Implement /sync API response struct

src/github.com/matrix-org/dendrite/clientapi/sync/requestpool.go

@@ -138,12 +138,12 @@ func (rp *RequestPool) waitForEvents(req syncRequest) syncapi.StreamPosition {
 	return currentPos
 }
 
-func (rp *RequestPool) currentSyncForUser(req syncRequest) ([]gomatrixserverlib.Event, error) {
+func (rp *RequestPool) currentSyncForUser(req syncRequest) (*syncapi.Response, error) {
 	currentPos := rp.waitForEvents(req)
 
-	// TODO: ignored users
+	// TODO: handle ignored users
 
-	// Implement https://github.com/matrix-org/synapse/blob/v0.19.3/synapse/handlers/sync.py#L821
+	// TODO: Implement https://github.com/matrix-org/synapse/blob/v0.19.3/synapse/handlers/sync.py#L821
 	// 1) Get the CURRENT joined room list for this user
 	// 2) Get membership list changes for this user between the provided stream position and now.
 	// 3) For each room which has membership list changes:
@@ -153,7 +153,23 @@ func (rp *RequestPool) currentSyncForUser(req syncRequest) ([]gomatrixserverlib.
 	//   c) Check if the user is CURRENTLY left/banned. If so, add room to 'archived' block. // Synapse has a TODO: How do we handle ban -> leave in same batch?
 	// 4) Add joined rooms (joined room list)
 
-	return rp.db.EventsInRange(int64(req.since), int64(currentPos))
+	events, err := rp.db.EventsInRange(int64(req.since), int64(currentPos))
+	if err != nil {
+		return nil, err
+	}
+
+	res := syncapi.NewResponse()
+	// for now, dump everything as join timeline events
+	for _, ev := range events {
+		roomData := res.Rooms.Join[ev.RoomID()]
+		roomData.Timeline.Events = append(roomData.Timeline.Events, ev)
+		res.Rooms.Join[ev.RoomID()] = roomData
+	}
+
+	// Make sure we send the next_batch as a string. We don't want to confuse clients by sending this
+	// as an integer even though (at the moment) it is.
+	res.NextBatch = currentPos.String()
+	return res, nil
 }
 
 func getTimeout(timeoutMS string) time.Duration {

src/github.com/matrix-org/dendrite/clientapi/sync/syncapi/syncapi.go

@@ -1,4 +1,112 @@
 package syncapi
 
+import (
+	"strconv"
+
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
 // StreamPosition represents the offset in the sync stream a client is at.
 type StreamPosition int64
+
+// String implements the Stringer interface.
+func (sp StreamPosition) String() string {
+	return strconv.FormatInt(int64(sp), 10)
+}
+
+// Response represents a /sync API response. See https://matrix.org/docs/spec/client_server/r0.2.0.html#get-matrix-client-r0-sync
+type Response struct {
+	NextBatch   string `json:"next_batch"`
+	AccountData struct {
+		Events []gomatrixserverlib.Event `json:"events"`
+	} `json:"account_data"`
+	Presence struct {
+		Events []gomatrixserverlib.Event `json:"events"`
+	} `json:"presence"`
+	Rooms struct {
+		Join   map[string]JoinResponse   `json:"join"`
+		Invite map[string]InviteResponse `json:"invite"`
+		Leave  map[string]LeaveResponse  `json:"leave"`
+	} `json:"rooms"`
+}
+
+// NewResponse creates an empty response with initialised maps.
+func NewResponse() *Response {
+	res := Response{}
+	// Pre-initalise the maps. Synapse will return {} even if there are no rooms under a specific section,
+	// so let's do the same thing. Bonus: this means we can't get dreaded 'assignment to entry in nil map' errors.
+	res.Rooms.Join = make(map[string]JoinResponse)
+	res.Rooms.Invite = make(map[string]InviteResponse)
+	res.Rooms.Leave = make(map[string]LeaveResponse)
+
+	// Also pre-intialise empty slices or else we'll insert 'null' instead of '[]' for the value.
+	// TODO: We really shouldn't have to do all this to coerce encoding/json to Do The Right Thing. We should
+	//       really be using our own Marshal/Unmarshal implementations otherwise this may prove to be a CPU bottleneck.
+	//       This also applies to NewJoinResponse, NewInviteResponse and NewLeaveResponse.
+	res.AccountData.Events = make([]gomatrixserverlib.Event, 0)
+	res.Presence.Events = make([]gomatrixserverlib.Event, 0)
+
+	return &res
+}
+
+// JoinResponse represents a /sync response for a room which is under the 'join' key.
+type JoinResponse struct {
+	State struct {
+		Events []gomatrixserverlib.Event `json:"events"`
+	} `json:"state"`
+	Timeline struct {
+		Events    []gomatrixserverlib.Event `json:"events"`
+		Limited   bool                      `json:"limited"`
+		PrevBatch string                    `json:"prev_batch"`
+	} `json:"timeline"`
+	Ephemeral struct {
+		Events []gomatrixserverlib.Event `json:"events"`
+	} `json:"ephemeral"`
+	AccountData struct {
+		Events []gomatrixserverlib.Event `json:"events"`
+	} `json:"account_data"`
+}
+
+// NewJoinResponse creates an empty response with initialised arrays.
+func NewJoinResponse() *JoinResponse {
+	res := JoinResponse{}
+	res.State.Events = make([]gomatrixserverlib.Event, 0)
+	res.Timeline.Events = make([]gomatrixserverlib.Event, 0)
+	res.Ephemeral.Events = make([]gomatrixserverlib.Event, 0)
+	res.AccountData.Events = make([]gomatrixserverlib.Event, 0)
+	return &res
+}
+
+// InviteResponse represents a /sync response for a room which is under the 'invite' key.
+type InviteResponse struct {
+	InviteState struct {
+		Events []gomatrixserverlib.Event
+	} `json:"invite_state"`
+}
+
+// NewInviteResponse creates an empty response with initialised arrays.
+func NewInviteResponse() *InviteResponse {
+	res := InviteResponse{}
+	res.InviteState.Events = make([]gomatrixserverlib.Event, 0)
+	return &res
+}
+
+// LeaveResponse represents a /sync response for a room which is under the 'leave' key.
+type LeaveResponse struct {
+	State struct {
+		Events []gomatrixserverlib.Event `json:"events"`
+	} `json:"state"`
+	Timeline struct {
+		Events    []gomatrixserverlib.Event `json:"events"`
+		Limited   bool                      `json:"limited"`
+		PrevBatch string                    `json:"prev_batch"`
+	} `json:"timeline"`
+}
+
+// NewLeaveResponse creates an empty response with initialised arrays.
+func NewLeaveResponse() *LeaveResponse {
+	res := LeaveResponse{}
+	res.State.Events = make([]gomatrixserverlib.Event, 0)
+	res.Timeline.Events = make([]gomatrixserverlib.Event, 0)
+	return &res
+}