/
concurrent_lru.go
142 lines (116 loc) · 2.9 KB
/
concurrent_lru.go
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/*
* 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 concurrent_lru
import (
"github.com/IrineSistiana/mosdns/v4/pkg/lru"
"hash/maphash"
"sync"
)
type ShardedLRU[V any] struct {
seed maphash.Seed
l []*ConcurrentLRU[string, V]
}
func NewShardedLRU[V any](
shardNum, maxSizePerShard int,
onEvict func(key string, v V),
) *ShardedLRU[V] {
cl := &ShardedLRU[V]{
seed: maphash.MakeSeed(),
l: make([]*ConcurrentLRU[string, V], shardNum),
}
for i := range cl.l {
cl.l[i] = &ConcurrentLRU[string, V]{
lru: lru.NewLRU[string, V](maxSizePerShard, onEvict),
}
}
return cl
}
func (c *ShardedLRU[V]) Add(key string, v V) {
sl := c.getShard(key)
sl.Add(key, v)
}
func (c *ShardedLRU[V]) Del(key string) {
sl := c.getShard(key)
sl.Del(key)
}
func (c *ShardedLRU[V]) Clean(f func(key string, v V) (remove bool)) (removed int) {
for i := range c.l {
removed += c.l[i].Clean(f)
}
return removed
}
func (c *ShardedLRU[V]) Get(key string) (v V, ok bool) {
sl := c.getShard(key)
v, ok = sl.Get(key)
return
}
func (c *ShardedLRU[V]) Len() int {
sum := 0
for _, shard := range c.l {
sum += shard.Len()
}
return sum
}
func (c *ShardedLRU[V]) shardNum() int {
return len(c.l)
}
func (c *ShardedLRU[V]) getShard(key string) *ConcurrentLRU[string, V] {
h := maphash.Hash{}
h.SetSeed(c.seed)
h.WriteString(key)
n := h.Sum64() % uint64(c.shardNum())
return c.l[n]
}
// ConcurrentLRU is a lru.LRU with a lock.
// It is concurrent safe.
type ConcurrentLRU[K comparable, V any] struct {
sync.Mutex
lru *lru.LRU[K, V]
}
func NewConecurrentLRU[K comparable, V any](maxSize int, onEvict func(key K, v V)) *ConcurrentLRU[K, V] {
return &ConcurrentLRU[K, V]{
lru: lru.NewLRU[K, V](maxSize, onEvict),
}
}
func (c *ConcurrentLRU[K, V]) Add(key K, v V) {
c.Lock()
defer c.Unlock()
c.lru.Add(key, v)
}
func (c *ConcurrentLRU[K, V]) Del(key K) {
c.Lock()
defer c.Unlock()
c.lru.Del(key)
}
func (c *ConcurrentLRU[K, V]) Clean(f func(key K, v V) (remove bool)) (removed int) {
c.Lock()
defer c.Unlock()
return c.lru.Clean(f)
}
func (c *ConcurrentLRU[K, V]) Get(key K) (v V, ok bool) {
c.Lock()
defer c.Unlock()
v, ok = c.lru.Get(key)
return
}
func (c *ConcurrentLRU[K, V]) Len() int {
c.Lock()
defer c.Unlock()
return c.lru.Len()
}