136 lines
2.7 KiB
Go
136 lines
2.7 KiB
Go
/*
|
|
* Copyright (C) 2020-2022, IrineSistiana
|
|
*
|
|
* This file is part of mosdns.
|
|
*
|
|
* mosdns is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* mosdns is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <https://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
package lru
|
|
|
|
import (
|
|
"fmt"
|
|
"github.com/IrineSistiana/mosdns/v5/pkg/list"
|
|
)
|
|
|
|
type LRU[K comparable, V any] struct {
|
|
maxSize int
|
|
onEvict func(key K, v V)
|
|
|
|
l *list.List[KV[K, V]]
|
|
m map[K]*list.Elem[KV[K, V]]
|
|
}
|
|
|
|
type KV[K comparable, V any] struct {
|
|
key K
|
|
v V
|
|
}
|
|
|
|
func NewLRU[K comparable, V any](maxSize int, onEvict func(key K, v V)) *LRU[K, V] {
|
|
if maxSize <= 0 {
|
|
panic(fmt.Sprintf("LRU: invalid max size: %d", maxSize))
|
|
}
|
|
|
|
return &LRU[K, V]{
|
|
maxSize: maxSize,
|
|
onEvict: onEvict,
|
|
l: list.New[KV[K, V]](),
|
|
m: make(map[K]*list.Elem[KV[K, V]]),
|
|
}
|
|
}
|
|
|
|
func (q *LRU[K, V]) Add(key K, v V) {
|
|
if e, ok := q.m[key]; ok { // update existed key
|
|
e.Value.v = v
|
|
q.l.PushBack(q.l.PopElem(e))
|
|
return
|
|
}
|
|
|
|
o := q.Len() - q.maxSize + 1
|
|
for o > 0 {
|
|
key, v, _ := q.PopOldest()
|
|
if q.onEvict != nil {
|
|
q.onEvict(key, v)
|
|
}
|
|
o--
|
|
}
|
|
|
|
e := list.NewElem(KV[K, V]{
|
|
key: key,
|
|
v: v,
|
|
})
|
|
q.m[key] = e
|
|
q.l.PushBack(e)
|
|
}
|
|
|
|
func (q *LRU[K, V]) Del(key K) {
|
|
e := q.m[key]
|
|
if e != nil {
|
|
q.delElem(e)
|
|
}
|
|
}
|
|
|
|
func (q *LRU[K, V]) delElem(e *list.Elem[KV[K, V]]) {
|
|
key, v := e.Value.key, e.Value.v
|
|
q.l.PopElem(e)
|
|
delete(q.m, key)
|
|
if q.onEvict != nil {
|
|
q.onEvict(key, v)
|
|
}
|
|
}
|
|
|
|
func (q *LRU[K, V]) PopOldest() (key K, v V, ok bool) {
|
|
e := q.l.Front()
|
|
if e != nil {
|
|
q.l.PopElem(e)
|
|
key, v = e.Value.key, e.Value.v
|
|
delete(q.m, key)
|
|
ok = true
|
|
return
|
|
}
|
|
return
|
|
}
|
|
|
|
func (q *LRU[K, V]) Clean(f func(key K, v V) (remove bool)) (removed int) {
|
|
e := q.l.Front()
|
|
for e != nil {
|
|
next := e.Next() // Delete e will clean its pointers. Save it first.
|
|
key, v := e.Value.key, e.Value.v
|
|
if remove := f(key, v); remove {
|
|
q.delElem(e)
|
|
removed++
|
|
}
|
|
e = next
|
|
}
|
|
return removed
|
|
}
|
|
|
|
func (q *LRU[K, V]) Flush() {
|
|
q.l = list.New[KV[K, V]]()
|
|
q.m = make(map[K]*list.Elem[KV[K, V]])
|
|
}
|
|
|
|
func (q *LRU[K, V]) Get(key K) (v V, ok bool) {
|
|
e, ok := q.m[key]
|
|
if !ok {
|
|
return
|
|
}
|
|
q.l.PushBack(q.l.PopElem(e))
|
|
return e.Value.v, true
|
|
}
|
|
|
|
func (q *LRU[K, V]) Len() int {
|
|
return q.l.Len()
|
|
}
|