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dendrite/syncapi/streams/stream_pdu.go
Till 0f777d421c
Remove empty fields from /sync response (#2755)
First attempt at removing empty fields from `/sync` responses. Needs
https://github.com/matrix-org/sytest/pull/1298 to keep Sytest happy.

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
2022-10-05 13:47:13 +01:00

632 lines
22 KiB
Go

package streams
import (
"context"
"database/sql"
"fmt"
"sort"
"time"
"github.com/matrix-org/dendrite/internal/caching"
roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/syncapi/internal"
"github.com/matrix-org/dendrite/syncapi/storage"
"github.com/matrix-org/dendrite/syncapi/types"
userapi "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/sirupsen/logrus"
"github.com/tidwall/gjson"
"github.com/matrix-org/dendrite/syncapi/notifier"
)
// The max number of per-room goroutines to have running.
// Too high and this will consume lots of CPU, too low and complete
// sync responses will take longer to process.
const PDU_STREAM_WORKERS = 256
// The maximum number of tasks that can be queued in total before
// backpressure will build up and the rests will start to block.
const PDU_STREAM_QUEUESIZE = PDU_STREAM_WORKERS * 8
type PDUStreamProvider struct {
DefaultStreamProvider
// userID+deviceID -> lazy loading cache
lazyLoadCache caching.LazyLoadCache
rsAPI roomserverAPI.SyncRoomserverAPI
notifier *notifier.Notifier
}
func (p *PDUStreamProvider) Setup(
ctx context.Context, snapshot storage.DatabaseTransaction,
) {
p.DefaultStreamProvider.Setup(ctx, snapshot)
p.latestMutex.Lock()
defer p.latestMutex.Unlock()
id, err := snapshot.MaxStreamPositionForPDUs(ctx)
if err != nil {
panic(err)
}
p.latest = id
}
func (p *PDUStreamProvider) CompleteSync(
ctx context.Context,
snapshot storage.DatabaseTransaction,
req *types.SyncRequest,
) types.StreamPosition {
from := types.StreamPosition(0)
to := p.LatestPosition(ctx)
// Get the current sync position which we will base the sync response on.
// For complete syncs, we want to start at the most recent events and work
// backwards, so that we show the most recent events in the room.
r := types.Range{
From: to,
To: 0,
Backwards: true,
}
// Extract room state and recent events for all rooms the user is joined to.
joinedRoomIDs, err := snapshot.RoomIDsWithMembership(ctx, req.Device.UserID, gomatrixserverlib.Join)
if err != nil {
req.Log.WithError(err).Error("p.DB.RoomIDsWithMembership failed")
return from
}
stateFilter := req.Filter.Room.State
eventFilter := req.Filter.Room.Timeline
if err = p.addIgnoredUsersToFilter(ctx, snapshot, req, &eventFilter); err != nil {
req.Log.WithError(err).Error("unable to update event filter with ignored users")
}
// Invalidate the lazyLoadCache, otherwise we end up with missing displaynames/avatars
// TODO: This might be inefficient, when joined to many and/or large rooms.
for _, roomID := range joinedRoomIDs {
joinedUsers := p.notifier.JoinedUsers(roomID)
for _, sharedUser := range joinedUsers {
p.lazyLoadCache.InvalidateLazyLoadedUser(req.Device, roomID, sharedUser)
}
}
// Build up a /sync response. Add joined rooms.
for _, roomID := range joinedRoomIDs {
jr, jerr := p.getJoinResponseForCompleteSync(
ctx, snapshot, roomID, r, &stateFilter, &eventFilter, req.WantFullState, req.Device, false,
)
if jerr != nil {
req.Log.WithError(jerr).Error("p.getJoinResponseForCompleteSync failed")
if err == context.DeadlineExceeded || err == context.Canceled || err == sql.ErrTxDone {
return from
}
continue
}
req.Response.Rooms.Join[roomID] = jr
req.Rooms[roomID] = gomatrixserverlib.Join
}
// Add peeked rooms.
