dendrite/syncapi/storage/shared/syncserver.go

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package shared
import (
"context"
"database/sql"
"encoding/json"
"fmt"
"time"
"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
"github.com/matrix-org/dendrite/common"
"github.com/matrix-org/dendrite/eduserver/cache"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/syncapi/storage/tables"
"github.com/matrix-org/dendrite/syncapi/types"
"github.com/matrix-org/gomatrixserverlib"
"github.com/sirupsen/logrus"
)
// Database is a temporary struct until we have made syncserver.go the same for both pq/sqlite
// For now this contains the shared functions
type Database struct {
DB *sql.DB
Invites tables.Invites
AccountData tables.AccountData
OutputEvents tables.Events
Topology tables.Topology
CurrentRoomState tables.CurrentRoomState
BackwardExtremities tables.BackwardsExtremities
EDUCache *cache.EDUCache
}
// Events lookups a list of event by their event ID.
// Returns a list of events matching the requested IDs found in the database.
// If an event is not found in the database then it will be omitted from the list.
// Returns an error if there was a problem talking with the database.
// Does not include any transaction IDs in the returned events.
func (d *Database) Events(ctx context.Context, eventIDs []string) ([]gomatrixserverlib.HeaderedEvent, error) {
streamEvents, err := d.OutputEvents.SelectEvents(ctx, nil, eventIDs)
if err != nil {
return nil, err
}
// We don't include a device here as we only include transaction IDs in
// incremental syncs.
return d.StreamEventsToEvents(nil, streamEvents), nil
}
// GetEventsInStreamingRange retrieves all of the events on a given ordering using the
// given extremities and limit.
func (d *Database) GetEventsInStreamingRange(
ctx context.Context,
from, to *types.StreamingToken,
roomID string, limit int,
backwardOrdering bool,
) (events []types.StreamEvent, err error) {
if backwardOrdering {
// When using backward ordering, we want the most recent events first.
if events, err = d.OutputEvents.SelectRecentEvents(
ctx, nil, roomID, to.PDUPosition(), from.PDUPosition(), limit, false, false,
); err != nil {
return
}
} else {
// When using forward ordering, we want the least recent events first.
if events, err = d.OutputEvents.SelectEarlyEvents(
ctx, nil, roomID, from.PDUPosition(), to.PDUPosition(), limit,
); err != nil {
return
}
}
return events, err
}
func (d *Database) AddTypingUser(
userID, roomID string, expireTime *time.Time,
) types.StreamPosition {
return types.StreamPosition(d.EDUCache.AddTypingUser(userID, roomID, expireTime))
}
func (d *Database) RemoveTypingUser(
userID, roomID string,
) types.StreamPosition {
return types.StreamPosition(d.EDUCache.RemoveUser(userID, roomID))
}
func (d *Database) SetTypingTimeoutCallback(fn cache.TimeoutCallbackFn) {
d.EDUCache.SetTimeoutCallback(fn)
}
func (d *Database) AllJoinedUsersInRooms(ctx context.Context) (map[string][]string, error) {
return d.CurrentRoomState.SelectJoinedUsers(ctx)
}
func (d *Database) GetStateEvent(
ctx context.Context, roomID, evType, stateKey string,
) (*gomatrixserverlib.HeaderedEvent, error) {
return d.CurrentRoomState.SelectStateEvent(ctx, roomID, evType, stateKey)
}
func (d *Database) GetStateEventsForRoom(
ctx context.Context, roomID string, stateFilter *gomatrixserverlib.StateFilter,
) (stateEvents []gomatrixserverlib.HeaderedEvent, err error) {
err = common.WithTransaction(d.DB, func(txn *sql.Tx) error {
stateEvents, err = d.CurrentRoomState.SelectCurrentState(ctx, txn, roomID, stateFilter)
return err
})
return
}
func (d *Database) SyncStreamPosition(ctx context.Context) (types.StreamPosition, error) {
var maxID int64
var err error
err = common.WithTransaction(d.DB, func(txn *sql.Tx) error {
maxID, err = d.OutputEvents.SelectMaxEventID(ctx, txn)
if err != nil {
return err
}
var maxAccountDataID int64
maxAccountDataID, err = d.AccountData.SelectMaxAccountDataID(ctx, txn)
if err != nil {
return err
}
if maxAccountDataID > maxID {
maxID = maxAccountDataID
}
var maxInviteID int64
maxInviteID, err = d.Invites.SelectMaxInviteID(ctx, txn)
if err != nil {
return err
}
if maxInviteID > maxID {
maxID = maxInviteID
}
return nil
})
return types.StreamPosition(maxID), err
}
// AddInviteEvent stores a new invite event for a user.
