ccache/item.go
2014-03-23 07:53:29 +08:00

55 lines
920 B
Go

package ccache
import (
"container/list"
"sync"
"sync/atomic"
"time"
)
type TrackedItem interface {
Value() interface{}
Release()
}
type nilItem struct{}
func (n *nilItem) Value() interface{} { return nil }
func (n *nilItem) Release() {}
var NilTracked = new(nilItem)
type Item struct {
key string
sync.RWMutex
promotions int32
refCount int32
expires time.Time
value interface{}
element *list.Element
}
func newItem(key string, value interface{}, expires time.Time) *Item {
return &Item{
key: key,
value: value,
promotions: -1,
expires: expires,
}
}
func (i *Item) shouldPromote(getsPerPromote int32) bool {
return atomic.AddInt32(&i.promotions, 1) == getsPerPromote
}
func (i *Item) Value() interface{} {
return i.value
}
func (i *Item) track() {
atomic.AddInt32(&i.refCount, 1)
}
func (i *Item) Release() {
atomic.AddInt32(&i.refCount, -1)
}