缓存策略实现LFU算法/实现内存缓存自动Flush数据到磁盘

2025-11-04 15:51:54 +08:00 · 2021-11-13 21:30:24 +08:00
parent 188fe12a0b
commit 07cb2bb303
20 changed files with 1100 additions and 89 deletions
--- a/go.mod
+++ b/go.mod
@@ -16,14 +16,16 @@ require (
 	github.com/go-ole/go-ole v1.2.4 // indirect
 	github.com/go-yaml/yaml v2.1.0+incompatible
 	github.com/golang/protobuf v1.5.2
-	github.com/iwind/TeaGo v0.0.0-20210628135026-38575a4ab060
+	github.com/iwind/TeaGo v0.0.0-20211026123858-7de7a21cad24
 	github.com/iwind/gofcgi v0.0.0-20210528023741-a92711d45f11
 	github.com/iwind/gosock v0.0.0-20210722083328-12b2d66abec3
 	github.com/iwind/gowebp v0.0.0-20211029040624-7331ecc78ed8
+	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/jsummers/gobmp v0.0.0-20151104160322-e2ba15ffa76e // indirect
 	github.com/lionsoul2014/ip2region v2.2.0-release+incompatible
-	github.com/mattn/go-sqlite3 v2.0.3+incompatible
+	github.com/mattn/go-sqlite3 v1.14.9
 	github.com/miekg/dns v1.1.43
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/mssola/user_agent v0.5.2
 	github.com/pires/go-proxyproto v0.6.1
 	github.com/shirou/gopsutil v3.21.5+incompatible
--- a/go.sum
+++ b/go.sum
@@ -78,6 +78,8 @@ github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/iwind/TeaGo v0.0.0-20210628135026-38575a4ab060 h1:qdLtK4PDXxk2vMKkTWl5Fl9xqYuRCukzWAgJbLHdfOo=
 github.com/iwind/TeaGo v0.0.0-20210628135026-38575a4ab060/go.mod h1:KU4mS7QNiZ7QWEuDBk1zw0/Q2LrAPZv3tycEFBsuUwc=
+github.com/iwind/TeaGo v0.0.0-20211026123858-7de7a21cad24 h1:1cGulkD2SNJJRok5OKwyhP/Ddm+PgSWKOupn0cR36/A=
+github.com/iwind/TeaGo v0.0.0-20211026123858-7de7a21cad24/go.mod h1:KU4mS7QNiZ7QWEuDBk1zw0/Q2LrAPZv3tycEFBsuUwc=
 github.com/iwind/gofcgi v0.0.0-20210528023741-a92711d45f11 h1:DaQjoWZhLNxjhIXedVg4/vFEtHkZhK4IjIwsWdyzBLg=
 github.com/iwind/gofcgi v0.0.0-20210528023741-a92711d45f11/go.mod h1:JtbX20untAjUVjZs1ZBtq80f5rJWvwtQNRL6EnuYRnY=
 github.com/iwind/gosock v0.0.0-20210722083328-12b2d66abec3 h1:aBSonas7vFcgTj9u96/bWGILGv1ZbUSTLiOzcI1ZT6c=
@@ -85,6 +87,8 @@ github.com/iwind/gosock v0.0.0-20210722083328-12b2d66abec3/go.mod h1:H5Q7SXwbx3a
 github.com/iwind/gowebp v0.0.0-20211029040624-7331ecc78ed8 h1:AojsHz9Es9B3He2MQQxeRq3TyD//o9huxUo7r1wh44g=
 github.com/iwind/gowebp v0.0.0-20211029040624-7331ecc78ed8/go.mod h1:QJBY2txYhLMzwLO29iB5ujDJ3s3V7DsZ582nw4Ss+tM=
 github.com/json-iterator/go v1.1.10/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
+github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
+github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/jsummers/gobmp v0.0.0-20151104160322-e2ba15ffa76e h1:LvL4XsI70QxOGHed6yhQtAU34Kx3Qq2wwBzGFKY8zKk=
 github.com/jsummers/gobmp v0.0.0-20151104160322-e2ba15ffa76e/go.mod h1:kLgvv7o6UM+0QSf0QjAse3wReFDsb9qbZJdfexWlrQw=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
@@ -96,12 +100,18 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/lionsoul2014/ip2region v2.2.0-release+incompatible h1:1qp9iks+69h7IGLazAplzS9Ca14HAxuD5c0rbFdPGy4=
 github.com/lionsoul2014/ip2region v2.2.0-release+incompatible/go.mod h1:+ZBN7PBoh5gG6/y0ZQ85vJDBe21WnfbRrQQwTfliJJI=
+github.com/mattn/go-sqlite3 v1.14.9 h1:10HX2Td0ocZpYEjhilsuo6WWtUqttj2Kb0KtD86/KYA=
+github.com/mattn/go-sqlite3 v1.14.9/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/mattn/go-sqlite3 v2.0.3+incompatible h1:gXHsfypPkaMZrKbD5209QV9jbUTJKjyR5WD3HYQSd+U=
 github.com/mattn/go-sqlite3 v2.0.3+incompatible/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
 github.com/miekg/dns v1.1.43 h1:JKfpVSCB84vrAmHzyrsxB5NAr5kLoMXZArPSw7Qlgyg=
 github.com/miekg/dns v1.1.43/go.mod h1:+evo5L0630/F6ca/Z9+GAqzhjGyn8/c+TBaOyfEl0V4=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
+github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg=
+github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
+github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9Gz0M=
+github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
 github.com/mssola/user_agent v0.5.2 h1:CZkTUahjL1+OcZ5zv3kZr8QiJ8jy2H08vZIEkBeRbxo=
 github.com/mssola/user_agent v0.5.2/go.mod h1:TTPno8LPY3wAIEKRpAtkdMT0f8SE24pLRGPahjCH4uw=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
--- a/internal/caches/item.go
+++ b/internal/caches/item.go
@@ -2,6 +2,7 @@ package caches

 import (
 	"github.com/TeaOSLab/EdgeNode/internal/utils"
+	"time"
 )

 type ItemType = int
@@ -11,6 +12,12 @@ const (
 	ItemTypeMemory ItemType = 2
 )