// If the invite was successfully stored this returns the stream ID it was stored at.
// Returns an error if there was a problem communicating with the database.
func (d *Database) AddInviteEvent(
ctx context.Context, inviteEvent gomatrixserverlib.HeaderedEvent,
) (sp types.StreamPosition, err error) {
err = common.WithTransaction(d.DB, func(txn *sql.Tx) error {
sp, err = d.Invites.InsertInviteEvent(ctx, txn, inviteEvent)
return err
})
return
}
// RetireInviteEvent removes an old invite event from the database.
// Returns an error if there was a problem communicating with the database.
func (d *Database) RetireInviteEvent(
ctx context.Context, inviteEventID string,
) error {
// TODO: Record that invite has been retired in a stream so that we can
// notify the user in an incremental sync.
err := d.Invites.DeleteInviteEvent(ctx, inviteEventID)
return err
}
// GetAccountDataInRange returns all account data for a given user inserted or
// updated between two given positions
// Returns a map following the format data[roomID] = []dataTypes
// If no data is retrieved, returns an empty map
// If there was an issue with the retrieval, returns an error
func (d *Database) GetAccountDataInRange(
ctx context.Context, userID string, oldPos, newPos types.StreamPosition,
accountDataFilterPart *gomatrixserverlib.EventFilter,
) (map[string][]string, error) {
return d.AccountData.SelectAccountDataInRange(ctx, userID, oldPos, newPos, accountDataFilterPart)
}
// UpsertAccountData keeps track of new or updated account data, by saving the type
// of the new/updated data, and the user ID and room ID the data is related to (empty)
// room ID means the data isn't specific to any room)
// If no data with the given type, user ID and room ID exists in the database,
// creates a new row, else update the existing one
// Returns an error if there was an issue with the upsert
func (d *Database) UpsertAccountData(
ctx context.Context, userID, roomID, dataType string,
) (sp types.StreamPosition, err error) {
err = common.WithTransaction(d.DB, func(txn *sql.Tx) error {
sp, err = d.AccountData.InsertAccountData(ctx, txn, userID, roomID, dataType)
return err
})
return
}
func (d *Database) StreamEventsToEvents(device *authtypes.Device, in []types.StreamEvent) []gomatrixserverlib.HeaderedEvent {
out := make([]gomatrixserverlib.HeaderedEvent, len(in))
for i := 0; i < len(in); i++ {
out[i] = in[i].HeaderedEvent
if device != nil && in[i].TransactionID != nil {
if device.UserID == in[i].Sender() && device.SessionID == in[i].TransactionID.SessionID {
err := out[i].SetUnsignedField(
"transaction_id", in[i].TransactionID.TransactionID,
)
if err != nil {
logrus.WithFields(logrus.Fields{
"event_id": out[i].EventID(),
}).WithError(err).Warnf("Failed to add transaction ID to event")
}
}
}
}
return out
}
// handleBackwardExtremities adds this event as a backwards extremity if and only if we do not have all of
// the events listed in the event's 'prev_events'. This function also updates the backwards extremities table
// to account for the fact that the given event is no longer a backwards extremity, but may be marked as such.
func (d *Database) handleBackwardExtremities(ctx context.Context, txn *sql.Tx, ev *gomatrixserverlib.HeaderedEvent) error {
if err := d.BackwardExtremities.DeleteBackwardExtremity(ctx, txn, ev.RoomID(), ev.EventID()); err != nil {
return err
}
// Check if we have all of the event's previous events. If an event is
// missing, add it to the room's backward extremities.
prevEvents, err := d.OutputEvents.SelectEvents(ctx, txn, ev.PrevEventIDs())
if err != nil {
return err
}
var found bool
for _, eID := range ev.PrevEventIDs() {
found = false
for _, prevEv := range prevEvents {
if eID == prevEv.EventID() {
found = true
}
}
// If the event is missing, consider it a backward extremity.
