A hit opens the variant file and nothing else: its content type comes
from the file's first bytes, and a file in no output format is a miss.
Its access time and hit count, and the access time of a cached source a
miss uses, are handed without waiting to the goroutine that wrote late
counts, which now writes every count and access time once a second;
each kind of access time waits in a channel of 10,000 that drops the
rest. checkNegativeCache leaves expired rows to CleanExpired. The .meta
files, metaCache, Lookup and golang-lru go, with their tests. make bench
runs a parallel cache hit benchmark with Go on the host, outside make
check.
Model: opus-5-5
