You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
89 lines
1.5 KiB
Go
89 lines
1.5 KiB
Go
package lru
|
|
|
|
import (
|
|
"container/list"
|
|
"sync"
|
|
)
|
|
|
|
type node struct {
|
|
k interface{}
|
|
v interface{}
|
|
}
|
|
|
|
type LRU struct {
|
|
mutex sync.RWMutex
|
|
maxLen int // if maxLen<=0 then no limit
|
|
lruList *list.List
|
|
datas map[interface{}]*list.Element
|
|
}
|
|
|
|
func New(maxLen int) *LRU {
|
|
return &LRU{
|
|
maxLen: maxLen,
|
|
lruList: list.New(),
|
|
datas: make(map[interface{}]*list.Element),
|
|
}
|
|
}
|
|
|
|
func (lc *LRU) PushFront(k, v interface{}) {
|
|
lc.mutex.Lock()
|
|
defer lc.mutex.Unlock()
|
|
|
|
if e, ok := lc.datas[k]; ok {
|
|
e.Value.(*node).v = v
|
|
lc.lruList.MoveToFront(e)
|
|
} else {
|
|
e := lc.lruList.PushFront(&node{k, v})
|
|
lc.datas[k] = e
|
|
}
|
|
if lc.maxLen > 0 && lc.lruList.Len() > lc.maxLen {
|
|
lc.popTail()
|
|
}
|
|
}
|
|
|
|
func (lc *LRU) PopTail() (interface{}, bool) {
|
|
lc.mutex.Lock()
|
|
defer lc.mutex.Unlock()
|
|
|
|
return lc.popTail()
|
|
}
|
|
|
|
func (lc *LRU) Get(k interface{}) (interface{}, bool) {
|
|
lc.mutex.Lock()
|
|
defer lc.mutex.Unlock()
|
|
|
|
if e, ok := lc.datas[k]; ok {
|
|
lc.lruList.MoveToFront(e)
|
|
return e.Value.(*node).v, ok
|
|
}
|
|
return nil, false
|
|
}
|
|
|
|
func (lc *LRU) Del(k interface{}) {
|
|
lc.mutex.Lock()
|
|
defer lc.mutex.Unlock()
|
|
lc.del(k)
|
|
}
|
|
|
|
func (lc *LRU) Len() int {
|
|
lc.mutex.RLock()
|
|
defer lc.mutex.RUnlock()
|
|
return lc.lruList.Len()
|
|
}
|
|
|
|
func (lc *LRU) popTail() (interface{}, bool) {
|
|
e := lc.lruList.Back()
|
|
if e != nil {
|
|
lc.del(e.Value.(*node).k)
|
|
return e.Value.(*node).v, true
|
|
}
|
|
return nil, false
|
|
}
|
|
|
|
func (lc *LRU) del(k interface{}) {
|
|
if e, ok := lc.datas[k]; ok {
|
|
delete(lc.datas, k)
|
|
lc.lruList.Remove(e)
|
|
}
|
|
}
|