if !found {
if err = d.BackwardExtremities.InsertsBackwardExtremity(ctx, txn, ev.RoomID(), ev.EventID(), eID); err != nil {
return err
}
}
}
return nil
}
func (d *Database) WriteEvent(
ctx context.Context,
ev *gomatrixserverlib.HeaderedEvent,
addStateEvents []gomatrixserverlib.HeaderedEvent,
addStateEventIDs, removeStateEventIDs []string,
transactionID *api.TransactionID, excludeFromSync bool,
) (pduPosition types.StreamPosition, returnErr error) {
returnErr = common.WithTransaction(d.DB, func(txn *sql.Tx) error {
var err error
pos, err := d.OutputEvents.InsertEvent(
ctx, txn, ev, addStateEventIDs, removeStateEventIDs, transactionID, excludeFromSync,
)
if err != nil {
return err
}
pduPosition = pos
if err = d.Topology.InsertEventInTopology(ctx, txn, ev, pos); err != nil {
return err
}
if err = d.handleBackwardExtremities(ctx, txn, ev); err != nil {
return err
}
if len(addStateEvents) == 0 && len(removeStateEventIDs) == 0 {
// Nothing to do, the event may have just been a message event.
return nil
}
return d.updateRoomState(ctx, txn, removeStateEventIDs, addStateEvents, pduPosition)
})
return pduPosition, returnErr
}
func (d *Database) updateRoomState(
ctx context.Context, txn *sql.Tx,
removedEventIDs []string,
addedEvents []gomatrixserverlib.HeaderedEvent,
pduPosition types.StreamPosition,
) error {
// remove first, then add, as we do not ever delete state, but do replace state which is a remove followed by an add.
for _, eventID := range removedEventIDs {
if err := d.CurrentRoomState.DeleteRoomStateByEventID(ctx, txn, eventID); err != nil {
return err
}
}
for _, event := range addedEvents {
if event.StateKey() == nil {
// ignore non state events
continue
}
var membership *string
if event.Type() == "m.room.member" {
value, err := event.Membership()
if err != nil {
return err
}
membership = &value
}
if err := d.CurrentRoomState.UpsertRoomState(ctx, txn, event, membership, pduPosition); err != nil {
return err
}
}
return nil
}
func (d *Database) GetEventsInTopologicalRange(
ctx context.Context,
from, to *types.TopologyToken,
roomID string, limit int,
backwardOrdering bool,
) (events []types.StreamEvent, err error) {
// Determine the backward and forward limit, i.e. the upper and lower
// limits to the selection in the room's topology, from the direction.
var backwardLimit, forwardLimit, forwardMicroLimit types.StreamPosition
if backwardOrdering {
// Backward ordering is antichronological (latest event to oldest
// one).
backwardLimit = to.Depth()
forwardLimit = from.Depth()
forwardMicroLimit = from.PDUPosition()
} else {
// Forward ordering is chronological (oldest event to latest one).
backwardLimit = from.Depth()
forwardLimit = to.Depth()
}
// Select the event IDs from the defined range.
var eIDs []string
eIDs, err = d.Topology.SelectEventIDsInRange(
ctx, nil, roomID, backwardLimit, forwardLimit, forwardMicroLimit, limit, !backwardOrdering,
)
if err != nil {
return
}
// Retrieve the events' contents using their IDs.
events, err = d.OutputEvents.SelectEvents(ctx, nil, eIDs)
return
}
func (d *Database) SyncPosition(ctx context.Context) (tok types.StreamingToken, err error) {
err = common.WithTransaction(d.DB, func(txn *sql.Tx) error {
pos, err := d.SyncPositionTx(ctx, txn)
if err != nil {
return err
}
tok = pos
return nil
})
return
}
func (d *Database) BackwardExtremitiesForRoom(
ctx context.Context, roomID string,
) (backwardExtremities []string, err error) {
return d.BackwardExtremities.SelectBackwardExtremitiesForRoom(ctx, roomID)
}
func (d *Database) MaxTopologicalPosition(
ctx context.Context, roomID string,
) (depth types.StreamPosition, stream types.StreamPosition, err error) {
return d.Topology.SelectMaxPositionInTopology(ctx, nil, roomID)
}
func (d *Database) EventsAtTopologicalPosition(
ctx context.Context, roomID string, pos types.StreamPosition,
) ([]types.StreamEvent, error) {
eIDs, err := d.Topology.SelectEventIDsFromPosition(ctx, nil, roomID, pos)
if err != nil {
return nil, err
}
return d.OutputEvents.SelectEvents(ctx, nil, eIDs)
}
func (d *Database) EventPositionInTopology(
ctx context.Context, eventID string,
) (depth types.StreamPosition, stream types.StreamPosition, err error) {
return d.Topology.SelectPositionInTopology(ctx, nil, eventID)
}
// TODO FIXME TEMPORARY PUBLIC
func (d *Database) SyncPositionTx(
ctx context.Context, txn *sql.Tx,
) (sp types.StreamingToken, err error) {
maxEventID, err := d.OutputEvents.SelectMaxEventID(ctx, txn)
if err != nil {
return sp, err
}
maxAccountDataID, err := d.AccountData.SelectMaxAccountDataID(ctx, txn)
if err != nil {
return sp, err
}
if maxAccountDataID > maxEventID {
maxEventID = maxAccountDataID
}
maxInviteID, err := d.Invites.SelectMaxInviteID(ctx, txn)
if err != nil {
return sp, err
}
if maxInviteID > maxEventID {
maxEventID = maxInviteID
}
sp = types.NewStreamToken(types.StreamPosition(maxEventID), types.StreamPosition(d.EDUCache.GetLatestSyncPosition()))
return
}
// addPDUDeltaToResponse adds all PDU deltas to a sync response.
