score has now meaning of ‘RTT’, maximum RTT is 10s
which is also the penalty for timeout
unknown servers are favorized as 10ms servers to
encourage resolver to try them out, if they contain
unknown glue they are most favourable

Merge branch 'cache-api-noglobal-wip' of gitlab.labs.nic.cz:knot/resolver into cache-api-noglobal-wip

the only condition of caching an answer is that it resolves a query and is not already cached
(ok, it must be negative at this point…)

if an authoritative answer comes and the server responds correctly, but appends out-of-bailiwick NS records, ignore them but resolve the query

previously it restarted query production for each NS, now it loops until it finds a suitor or bails out

this fixes a bug when storing NODATA without SOA,NS or any other ‘authoritative answer’ hint

since the zone cut is looked up after layers now, it
is pointless to search for minimized names from cache,
since this is the same operation as searching for a zone cut

if the query is satisfied from cache, it doesn’t need a zone cut lookup, so it may be deferred until an outbound query is about the be issued.

since the next CNAME target query was added on top, it replaced
the original ‘current query’, this caused recaching of an answer
if it came from cache (as the query flags have changed)

this prepares cache/txn structures to hold API as well, so we can get
rid of the global api

this fixes a problem when module is unloaded at runtime
and active

the bindings wrote the keys on completion, so they existed
and __newindex was never called - now current {storage|size}
are saved as cache.current_{storage|size}

memcached is a distributed caching system, it is a good fit
for building resolvers with shared and replicated cache