+// 计算当前周
+// 不要用YW，因为需要计算两周是否临近
+func currentWeek() int32 {
+	return int32(time.Now().Unix() / 604800)
+}
+
 type Item struct {
 	Type       ItemType `json:"type"`
 	Key        string   `json:"key"`
@@ -20,6 +27,10 @@ type Item struct {
 	MetaSize   int64    `json:"metaSize"`
 	Host       string   `json:"host"`     // 主机名
 	ServerId   int64    `json:"serverId"` // 服务ID
+
+	Week1Hits int64 `json:"week1Hits"`
+	Week2Hits int64 `json:"week2Hits"`
+	Week      int32 `json:"week"`
 }

 func (this *Item) IsExpired() bool {
@@ -27,9 +38,23 @@ func (this *Item) IsExpired() bool {
 }

 func (this *Item) TotalSize() int64 {
-	return this.Size() + this.MetaSize + int64(len(this.Key)) + int64(len(this.Host)) + 64
+	return this.Size() + this.MetaSize + int64(len(this.Key)) + int64(len(this.Host))
 }

 func (this *Item) Size() int64 {
 	return this.HeaderSize + this.BodySize
 }
+
+func (this *Item) IncreaseHit(week int32) {
+	if this.Week == week {
+		this.Week2Hits++
+	} else {
+		if week-this.Week == 1 {
+			this.Week1Hits = this.Week2Hits
+		} else {
+			this.Week1Hits = 0
+		}
+		this.Week2Hits = 1
+		this.Week = week
+	}
+}
--- a/internal/caches/item_test.go
+++ b/internal/caches/item_test.go
@@ -0,0 +1,82 @@
+// Copyright 2021 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package caches
+
+import (
+	"github.com/iwind/TeaGo/rands"
+	"github.com/iwind/TeaGo/types"
+	"runtime"
+	"testing"
+	"time"
+)
+
+func TestItem_IncreaseHit(t *testing.T) {
+	var week = currentWeek()
+
+	var item = &Item{}
+	//item.Week = 2704
+	item.Week2Hits = 100
+	item.IncreaseHit(week)
+	t.Log("week:", item.Week, "week1:", item.Week1Hits, "week2:", item.Week2Hits)
+
+	item.IncreaseHit(week)
+	t.Log("week:", item.Week, "week1:", item.Week1Hits, "week2:", item.Week2Hits)
+}
+
+func TestItems_Memory(t *testing.T) {
+	var stat = &runtime.MemStats{}
+	runtime.ReadMemStats(stat)
+	var memory1 = stat.HeapInuse
+
+	var items = []*Item{}
+	for i := 0; i < 10_000_000; i++ {
+		items = append(items, &Item{
+			Key: types.String(i),
+		})
+	}
+
+	runtime.ReadMemStats(stat)
+	var memory2 = stat.HeapInuse
+
+	t.Log(memory1, memory2, (memory2-memory1)/1024/1024, "M")
+
+	var weekItems = make(map[string]*Item, 10_000_000)
+
+	for _, item := range items {
+		weekItems[item.Key] = item
+	}
+
+	runtime.ReadMemStats(stat)
+	var memory3 = stat.HeapInuse
+	t.Log(memory2, memory3, (memory3-memory2)/1024/1024, "M")
+
+	time.Sleep(1 * time.Second)
+	t.Log(len(items), len(weekItems))
+}
+
+func TestItems_Memory2(t *testing.T) {
+	var stat = &runtime.MemStats{}
+	runtime.ReadMemStats(stat)
+	var memory1 = stat.HeapInuse
+
+	var items = map[int32]map[string]bool{}
+	for i := 0; i < 10_000_000; i++ {
+		var week = int32((time.Now().Unix() - int64(86400*rands.Int(0, 300))) / (86400 * 7))
+		m, ok := items[week]
+		if !ok {
+			m = map[string]bool{}
+			items[week] = m
+		}
+		m[types.String(int64(i)*1_000_000)] = true
+	}
+
+	runtime.ReadMemStats(stat)
+	var memory2 = stat.HeapInuse
+
+	t.Log(memory1, memory2, (memory2-memory1)/1024/1024, "M")
+
+	time.Sleep(1 * time.Second)
+	for w, i := range items {
+		t.Log(w, len(i))
+	}
+}
--- a/internal/caches/list_file.go
+++ b/internal/caches/list_file.go
@@ -8,6 +8,7 @@ import (
 	"github.com/TeaOSLab/EdgeNode/internal/ttlcache"
 	"github.com/TeaOSLab/EdgeNode/internal/utils"
 	"github.com/iwind/TeaGo/lists"
+	timeutil "github.com/iwind/TeaGo/utils/time"
 	_ "github.com/mattn/go-sqlite3"
 	"os"
 	"strconv"
@@ -24,6 +25,7 @@ type FileList struct {
 	onAdd    func(item *Item)
 	onRemove func(item *Item)

+	// cacheItems
 	existsByHashStmt *sql.Stmt // 根据hash检查是否存在
 	insertStmt       *sql.Stmt // 写入数据
 	selectByHashStmt *sql.Stmt // 使用hash查询数据
@@ -32,8 +34,15 @@ type FileList struct {
 	purgeStmt        *sql.Stmt // 清理
 	deleteAllStmt    *sql.Stmt // 删除所有数据

+	// hits
+	insertHitStmt       *sql.Stmt // 写入数据
+	increaseHitStmt     *sql.Stmt // 增加点击量
+	deleteHitByHashStmt *sql.Stmt // 根据hash删除数据
+	lfuHitsStmt         *sql.Stmt // 读取老的数据
+
 	oldTables      []string
 	itemsTableName string
+	hitsTableName  string

 	isClosed bool

@@ -59,6 +68,7 @@ func (this *FileList) Init() error {
 	}

 	this.itemsTableName = "cacheItems_v2"
+	this.hitsTableName = "hits"

 	var dir = this.dir
 	if dir == "/" {
@@ -141,6 +151,23 @@ func (this *FileList) Init() error {
 		return err
 	}

+	this.insertHitStmt, err = this.db.Prepare(`INSERT INTO "` + this.hitsTableName + `" ("hash", "week2Hits", "week") VALUES (?, 1, ?)`)
+
+	this.increaseHitStmt, err = this.db.Prepare(`INSERT INTO "` + this.hitsTableName + `" ("hash", "week2Hits", "week") VALUES (?, 1, ?) ON CONFLICT("hash") DO UPDATE SET "week1Hits"=IIF("week"=?, "week1Hits", "week2Hits"), "week2Hits"=IIF("week"=?, "week2Hits"+1, 1), "week"=?`)
+	if err != nil {
+		return err
+	}
+
+	this.deleteHitByHashStmt, err = this.db.Prepare(`DELETE FROM "` + this.hitsTableName + `" WHERE "hash"=?`)
+	if err != nil {
+		return err
+	}
+
+	this.lfuHitsStmt, err = this.db.Prepare(`SELECT "hash" FROM "` + this.hitsTableName + `" ORDER BY "week" ASC, "week1Hits"+"week2Hits" ASC LIMIT ?`)
+	if err != nil {
+		return err
+	}
+
 	return nil
 }