// IDs of all rooms the user joined are returned so EDU deltas can be added for them.
func (d *Database) addPDUDeltaToResponse(
ctx context.Context,
device authtypes.Device,
fromPos, toPos types.StreamPosition,
numRecentEventsPerRoom int,
wantFullState bool,
res *types.Response,
) (joinedRoomIDs []string, err error) {
txn, err := d.DB.BeginTx(ctx, &txReadOnlySnapshot)
if err != nil {
return nil, err
}
var succeeded bool
defer func() {
txerr := common.EndTransaction(txn, &succeeded)
if err == nil && txerr != nil {
err = txerr
}
}()
stateFilter := gomatrixserverlib.DefaultStateFilter() // TODO: use filter provided in request
// Work out which rooms to return in the response. This is done by getting not only the currently
// joined rooms, but also which rooms have membership transitions for this user between the 2 PDU stream positions.
// This works out what the 'state' key should be for each room as well as which membership block
// to put the room into.
var deltas []stateDelta
if !wantFullState {
deltas, joinedRoomIDs, err = d.getStateDeltas(
ctx, &device, txn, fromPos, toPos, device.UserID, &stateFilter,
)
} else {
deltas, joinedRoomIDs, err = d.getStateDeltasForFullStateSync(
ctx, &device, txn, fromPos, toPos, device.UserID, &stateFilter,
)
}
if err != nil {
return nil, err
}
for _, delta := range deltas {
err = d.addRoomDeltaToResponse(ctx, &device, txn, fromPos, toPos, delta, numRecentEventsPerRoom, res)
if err != nil {
return nil, err
}
}
// TODO: This should be done in getStateDeltas
if err = d.AddInvitesToResponse(ctx, txn, device.UserID, fromPos, toPos, res); err != nil {
return nil, err
}
succeeded = true
return joinedRoomIDs, nil
}
// addTypingDeltaToResponse adds all typing notifications to a sync response
// since the specified position.
func (d *Database) addTypingDeltaToResponse(
since types.StreamingToken,
joinedRoomIDs []string,
res *types.Response,
) error {
var jr types.JoinResponse
var ok bool
var err error
for _, roomID := range joinedRoomIDs {
if typingUsers, updated := d.EDUCache.GetTypingUsersIfUpdatedAfter(
roomID, int64(since.EDUPosition()),
); updated {
ev := gomatrixserverlib.ClientEvent{
Type: gomatrixserverlib.MTyping,
}
ev.Content, err = json.Marshal(map[string]interface{}{
"user_ids": typingUsers,
})
if err != nil {
return err
}
if jr, ok = res.Rooms.Join[roomID]; !ok {
jr = *types.NewJoinResponse()
}
jr.Ephemeral.Events = append(jr.Ephemeral.Events, ev)
res.Rooms.Join[roomID] = jr
}
}
return nil
}
// addEDUDeltaToResponse adds updates for EDUs of each type since fromPos if
// the positions of that type are not equal in fromPos and toPos.