peeks, err := snapshot.PeeksInRange(ctx, req.Device.UserID, req.Device.ID, r)
if err != nil {
req.Log.WithError(err).Error("p.DB.PeeksInRange failed")
return from
}
for _, peek := range peeks {
if !peek.Deleted {
var jr *types.JoinResponse
jr, err = p.getJoinResponseForCompleteSync(
ctx, snapshot, peek.RoomID, r, &stateFilter, &eventFilter, req.WantFullState, req.Device, true,
)
if err != nil {
req.Log.WithError(err).Error("p.getJoinResponseForCompleteSync failed")
if err == context.DeadlineExceeded || err == context.Canceled || err == sql.ErrTxDone {
return from
}
continue
}
req.Response.Rooms.Peek[peek.RoomID] = jr
}
}
return to
}
func (p *PDUStreamProvider) IncrementalSync(
ctx context.Context,
snapshot storage.DatabaseTransaction,
req *types.SyncRequest,
from, to types.StreamPosition,
) (newPos types.StreamPosition) {
r := types.Range{
From: from,
To: to,
Backwards: from > to,
}
var err error
var stateDeltas []types.StateDelta
var syncJoinedRooms []string
stateFilter := req.Filter.Room.State
eventFilter := req.Filter.Room.Timeline
if req.WantFullState {
if stateDeltas, syncJoinedRooms, err = snapshot.GetStateDeltasForFullStateSync(ctx, req.Device, r, req.Device.UserID, &stateFilter); err != nil {
req.Log.WithError(err).Error("p.DB.GetStateDeltasForFullStateSync failed")
return from
}
} else {
if stateDeltas, syncJoinedRooms, err = snapshot.GetStateDeltas(ctx, req.Device, r, req.Device.UserID, &stateFilter); err != nil {
req.Log.WithError(err).Error("p.DB.GetStateDeltas failed")
return from
}
}
for _, roomID := range syncJoinedRooms {
req.Rooms[roomID] = gomatrixserverlib.Join
}
if len(stateDeltas) == 0 {
return to
}
if err = p.addIgnoredUsersToFilter(ctx, snapshot, req, &eventFilter); err != nil {
req.Log.WithError(err).Error("unable to update event filter with ignored users")
}
newPos = from
for _, delta := range stateDeltas {
newRange := r
// If this room was joined in this sync, try to fetch
// as much timeline events as allowed by the filter.
if delta.NewlyJoined {
// Reverse the range, so we get the most recent first.
// This will be limited by the eventFilter.
newRange = types.Range{
From: r.To,
To: 0,
Backwards: true,
}
}
var pos types.StreamPosition
if pos, err = p.addRoomDeltaToResponse(ctx, snapshot, req.Device, newRange, delta, &eventFilter, &stateFilter, req.Response); err != nil {
req.Log.WithError(err).Error("d.addRoomDeltaToResponse failed")
if err == context.DeadlineExceeded || err == context.Canceled || err == sql.ErrTxDone {
return newPos
}
continue
}
// Reset the position, as it is only for the special case of newly joined rooms
if delta.NewlyJoined {
pos = newRange.From
}
switch {
case r.Backwards && pos < newPos:
fallthrough
case !r.Backwards && pos > newPos:
newPos = pos
}
}
return newPos
}
// nolint:gocyclo
func (p *PDUStreamProvider) addRoomDeltaToResponse(
ctx context.Context,
snapshot storage.DatabaseTransaction,
device *userapi.Device,
r types.Range,
delta types.StateDelta,
eventFilter *gomatrixserverlib.RoomEventFilter,
stateFilter *gomatrixserverlib.StateFilter,
res *types.Response,
) (types.StreamPosition, error) {
if delta.MembershipPos > 0 && delta.Membership == gomatrixserverlib.Leave {
// make sure we don't leak recent events after the leave event.
// TODO: History visibility makes this somewhat complex to handle correctly. For example:
// TODO: This doesn't work for join -> leave in a single /sync request (see events prior to join).
