Method PerformOutboundPeek

federationapi/internal/perform.go:307–385

PerformOutboundPeekRequest implements api.FederationInternalAPI

(
	ctx context.Context,
	request *api.PerformOutboundPeekRequest,
	response *api.PerformOutboundPeekResponse,
)

// PerformOutboundPeekRequest implements api.FederationInternalAPI
func (r *FederationInternalAPI) PerformOutboundPeek(
	ctx context.Context,
	request *api.PerformOutboundPeekRequest,
	response *api.PerformOutboundPeekResponse,
) error {
	// Look up the supported room versions.
	var supportedVersions []gomatrixserverlib.RoomVersion
	for version := range version.SupportedRoomVersions() {
		supportedVersions = append(supportedVersions, version)
	}

	// Deduplicate the server names we were provided but keep the ordering
	// as this encodes useful information about which servers are most likely
	// to respond.
	seenSet := make(map[gomatrixserverlib.ServerName]bool)
	var uniqueList []gomatrixserverlib.ServerName
	for _, srv := range request.ServerNames {
		if seenSet[srv] {
			continue
		}
		seenSet[srv] = true
		uniqueList = append(uniqueList, srv)
	}
	request.ServerNames = uniqueList

	// See if there's an existing outbound peek for this room ID with
	// one of the specified servers.
	if peeks, err := r.db.GetOutboundPeeks(ctx, request.RoomID); err == nil {
		for _, peek := range peeks {
			if _, ok := seenSet[peek.ServerName]; ok {
				return nil
			}
		}
	}

	// Try each server that we were provided until we land on one that
	// successfully completes the peek
	var lastErr error
	for _, serverName := range request.ServerNames {
		if err := r.performOutboundPeekUsingServer(
			ctx,
			request.RoomID,
			serverName,
			supportedVersions,
		); err != nil {
			logrus.WithError(err).WithFields(logrus.Fields{
				"server_name": serverName,
				"room_id":     request.RoomID,
			}).Warnf("Failed to peek room through server")
			lastErr = err
			continue
		}

		// We're all good.
		return nil
	}

	// If we reach here then we didn't complete a peek for some reason.