// TODO FIXME TEMPORARY PUBLIC
func (d *Database) AddEDUDeltaToResponse(
fromPos, toPos types.StreamingToken,
joinedRoomIDs []string,
res *types.Response,
) (err error) {
if fromPos.EDUPosition() != toPos.EDUPosition() {
err = d.addTypingDeltaToResponse(
fromPos, joinedRoomIDs, res,
)
}
return
}
func (d *Database) IncrementalSync(
ctx context.Context,
device authtypes.Device,
fromPos, toPos types.StreamingToken,
numRecentEventsPerRoom int,
wantFullState bool,
) (*types.Response, error) {
nextBatchPos := fromPos.WithUpdates(toPos)
res := types.NewResponse(nextBatchPos)
var joinedRoomIDs []string
var err error
if fromPos.PDUPosition() != toPos.PDUPosition() || wantFullState {
joinedRoomIDs, err = d.addPDUDeltaToResponse(
ctx, device, fromPos.PDUPosition(), toPos.PDUPosition(), numRecentEventsPerRoom, wantFullState, res,
)
} else {
joinedRoomIDs, err = d.CurrentRoomState.SelectRoomIDsWithMembership(
ctx, nil, device.UserID, gomatrixserverlib.Join,
)
}
if err != nil {
return nil, err
}
err = d.AddEDUDeltaToResponse(
fromPos, toPos, joinedRoomIDs, res,
)
if err != nil {
return nil, err
}
return res, nil
}
// getResponseWithPDUsForCompleteSync creates a response and adds all PDUs needed
// to it. It returns toPos and joinedRoomIDs for use of adding EDUs.
func (d *Database) getResponseWithPDUsForCompleteSync(
ctx context.Context,
userID string,
numRecentEventsPerRoom int,
) (
res *types.Response,
toPos types.StreamingToken,
joinedRoomIDs []string,
err error,
) {
// This needs to be all done in a transaction as we need to do multiple SELECTs, and we need to have
// a consistent view of the database throughout. This includes extracting the sync position.
// This does have the unfortunate side-effect that all the matrixy logic resides in this function,
// but it's better to not hide the fact that this is being done in a transaction.
txn, err := d.DB.BeginTx(ctx, &txReadOnlySnapshot)
if err != nil {
return
}
var succeeded bool
defer func() {
txerr := common.EndTransaction(txn, &succeeded)
if err == nil && txerr != nil {
err = txerr
}
}()
// Get the current sync position which we will base the sync response on.
toPos, err = d.SyncPositionTx(ctx, txn)
if err != nil {
return
}
res = types.NewResponse(toPos)
// Extract room state and recent events for all rooms the user is joined to.
joinedRoomIDs, err = d.CurrentRoomState.SelectRoomIDsWithMembership(ctx, txn, userID, gomatrixserverlib.Join)
if err != nil {
return
}
stateFilter := gomatrixserverlib.DefaultStateFilter() // TODO: use filter provided in request
// Build up a /sync response. Add joined rooms.
for _, roomID := range joinedRoomIDs {
var stateEvents []gomatrixserverlib.HeaderedEvent
stateEvents, err = d.CurrentRoomState.SelectCurrentState(ctx, txn, roomID, &stateFilter)
if err != nil {
return
}
// 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
var recentStreamEvents []types.StreamEvent
recentStreamEvents, err = d.OutputEvents.SelectRecentEvents(
ctx, txn, roomID, types.StreamPosition(0), toPos.PDUPosition(),
numRecentEventsPerRoom, true, true,
)
if err != nil {
return
}
// Retrieve the backward topology position, i.e. the position of the
// oldest event in the room's topology.
var prevBatchStr string
if len(recentStreamEvents) > 0 {
var backwardTopologyPos, backwardStreamPos types.StreamPosition
backwardTopologyPos, backwardStreamPos, err = d.Topology.SelectPositionInTopology(ctx, txn, recentStreamEvents[0].EventID())
if err != nil {
return
}
prevBatch := types.NewTopologyToken(backwardTopologyPos, backwardStreamPos)
prevBatch.Decrement()
prevBatchStr = prevBatch.String()
}
// We don't include a device here as we don't need to send down
// transaction IDs for complete syncs
recentEvents := d.StreamEventsToEvents(nil, recentStreamEvents)
stateEvents = removeDuplicates(stateEvents, recentEvents)
jr := types.NewJoinResponse()
jr.Timeline.PrevBatch = prevBatchStr
jr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(recentEvents, gomatrixserverlib.FormatSync)
jr.Timeline.Limited = true
jr.State.Events = gomatrixserverlib.HeaderedToClientEvents(stateEvents, gomatrixserverlib.FormatSync)
res.Rooms.Join[roomID] = *jr
}
if err = d.AddInvitesToResponse(ctx, txn, userID, 0, toPos.PDUPosition(), res); err != nil {
return
}
succeeded = true
return res, toPos, joinedRoomIDs, err
}
func (d *Database) CompleteSync(
ctx context.Context, userID string, numRecentEventsPerRoom int,
) (*types.Response, error) {
res, toPos, joinedRoomIDs, err := d.getResponseWithPDUsForCompleteSync(
ctx, userID, numRecentEventsPerRoom,
)
if err != nil {
return nil, err
}
// Use a zero value SyncPosition for fromPos so all EDU states are added.