// TODO: This will fail on join -> leave -> sensitive msg -> join -> leave
// in a single /sync request
// This is all "okay" assuming history_visibility == "shared" which it is by default.
r.To = delta.MembershipPos
}
recentStreamEvents, limited, err := snapshot.RecentEvents(
ctx, delta.RoomID, r,
eventFilter, true, true,
)
if err != nil {
if err == sql.ErrNoRows {
return r.To, nil
}
return r.From, fmt.Errorf("p.DB.RecentEvents: %w", err)
}
recentEvents := snapshot.StreamEventsToEvents(device, recentStreamEvents)
delta.StateEvents = removeDuplicates(delta.StateEvents, recentEvents) // roll back
prevBatch, err := snapshot.GetBackwardTopologyPos(ctx, recentStreamEvents)
if err != nil {
return r.From, fmt.Errorf("p.DB.GetBackwardTopologyPos: %w", err)
}
// If we didn't return any events at all then don't bother doing anything else.
if len(recentEvents) == 0 && len(delta.StateEvents) == 0 {
return r.To, nil
}
// Sort the events so that we can pick out the latest events from both sections.
recentEvents = gomatrixserverlib.HeaderedReverseTopologicalOrdering(recentEvents, gomatrixserverlib.TopologicalOrderByPrevEvents)
delta.StateEvents = gomatrixserverlib.HeaderedReverseTopologicalOrdering(delta.StateEvents, gomatrixserverlib.TopologicalOrderByAuthEvents)
// Work out what the highest stream position is for all of the events in this
// room that were returned.
latestPosition := r.To
updateLatestPosition := func(mostRecentEventID string) {
var pos types.StreamPosition
if _, pos, err = snapshot.PositionInTopology(ctx, mostRecentEventID); err == nil {
switch {
case r.Backwards && pos < latestPosition:
fallthrough
case !r.Backwards && pos > latestPosition:
latestPosition = pos
}
}
}
if stateFilter.LazyLoadMembers {
delta.StateEvents, err = p.lazyLoadMembers(
ctx, snapshot, delta.RoomID, true, limited, stateFilter,
device, recentEvents, delta.StateEvents,
)
if err != nil && err != sql.ErrNoRows {
return r.From, fmt.Errorf("p.lazyLoadMembers: %w", err)
}
}
hasMembershipChange := false
for _, recentEvent := range recentStreamEvents {
if recentEvent.Type() == gomatrixserverlib.MRoomMember && recentEvent.StateKey() != nil {
hasMembershipChange = true
break
}
}
// Applies the history visibility rules
events, err := applyHistoryVisibilityFilter(ctx, snapshot, p.rsAPI, delta.RoomID, device.UserID, eventFilter.Limit, recentEvents)
if err != nil {
logrus.WithError(err).Error("unable to apply history visibility filter")
}
if len(delta.StateEvents) > 0 {
updateLatestPosition(delta.StateEvents[len(delta.StateEvents)-1].EventID())
}
if len(events) > 0 {
updateLatestPosition(events[len(events)-1].EventID())
}
switch delta.Membership {
case gomatrixserverlib.Join:
jr := types.NewJoinResponse()
if hasMembershipChange {
p.addRoomSummary(ctx, snapshot, jr, delta.RoomID, device.UserID, latestPosition)
}
jr.Timeline.PrevBatch = &prevBatch
jr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(events, gomatrixserverlib.FormatSync)
// If we are limited by the filter AND the history visibility filter
// didn't "remove" events, return that the response is limited.
jr.Timeline.Limited = limited && len(events) == len(recentEvents)
jr.State.Events = gomatrixserverlib.HeaderedToClientEvents(delta.StateEvents, gomatrixserverlib.FormatSync)
res.Rooms.Join[delta.RoomID] = jr
case gomatrixserverlib.Peek:
jr := types.NewJoinResponse()
jr.Timeline.PrevBatch = &prevBatch
// TODO: Apply history visibility on peeked rooms
jr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(recentEvents, gomatrixserverlib.FormatSync)
jr.Timeline.Limited = limited
jr.State.Events = gomatrixserverlib.HeaderedToClientEvents(delta.StateEvents, gomatrixserverlib.FormatSync)
res.Rooms.Peek[delta.RoomID] = jr
case gomatrixserverlib.Leave:
fallthrough // transitions to leave are the same as ban
case gomatrixserverlib.Ban:
lr := types.NewLeaveResponse()
lr.Timeline.PrevBatch = &prevBatch
lr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(events, gomatrixserverlib.FormatSync)
// If we are limited by the filter AND the history visibility filter
// didn't "remove" events, return that the response is limited.
