// newRangeDescriptorCache returns a new RangeDescriptorCache which
// uses the given RangeDescriptorDB as the underlying source of range
// descriptors.
func newRangeDescriptorCache(db RangeDescriptorDB, size int) *rangeDescriptorCache {
rdc := &rangeDescriptorCache{db: db}
rdc.rangeCache.cache = cache.NewOrderedCache(cache.Config{
Policy: cache.CacheLRU,
ShouldEvict: func(n int, _, _ interface{}) bool {
return n > size
},
})
rdc.lookupRequests.inflight = make(map[lookupRequestKey]lookupRequest)
return rdc
}
// newRaftEntryCache returns a new RaftEntryCache with the given
// maximum size in bytes.
func newRaftEntryCache(maxBytes uint64) *raftEntryCache {
rec := &raftEntryCache{
cache: cache.NewOrderedCache(cache.Config{Policy: cache.CacheLRU}),
}
// The raft entry cache mutex will be held when the ShouldEvict
// and OnEvicted callbacks are invoked.
//
// On ShouldEvict, compare the total size of the cache in bytes to the
// configured maxBytes. We also insist that at least one entry remains
// in the cache to prevent the case where a very large entry isn't able
// to be cached at all.
rec.cache.Config.ShouldEvict = func(n int, k, v interface{}) bool {
return rec.bytes > maxBytes && n >= 1
}
rec.cache.Config.OnEvicted = func(k, v interface{}) {
ent := v.(raftpb.Entry)
rec.bytes -= uint64(ent.Size())
}
return rec
}