err = d.AddEDUDeltaToResponse(
types.NewStreamToken(0, 0), toPos, joinedRoomIDs, res,
)
if err != nil {
return nil, err
}
return res, nil
}
var txReadOnlySnapshot = sql.TxOptions{
// Set the isolation level so that we see a snapshot of the database.
// In PostgreSQL repeatable read transactions will see a snapshot taken
// at the first query, and since the transaction is read-only it can't
// run into any serialisation errors.
// https://www.postgresql.org/docs/9.5/static/transaction-iso.html#XACT-REPEATABLE-READ
Isolation: sql.LevelRepeatableRead,
ReadOnly: true,
}
// TODO FIXME temporary public
func (d *Database) AddInvitesToResponse(
ctx context.Context, txn *sql.Tx,
userID string,
fromPos, toPos types.StreamPosition,
res *types.Response,
) error {
invites, err := d.Invites.SelectInviteEventsInRange(
ctx, txn, userID, fromPos, toPos,
)
if err != nil {
return err
}
for roomID, inviteEvent := range invites {
ir := types.NewInviteResponse(inviteEvent)
res.Rooms.Invite[roomID] = *ir
}
return nil
}
// Retrieve the backward topology position, i.e. the position of the
// oldest event in the room's topology.
func (d *Database) getBackwardTopologyPos(
ctx context.Context, txn *sql.Tx,
events []types.StreamEvent,
) (types.TopologyToken, error) {
zeroToken := types.NewTopologyToken(0, 0)
if len(events) == 0 {
return zeroToken, nil
}
pos, spos, err := d.Topology.SelectPositionInTopology(ctx, txn, events[0].EventID())
if err != nil {
return zeroToken, err
}
tok := types.NewTopologyToken(pos, spos)
tok.Decrement()
return tok, nil
}
// addRoomDeltaToResponse adds a room state delta to a sync response
func (d *Database) addRoomDeltaToResponse(
ctx context.Context,
device *authtypes.Device,
txn *sql.Tx,
fromPos, toPos types.StreamPosition,
delta stateDelta,
numRecentEventsPerRoom int,
res *types.Response,
) error {
endPos := toPos
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.
endPos = delta.membershipPos
}
recentStreamEvents, err := d.OutputEvents.SelectRecentEvents(
ctx, txn, delta.roomID, types.StreamPosition(fromPos), types.StreamPosition(endPos),
numRecentEventsPerRoom, 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, txn, recentStreamEvents)
if err != nil {
return err
}
switch delta.membership {
case gomatrixserverlib.Join:
jr := types.NewJoinResponse()
jr.Timeline.PrevBatch = prevBatch.String()
jr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(recentEvents, gomatrixserverlib.FormatSync)
jr.Timeline.Limited = false // TODO: if len(events) >= numRecents + 1 and then set limited:true
jr.State.Events = gomatrixserverlib.HeaderedToClientEvents(delta.stateEvents, gomatrixserverlib.FormatSync)
res.Rooms.Join[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.String()
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
}
// fetchStateEvents converts the set of event IDs into a set of events. It will fetch any which are missing from the database.
// Returns a map of room ID to list of events.
func (d *Database) fetchStateEvents(
ctx context.Context, txn *sql.Tx,
roomIDToEventIDSet map[string]map[string]bool,
eventIDToEvent map[string]types.StreamEvent,
) (map[string][]types.StreamEvent, error) {
stateBetween := make(map[string][]types.StreamEvent)
missingEvents := make(map[string][]string)
for roomID, ids := range roomIDToEventIDSet {
events := stateBetween[roomID]
for id, need := range ids {
if !need {
continue // deleted state
}
e, ok := eventIDToEvent[id]
if ok {
events = append(events, e)
} else {
m := missingEvents[roomID]
m = append(m, id)
missingEvents[roomID] = m
}
}
stateBetween[roomID] = events
}
if len(missingEvents) > 0 {
// This happens when add_state_ids has an event ID which is not in the provided range.
