Peeking via MSC2753 (#1370)

Initial implementation of MSC2753, as tested by https://github.com/matrix-org/sytest/pull/944.
Doesn't yet handle unpeeks, peeked EDUs, or history viz changing during a peek - these will follow.
https://github.com/matrix-org/dendrite/pull/1370 has full details.

2 files changed, 29 insertions, 0 deletions

diff --git a/roomserver/inthttp/client.go b/roomserver/inthttp/client.go
index b414b0d8..1ff1fc82 100644
--- a/roomserver/inthttp/client.go
+++ b/roomserver/inthttp/client.go
@@ -26,6 +26,7 @@ const (
 
 	// Perform operations
 	RoomserverPerformInvitePath   = "/roomserver/performInvite"
+	RoomserverPerformPeekPath     = "/roomserver/performPeek"
 	RoomserverPerformJoinPath     = "/roomserver/performJoin"
 	RoomserverPerformLeavePath    = "/roomserver/performLeave"
 	RoomserverPerformBackfillPath = "/roomserver/performBackfill"
@@ -185,6 +186,23 @@ func (h *httpRoomserverInternalAPI) PerformJoin(
 	}
 }
 
+func (h *httpRoomserverInternalAPI) PerformPeek(
+	ctx context.Context,
+	request *api.PerformPeekRequest,
+	response *api.PerformPeekResponse,
+) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "PerformPeek")
+	defer span.Finish()
+
+	apiURL := h.roomserverURL + RoomserverPerformPeekPath
+	err := httputil.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+	if err != nil {
+		response.Error = &api.PerformError{
+			Msg: fmt.Sprintf("failed to communicate with roomserver: %s", err),
+		}
+	}
+}
+
 func (h *httpRoomserverInternalAPI) PerformLeave(
 	ctx context.Context,
 	request *api.PerformLeaveRequest,
diff --git a/roomserver/inthttp/server.go b/roomserver/inthttp/server.go
index 97f2a360..5816d4d8 100644
--- a/roomserver/inthttp/server.go
+++ b/roomserver/inthttp/server.go
@@ -63,6 +63,17 @@ func AddRoutes(r api.RoomserverInternalAPI, internalAPIMux *mux.Router) {
 			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
 		}),
 	)
+	internalAPIMux.Handle(RoomserverPerformPeekPath,
+		httputil.MakeInternalAPI("performPeek", func(req *http.Request) util.JSONResponse {
+			var request api.PerformPeekRequest
+			var response api.PerformPeekResponse
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			r.PerformPeek(req.Context(), &request, &response)
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
 	internalAPIMux.Handle(RoomserverPerformPublishPath,
 		httputil.MakeInternalAPI("performPublish", func(req *http.Request) util.JSONResponse {
 			var request api.PerformPublishRequest