@@ -159,6 +186,11 @@ func (this *FileList) Add(hash string, item *Item) error {
 		return err
 	}

+	_, err = this.insertHitStmt.Exec(hash, timeutil.Format("YW"))
+	if err != nil {
+		return err
+	}
+
 	atomic.AddInt64(&this.total, 1)

 	if this.onAdd != nil {
@@ -253,6 +285,11 @@ func (this *FileList) Remove(hash string) error {
 		return err
 	}

+	_, err = this.deleteHitByHashStmt.Exec(hash)
+	if err != nil {
+		return err
+	}
+
 	atomic.AddInt64(&this.total, -1)

 	if this.onRemove != nil {
@@ -265,9 +302,9 @@ func (this *FileList) Remove(hash string) error {
 // Purge 清理过期的缓存
 // count 每次遍历的最大数量，控制此数字可以保证每次清理的时候不用花太多时间
 // callback 每次发现过期key的调用
-func (this *FileList) Purge(count int, callback func(hash string) error) error {
+func (this *FileList) Purge(count int, callback func(hash string) error) (int, error) {
 	if this.isClosed {
-		return nil
+		return 0, nil
 	}

 	if count <= 0 {
@@ -275,11 +312,56 @@ func (this *FileList) Purge(count int, callback func(hash string) error) error {
 	}

 	rows, err := this.purgeStmt.Query(time.Now().Unix(), count)
+	if err != nil {
+		return 0, err
+	}
+
+	hashStrings := []string{}
+	var countFound = 0
+	for rows.Next() {
+		var hash string
+		err = rows.Scan(&hash)
+		if err != nil {
+			_ = rows.Close()
+			return 0, err
+		}
+		hashStrings = append(hashStrings, hash)
+		countFound++
+	}
+	_ = rows.Close() // 不能使用defer，防止读写冲突
+
+	// 不在 rows.Next() 循环中操作是为了避免死锁
+	for _, hash := range hashStrings {
+		err = this.Remove(hash)
+		if err != nil {
+			return 0, err
+		}
+
+		err = callback(hash)
+		if err != nil {
+			return 0, err
+		}
+	}
+
+	return countFound, nil
+}
+
+func (this *FileList) PurgeLFU(count int, callback func(hash string) error) error {
+	if this.isClosed {
+		return nil
+	}
+
+	if count <= 0 {
+		return nil
+	}
+
+	rows, err := this.lfuHitsStmt.Query(count)
 	if err != nil {
 		return err
 	}

 	hashStrings := []string{}
+	var countFound = 0
 	for rows.Next() {
 		var hash string
 		err = rows.Scan(&hash)
@@ -288,6 +370,7 @@ func (this *FileList) Purge(count int, callback func(hash string) error) error {
 			return err
 		}
 		hashStrings = append(hashStrings, hash)
+		countFound++
 	}
 	_ = rows.Close() // 不能使用defer，防止读写冲突

@@ -303,7 +386,6 @@ func (this *FileList) Purge(count int, callback func(hash string) error) error {
 			return err
 		}
 	}
-
 	return nil
 }

@@ -347,6 +429,13 @@ func (this *FileList) Count() (int64, error) {
 	return atomic.LoadInt64(&this.total), nil
 }

+// IncreaseHit 增加点击量
+func (this *FileList) IncreaseHit(hash string) error {
+	var week = timeutil.Format("YW")
+	_, err := this.increaseHitStmt.Exec(hash, week, week, week, week)
+	return err
+}
+
 // OnAdd 添加事件
 func (this *FileList) OnAdd(f func(item *Item)) {
 	this.onAdd = f
@@ -371,6 +460,11 @@ func (this *FileList) Close() error {
 		_ = this.purgeStmt.Close()
 		_ = this.deleteAllStmt.Close()

+		_ = this.insertHitStmt.Close()
+		_ = this.increaseHitStmt.Close()
+		_ = this.deleteHitByHashStmt.Close()
+		_ = this.lfuHitsStmt.Close()
+
 		return this.db.Close()
 	}
 	return nil
@@ -378,6 +472,7 @@ func (this *FileList) Close() error {

 // 初始化
 func (this *FileList) initTables(db *sql.DB, times int) error {
+	{
 		_, err := db.Exec(`CREATE TABLE IF NOT EXISTS "` + this.itemsTableName + `" (
  "id" integer NOT NULL PRIMARY KEY AUTOINCREMENT,
  "hash" varchar(32),
@@ -423,6 +518,35 @@ ON "` + this.itemsTableName + `" (

 			return err
 		}
+	}
+
+	{
+		_, err := db.Exec(`CREATE TABLE IF NOT EXISTS "` + this.hitsTableName + `" (
+  "id" integer NOT NULL PRIMARY KEY AUTOINCREMENT,
+  "hash" varchar(32),
+  "week1Hits" integer DEFAULT 0,
+  "week2Hits" integer DEFAULT 0,
+  "week" varchar(6)
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS "hits_hash"
+ON "` + this.hitsTableName + `" (
+  "hash" ASC
+);
+`)
+		if err != nil {
+			// 尝试删除重建
+			if times < 3 {
+				_, dropErr := db.Exec(`DROP TABLE "` + this.hitsTableName + `"`)
+				if dropErr == nil {
+					return this.initTables(db, times+1)
+				}
+				return err
+			}
+
+			return err
+		}
+	}

 	return nil
 }
--- a/internal/caches/list_file_test.go
+++ b/internal/caches/list_file_test.go
@@ -5,6 +5,7 @@ package caches
 import (
 	"github.com/iwind/TeaGo/Tea"
 	"github.com/iwind/TeaGo/rands"
+	"github.com/iwind/TeaGo/types"
 	stringutil "github.com/iwind/TeaGo/utils/string"
 	"strconv"
 	"sync"
@@ -184,7 +185,7 @@ func TestFileList_Purge(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = list.Purge(2, func(hash string) error {
+	_, err = list.Purge(2, func(hash string) error {
 		t.Log(hash)
 		return nil
 	})
@@ -257,6 +258,50 @@ func TestFileList_Conflict(t *testing.T) {
 	t.Log("after exists")
 }