// We need to explicitly fetch them.
allMissingEventIDs := []string{}
for _, missingEvIDs := range missingEvents {
allMissingEventIDs = append(allMissingEventIDs, missingEvIDs...)
}
evs, err := d.fetchMissingStateEvents(ctx, txn, allMissingEventIDs)
if err != nil {
return nil, err
}
// we know we got them all otherwise an error would've been returned, so just loop the events
for _, ev := range evs {
roomID := ev.RoomID()
stateBetween[roomID] = append(stateBetween[roomID], ev)
}
}
return stateBetween, nil
}
func (d *Database) fetchMissingStateEvents(
ctx context.Context, txn *sql.Tx, eventIDs []string,
) ([]types.StreamEvent, error) {
// Fetch from the events table first so we pick up the stream ID for the
// event.
events, err := d.OutputEvents.SelectEvents(ctx, txn, eventIDs)
if err != nil {
return nil, err
}
have := map[string]bool{}
for _, event := range events {
have[event.EventID()] = true
}
var missing []string
for _, eventID := range eventIDs {
if !have[eventID] {
missing = append(missing, eventID)
}
}
if len(missing) == 0 {
return events, nil
}
// If they are missing from the events table then they should be state
// events that we received from outside the main event stream.
// These should be in the room state table.
stateEvents, err := d.CurrentRoomState.SelectEventsWithEventIDs(ctx, txn, missing)
if err != nil {
return nil, err
}
if len(stateEvents) != len(missing) {
return nil, fmt.Errorf("failed to map all event IDs to events: (got %d, wanted %d)", len(stateEvents), len(missing))
}
events = append(events, stateEvents...)
return events, nil
}
// getStateDeltas returns the state deltas between fromPos and toPos,
// exclusive of oldPos, inclusive of newPos, for the rooms in which
// the user has new membership events.
// A list of joined room IDs is also returned in case the caller needs it.
func (d *Database) getStateDeltas(
ctx context.Context, device *authtypes.Device, txn *sql.Tx,
fromPos, toPos types.StreamPosition, userID string,
stateFilter *gomatrixserverlib.StateFilter,
) ([]stateDelta, []string, error) {
// Implement membership change algorithm: https://github.com/matrix-org/synapse/blob/v0.19.3/synapse/handlers/sync.py#L821
// - Get membership list changes for this user in this sync response
// - For each room which has membership list changes:
// * Check if the room is 'newly joined' (insufficient to just check for a join event because we allow dupe joins TODO).
// If it is, then we need to send the full room state down (and 'limited' is always true).
// * Check if user is still CURRENTLY invited to the room. If so, add room to 'invited' block.
// * Check if the user is CURRENTLY (TODO) left/banned. If so, add room to 'archived' block.
// - Get all CURRENTLY joined rooms, and add them to 'joined' block.
var deltas []stateDelta
// get all the state events ever between these two positions
stateNeeded, eventMap, err := d.OutputEvents.SelectStateInRange(ctx, txn, fromPos, toPos, stateFilter)
if err != nil {
return nil, nil, err
}
state, err := d.fetchStateEvents(ctx, txn, stateNeeded, eventMap)
if err != nil {
return nil, nil, err
}
for roomID, stateStreamEvents := range state {
for _, ev := range stateStreamEvents {
// TODO: Currently this will incorrectly add rooms which were ALREADY joined but they sent another no-op join event.
// We should be checking if the user was already joined at fromPos and not proceed if so. As a result of this,
// dupe join events will result in the entire room state coming down to the client again. This is added in
// the 'state' part of the response though, so is transparent modulo bandwidth concerns as it is not added to
// the timeline.
