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dendrite/roomserver/internal/input/input_events.go
Neil Alexander d821f9d3c9
Deep checking of forward extremities (#1491)
* Deep forward extremity calculation

* Use updater txn

* Update error

* Update error

* Create previous event references in StoreEvent

* Use latest events updater to row-lock prev events

* Fix unexpected fallthrough

* Fix deadlock

* Don't roll back

* Update comments in calculateLatest

* Don't include events that we can't find references for in the forward extremities

* Add another passing test
2020-10-07 14:05:33 +01:00

222 lines
7.8 KiB
Go

// Copyright 2017 Vector Creations Ltd
// Copyright 2018 New Vector Ltd
// Copyright 2019-2020 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 input
import (
"context"
"fmt"
"github.com/matrix-org/dendrite/internal/eventutil"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/internal/helpers"
"github.com/matrix-org/dendrite/roomserver/state"
"github.com/matrix-org/dendrite/roomserver/types"
"github.com/matrix-org/gomatrixserverlib"
"github.com/sirupsen/logrus"
)
// processRoomEvent can only be called once at a time
//
// TODO(#375): This should be rewritten to allow concurrent calls. The
// difficulty is in ensuring that we correctly annotate events with the correct
// state deltas when sending to kafka streams
// TODO: Break up function - we should probably do transaction ID checks before calling this.
// nolint:gocyclo
func (r *Inputer) processRoomEvent(
ctx context.Context,
input *api.InputRoomEvent,
) (eventID string, err error) {
// Parse and validate the event JSON
headered := input.Event
event := headered.Unwrap()
// Check that the event passes authentication checks and work out
// the numeric IDs for the auth events.
isRejected := false
authEventNIDs, rejectionErr := helpers.CheckAuthEvents(ctx, r.DB, headered, input.AuthEventIDs)
if rejectionErr != nil {
logrus.WithError(rejectionErr).WithField("event_id", event.EventID()).WithField("auth_event_ids", input.AuthEventIDs).Error("helpers.CheckAuthEvents failed for event, rejecting event")
isRejected = true
}
var softfail bool
if input.Kind == api.KindNew {
// Check that the event passes authentication checks based on the
// current room state.
softfail, err = helpers.CheckForSoftFail(ctx, r.DB, headered, input.StateEventIDs)
if err != nil {
logrus.WithFields(logrus.Fields{
"event_id": event.EventID(),
"type": event.Type(),
"room": event.RoomID(),
}).WithError(err).Info("Error authing soft-failed event")
}
}
// If we don't have a transaction ID then get one.
if input.TransactionID != nil {
tdID := input.TransactionID
eventID, err = r.DB.GetTransactionEventID(
ctx, tdID.TransactionID, tdID.SessionID, event.Sender(),
)
// On error OR event with the transaction already processed/processesing
if err != nil || eventID != "" {
return
}
}
// Store the event.
_, stateAtEvent, redactionEvent, redactedEventID, err := r.DB.StoreEvent(ctx, event, input.TransactionID, authEventNIDs, isRejected)
if err != nil {
return "", fmt.Errorf("r.DB.StoreEvent: %w", err)
}
// if storing this event results in it being redacted then do so.
if !isRejected && redactedEventID == event.EventID() {
r, rerr := eventutil.RedactEvent(redactionEvent, &event)
if rerr != nil {
return "", fmt.Errorf("eventutil.RedactEvent: %w", rerr)
}
event = *r
}
// For outliers we can stop after we've stored the event itself as it
// doesn't have any associated state to store and we don't need to
// notify anyone about it.
if input.Kind == api.KindOutlier {
logrus.WithFields(logrus.Fields{
"event_id": event.EventID(),
"type": event.Type(),
"room": event.RoomID(),
"sender": event.Sender(),
}).Debug("Stored outlier")
return event.EventID(), nil
}
roomInfo, err := r.DB.RoomInfo(ctx, event.RoomID())
