dendrite/setup/mscs/msc2946/msc2946.go

374 lines
11 KiB
Go

// Copyright 2021 The Matrix.org Foundation C.I.C.
//
// 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.
// Package msc2946 'Spaces Summary' implements https://github.com/matrix-org/matrix-doc/pull/2946
package msc2946
import (
"context"
"fmt"
"net/http"
"sync"
"github.com/gorilla/mux"
chttputil "github.com/matrix-org/dendrite/clientapi/httputil"
"github.com/matrix-org/dendrite/internal/hooks"
"github.com/matrix-org/dendrite/internal/httputil"
roomserver "github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/setup"
userapi "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
"github.com/tidwall/gjson"
)
const (
ConstCreateEventContentKey = "org.matrix.msc1772.type"
ConstSpaceChildEventType = "org.matrix.msc1772.space.child"
ConstSpaceParentEventType = "org.matrix.msc1772.space.parent"
)
// SpacesRequest is the request body to POST /_matrix/client/r0/rooms/{roomID}/spaces
type SpacesRequest struct {
MaxRoomsPerSpace int `json:"max_rooms_per_space"`
Limit int `json:"limit"`
Batch string `json:"batch"`
}
// Defaults sets the request defaults
func (r *SpacesRequest) Defaults() {
r.Limit = 100
r.MaxRoomsPerSpace = -1
}
// SpacesResponse is the response body to POST /_matrix/client/r0/rooms/{roomID}/spaces
type SpacesResponse struct {
NextBatch string `json:"next_batch"`
// Rooms are nodes on the space graph.
Rooms []Room `json:"rooms"`
// Events are edges on the space graph, exclusively m.space.child or m.space.parent events
Events []gomatrixserverlib.ClientEvent `json:"events"`
}
// Room is a node on the space graph
type Room struct {
gomatrixserverlib.PublicRoom
NumRefs int `json:"num_refs"`
RoomType string `json:"room_type"`
}
// Enable this MSC
func Enable(
base *setup.BaseDendrite, rsAPI roomserver.RoomserverInternalAPI, userAPI userapi.UserInternalAPI,
) error {
db, err := NewDatabase(&base.Cfg.MSCs.Database)
if err != nil {
return fmt.Errorf("Cannot enable MSC2946: %w", err)
}
hooks.Enable()
hooks.Attach(hooks.KindNewEventPersisted, func(headeredEvent interface{}) {
he := headeredEvent.(*gomatrixserverlib.HeaderedEvent)
hookErr := db.StoreReference(context.Background(), he)
if hookErr != nil {
util.GetLogger(context.Background()).WithError(hookErr).WithField("event_id", he.EventID()).Error(
"failed to StoreReference",
)
}
})
base.PublicClientAPIMux.Handle("/unstable/rooms/{roomID}/spaces",
httputil.MakeAuthAPI("spaces", userAPI, spacesHandler(db, rsAPI)),
).Methods(http.MethodPost, http.MethodOptions)
return nil
}
func spacesHandler(db Database, rsAPI roomserver.RoomserverInternalAPI) func(*http.Request, *userapi.Device) util.JSONResponse {
return func(req *http.Request, device *userapi.Device) util.JSONResponse {
inMemoryBatchCache := make(map[string]set)
// Extract the room ID from the request. Sanity check request data.
params, err := httputil.URLDecodeMapValues(mux.Vars(req))
if err != nil {
return util.ErrorResponse(err)
}
roomID := params["roomID"]
var r SpacesRequest
r.Defaults()
if resErr := chttputil.UnmarshalJSONRequest(req, &r); resErr != nil {
return *resErr
}
if r.Limit > 100 {
r.Limit = 100
}
w := walker{
req: &r,
rootRoomID: roomID,
caller: device,
ctx: req.Context(),
db: db,
rsAPI: rsAPI,
inMemoryBatchCache: inMemoryBatchCache,
}
res := w.walk()
return util.JSONResponse{
Code: 200,
JSON: res,
}
}
}
type walker struct {
req *SpacesRequest
rootRoomID string
caller *userapi.Device
db Database
rsAPI roomserver.RoomserverInternalAPI
ctx context.Context
// user ID|device ID|batch_num => event/room IDs sent to client
inMemoryBatchCache map[string]set
mu sync.Mutex
}
func (w *walker) alreadySent(id string) bool {
w.mu.Lock()
defer w.mu.Unlock()
m, ok := w.inMemoryBatchCache[w.caller.UserID+"|"+w.caller.ID]
if !ok {
return false
}
return m[id]
}
func (w *walker) markSent(id string) {
w.mu.Lock()
defer w.mu.Unlock()
m := w.inMemoryBatchCache[w.caller.UserID+"|"+w.caller.ID]
if m == nil {
m = make(set)
}
m[id] = true
w.inMemoryBatchCache[w.caller.UserID+"|"+w.caller.ID] = m
}
// nolint:gocyclo
func (w *walker) walk() *SpacesResponse {
var res SpacesResponse
// Begin walking the graph starting with the room ID in the request in a queue of unvisited rooms
unvisited := []string{w.rootRoomID}
processed := make(set)
for len(unvisited) > 0 {
roomID := unvisited[0]
unvisited = unvisited[1:]
// If this room has already been processed, skip. NB: do not remember this between calls
if processed[roomID] || roomID == "" {
continue
}
// Mark this room as processed.
processed[roomID] = true
// Is the caller currently joined to the room or is the room `world_readable`
// If no, skip this room. If yes, continue.
if !w.authorised(roomID) {
continue
}
// Get all `m.space.child` and `m.space.parent` state events for the room. *In addition*, get
// all `m.space.child` and `m.space.parent` state events which *point to* (via `state_key` or `content.room_id`)
// this room. This requires servers to store reverse lookups.