lr.Timeline.Limited = limited && len(events) == len(recentEvents)
lr.State.Events = gomatrixserverlib.HeaderedToClientEvents(delta.StateEvents, gomatrixserverlib.FormatSync)
res.Rooms.Leave[delta.RoomID] = lr
}
return latestPosition, nil
}
// applyHistoryVisibilityFilter gets the current room state and supplies it to ApplyHistoryVisibilityFilter, to make
// sure we always return the required events in the timeline.
func applyHistoryVisibilityFilter(
ctx context.Context,
snapshot storage.DatabaseTransaction,
rsAPI roomserverAPI.SyncRoomserverAPI,
roomID, userID string,
limit int,
recentEvents []*gomatrixserverlib.HeaderedEvent,
) ([]*gomatrixserverlib.HeaderedEvent, error) {
// We need to make sure we always include the latest states events, if they are in the timeline.
// We grep at least limit * 2 events, to ensure we really get the needed events.
stateEvents, err := snapshot.CurrentState(ctx, roomID, &gomatrixserverlib.StateFilter{Limit: limit * 2}, nil)
if err != nil {
// Not a fatal error, we can continue without the stateEvents,
// they are only needed if there are state events in the timeline.
logrus.WithError(err).Warnf("Failed to get current room state for history visibility")
}
alwaysIncludeIDs := make(map[string]struct{}, len(stateEvents))
for _, ev := range stateEvents {
alwaysIncludeIDs[ev.EventID()] = struct{}{}
}
startTime := time.Now()
events, err := internal.ApplyHistoryVisibilityFilter(ctx, snapshot, rsAPI, recentEvents, alwaysIncludeIDs, userID, "sync")
if err != nil {
return nil, err
}
logrus.WithFields(logrus.Fields{
"duration": time.Since(startTime),
"room_id": roomID,
"before": len(recentEvents),
"after": len(events),
}).Trace("Applied history visibility (sync)")
return events, nil
}
func (p *PDUStreamProvider) addRoomSummary(ctx context.Context, snapshot storage.DatabaseTransaction, jr *types.JoinResponse, roomID, userID string, latestPosition types.StreamPosition) {
// Work out how many members are in the room.
joinedCount, _ := snapshot.MembershipCount(ctx, roomID, gomatrixserverlib.Join, latestPosition)
invitedCount, _ := snapshot.MembershipCount(ctx, roomID, gomatrixserverlib.Invite, latestPosition)
jr.Summary.JoinedMemberCount = &joinedCount
jr.Summary.InvitedMemberCount = &invitedCount
fetchStates := []gomatrixserverlib.StateKeyTuple{
{EventType: gomatrixserverlib.MRoomName},
{EventType: gomatrixserverlib.MRoomCanonicalAlias},
}
// Check if the room has a name or a canonical alias
latestState := &roomserverAPI.QueryLatestEventsAndStateResponse{}
err := p.rsAPI.QueryLatestEventsAndState(ctx, &roomserverAPI.QueryLatestEventsAndStateRequest{StateToFetch: fetchStates, RoomID: roomID}, latestState)
if err != nil {
return
}
// Check if the room has a name or canonical alias, if so, return.
for _, ev := range latestState.StateEvents {
switch ev.Type() {
case gomatrixserverlib.MRoomName:
if gjson.GetBytes(ev.Content(), "name").Str != "" {
return
}
case gomatrixserverlib.MRoomCanonicalAlias:
if gjson.GetBytes(ev.Content(), "alias").Str != "" {
return
}
}
}
heroes, err := snapshot.GetRoomHeroes(ctx, roomID, userID, []string{"join", "invite"})
if err != nil {
return
}
sort.Strings(heroes)
jr.Summary.Heroes = heroes
}
func (p *PDUStreamProvider) getJoinResponseForCompleteSync(
ctx context.Context,
snapshot storage.DatabaseTransaction,
roomID string,
r types.Range,
stateFilter *gomatrixserverlib.StateFilter,
eventFilter *gomatrixserverlib.RoomEventFilter,
wantFullState bool,
device *userapi.Device,
isPeek bool,
) (jr *types.JoinResponse, err error) {
jr = types.NewJoinResponse()
// TODO: When filters are added, we may need to call this multiple times to get enough events.