if err != nil {
return "", fmt.Errorf("r.DB.RoomInfo: %w", err)
}
if roomInfo == nil {
return "", fmt.Errorf("r.DB.RoomInfo missing for room %s", event.RoomID())
}
if stateAtEvent.BeforeStateSnapshotNID == 0 {
// We haven't calculated a state for this event yet.
// Lets calculate one.
err = r.calculateAndSetState(ctx, input, *roomInfo, &stateAtEvent, event, isRejected)
if err != nil {
return "", fmt.Errorf("r.calculateAndSetState: %w", err)
}
}
// We stop here if the event is rejected: We've stored it but won't update forward extremities or notify anyone about it.
if isRejected || softfail {
logrus.WithFields(logrus.Fields{
"event_id": event.EventID(),
"type": event.Type(),
"room": event.RoomID(),
"soft_fail": softfail,
"sender": event.Sender(),
}).Debug("Stored rejected event")
return event.EventID(), rejectionErr
}
if err = r.updateLatestEvents(
ctx, // context
roomInfo, // room info for the room being updated
stateAtEvent, // state at event (below)
event, // event
input.SendAsServer, // send as server
input.TransactionID, // transaction ID
input.HasState, // rewrites state?
); err != nil {
return "", fmt.Errorf("r.updateLatestEvents: %w", err)
}
// processing this event resulted in an event (which may not be the one we're processing)
// being redacted. We are guaranteed to have both sides (the redaction/redacted event),
// so notify downstream components to redact this event - they should have it if they've
// been tracking our output log.
if redactedEventID != "" {
err = r.WriteOutputEvents(event.RoomID(), []api.OutputEvent{
{
Type: api.OutputTypeRedactedEvent,
RedactedEvent: &api.OutputRedactedEvent{
RedactedEventID: redactedEventID,
RedactedBecause: redactionEvent.Headered(headered.RoomVersion),
},
},
})
if err != nil {
return "", fmt.Errorf("r.WriteOutputEvents: %w", err)
}
}
// Update the extremities of the event graph for the room
return event.EventID(), nil
}
func (r *Inputer) calculateAndSetState(
ctx context.Context,
input *api.InputRoomEvent,
roomInfo types.RoomInfo,
stateAtEvent *types.StateAtEvent,
event gomatrixserverlib.Event,
isRejected bool,
) error {
var err error
roomState := state.NewStateResolution(r.DB, roomInfo)
if input.HasState && !isRejected {
// Check here if we think we're in the room already.
stateAtEvent.Overwrite = true
var joinEventNIDs []types.EventNID
// Request join memberships only for local users only.
if joinEventNIDs, err = r.DB.GetMembershipEventNIDsForRoom(ctx, roomInfo.RoomNID, true, true); err == nil {
// If we have no local users that are joined to the room then any state about
// the room that we have is quite possibly out of date. Therefore in that case
// we should overwrite it rather than merge it.
stateAtEvent.Overwrite = len(joinEventNIDs) == 0
}
// We've been told what the state at the event is so we don't need to calculate it.
// Check that those state events are in the database and store the state.
var entries []types.StateEntry
if entries, err = r.DB.StateEntriesForEventIDs(ctx, input.StateEventIDs); err != nil {
return fmt.Errorf("r.DB.StateEntriesForEventIDs: %w", err)
}
entries = types.DeduplicateStateEntries(entries)
if stateAtEvent.BeforeStateSnapshotNID, err = r.DB.AddState(ctx, roomInfo.RoomNID, nil, entries); err != nil {
return fmt.Errorf("r.DB.AddState: %w", err)
}
} else {
stateAtEvent.Overwrite = false
// We haven't been told what the state at the event is so we need to calculate it from the prev_events
if stateAtEvent.BeforeStateSnapshotNID, err = roomState.CalculateAndStoreStateBeforeEvent(ctx, event, isRejected); err != nil {
return fmt.Errorf("roomState.CalculateAndStoreStateBeforeEvent: %w", err)
}
}
err = r.DB.SetState(ctx, stateAtEvent.EventNID, stateAtEvent.BeforeStateSnapshotNID)
if err != nil {
return fmt.Errorf("r.DB.SetState: %w", err)
}
return nil
}