refs, err := w.references(roomID)
if err != nil {
util.GetLogger(w.ctx).WithError(err).WithField("room_id", roomID).Error("failed to extract references for room")
continue
}
// If this room has not ever been in `rooms` (across multiple requests), extract the
// `PublicRoomsChunk` for this room.
if !w.alreadySent(roomID) {
pubRoom := w.publicRoomsChunk(roomID)
roomType := ""
create := w.stateEvent(roomID, gomatrixserverlib.MRoomCreate, "")
if create != nil {
roomType = gjson.GetBytes(create.Content(), ConstCreateEventContentKey).Str
}
// Add the total number of events to `PublicRoomsChunk` under `num_refs`. Add `PublicRoomsChunk` to `rooms`.
res.Rooms = append(res.Rooms, Room{
PublicRoom: *pubRoom,
NumRefs: refs.len(),
RoomType: roomType,
})
}
uniqueRooms := make(set)
// If this is the root room from the original request, insert all these events into `events` if
// they haven't been added before (across multiple requests).
if w.rootRoomID == roomID {
for _, ev := range refs.events() {
if !w.alreadySent(ev.EventID()) {
res.Events = append(res.Events, gomatrixserverlib.HeaderedToClientEvent(
ev, gomatrixserverlib.FormatAll,
))
uniqueRooms[ev.RoomID()] = true
uniqueRooms[SpaceTarget(ev)] = true
w.markSent(ev.EventID())
}
}
} else {
// Else add them to `events` honouring the `limit` and `max_rooms_per_space` values. If either
// are exceeded, stop adding events. If the event has already been added, do not add it again.
numAdded := 0
for _, ev := range refs.events() {
if w.req.Limit > 0 && len(res.Events) >= w.req.Limit {
break
}
if w.req.MaxRoomsPerSpace > 0 && numAdded >= w.req.MaxRoomsPerSpace {
break
}
if w.alreadySent(ev.EventID()) {
continue
}
res.Events = append(res.Events, gomatrixserverlib.HeaderedToClientEvent(
ev, gomatrixserverlib.FormatAll,
))
uniqueRooms[ev.RoomID()] = true
uniqueRooms[SpaceTarget(ev)] = true
w.markSent(ev.EventID())
// we don't distinguish between child state events and parent state events for the purposes of
// max_rooms_per_space, maybe we should?
numAdded++
}
}
// For each referenced room ID in the events being returned to the caller (both parent and child)
// add the room ID to the queue of unvisited rooms. Loop from the beginning.
for roomID := range uniqueRooms {
unvisited = append(unvisited, roomID)
}
}
return &res
}
func (w *walker) stateEvent(roomID, evType, stateKey string) *gomatrixserverlib.HeaderedEvent {
var queryRes roomserver.QueryCurrentStateResponse
tuple := gomatrixserverlib.StateKeyTuple{
EventType: evType,
StateKey: stateKey,
}
err := w.rsAPI.QueryCurrentState(w.ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID,
StateTuples: []gomatrixserverlib.StateKeyTuple{tuple},
}, &queryRes)
if err != nil {
return nil
}
return queryRes.StateEvents[tuple]
}
func (w *walker) publicRoomsChunk(roomID string) *gomatrixserverlib.PublicRoom {
pubRooms, err := roomserver.PopulatePublicRooms(w.ctx, []string{roomID}, w.rsAPI)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to PopulatePublicRooms")
return nil
}
if len(pubRooms) == 0 {
return nil
}
return &pubRooms[0]
}
// authorised returns true iff the user is joined this room or the room is world_readable
func (w *walker) authorised(roomID string) bool {
hisVisTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomHistoryVisibility,
StateKey: "",
}
roomMemberTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomMember,
StateKey: w.caller.UserID,
}
var queryRes roomserver.QueryCurrentStateResponse
err := w.rsAPI.QueryCurrentState(w.ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID,
StateTuples: []gomatrixserverlib.StateKeyTuple{
hisVisTuple, roomMemberTuple,
},
}, &queryRes)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to QueryCurrentState")
return false
}
memberEv := queryRes.StateEvents[roomMemberTuple]
hisVisEv := queryRes.StateEvents[hisVisTuple]
if memberEv != nil {
membership, _ := memberEv.Membership()
if membership == gomatrixserverlib.Join {
return true
}
}
if hisVisEv != nil {
hisVis, _ := hisVisEv.HistoryVisibility()
if hisVis == "world_readable" {
return true
}
}
return false
}
// references returns all references pointing to or from this room.
func (w *walker) references(roomID string) (eventLookup, error) {
events, err := w.db.References(w.ctx, roomID)
if err != nil {
return nil, err
}
el := make(eventLookup)
for _, ev := range events {
// only return events that have a `via` key as per MSC1772
// else we'll incorrectly walk redacted events (as the link
// is in the state_key)
if gjson.GetBytes(ev.Content(), "via").Exists() {
el.set(ev)
}
}
return el, nil
}
// state event lookup across multiple rooms keyed on event type
// NOT THREAD SAFE
type eventLookup map[string][]*gomatrixserverlib.HeaderedEvent
func (el eventLookup) set(ev *gomatrixserverlib.HeaderedEvent) {
evs := el[ev.Type()]
if evs == nil {
evs = make([]*gomatrixserverlib.HeaderedEvent, 0)
}
evs = append(evs, ev)
el[ev.Type()] = evs
}
func (el eventLookup) len() int {
sum := 0
for _, evs := range el {
sum += len(evs)
}
return sum
}
func (el eventLookup) events() (events []*gomatrixserverlib.HeaderedEvent) {
for _, evs := range el {
events = append(events, evs...)
}
return
}
type set map[string]bool