Implement "full_state" query parameter for /sync (#751)

Closes #637.
This commit is contained in:
Alex Chen 2019-08-01 12:36:13 +08:00 committed by GitHub
parent 0dcf0a7d64
commit 3578d77d25
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3 changed files with 117 additions and 29 deletions

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@ -241,6 +241,7 @@ func (d *SyncServerDatasource) addPDUDeltaToResponse(
device authtypes.Device,
fromPos, toPos int64,
numRecentEventsPerRoom int,
wantFullState bool,
res *types.Response,
) ([]string, error) {
txn, err := d.db.BeginTx(ctx, &txReadOnlySnapshot)
@ -254,7 +255,13 @@ func (d *SyncServerDatasource) addPDUDeltaToResponse(
// 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.
deltas, joinedRoomIDs, err := d.getStateDeltas(ctx, &device, txn, fromPos, toPos, device.UserID)
var deltas []stateDelta
var joinedRoomIDs []string
if !wantFullState {
deltas, joinedRoomIDs, err = d.getStateDeltas(ctx, &device, txn, fromPos, toPos, device.UserID)
} else {
deltas, joinedRoomIDs, err = d.getStateDeltasForFullStateSync(ctx, &device, txn, fromPos, toPos, device.UserID)
}
if err != nil {
return nil, err
}
@ -336,15 +343,16 @@ func (d *SyncServerDatasource) IncrementalSync(
device authtypes.Device,
fromPos, toPos types.SyncPosition,
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 {
if fromPos.PDUPosition != toPos.PDUPosition || wantFullState {
joinedRoomIDs, err = d.addPDUDeltaToResponse(
ctx, device, fromPos.PDUPosition, toPos.PDUPosition, numRecentEventsPerRoom, res,
ctx, device, fromPos.PDUPosition, toPos.PDUPosition, numRecentEventsPerRoom, wantFullState, res,
)
} else {
joinedRoomIDs, err = d.roomstate.selectRoomIDsWithMembership(
@ -593,21 +601,30 @@ func (d *SyncServerDatasource) addRoomDeltaToResponse(
recentEvents := streamEventsToEvents(device, recentStreamEvents)
delta.stateEvents = removeDuplicates(delta.stateEvents, recentEvents) // roll back
var prevPDUPos int64
if len(recentEvents) == 0 {
if len(delta.stateEvents) == 0 {
// Don't bother appending empty room entries
if len(recentEvents) == 0 && len(delta.stateEvents) == 0 {
return nil
}
// If full_state=true and since is already up to date, then we'll have
// state events but no recent events.
prevPDUPos = toPos - 1
} else {
prevPDUPos = recentStreamEvents[0].streamPosition - 1
}
if prevPDUPos <= 0 {
prevPDUPos = 1
}
switch delta.membership {
case membershipJoin:
jr := types.NewJoinResponse()
if prevPDUPos := recentStreamEvents[0].streamPosition - 1; prevPDUPos > 0 {
// Use the short form of batch token for prev_batch
jr.Timeline.PrevBatch = strconv.FormatInt(prevPDUPos, 10)
} else {
// Use the short form of batch token for prev_batch
jr.Timeline.PrevBatch = "1"
}
jr.Timeline.Events = gomatrixserverlib.ToClientEvents(recentEvents, gomatrixserverlib.FormatSync)
jr.Timeline.Limited = false // TODO: if len(events) >= numRecents + 1 and then set limited:true
jr.State.Events = gomatrixserverlib.ToClientEvents(delta.stateEvents, gomatrixserverlib.FormatSync)
@ -618,13 +635,8 @@ func (d *SyncServerDatasource) addRoomDeltaToResponse(
// TODO: recentEvents may contain events that this user is not allowed to see because they are
// no longer in the room.
lr := types.NewLeaveResponse()
if prevPDUPos := recentStreamEvents[0].streamPosition - 1; prevPDUPos > 0 {
// Use the short form of batch token for prev_batch
lr.Timeline.PrevBatch = strconv.FormatInt(prevPDUPos, 10)
} else {
// Use the short form of batch token for prev_batch
lr.Timeline.PrevBatch = "1"
}
lr.Timeline.Events = gomatrixserverlib.ToClientEvents(recentEvents, gomatrixserverlib.FormatSync)
lr.Timeline.Limited = false // TODO: if len(events) >= numRecents + 1 and then set limited:true
lr.State.Events = gomatrixserverlib.ToClientEvents(delta.stateEvents, gomatrixserverlib.FormatSync)
@ -758,15 +770,11 @@ func (d *SyncServerDatasource) getStateDeltas(
if membership := getMembershipFromEvent(&ev.Event, userID); membership != "" {
if membership == membershipJoin {
// send full room state down instead of a delta
var allState []gomatrixserverlib.Event
allState, err = d.roomstate.selectCurrentState(ctx, txn, roomID)
var s []streamEvent
s, err = d.currentStateStreamEventsForRoom(ctx, txn, roomID)
if err != nil {
return nil, nil, err
}
s := make([]streamEvent, len(allState))
for i := 0; i < len(s); i++ {
s[i] = streamEvent{Event: allState[i], streamPosition: 0}
}
state[roomID] = s
continue // we'll add this room in when we do joined rooms
}
@ -798,6 +806,79 @@ func (d *SyncServerDatasource) getStateDeltas(
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 *SyncServerDatasource) getStateDeltasForFullStateSync(
ctx context.Context, device *authtypes.Device, txn *sql.Tx,
fromPos, toPos int64, userID string,
) ([]stateDelta, []string, error) {
joinedRoomIDs, err := d.roomstate.selectRoomIDsWithMembership(ctx, txn, userID, "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)
if stateErr != nil {
return nil, nil, stateErr
}
deltas = append(deltas, stateDelta{
membership: "join",
stateEvents: streamEventsToEvents(device, s),
roomID: joinedRoomID,
})
}
// Get all the state events ever between these two positions
stateNeeded, eventMap, err := d.events.selectStateInRange(ctx, txn, fromPos, toPos)
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 != "join" { // We've already added full state for all joined rooms above.
deltas = append(deltas, stateDelta{
membership: membership,
membershipPos: ev.streamPosition,
stateEvents: streamEventsToEvents(device, stateStreamEvents),
roomID: roomID,
})
}
break
}
}
}
return deltas, joinedRoomIDs, nil
}
func (d *SyncServerDatasource) currentStateStreamEventsForRoom(
ctx context.Context, txn *sql.Tx, roomID string,
) ([]streamEvent, error) {
allState, err := d.roomstate.selectCurrentState(ctx, txn, roomID)
if err != nil {
return nil, err
}
s := make([]streamEvent, len(allState))
for i := 0; i < len(s); i++ {
s[i] = streamEvent{Event: allState[i], streamPosition: 0}
}
return s, nil
}
// streamEventsToEvents converts streamEvent to Event. If device is non-nil and
// matches the streamevent.transactionID device then the transaction ID gets
// added to the unsigned section of the output event.

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@ -65,8 +65,7 @@ func (rp *RequestPool) OnIncomingSyncRequest(req *http.Request, device *authtype
currPos := rp.notifier.CurrentPosition()
// If this is an initial sync or timeout=0 we return immediately
if syncReq.since == nil || syncReq.timeout == 0 {
if shouldReturnImmediately(syncReq) {
syncData, err = rp.currentSyncForUser(*syncReq, currPos)
if err != nil {
return httputil.LogThenError(req, err)
@ -135,7 +134,7 @@ func (rp *RequestPool) currentSyncForUser(req syncRequest, latestPos types.SyncP
if req.since == nil {
res, err = rp.db.CompleteSync(req.ctx, req.device.UserID, req.limit)
} else {
res, err = rp.db.IncrementalSync(req.ctx, req.device, *req.since, latestPos, req.limit)
res, err = rp.db.IncrementalSync(req.ctx, req.device, *req.since, latestPos, req.limit, req.wantFullState)
}
if err != nil {
@ -216,3 +215,10 @@ func (rp *RequestPool) appendAccountData(
return data, nil
}
// shouldReturnImmediately returns whether the /sync request is an initial sync,
// or timeout=0, or full_state=true, in any of the cases the request should
// return immediately.
func shouldReturnImmediately(syncReq *syncRequest) bool {
return syncReq.since == nil || syncReq.timeout == 0 || syncReq.wantFullState
}

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@ -158,3 +158,4 @@ Inbound federation rejects remote attempts to join local users to rooms
Inbound federation rejects remote attempts to kick local users to rooms
An event which redacts itself should be ignored
A pair of events which redact each other should be ignored
Full state sync includes joined rooms