, Sequence, Set, Tuple
import attr
from synapse.api.constants import EventContentFields, EventTypes, HistoryVisibility
from synapse.api.errors import AuthError
@ -54,7 +56,7 @@ class SpaceSummaryHandler:
max_rooms_per_space: Optional[int] = None,
) -> JsonDict:
"""
Implementation of the space summary API
Implementation of the space summary C-S API
Args:
requester: user id of the user making this request
@ -66,7 +68,7 @@ class SpaceSummaryHandler:
max_rooms_per_space: an optional limit on the number of child rooms we will
return. This does not apply to the root room (ie, room_id), and
is overridden by ROOMS_PER_SPACE_LIMIT.
is overridden by MAX_ROOMS_PER_SPACE.
Returns:
summary dict to return
@ -76,68 +78,154 @@ class SpaceSummaryHandler:
await self._auth.check_user_in_room_or_world_readable(room_id, requester)
# the queue of rooms to process
room_queue = deque((room_id,))
room_queue = deque((_RoomQueueEntry(room_id),))
processed_rooms = set() # type: Set[str]
rooms_result = [] # type: List[JsonDict]
events_result = [] # type: List[JsonDict]
now = self._clock.time_msec()
while room_queue and len(rooms_result) < MAX_ROOMS:
queue_entry = room_queue.popleft()
room_id = queue_entry.room_id
logger.debug("Processing room %s", room_id)
processed_rooms.add(room_id)
# The client-specified max_rooms_per_space limit doesn't apply to the
# room_id specified in the request, so we ignore it if this is the
# first room we are processing.
max_children = max_rooms_per_space if processed_rooms else None
rooms, events = await self._summarize_local_room(
requester, room_id, suggested_only, max_children
)
rooms_result.extend(rooms)
events_result.extend(events)
# add any children that we haven't already processed to the queue
for edge_event in events:
if edge_event["state_key"] not in processed_rooms:
room_queue.append(_RoomQueueEntry(edge_event["state_key"]))
return {"rooms": rooms_result, "events": events_result}
async def federation_space_summary(
self,
room_id: str,
suggested_only: bool,
max_rooms_per_space: Optional[int],
exclude_rooms: Iterable[str],
) -> JsonDict:
"""
Implementation of the space summary Federation API
Args:
room_id: room id to start the summary at
suggested_only: whether we should only return children with the "suggested"
flag set.
max_rooms_per_space: an optional limit on the number of child rooms we will
return. Unlike the C-S API, this applies to the root room (room_id).
It is clipped to MAX_ROOMS_PER_SPACE.
exclude_rooms: a list of rooms to skip over (presumably because the
calling server has already seen them).
Returns:
summary dict to return
"""
# the queue of rooms to process
room_queue = deque((room_id,))
# the set of rooms that we should not walk further. Initialise it with the
# excluded-rooms list; we will add other rooms as we process them so that
# we do not loop.
processed_rooms = set(exclude_rooms) # type: Set[str]
rooms_result = [] # type: List[JsonDict]
events_result = [] # type: List[JsonDict]
while room_queue and len(rooms_result) < MAX_ROOMS:
room_id = room_queue.popleft()
logger.debug("Processing room %s", room_id)
processed_rooms.add(room_id)
try:
await self._auth.check_user_in_room_or_world_readable(
room_id, requester
)
except AuthError:
logger.info(
"user %s cannot view room %s, omitting from summary",
requester,
room_id,
)
continue
rooms, events = await self._summarize_local_room(
None, room_id, suggested_only, max_rooms_per_space
)
room_entry = await self._build_room_entry(room_id)
rooms_result.append(room_entry)
rooms_result.extend(rooms)
events_result.extend(events)
# look for child rooms/spaces.
child_events = await self._get_child_events(room_id)
if suggested_only:
# we only care about suggested children
child_events = filter(_is_suggested_child_event, child_events)
# The client-specified max_rooms_per_space limit doesn't apply to the
# room_id specified in the request, so we ignore it if this is the
# first room we are processing. Otherwise, apply any client-specified
# limit, capping to our built-in limit.
if max_rooms_per_space is not None and len(processed_rooms) > 1:
max_rooms = min(MAX_ROOMS_PER_SPACE, max_rooms_per_space)
else:
max_rooms = MAX_ROOMS_PER_SPACE
for edge_event in itertools.islice(child_events, max_rooms):
edge_room_id = edge_event.state_key
events_result.append(
await self._event_serializer.serialize_event(
edge_event,
time_now=now,
event_format=format_event_for_client_v2,
)
)
# if we haven't yet visited the target of this link, add it to the queue
if edge_room_id not in processed_rooms:
room_queue.append(edge_room_id)
# add any children that we haven't already processed to the queue
for edge_event in events:
if edge_event["state_key"] not in processed_rooms:
room_queue.append(edge_event["state_key"])
return {"rooms": rooms_result, "events": events_result}
async def _summarize_local_room(
self,
requester: Optional[str],
room_id: str,
suggested_only: bool,
max_children: Optional[int],
) -> Tuple[Sequence[JsonDict], Sequence[JsonDict]]:
if not await self._is_room_accessible(room_id, requester):
return (), ()
room_entry = await self._build_room_entry(room_id)
# look for child rooms/spaces.
child_events = await self._get_child_events(room_id)
if suggested_only:
# we only care about suggested children
child_events = filter(_is_suggested_child_event, child_events)
if max_children is None or max_children > MAX_ROOMS_PER_SPACE:
max_children = MAX_ROOMS_PER_SPACE
now = self._clock.time_msec()
events_result = [] # type: List[JsonDict]
for edge_event in itertools.islice(child_events, max_children):
events_result.append(
await self._event_serializer.serialize_event(
edge_event,
time_now=now,
event_format=format_event_for_client_v2,
)
)
return (room_entry,), events_result
async def _is_room_accessible(self, room_id: str, requester: Optional[str]) -> bool:
# if we have an authenticated requesting user, first check if they are in the
# room
if requester:
try:
await self._auth.check_user_in_room(room_id, requester)
return True
except AuthError:
pass
# otherwise, check if the room is peekable
hist_vis_ev = await self._state_handler.get_current_state(
room_id, EventTypes.RoomHistoryVisibility, ""
)
if hist_vis_ev:
hist_vis = hist_vis_ev.content.get("history_visibility")
if hist_vis == HistoryVisibility.WORLD_READABLE:
return True
logger.info(
"room %s is unpeekable and user %s is not a member, omitting from summary",
room_id,
requester,
)
return False
async def _build_room_entry(self, room_id: str) -> JsonDict:
"""Generate en entry suitable for the 'rooms' list in the summary response"""
stats = await self._store.get_room_with_stats(room_id)
@ -191,6 +279,11 @@ class SpaceSummaryHandler:
return (e for e in events if e.content.get("via"))
@attr.s(frozen=True, slots=True)
class _RoomQueueEntry:
room_id = attr.ib(type=str)
def _is_suggested_child_event(edge_event: EventBase) -> bool:
suggested = edge_event.content.get("suggested")
if isinstance(suggested, bool) and suggested: