dendrite/syncapi/storage/shared/sync_pdu.go
Neil Alexander 0769412df5
Fix peeks
2021-07-27 13:42:14 +01:00

293 lines
10 KiB
Go

package shared
import (
"context"
"database/sql"
"fmt"
"github.com/matrix-org/dendrite/internal/sqlutil"
"github.com/matrix-org/dendrite/syncapi/types"
userapi "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib"
)
func (d *Database) PDUCompleteSync(
ctx context.Context,
req *types.SyncRequest,
joinedRoomIDs []string,
r types.Range,
stateFilter *gomatrixserverlib.StateFilter,
eventFilter *gomatrixserverlib.RoomEventFilter,
) error {
txn, err := d.readOnlySnapshot(ctx)
if err != nil {
return fmt.Errorf("d.readOnlySnapshot: %w", err)
}
var succeeded bool
defer sqlutil.EndTransactionWithCheck(txn, &succeeded, &err)
for _, roomID := range joinedRoomIDs {
var jr *types.JoinResponse
jr, err = d.getJoinResponseForCompleteSync(
ctx, txn, roomID, r, stateFilter, eventFilter, req.WantFullState, req.Device,
)
if err != nil {
return fmt.Errorf("d.getJoinResponseForCompleteSync: %w", err)
}
req.Response.Rooms.Join[roomID] = *jr
req.Rooms[roomID] = gomatrixserverlib.Join
}
peeks, err := d.Peeks.SelectPeeksInRange(ctx, txn, req.Device.UserID, req.Device.ID, r)
if err != nil {
return fmt.Errorf("d.Peeks.SelectPeeksInRange: %w", err)
}
for _, peek := range peeks {
if !peek.Deleted {
var jr *types.JoinResponse
jr, err = d.getJoinResponseForCompleteSync(
ctx, txn, peek.RoomID, r, stateFilter, eventFilter, req.WantFullState, req.Device,
)
if err != nil {
return fmt.Errorf("d.getJoinResponseForCompleteSync: %w", err)
}
req.Response.Rooms.Peek[peek.RoomID] = *jr
}
}
succeeded = true
return nil
}
func (d *Database) PDUIncrementalSync(
ctx context.Context,
req *types.SyncRequest,
r types.Range,
from, to types.StreamPosition,
) error {
txn, err := d.readOnlySnapshot(ctx)
if err != nil {
return fmt.Errorf("d.readOnlySnapshot: %w", err)
}
var succeeded bool
defer sqlutil.EndTransactionWithCheck(txn, &succeeded, &err)
var stateDeltas []types.StateDelta
var joinedRooms []string
stateFilter := req.Filter.Room.State
eventFilter := req.Filter.Room.Timeline
if req.WantFullState {
if stateDeltas, joinedRooms, err = d.getStateDeltasForFullStateSync(ctx, txn, req.Device, r, req.Device.UserID, &stateFilter); err != nil {
req.Log.WithError(err).Error("p.DB.GetStateDeltasForFullStateSync failed")
return fmt.Errorf("d.GetStateDeltasForFullStateSync: %w", err)
}
} else {
if stateDeltas, joinedRooms, err = d.getStateDeltas(ctx, txn, req.Device, r, req.Device.UserID, &stateFilter); err != nil {
req.Log.WithError(err).Error("p.DB.GetStateDeltas failed")
return nil
}
}
for _, roomID := range joinedRooms {
req.Rooms[roomID] = gomatrixserverlib.Join
}
for _, delta := range stateDeltas {
if err = d.addRoomDeltaToResponse(ctx, txn, req.Device, r, delta, &eventFilter, req.Response); err != nil {
req.Log.WithError(err).Error("d.addRoomDeltaToResponse failed")
return nil
}
}
succeeded = true
return nil
}
func (d *Database) addRoomDeltaToResponse(
ctx context.Context,
txn *sql.Tx,
device *userapi.Device,
r types.Range,
delta types.StateDelta,
eventFilter *gomatrixserverlib.RoomEventFilter,
res *types.Response,
) 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 := d.OutputEvents.SelectRecentEvents(
ctx, txn, delta.RoomID, r,
eventFilter, true, true,
)
if err != nil {
return err
}
recentEvents := d.StreamEventsToEvents(device, recentStreamEvents)
delta.StateEvents = removeDuplicates(delta.StateEvents, recentEvents) // roll back
prevBatch, err := d.GetBackwardTopologyPos(ctx, recentStreamEvents)
if err != nil {
return err
}
// XXX: should we ever get this far if we have no recent events or state in this room?