+func TestFileList_IIF(t *testing.T) {
+	list := NewFileList(Tea.Root + "/data").(*FileList)
+	err := list.Init()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	rows, err := list.db.Query("SELECT IIF(0, 2, 3)")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		_ = rows.Close()
+	}()
+
+	if rows.Next() {
+		var result int
+		err = rows.Scan(&result)
+		if err != nil {
+			t.Fatal(err)
+		}
+		t.Log("result:", result)
+	}
+}
+
+func TestFileList_IncreaseHit(t *testing.T) {
+	list := NewFileList(Tea.Root + "/data")
+	err := list.Init()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var before = time.Now()
+	defer func() {
+		t.Log(time.Since(before).Seconds()*1000, "ms")
+	}()
+	for i := 0; i < 1000_000; i++ {
+		err = list.IncreaseHit(stringutil.Md5("abc" + types.String(i)))
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Log("ok")
+}
+
 func BenchmarkFileList_Exist(b *testing.B) {
 	list := NewFileList(Tea.Root + "/data")
 	err := list.Init()
--- a/internal/caches/list_interface.go
+++ b/internal/caches/list_interface.go
@@ -22,7 +22,10 @@ type ListInterface interface {
 	Remove(hash string) error

 	// Purge 清理过期数据
-	Purge(count int, callback func(hash string) error) error
+	Purge(count int, callback func(hash string) error) (int, error)
+
+	// PurgeLFU 清理LFU数据
+	PurgeLFU(count int, callback func(hash string) error) error

 	// CleanAll 清除所有缓存
 	CleanAll() error
@@ -41,4 +44,7 @@ type ListInterface interface {

 	// Close 关闭
 	Close() error
+
+	// IncreaseHit 增加点击量
+	IncreaseHit(hash string) error
 }
--- a/internal/caches/list_memory.go
+++ b/internal/caches/list_memory.go
@@ -5,12 +5,19 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"testing"
 )

 // MemoryList 内存缓存列表管理
 type MemoryList struct {
+	count int64
+
 	itemMaps map[string]map[string]*Item // prefix => { hash => item }
+
+	weekItemMaps map[int32]map[string]bool // week => { hash => true }
+	minWeek      int32
+
 	prefixes []string
 	locker   sync.RWMutex
 	onAdd    func(item *Item)
@@ -22,6 +29,8 @@ type MemoryList struct {
 func NewMemoryList() ListInterface {
 	return &MemoryList{
 		itemMaps:     map[string]map[string]*Item{},
+		weekItemMaps: map[int32]map[string]bool{},
+		minWeek:      currentWeek(),
 	}
 }

@@ -43,11 +52,19 @@ func (this *MemoryList) Reset() error {
 	for key := range this.itemMaps {
 		this.itemMaps[key] = map[string]*Item{}
 	}
+	this.weekItemMaps = map[int32]map[string]bool{}
 	this.locker.Unlock()
+
+	atomic.StoreInt64(&this.count, 0)
+
 	return nil
 }

 func (this *MemoryList) Add(hash string, item *Item) error {
+	if item.Week == 0 {
+		item.Week = currentWeek()
+	}
+
 	this.locker.Lock()

 	prefix := this.prefix(hash)
@@ -60,9 +77,20 @@ func (this *MemoryList) Add(hash string, item *Item) error {
 	// 先删除，为了可以正确触发统计
 	oldItem, ok := itemMap[hash]
 	if ok {
+		// 从week map中删除
+		if oldItem.Week > 0 {
+			wm, ok := this.weekItemMaps[oldItem.Week]
+			if ok {
+				delete(wm, hash)
+			}
+		}
+
+		// 回调
 		if this.onRemove != nil {
 			this.onRemove(oldItem)
 		}
+	} else {
+		atomic.AddInt64(&this.count, 1)
 	}

 	// 添加
@@ -71,6 +99,15 @@ func (this *MemoryList) Add(hash string, item *Item) error {
 	}

 	itemMap[hash] = item
+
+	// week map
+	wm, ok := this.weekItemMaps[item.Week]
+	if ok {
+		wm[hash] = true
+	} else {
+		this.weekItemMaps[item.Week] = map[string]bool{hash: true}
+	}
+
 	this.locker.Unlock()
 	return nil
 }
@@ -122,7 +159,17 @@ func (this *MemoryList) Remove(hash string) error {
 		if this.onRemove != nil {
 			this.onRemove(item)
 		}
+
+		atomic.AddInt64(&this.count, -1)
 		delete(itemMap, hash)
+
+		// week map
+		if item.Week > 0 {
+			wm, ok := this.weekItemMaps[item.Week]
+			if ok {
+				delete(wm, hash)
+			}
+		}
 	}

 	this.locker.Unlock()
@@ -132,7 +179,7 @@ func (this *MemoryList) Remove(hash string) error {
 // Purge 清理过期的缓存
 // count 每次遍历的最大数量，控制此数字可以保证每次清理的时候不用花太多时间
 // callback 每次发现过期key的调用
-func (this *MemoryList) Purge(count int, callback func(hash string) error) error {
+func (this *MemoryList) Purge(count int, callback func(hash string) error) (int, error) {
 	this.locker.Lock()
 	deletedHashList := []string{}

@@ -146,8 +193,9 @@ func (this *MemoryList) Purge(count int, callback func(hash string) error) error
 	itemMap, ok := this.itemMaps[prefix]
 	if !ok {
 		this.locker.Unlock()
-		return nil
+		return 0, nil
 	}
+	var countFound = 0
 	for hash, item := range itemMap {
 		if count <= 0 {
 			break
@@ -157,14 +205,100 @@ func (this *MemoryList) Purge(count int, callback func(hash string) error) error
 			if this.onRemove != nil {
 				this.onRemove(item)
 			}
+
+			atomic.AddInt64(&this.count, -1)
 			delete(itemMap, hash)
 			deletedHashList = append(deletedHashList, hash)
+
+			// week map
+			if item.Week > 0 {
+				wm, ok := this.weekItemMaps[item.Week]
+				if ok {
+					delete(wm, hash)
+				}
+			}
+
+			countFound++
 		}

 		count--
 	}
 	this.locker.Unlock()

