frostfs-node/cmd/neofs-node/cache.go
Leonard Lyubich 34a51ed38b [#419] cmd/node: Cache containers read from sidechain
Implement LRU cache for values read from the network. Implement LRU cache of
containers read from sidechain. Use it as a container storage in neofs-node
app. Current cache size is set to 100, TTL is 30s (constants).

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2021-03-04 16:33:29 +03:00

110 lines
2.1 KiB
Go

package main
import (
"sync"
"time"
lru "github.com/hashicorp/golang-lru"
containerSDK "github.com/nspcc-dev/neofs-api-go/pkg/container"
"github.com/nspcc-dev/neofs-node/pkg/core/container"
)
type netValueReader func(interface{}) (interface{}, error)
type valueWithTime struct {
v interface{}
t time.Time
}
// entity that provides TTL cache interface.
type ttlNetCache struct {
mtx sync.Mutex
ttl time.Duration
sz int
cache *lru.Cache
netRdr netValueReader
}
// complicates netValueReader with TTL caching mechanism.
func newNetworkTTLCache(sz int, ttl time.Duration, netRdr netValueReader) *ttlNetCache {
cache, err := lru.New(sz)
fatalOnErr(err)
return &ttlNetCache{
ttl: ttl,
sz: sz,
cache: cache,
netRdr: netRdr,
}
}
// reads value by the key.
//
// updates the value from the network on cache miss or by TTL.
//
// returned value should not be modified.
func (c *ttlNetCache) get(key interface{}) (interface{}, error) {
c.mtx.Lock()
defer c.mtx.Unlock()
val, ok := c.cache.Peek(key)
if ok {
valWithTime := val.(*valueWithTime)
if time.Since(valWithTime.t) < c.ttl {
valWithTime.t = time.Now()
return valWithTime.v, nil
}
c.cache.Remove(key)
}
val, err := c.netRdr(key)
if err != nil {
return nil, err
}
c.cache.Add(key, &valueWithTime{
v: val,
t: time.Now(),
})
return val, nil
}
// wrapper over TTL cache of values read from the network
// that implements container storage.
type ttlContainerStorage ttlNetCache
func newCachedContainerStorage(v container.Source) container.Source {
const (
containerCacheSize = 100
containerCacheTTL = 30 * time.Second
)
lruCnrCache := newNetworkTTLCache(containerCacheSize, containerCacheTTL, func(key interface{}) (interface{}, error) {
cid := containerSDK.NewID()
err := cid.Parse(key.(string))
if err != nil {
return nil, err
}
return v.Get(cid)
})
return (*ttlContainerStorage)(lruCnrCache)
}
func (s *ttlContainerStorage) Get(cid *containerSDK.ID) (*containerSDK.Container, error) {
val, err := (*ttlNetCache)(s).get(cid.String())
if err != nil {
return nil, err
}
return val.(*containerSDK.Container), nil
}