NFD » ndn-cxx

For unrelated reasons, I was looking at ndns code the other day and I found this: https://github.com/named-data/ndns/blob/002bb42222b6d6ca17864e0965833b1fb4e31361/src/validator/certificate-fetcher-ndns-cert.cpp#L182

I believe we should centralize this mechanism of exponential retry + jitter for certificate fetchers, instead of reimplementing the same logic in every subclass. Ideally we should use SegmentFetcher, if that's not possible then the CertificateFetcher base class or some other utility class should provide this facility. It's pretty clear that it's relatively easy to get this logic wrong and reimplementing it everywhere is just asking for bugs.

we should centralize this mechanism of exponential retry + jitter for certificate fetchers, instead of reimplementing the same logic in every subclass. Ideally we should use SegmentFetcher

Exponential retry applies not only to segmented object, but also to all other Interests. Thus, it belongs to DataFetcher type. SegmentFetcher can then use DataFetcher to retrieve individual segments.