+	// 执行外部操作
+	for _, hash := range deletedHashList {
+		if callback != nil {
+			err := callback(hash)
+			if err != nil {
+				return 0, err
+			}
+		}
+	}
+	return countFound, nil
+}
+
+func (this *MemoryList) PurgeLFU(count int, callback func(hash string) error) error {
+	if count <= 0 {
+		return nil
+	}
+
+	var week = currentWeek()
+	if this.minWeek > week {
+		this.minWeek = week
+	}
+
+	var deletedHashList = []string{}
+
+Loop:
+	for w := this.minWeek; w <= week; w++ {
+		this.minWeek = w
+
+		this.locker.Lock()
+		wm, ok := this.weekItemMaps[w]
+		if ok {
+			var wc = len(wm)
+			if wc == 0 {
+				delete(this.weekItemMaps, w)
+			} else {
+				if wc <= count {
+					delete(this.weekItemMaps, w)
+				}
+
+				// TODO 未来支持按照点击量排序
+				for hash := range wm {
+					count--
+
+					if count < 0 {
+						this.locker.Unlock()
+						break Loop
+					}
+
+					delete(wm, hash)
+
+					itemMap, ok := this.itemMaps[this.prefix(hash)]
+					if !ok {
+						continue
+					}
+					item, ok := itemMap[hash]
+					if !ok {
+						continue
+					}
+
+					if this.onRemove != nil {
+						this.onRemove(item)
+					}
+
+					atomic.AddInt64(&this.count, -1)
+					delete(itemMap, hash)
+					deletedHashList = append(deletedHashList, hash)
+				}
+			}
+		} else {
+			delete(this.weekItemMaps, w)
+		}
+		this.locker.Unlock()
+	}
+
 	// 执行外部操作
 	for _, hash := range deletedHashList {
 		if callback != nil {
@@ -174,6 +308,7 @@ func (this *MemoryList) Purge(count int, callback func(hash string) error) error
 			}
 		}
 	}
+
 	return nil
 }

@@ -206,13 +341,8 @@ func (this *MemoryList) Stat(check func(hash string) bool) (*Stat, error) {

 // Count 总数量
 func (this *MemoryList) Count() (int64, error) {
-	this.locker.RLock()
-	var count = 0
-	for _, itemMap := range this.itemMaps {
-		count += len(itemMap)
-	}
-	this.locker.RUnlock()
-	return int64(count), nil
+	var count = atomic.LoadInt64(&this.count)
+	return count, nil
 }

 // OnAdd 添加事件
@@ -229,6 +359,41 @@ func (this *MemoryList) Close() error {
 	return nil
 }

+// IncreaseHit 增加点击量
+func (this *MemoryList) IncreaseHit(hash string) error {
+	this.locker.Lock()
+
+	itemMap, ok := this.itemMaps[this.prefix(hash)]
+	if !ok {
+		this.locker.Unlock()
+		return nil
+	}
+
+	item, ok := itemMap[hash]
+	if ok {
+		var week = currentWeek()
+
+		// 交换位置
+		if item.Week > 0 && item.Week != week {
+			wm, ok := this.weekItemMaps[item.Week]
+			if ok {
+				delete(wm, hash)
+			}
+			wm, ok = this.weekItemMaps[week]
+			if ok {
+				wm[hash] = true
+			} else {
+				this.weekItemMaps[week] = map[string]bool{hash: true}
+			}
+		}
+
+		item.IncreaseHit(week)
+	}
+
+	this.locker.Unlock()
+	return nil
+}
+
 func (this *MemoryList) print(t *testing.T) {
 	this.locker.Lock()
 	for _, itemMap := range this.itemMaps {
--- a/internal/caches/list_memory_test.go
+++ b/internal/caches/list_memory_test.go
@@ -31,6 +31,8 @@ func TestMemoryList_Add(t *testing.T) {
 	})
 	t.Log(list.prefixes)
 	logs.PrintAsJSON(list.itemMaps, t)
+	logs.PrintAsJSON(list.weekItemMaps, t)
+	t.Log(list.Count())
 }

 func TestMemoryList_Remove(t *testing.T) {
@@ -48,6 +50,8 @@ func TestMemoryList_Remove(t *testing.T) {
 	})
 	_ = list.Remove("b")
 	list.print(t)
+	logs.PrintAsJSON(list.weekItemMaps, t)
+	t.Log(list.Count())
 }

 func TestMemoryList_Purge(t *testing.T) {
@@ -73,19 +77,22 @@ func TestMemoryList_Purge(t *testing.T) {
 		ExpiredAt:  time.Now().Unix() - 2,
 		HeaderSize: 1024,
 	})
-	_ = list.Purge(100, func(hash string) error {
+	_, _ = list.Purge(100, func(hash string) error {
 		t.Log("delete:", hash)
 		return nil
 	})
 	list.print(t)
+	logs.PrintAsJSON(list.weekItemMaps, t)

 	for i := 0; i < 1000; i++ {
-		_ = list.Purge(100, func(hash string) error {
+		_, _ = list.Purge(100, func(hash string) error {
 			t.Log("delete:", hash)
 			return nil
 		})
 		t.Log(list.purgeIndex)
 	}
+
+	t.Log(list.Count())
 }

 func TestMemoryList_Purge_Large_List(t *testing.T) {
@@ -139,7 +146,7 @@ func TestMemoryList_CleanPrefix(t *testing.T) {
 	_ = list.Init()
 	before := time.Now()
 	for i := 0; i < 1_000_000; i++ {
-		key := "http://www.teaos.cn/hello/" + strconv.Itoa(i/10000) + "/" + strconv.Itoa(i) + ".html"
+		key := "https://www.teaos.cn/hello/" + strconv.Itoa(i/10000) + "/" + strconv.Itoa(i) + ".html"
 		_ = list.Add(fmt.Sprintf("%d", xxhash.Sum64String(key)), &Item{
 			Key:        key,
 			ExpiredAt:  time.Now().Unix() + 3600,
@@ -150,7 +157,7 @@ func TestMemoryList_CleanPrefix(t *testing.T) {
 	t.Log(time.Since(before).Seconds()*1000, "ms")

 	before = time.Now()
-	err := list.CleanPrefix("http://www.teaos.cn/hello/10")
+	err := list.CleanPrefix("https://www.teaos.cn/hello/10")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -162,11 +169,77 @@ func TestMemoryList_CleanPrefix(t *testing.T) {
 	t.Log(time.Since(before).Seconds()*1000, "ms")
 }

