1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
package filecache
import (
"time"
"github.com/anacrolix/missinggo/orderedmap"
)
type lru struct {
o orderedmap.OrderedMap
oKeys map[policyItemKey]lruKey
}
type lruKey struct {
item policyItemKey
used time.Time
}
func (me lruKey) Before(other lruKey) bool {
if me.used.Equal(other.used) {
return me.item.Before(other.item)
}
return me.used.Before(other.used)
}
var _ Policy = (*lru)(nil)
func (me *lru) Choose() (ret policyItemKey) {
any := false
me.o.Iter(func(i interface{}) bool {
ret = i.(lruKey).item
any = true
return false
})
if !any {
panic("cache empty")
}
return
}
func (me *lru) Used(k policyItemKey, at time.Time) {
if me.o == nil {
me.o = orderedmap.NewGoogleBTree(func(l, r interface{}) bool {
return l.(lruKey).Before(r.(lruKey))
})
} else {
me.o.Unset(me.oKeys[k])
}
lk := lruKey{k, at}
me.o.Set(lk, lk)
if me.oKeys == nil {
me.oKeys = make(map[policyItemKey]lruKey)
}
me.oKeys[k] = lk
}
func (me *lru) Forget(k policyItemKey) {
if me.o != nil {
me.o.Unset(me.oKeys[k])
}
delete(me.oKeys, k)
}
func (me *lru) NumItems() int {
return len(me.oKeys)
}
|