// See: https://github.com/matrix-org/synapse/blob/v0.19.3/synapse/handlers/sync.py#L316
recentStreamEvents, limited, err := snapshot.RecentEvents(
ctx, roomID, r, eventFilter, true, true,
)
if err != nil {
if err == sql.ErrNoRows {
return jr, nil
}
return
}
// Work our way through the timeline events and pick out the event IDs
// of any state events that appear in the timeline. We'll specifically
// exclude them at the next step, so that we don't get duplicate state
// events in both `recentStreamEvents` and `stateEvents`.
var excludingEventIDs []string
if !wantFullState {
excludingEventIDs = make([]string, 0, len(recentStreamEvents))
for _, event := range recentStreamEvents {
if event.StateKey() != nil {
excludingEventIDs = append(excludingEventIDs, event.EventID())
}
}
}
stateEvents, err := snapshot.CurrentState(ctx, roomID, stateFilter, excludingEventIDs)
if err != nil {
return
}
// Retrieve the backward topology position, i.e. the position of the
// oldest event in the room's topology.
var prevBatch *types.TopologyToken
if len(recentStreamEvents) > 0 {
var backwardTopologyPos, backwardStreamPos types.StreamPosition
backwardTopologyPos, backwardStreamPos, err = snapshot.PositionInTopology(ctx, recentStreamEvents[0].EventID())
if err != nil {
return
}
prevBatch = &types.TopologyToken{
Depth: backwardTopologyPos,
PDUPosition: backwardStreamPos,
}
prevBatch.Decrement()
}
p.addRoomSummary(ctx, snapshot, jr, roomID, device.UserID, r.From)
// We don't include a device here as we don't need to send down
// transaction IDs for complete syncs, but we do it anyway because Sytest demands it for:
// "Can sync a room with a message with a transaction id" - which does a complete sync to check.
recentEvents := snapshot.StreamEventsToEvents(device, recentStreamEvents)
stateEvents = removeDuplicates(stateEvents, recentEvents)
events := recentEvents
// Only apply history visibility checks if the response is for joined rooms
if !isPeek {
events, err = applyHistoryVisibilityFilter(ctx, snapshot, p.rsAPI, roomID, device.UserID, eventFilter.Limit, recentEvents)
if err != nil {
logrus.WithError(err).Error("unable to apply history visibility filter")
}
}
// If we are limited by the filter AND the history visibility filter
// didn't "remove" events, return that the response is limited.
limited = limited && len(events) == len(recentEvents)
if stateFilter.LazyLoadMembers {
if err != nil {
return nil, err
}
stateEvents, err = p.lazyLoadMembers(
ctx, snapshot, roomID,
false, limited, stateFilter,
device, recentEvents, stateEvents,
)
if err != nil && err != sql.ErrNoRows {
return nil, err
}
}
jr.Timeline.PrevBatch = prevBatch
jr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(events, gomatrixserverlib.FormatSync)
// If we are limited by the filter AND the history visibility filter
// didn't "remove" events, return that the response is limited.