+func TestMemoryList_PurgeLFU(t *testing.T) {
+	var list = NewMemoryList().(*MemoryList)
+	list.minWeek = 2704
+
+	var before = time.Now()
+	defer func() {
+		t.Log(time.Since(before).Seconds()*1000, "ms")
+	}()
+
+	t.Log("current week:", currentWeek())
+
+	_ = list.Add("1", &Item{})
+	_ = list.Add("2", &Item{})
+	_ = list.Add("3", &Item{})
+	_ = list.Add("4", &Item{})
+	_ = list.Add("5", &Item{})
+	_ = list.Add("6", &Item{Week: 2704})
+	_ = list.Add("7", &Item{Week: 2704})
+	_ = list.Add("8", &Item{Week: 2705})
+
+	err := list.PurgeLFU(2, func(hash string) error {
+		t.Log("purge lfu:", hash)
+		return nil
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Log("ok")
+
+	logs.PrintAsJSON(list.weekItemMaps, t)
+	t.Log(list.Count())
+}
+
+func TestMemoryList_IncreaseHit(t *testing.T) {
+	var list = NewMemoryList().(*MemoryList)
+	var item = &Item{}
+	item.Week = 2705
+	item.Week2Hits = 100
+
+	_ = list.Add("a", &Item{})
+	_ = list.Add("a", item)
+	t.Log("hits1:", item.Week1Hits, "hits2:", item.Week2Hits, "week:", item.Week)
+	logs.PrintAsJSON(list.weekItemMaps, t)
+
+	_ = list.IncreaseHit("a")
+	t.Log("hits1:", item.Week1Hits, "hits2:", item.Week2Hits, "week:", item.Week)
+	logs.PrintAsJSON(list.weekItemMaps, t)
+
+	_ = list.IncreaseHit("a")
+	t.Log("hits1:", item.Week1Hits, "hits2:", item.Week2Hits, "week:", item.Week)
+	logs.PrintAsJSON(list.weekItemMaps, t)
+}
+
+func TestMemoryList_CleanAll(t *testing.T) {
+	var list = NewMemoryList().(*MemoryList)
+	var item = &Item{}
+	item.Week = 2705
+	item.Week2Hits = 100
+
+	_ = list.Add("a", &Item{})
+	_ = list.CleanAll()
+	logs.PrintAsJSON(list.itemMaps, t)
+	logs.PrintAsJSON(list.weekItemMaps, t)
+	t.Log(list.Count())
+}
+
 func TestMemoryList_GC(t *testing.T) {
 	list := NewMemoryList().(*MemoryList)
 	_ = list.Init()
 	for i := 0; i < 1_000_000; i++ {
-		key := "http://www.teaos.cn/hello" + strconv.Itoa(i/100000) + "/" + strconv.Itoa(i) + ".html"
+		key := "https://www.teaos.cn/hello" + strconv.Itoa(i/100000) + "/" + strconv.Itoa(i) + ".html"
 		_ = list.Add(fmt.Sprintf("%d", xxhash.Sum64String(key)), &Item{
 			Key:        key,
 			ExpiredAt:  0,
--- a/internal/caches/manager.go
+++ b/internal/caches/manager.go
@@ -135,7 +135,7 @@ func (this *Manager) NewStorageWithPolicy(policy *serverconfigs.HTTPCachePolicy)
 	case serverconfigs.CachePolicyStorageFile:
 		return NewFileStorage(policy)
 	case serverconfigs.CachePolicyStorageMemory:
-		return NewMemoryStorage(policy)
+		return NewMemoryStorage(policy, nil)
 	}
 	return nil
 }
--- a/internal/caches/storage_file.go
+++ b/internal/caches/storage_file.go
@@ -11,10 +11,13 @@ import (
 	"github.com/TeaOSLab/EdgeNode/internal/remotelogs"
 	"github.com/TeaOSLab/EdgeNode/internal/utils"
 	"github.com/iwind/TeaGo/Tea"
+	"github.com/iwind/TeaGo/rands"
+	"github.com/iwind/TeaGo/types"
 	stringutil "github.com/iwind/TeaGo/utils/string"
 	"golang.org/x/text/language"
 	"golang.org/x/text/message"
 	"io"
+	"math"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -165,12 +168,16 @@ func (this *FileStorage) Init() error {
 				Life:        this.policy.Life,
 				MinLife:     this.policy.MinLife,
 				MaxLife:     this.policy.MaxLife,
+
+				MemoryAutoPurgeCount:    this.policy.MemoryAutoPurgeCount,
+				MemoryAutoPurgeInterval: this.policy.MemoryAutoPurgeInterval,
+				MemoryLFUFreePercent:    this.policy.MemoryLFUFreePercent,
 			}
 			err = memoryPolicy.Init()
 			if err != nil {
 				return err
 			}
-			memoryStorage := NewMemoryStorage(memoryPolicy)
+			memoryStorage := NewMemoryStorage(memoryPolicy, this)
 			err = memoryStorage.Init()
 			if err != nil {
 				return err
@@ -227,6 +234,17 @@ func (this *FileStorage) OpenReader(key string) (Reader, error) {
 		return nil, err
 	}

+	// 增加点击量
+	// 1/1000采样
+	// TODO 考虑是否在缓存策略里设置
+	if rands.Int(0, 1000) == 0 {
+		var hitErr = this.list.IncreaseHit(hash)
+		if hitErr != nil {
+			// 此错误可以忽略
+			remotelogs.Error("CACHE", "increase hit failed: "+hitErr.Error())
+		}
+	}
+
 	isOk = true
 	return reader, nil
 }
@@ -398,7 +416,7 @@ func (this *FileStorage) AddToList(item *Item) {
 		}
 	}

-	item.MetaSize = SizeMeta
+	item.MetaSize = SizeMeta + 128
 	hash := stringutil.Md5(item.Key)
 	err := this.list.Add(hash, item)
 	if err != nil && !strings.Contains(err.Error(), "UNIQUE constraint failed") {
@@ -619,7 +637,14 @@ func (this *FileStorage) initList() error {
 	}()

 	// 启动定时清理任务
-	this.ticker = utils.NewTicker(30 * time.Second)
+	var autoPurgeInterval = this.policy.PersistenceAutoPurgeInterval
+	if autoPurgeInterval <= 0 {
+		autoPurgeInterval = 30
+		if Tea.IsTesting() {
+			autoPurgeInterval = 10
+		}
+	}
+	this.ticker = utils.NewTicker(time.Duration(autoPurgeInterval) * time.Second)
 	events.On(events.EventQuit, func() {
 		remotelogs.Println("CACHE", "quit clean timer")
 		var ticker = this.ticker
@@ -730,7 +755,42 @@ func (this *FileStorage) decodeFile(path string) (*Item, error) {

