frostfs-sdk-go/pool/cache.go
Leonard Lyubich 552c7875bf [#197] session: Refactor and document the package
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2022-04-27 11:09:29 +03:00

71 lines
1.5 KiB
Go

package pool
import (
"strings"
"sync/atomic"
lru "github.com/hashicorp/golang-lru"
"github.com/nspcc-dev/neofs-sdk-go/session"
)
type sessionCache struct {
cache *lru.Cache
currentEpoch uint64
}
type cacheValue struct {
token session.Object
}
func newCache() (*sessionCache, error) {
cache, err := lru.New(100)
if err != nil {
return nil, err
}
return &sessionCache{cache: cache}, nil
}
// Get returns a copy of the session token from the cache without signature
// and context related fields. Returns nil if token is missing in the cache.
// It is safe to modify and re-sign returned session token.
func (c *sessionCache) Get(key string) (session.Object, bool) {
valueRaw, ok := c.cache.Get(key)
if !ok {
return session.Object{}, false
}
value := valueRaw.(*cacheValue)
if c.expired(value) {
c.cache.Remove(key)
return session.Object{}, false
}
return value.token, true
}
func (c *sessionCache) Put(key string, token session.Object) bool {
return c.cache.Add(key, &cacheValue{
token: token,
})
}
func (c *sessionCache) DeleteByPrefix(prefix string) {
for _, key := range c.cache.Keys() {
if strings.HasPrefix(key.(string), prefix) {
c.cache.Remove(key)
}
}
}
func (c *sessionCache) updateEpoch(newEpoch uint64) {
epoch := atomic.LoadUint64(&c.currentEpoch)
if newEpoch > epoch {
atomic.StoreUint64(&c.currentEpoch, newEpoch)
}
}
func (c *sessionCache) expired(val *cacheValue) bool {
epoch := atomic.LoadUint64(&c.currentEpoch)
return val.token.ExpiredAt(epoch)
}