Method handleFetcherKeys

federationapi/internal/keys.go:181–248

handleFetcherKeys handles cases where a fetcher can satisfy the remaining requests.

(
	ctx context.Context,
	_ gomatrixserverlib.Timestamp,
	fetcher gomatrixserverlib.KeyFetcher,
	requests map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.Timestamp,
	results map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult,
)

// handleFetcherKeys handles cases where a fetcher can satisfy
// the remaining requests.
func (s *FederationInternalAPI) handleFetcherKeys(
	ctx context.Context,
	_ gomatrixserverlib.Timestamp,
	fetcher gomatrixserverlib.KeyFetcher,
	requests map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.Timestamp,
	results map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult,
) error {
	logrus.WithFields(logrus.Fields{
		"fetcher_name": fetcher.FetcherName(),
	}).Infof("Fetching %d key(s)", len(requests))

	// Create a context that limits our requests to 30 seconds.
	fetcherCtx, fetcherCancel := context.WithTimeout(ctx, time.Second*30)
	defer fetcherCancel()

	// Try to fetch the keys.
	fetcherResults, err := fetcher.FetchKeys(fetcherCtx, requests)
	if err != nil {
		return fmt.Errorf("fetcher.FetchKeys: %w", err)
	}

	// Build a map of the results that we want to commit to the
	// database. We do this in a separate map because otherwise we
	// might end up trying to rewrite database entries.
	storeResults := map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult{}

	// Now let's look at the results that we got from this fetcher.
	for req, res := range fetcherResults {
		if prev, ok := results[req]; ok {
			// We've already got a previous entry for this request
			// so let's see if the newly retrieved one contains a more
			// up-to-date validity period.
			if res.ValidUntilTS > prev.ValidUntilTS {
				// This key is newer than the one we had so let's store
				// it in the database.
				storeResults[req] = res
			}
		} else {
			// We didn't already have a previous entry for this request
			// so store it in the database anyway for now.
			storeResults[req] = res
		}

		// Update the results map with this new result. If nothing
		// else, we can try verifying against this key.
		results[req] = res

		// Remove it from the request list so we won't re-fetch it.
		delete(requests, req)
	}

	// Store the keys from our store map.
	if err = s.keyRing.KeyDatabase.StoreKeys(context.Background(), storeResults); err != nil {
		logrus.WithError(err).WithFields(logrus.Fields{
			"fetcher_name":  fetcher.FetcherName(),
			"database_name": s.keyRing.KeyDatabase.FetcherName(),
		}).Errorf("Failed to store keys in the database")
		return fmt.Errorf("server key API failed to store retrieved keys: %w", err)