func (ra *RegistrationAuthorityImpl) checkCertificatesPerFQDNSetLimit(ctx context.Context, names []string, limit ratelimit.RateLimitPolicy, regID int64) error {
	count, err := ra.SA.CountFQDNSets(ctx, limit.Window.Duration, names)
	if err != nil {
		return err
	}
	names = core.UniqueLowerNames(names)
	if int(count) > limit.GetThreshold(strings.Join(names, ","), regID) {
		return core.RateLimitedError(fmt.Sprintf(
			"Too many certificates already issued for exact set of domains: %s",
			strings.Join(names, ","),
		))
	}
	return nil
}

func (ra *RegistrationAuthorityImpl) checkCertificatesPerNameLimit(ctx context.Context, names []string, limit ratelimit.RateLimitPolicy, regID int64) error {
	names, err := domainsForRateLimiting(names)
	if err != nil {
		return err
	}
	now := ra.clk.Now()
	windowBegin := limit.WindowBegin(now)
	counts, err := ra.SA.CountCertificatesByNames(ctx, names, windowBegin, now)
	if err != nil {
		return err
	}
	var badNames []string
	for _, name := range names {
		count, ok := counts[name]
		if !ok {
			// Shouldn't happen, but let's be careful anyhow.
			return errors.New("StorageAuthority failed to return a count for every name")
		}
		if count >= limit.GetThreshold(name, regID) {
			badNames = append(badNames, name)
		}
	}
	if len(badNames) > 0 {
		// check if there is already a existing certificate for
		// the exact name set we are issuing for. If so bypass the
		// the certificatesPerName limit.
		exists, err := ra.SA.FQDNSetExists(ctx, names)
		if err != nil {
			return err
		}
		if exists {
			ra.certsForDomainStats.Inc("FQDNSetBypass", 1)
			return nil
		}
		domains := strings.Join(badNames, ", ")
		ra.certsForDomainStats.Inc("Exceeded", 1)
		ra.log.Info(fmt.Sprintf("Rate limit exceeded, CertificatesForDomain, regID: %d, domains: %s", regID, domains))
		return core.RateLimitedError(fmt.Sprintf(
			"Too many certificates already issued for: %s", domains))

	}
	ra.certsForDomainStats.Inc("Pass", 1)

	return nil
}