Function getState

federationapi/routing/state.go:97–150

(
	ctx context.Context,
	request *gomatrixserverlib.FederationRequest,
	rsAPI api.FederationRoomserverAPI,
	roomID string,
	eventID string,
)

}

func getState(
	ctx context.Context,
	request *gomatrixserverlib.FederationRequest,
	rsAPI api.FederationRoomserverAPI,
	roomID string,
	eventID string,
) (stateEvents, authEvents []*gomatrixserverlib.HeaderedEvent, errRes *util.JSONResponse) {
	// If we don't think we belong to this room then don't waste the effort
	// responding to expensive requests for it.
	if err := ErrorIfLocalServerNotInRoom(ctx, rsAPI, roomID); err != nil {
		return nil, nil, err
	}

	event, resErr := fetchEvent(ctx, rsAPI, eventID)
	if resErr != nil {
		return nil, nil, resErr
	}

	if event.RoomID() != roomID {
		return nil, nil, &util.JSONResponse{Code: http.StatusNotFound, JSON: jsonerror.NotFound("event does not belong to this room")}
	}
	resErr = allowedToSeeEvent(ctx, request.Origin(), rsAPI, eventID)
	if resErr != nil {
		return nil, nil, resErr
	}

	var response api.QueryStateAndAuthChainResponse
	err := rsAPI.QueryStateAndAuthChain(
		ctx,
		&api.QueryStateAndAuthChainRequest{
			RoomID:       roomID,
			PrevEventIDs: []string{eventID},
			AuthEventIDs: event.AuthEventIDs(),
		},
		&response,
	)
	if err != nil {
		resErr := util.ErrorResponse(err)
		return nil, nil, &resErr
	}

	if response.IsRejected {
		return nil, nil, &util.JSONResponse{
			Code: http.StatusNotFound,
			JSON: jsonerror.NotFound("Event not found"),
		}
	}

	if !response.RoomExists {
		return nil, nil, &util.JSONResponse{Code: http.StatusNotFound, JSON: nil}
	}

	return response.StateEvents, response.AuthChainEvents, nil
}

func getIDsFromEvent(events []*gomatrixserverlib.HeaderedEvent) []string {
	IDs := make([]string, len(events))