* Rename middleware to plugin
first pass; mostly used 'sed', few spots where I manually changed
text.
This still builds a coredns binary.
* fmt error
* Rename AddMiddleware to AddPlugin
* Readd AddMiddleware to remain backwards compat
* cache: add sharded cache implementation
Add Cache impl and a few tests. This cache is 256-way sharded, mainly
so each shard has it's own lock. The main cache structure is a readonly
jump plane into the right shard.
This should remove the single lock contention on the main lock and
provide more concurrent throughput - Obviously this hasn't been tested
or measured.
The key into the cache was made a uint32 (hash.fnv) and the hashing op
is not using strings.ToLower anymore remove any GC in that code path.
* here too
* Minimum shard size
* typos
* blurp
* small cleanups no defer
* typo
* Add freq based on Johns idea
* cherry-pick conflict resolv
* typo
* update from early code review from john
* add prefetch to the cache
* mw/cache: add prefetch
* remove println
* remove comment
* Fix tests
* Test prefetch in setup
* Add start of cache
* try add diff cache options
* Add hacky testcase
* not needed
* allow the use of a percentage for prefetch
If the TTL falls below xx% do a prefetch, if the record was popular.
Some other fixes and correctly prefetch only popular records.