if membership := getMembershipFromEvent(&ev.Event, userID); membership != "" {
if membership == gomatrixserverlib.Join {
// send full room state down instead of a delta
var s []types.StreamEvent
s, err = d.currentStateStreamEventsForRoom(ctx, txn, roomID, stateFilter)
if err != nil {
return nil, nil, err
}
state[roomID] = s
continue // we'll add this room in when we do joined rooms
}
deltas = append(deltas, stateDelta{
membership: membership,
membershipPos: ev.StreamPosition,
stateEvents: d.StreamEventsToEvents(device, stateStreamEvents),
roomID: roomID,
})
break
}
}
}
// Add in currently joined rooms
joinedRoomIDs, err := d.CurrentRoomState.SelectRoomIDsWithMembership(ctx, txn, userID, gomatrixserverlib.Join)
if err != nil {
return nil, nil, err
}
for _, joinedRoomID := range joinedRoomIDs {
deltas = append(deltas, stateDelta{
membership: gomatrixserverlib.Join,
stateEvents: d.StreamEventsToEvents(device, state[joinedRoomID]),
roomID: joinedRoomID,
})
}
return deltas, joinedRoomIDs, nil
}
// getStateDeltasForFullStateSync is a variant of getStateDeltas used for /sync
// requests with full_state=true.
// Fetches full state for all joined rooms and uses selectStateInRange to get
// updates for other rooms.
func (d *Database) getStateDeltasForFullStateSync(
ctx context.Context, device *authtypes.Device, txn *sql.Tx,
fromPos, toPos types.StreamPosition, userID string,
stateFilter *gomatrixserverlib.StateFilter,
) ([]stateDelta, []string, error) {
joinedRoomIDs, err := d.CurrentRoomState.SelectRoomIDsWithMembership(ctx, txn, userID, gomatrixserverlib.Join)
if err != nil {
return nil, nil, err
}
// Use a reasonable initial capacity
deltas := make([]stateDelta, 0, len(joinedRoomIDs))
// Add full states for all joined rooms
for _, joinedRoomID := range joinedRoomIDs {
s, stateErr := d.currentStateStreamEventsForRoom(ctx, txn, joinedRoomID, stateFilter)
if stateErr != nil {
return nil, nil, stateErr
}
deltas = append(deltas, stateDelta{
membership: gomatrixserverlib.Join,
stateEvents: d.StreamEventsToEvents(device, s),
roomID: joinedRoomID,
})
}
// Get all the state events ever between these two positions
stateNeeded, eventMap, err := d.OutputEvents.SelectStateInRange(ctx, txn, fromPos, toPos, stateFilter)
if err != nil {
return nil, nil, err
}
state, err := d.fetchStateEvents(ctx, txn, stateNeeded, eventMap)
if err != nil {
return nil, nil, err
}
for roomID, stateStreamEvents := range state {
for _, ev := range stateStreamEvents {
if membership := getMembershipFromEvent(&ev.Event, userID); membership != "" {
if membership != gomatrixserverlib.Join { // We've already added full state for all joined rooms above.
deltas = append(deltas, stateDelta{
membership: membership,
membershipPos: ev.StreamPosition,
stateEvents: d.StreamEventsToEvents(device, stateStreamEvents),
roomID: roomID,
})
}
break
}
}
}
return deltas, joinedRoomIDs, nil
}
func (d *Database) currentStateStreamEventsForRoom(
ctx context.Context, txn *sql.Tx, roomID string,
stateFilter *gomatrixserverlib.StateFilter,
) ([]types.StreamEvent, error) {
allState, err := d.CurrentRoomState.SelectCurrentState(ctx, txn, roomID, stateFilter)
if err != nil {
return nil, err
}
s := make([]types.StreamEvent, len(allState))
for i := 0; i < len(s); i++ {
s[i] = types.StreamEvent{HeaderedEvent: allState[i], StreamPosition: 0}
}
return s, nil
}
// There may be some overlap where events in stateEvents are already in recentEvents, so filter
// them out so we don't include them twice in the /sync response. They should be in recentEvents
// only, so clients get to the correct state once they have rolled forward.
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
}
// getMembershipFromEvent returns the value of content.membership iff the event is a state event
// with type 'm.room.member' and state_key of userID. Otherwise, an empty string is returned.
func getMembershipFromEvent(ev *gomatrixserverlib.Event, userID string) string {
if ev.Type() == "m.room.member" && ev.StateKeyEquals(userID) {
membership, err := ev.Membership()
if err != nil {
return ""
}
return membership
}
return ""
}
type stateDelta struct {
roomID string
stateEvents []gomatrixserverlib.HeaderedEvent
membership string
// The PDU stream position of the latest membership event for this user, if applicable.
// Can be 0 if there is no membership event in this delta.
membershipPos types.StreamPosition
}