 // 清理任务
 func (this *FileStorage) purgeLoop() {
-	err := this.list.Purge(1000, func(hash string) error {
+	// 计算是否应该开启LFU清理
+	var capacityBytes = this.policy.CapacityBytes()
+	var startLFU = false
+	var usedPercent = float32(this.TotalDiskSize()*100) / float32(capacityBytes)
+	var lfuFreePercent = this.policy.PersistenceLFUFreePercent
+	if lfuFreePercent <= 0 {
+		lfuFreePercent = 5
+	}
+	if capacityBytes > 0 {
+		if lfuFreePercent < 100 {
+			if usedPercent >= 100-lfuFreePercent {
+				startLFU = true
+			}
+		}
+	}
+
+	// 清理过期
+	{
+		var times = 1
+
+		// 空闲时间多清理
+		if utils.SharedFreeHoursManager.IsFreeHour() {
+			times = 5
+		}
+
+		// 处于LFU阈值时，多清理
+		if startLFU {
+			times = 5
+		}
+
+		var purgeCount = this.policy.PersistenceAutoPurgeCount
+		if purgeCount <= 0 {
+			purgeCount = 1000
+		}
+		for i := 0; i < times; i++ {
+			countFound, err := this.list.Purge(purgeCount, func(hash string) error {
 				path := this.hashPath(hash)
 				err := os.Remove(path)
 				if err != nil && !os.IsNotExist(err) {
@@ -740,6 +800,42 @@ func (this *FileStorage) purgeLoop() {
 			})
 			if err != nil {
 				remotelogs.Warn("CACHE", "purge file storage failed: "+err.Error())
+				continue
+			}
+
+			if countFound < purgeCount {
+				break
+			}
+
+			time.Sleep(1 * time.Second)
+		}
+	}
+
+	// 磁盘空间不足时，清除老旧的缓存
+	if startLFU {
+		var total, _ = this.list.Count()
+		if total > 0 {
+			var count = types.Int(math.Ceil(float64(total) * float64(lfuFreePercent*2) / 100))
+			if count > 0 {
+				// 限制单次清理的条数，防止占用太多系统资源
+				if count > 2000 {
+					count = 2000
+				}
+
+				remotelogs.Println("CACHE", "LFU purge policy '"+this.policy.Name+"' id: "+types.String(this.policy.Id)+", count: "+types.String(count))
+				err := this.list.PurgeLFU(count, func(hash string) error {
+					path := this.hashPath(hash)
+					err := os.Remove(path)
+					if err != nil && !os.IsNotExist(err) {
+						remotelogs.Error("CACHE", "purge '"+path+"' error: "+err.Error())
+					}
+					return nil
+				})
+				if err != nil {
+					remotelogs.Warn("CACHE", "purge file storage in LFU failed: "+err.Error())
+				}
+			}
+		}
 	}
 }

--- a/internal/caches/storage_memory.go
+++ b/internal/caches/storage_memory.go
@@ -6,6 +6,9 @@ import (
 	"github.com/TeaOSLab/EdgeNode/internal/remotelogs"
 	"github.com/TeaOSLab/EdgeNode/internal/utils"
 	"github.com/cespare/xxhash"
+	"github.com/iwind/TeaGo/rands"
+	"github.com/iwind/TeaGo/types"
+	"math"
 	"strconv"
 	"sync"
 	"sync/atomic"
@@ -26,22 +29,37 @@ func (this *MemoryItem) IsExpired() bool {
 }

 type MemoryStorage struct {
+	parentStorage StorageInterface
+
 	policy *serverconfigs.HTTPCachePolicy
 	list   ListInterface
 	locker *sync.RWMutex
-	valuesMap     map[uint64]*MemoryItem
-	ticker        *utils.Ticker
-	purgeDuration time.Duration
+
+	valuesMap map[uint64]*MemoryItem // hash => item
+	dirtyChan chan string            // hash chan
+
+	purgeTicker *utils.Ticker
+
 	totalSize     int64
 	writingKeyMap map[string]bool // key => bool
 }

-func NewMemoryStorage(policy *serverconfigs.HTTPCachePolicy) *MemoryStorage {
+func NewMemoryStorage(policy *serverconfigs.HTTPCachePolicy, parentStorage StorageInterface) *MemoryStorage {
+	var dirtyChan chan string
+	if parentStorage != nil {
+		var queueSize = policy.MemoryAutoFlushQueueSize
+		if queueSize <= 0 {
+			queueSize = 2048
+		}
+		dirtyChan = make(chan string, queueSize)
+	}
 	return &MemoryStorage{
+		parentStorage: parentStorage,
 		policy:        policy,
 		list:          NewMemoryList(),
 		locker:        &sync.RWMutex{},
 		valuesMap:     map[uint64]*MemoryItem{},
+		dirtyChan:     dirtyChan,
 		writingKeyMap: map[string]bool{},
 	}
 }
@@ -57,18 +75,26 @@ func (this *MemoryStorage) Init() error {
 		atomic.AddInt64(&this.totalSize, -item.TotalSize())
 	})

-	if this.purgeDuration <= 0 {
-		this.purgeDuration = 10 * time.Second
+	var autoPurgeInterval = this.policy.MemoryAutoPurgeInterval
+	if autoPurgeInterval <= 0 {
+		autoPurgeInterval = 5
 	}

 	// 启动定时清理任务
-	this.ticker = utils.NewTicker(this.purgeDuration)
+	this.purgeTicker = utils.NewTicker(time.Duration(autoPurgeInterval) * time.Second)
 	go func() {
-		for this.ticker.Next() {
+		for this.purgeTicker.Next() {
 			this.purgeLoop()
 		}
 	}()

+	// 启动定时Flush memory to disk任务
+	go func() {
+		for hash := range this.dirtyChan {
+			this.flushItem(hash)
+		}
+	}()
+
 	return nil
 }