jr.Timeline.Limited = limited && len(events) == len(recentEvents)
jr.State.Events = gomatrixserverlib.HeaderedToClientEvents(stateEvents, gomatrixserverlib.FormatSync)
return jr, nil
}
func (p *PDUStreamProvider) lazyLoadMembers(
ctx context.Context, snapshot storage.DatabaseTransaction, roomID string,
incremental, limited bool, stateFilter *gomatrixserverlib.StateFilter,
device *userapi.Device,
timelineEvents, stateEvents []*gomatrixserverlib.HeaderedEvent,
) ([]*gomatrixserverlib.HeaderedEvent, error) {
if len(timelineEvents) == 0 {
return stateEvents, nil
}
// Work out which memberships to include
timelineUsers := make(map[string]struct{})
if !incremental {
timelineUsers[device.UserID] = struct{}{}
}
// Add all users the client doesn't know about yet to a list
for _, event := range timelineEvents {
// Membership is not yet cached, add it to the list
if _, ok := p.lazyLoadCache.IsLazyLoadedUserCached(device, roomID, event.Sender()); !ok {
timelineUsers[event.Sender()] = struct{}{}
}
}
// Preallocate with the same amount, even if it will end up with fewer values
newStateEvents := make([]*gomatrixserverlib.HeaderedEvent, 0, len(stateEvents))
// Remove existing membership events we don't care about, e.g. users not in the timeline.events
for _, event := range stateEvents {
if event.Type() == gomatrixserverlib.MRoomMember && event.StateKey() != nil {
// If this is a gapped incremental sync, we still want this membership
isGappedIncremental := limited && incremental
// We want this users membership event, keep it in the list
stateKey := *event.StateKey()
if _, ok := timelineUsers[stateKey]; ok || isGappedIncremental {
newStateEvents = append(newStateEvents, event)
if !stateFilter.IncludeRedundantMembers {
p.lazyLoadCache.StoreLazyLoadedUser(device, roomID, stateKey, event.EventID())
}
delete(timelineUsers, stateKey)
}
} else {
newStateEvents = append(newStateEvents, event)
}
}
wantUsers := make([]string, 0, len(timelineUsers))
for userID := range timelineUsers {
wantUsers = append(wantUsers, userID)
}
// Query missing membership events
filter := gomatrixserverlib.DefaultStateFilter()
filter.Limit = stateFilter.Limit
filter.Senders = &wantUsers
filter.Types = &[]string{gomatrixserverlib.MRoomMember}
memberships, err := snapshot.GetStateEventsForRoom(ctx, roomID, &filter)
if err != nil {
return stateEvents, err
}
// cache the membership events
for _, membership := range memberships {
p.lazyLoadCache.StoreLazyLoadedUser(device, roomID, *membership.StateKey(), membership.EventID())
}
stateEvents = append(newStateEvents, memberships...)
return stateEvents, nil
}
// addIgnoredUsersToFilter adds ignored users to the eventfilter and
// the syncreq itself for further use in streams.
func (p *PDUStreamProvider) addIgnoredUsersToFilter(ctx context.Context, snapshot storage.DatabaseTransaction, req *types.SyncRequest, eventFilter *gomatrixserverlib.RoomEventFilter) error {
ignores, err := snapshot.IgnoresForUser(ctx, req.Device.UserID)
if err != nil {
if err == sql.ErrNoRows {
return nil
}
return err
}
req.IgnoredUsers = *ignores
userList := make([]string, 0, len(ignores.List))
for userID := range ignores.List {
userList = append(userList, userID)
}
if len(userList) > 0 {
eventFilter.NotSenders = &userList
}
return nil
}
func removeDuplicates(stateEvents, recentEvents []*gomatrixserverlib.HeaderedEvent) []*gomatrixserverlib.HeaderedEvent {
for _, recentEv := range recentEvents {
if recentEv.StateKey() == nil {
continue // not a state event
}
// TODO: This is a linear scan over all the current state events in this room. This will
// be slow for big rooms. We should instead sort the state events by event ID (ORDER BY)
// then do a binary search to find matching events, similar to what roomserver does.
for j := 0; j < len(stateEvents); j++ {
if stateEvents[j].EventID() == recentEv.EventID() {
// overwrite the element to remove with the last element then pop the last element.
// This is orders of magnitude faster than re-slicing, but doesn't preserve ordering
// (we don't care about the order of stateEvents)
stateEvents[j] = stateEvents[len(stateEvents)-1]
stateEvents = stateEvents[:len(stateEvents)-1]
break // there shouldn't be multiple events with the same event ID
}
}
}
return stateEvents
}