// in practice we do for peeks, but possibly not joins?
if len(recentEvents) == 0 && len(delta.StateEvents) == 0 {
return nil
}
switch delta.Membership {
case gomatrixserverlib.Join:
jr := types.NewJoinResponse()
jr.Timeline.PrevBatch = &prevBatch
jr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(recentEvents, gomatrixserverlib.FormatSync)
jr.Timeline.Limited = limited
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
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:
// TODO: recentEvents may contain events that this user is not allowed to see because they are
// no longer in the room.
lr := types.NewLeaveResponse()
lr.Timeline.PrevBatch = &prevBatch
lr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(recentEvents, gomatrixserverlib.FormatSync)
lr.Timeline.Limited = false // TODO: if len(events) >= numRecents + 1 and then set limited:true
lr.State.Events = gomatrixserverlib.HeaderedToClientEvents(delta.StateEvents, gomatrixserverlib.FormatSync)
res.Rooms.Leave[delta.RoomID] = *lr
}
return nil
}
func (d *Database) getJoinResponseForCompleteSync(
ctx context.Context,
txn *sql.Tx,
roomID string,
r types.Range,
stateFilter *gomatrixserverlib.StateFilter,
eventFilter *gomatrixserverlib.RoomEventFilter,
wantFullState bool,
device *userapi.Device,
) (jr *types.JoinResponse, err error) {
// 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 := d.OutputEvents.SelectRecentEvents(
ctx, txn, roomID, r, eventFilter, true, true,
)
if err != nil {
return
}
// Get the event IDs of the stream events we fetched. There's no point in us
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 := d.CurrentRoomState.SelectCurrentState(ctx, txn, roomID, stateFilter, excludingEventIDs)
if err != nil {
return
}
// TODO FIXME: We don't fully implement history visibility yet. To avoid leaking events which the
// user shouldn't see, we check the recent events and remove any prior to the join event of the user
// which is equiv to history_visibility: joined
joinEventIndex := -1
for i := len(recentStreamEvents) - 1; i >= 0; i-- {
ev := recentStreamEvents[i]
if ev.Type() == gomatrixserverlib.MRoomMember && ev.StateKeyEquals(device.UserID) {
membership, _ := ev.Membership()
if membership == "join" {
joinEventIndex = i
if i > 0 {
// the create event happens before the first join, so we should cut it at that point instead
if recentStreamEvents[i-1].Type() == gomatrixserverlib.MRoomCreate && recentStreamEvents[i-1].StateKeyEquals("") {
joinEventIndex = i - 1
break
}
}
break
}
}
}
if joinEventIndex != -1 {
// cut all events earlier than the join (but not the join itself)
recentStreamEvents = recentStreamEvents[joinEventIndex:]
limited = false // so clients know not to try to backpaginate
}
// 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 = d.PositionInTopology(ctx, recentStreamEvents[0].EventID())
if err != nil {
return
}
prevBatch = &types.TopologyToken{
Depth: backwardTopologyPos,
PDUPosition: backwardStreamPos,
}
prevBatch.Decrement()
}
// 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 := d.StreamEventsToEvents(device, recentStreamEvents)
stateEvents = removeDuplicates(stateEvents, recentEvents)
jr = types.NewJoinResponse()
jr.Timeline.PrevBatch = prevBatch
jr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(recentEvents, gomatrixserverlib.FormatSync)
jr.Timeline.Limited = limited
jr.State.Events = gomatrixserverlib.HeaderedToClientEvents(stateEvents, gomatrixserverlib.FormatSync)
return jr, 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
}