@@ -91,6 +117,18 @@ func (this *MemoryStorage) OpenReader(key string) (Reader, error) {
 			return nil, err
 		}
 		this.locker.RUnlock()
+
+		// 增加点击量
+		// 1/1000采样
+		// TODO 考虑是否在缓存策略里设置
+		if rands.Int(0, 1000) == 0 {
+			var hitErr = this.list.IncreaseHit(types.String(hash))
+			if hitErr != nil {
+				// 此错误可以忽略
+				remotelogs.Error("CACHE", "increase hit failed: "+hitErr.Error())
+			}
+		}
+
 		return reader, nil
 	}
 	this.locker.RUnlock()
@@ -145,7 +183,7 @@ func (this *MemoryStorage) OpenWriter(key string, expiredAt int64, status int) (
 	}

 	isWriting = true
-	return NewMemoryWriter(this.valuesMap, key, expiredAt, status, this.locker, func() {
+	return NewMemoryWriter(this, key, expiredAt, status, func() {
 		this.locker.Lock()
 		delete(this.writingKeyMap, key)
 		this.locker.Unlock()
@@ -210,8 +248,12 @@ func (this *MemoryStorage) Stop() {
 	this.valuesMap = map[uint64]*MemoryItem{}
 	this.writingKeyMap = map[string]bool{}
 	_ = this.list.Reset()
-	if this.ticker != nil {
-		this.ticker.Stop()
+	if this.purgeTicker != nil {
+		this.purgeTicker.Stop()
+	}
+
+	if this.parentStorage != nil && this.dirtyChan != nil {
+		close(this.dirtyChan)
 	}

 	_ = this.list.Close()
@@ -228,7 +270,7 @@ func (this *MemoryStorage) Policy() *serverconfigs.HTTPCachePolicy {

 // AddToList 将缓存添加到列表
 func (this *MemoryStorage) AddToList(item *Item) {
-	item.MetaSize = int64(len(item.Key)) + 32 /** 32是我们评估的数据结构的长度 **/
+	item.MetaSize = int64(len(item.Key)) + 128 /** 128是我们评估的数据结构的长度 **/
 	hash := fmt.Sprintf("%d", this.hash(item.Key))
 	_ = this.list.Add(hash, item)
 }
@@ -250,7 +292,28 @@ func (this *MemoryStorage) hash(key string) uint64 {

 // 清理任务
 func (this *MemoryStorage) purgeLoop() {
-	_ = this.list.Purge(2048, func(hash string) error {
+	// 计算是否应该开启LFU清理
+	var capacityBytes = this.policy.CapacityBytes()
+	var startLFU = false
+	var usedPercent = float32(this.TotalMemorySize()*100) / float32(capacityBytes)
+	var lfuFreePercent = this.policy.MemoryLFUFreePercent
+	if lfuFreePercent <= 0 {
+		lfuFreePercent = 5
+	}
+	if capacityBytes > 0 {
+		if lfuFreePercent < 100 {
+			if usedPercent >= 100-lfuFreePercent {
+				startLFU = true
+			}
+		}
+	}
+
+	// 清理过期
+	var purgeCount = this.policy.MemoryAutoPurgeCount
+	if purgeCount <= 0 {
+		purgeCount = 2000
+	}
+	_, _ = this.list.Purge(purgeCount, func(hash string) error {
 		uintHash, err := strconv.ParseUint(hash, 10, 64)
 		if err == nil {
 			this.locker.Lock()
@@ -259,6 +322,92 @@ func (this *MemoryStorage) purgeLoop() {
 		}
 		return nil
 	})
+
+	// LFU
+	if startLFU {
+		var total, _ = this.list.Count()
+		if total > 0 {
+			var count = types.Int(math.Ceil(float64(total) * float64(lfuFreePercent * 2) / 100))
+			if count > 0 {
+				// 限制单次清理的条数，防止占用太多系统资源
+				if count > 2000 {
+					count = 2000
+				}
+
+				remotelogs.Println("CACHE", "LFU purge policy '"+this.policy.Name+"' id: "+types.String(this.policy.Id)+", count: "+types.String(count))
+
+				err := this.list.PurgeLFU(count, func(hash string) error {
+					uintHash, err := strconv.ParseUint(hash, 10, 64)
+					if err == nil {
+						this.locker.Lock()
+						delete(this.valuesMap, uintHash)
+						this.locker.Unlock()
+					}
+					return nil
+				})
+				if err != nil {
+					remotelogs.Warn("CACHE", "purge memory storage in LFU failed: "+err.Error())
+				}
+			}
+		}
+	}
+}
+
+// Flush任务
+func (this *MemoryStorage) flushItem(key string) {
+	if this.parentStorage == nil {
+		return
+	}
+	var hash = this.hash(key)
+
+	this.locker.RLock()
+	item, ok := this.valuesMap[hash]
+	this.locker.RUnlock()
+
+	if !ok {
+		return
+	}
+	if !item.IsDone || item.IsExpired() {
+		return
+	}
+
+	writer, err := this.parentStorage.OpenWriter(key, item.ExpiredAt, item.Status)
+	if err != nil {
+		if !CanIgnoreErr(err) {
+			remotelogs.Error("CACHE", "flush items failed: open writer failed: "+err.Error())
+		}
+		return
+	}
+
+	_, err = writer.WriteHeader(item.HeaderValue)
+	if err != nil {
+		_ = writer.Discard()
+		remotelogs.Error("CACHE", "flush items failed: write header failed: "+err.Error())
+		return
+	}
+
+	_, err = writer.Write(item.BodyValue)
+	if err != nil {
+		_ = writer.Discard()
+		remotelogs.Error("CACHE", "flush items failed: writer body failed: "+err.Error())
+		return
+	}
+
+	err = writer.Close()
+	if err != nil {
+		_ = writer.Discard()
+		remotelogs.Error("CACHE", "flush items failed: close writer failed: "+err.Error())
+	}
+
+	this.parentStorage.AddToList(&Item{
+		Type:       writer.ItemType(),
+		Key:        key,
+		ExpiredAt:  item.ExpiredAt,
+		HeaderSize: writer.HeaderSize(),
+		BodySize:   writer.BodySize(),
+	})
+
+	return
 }

 func (this *MemoryStorage) memoryCapacityBytes() int64 {
--- a/internal/caches/storage_memory_test.go
+++ b/internal/caches/storage_memory_test.go
@@ -230,8 +230,9 @@ func TestMemoryStorage_Purge(t *testing.T) {
 }

 func TestMemoryStorage_Expire(t *testing.T) {
-	storage := NewMemoryStorage(&serverconfigs.HTTPCachePolicy{})
-	storage.purgeDuration = 5 * time.Second
+	storage := NewMemoryStorage(&serverconfigs.HTTPCachePolicy{
+		MemoryAutoPurgeInterval: 5,
+	})
 	err := storage.Init()
 	if err != nil {
 		t.Fatal(err)
--- a/internal/caches/writer_memory.go
+++ b/internal/caches/writer_memory.go
@@ -2,15 +2,14 @@ package caches

 import (
 	"github.com/cespare/xxhash"
-	"sync"
 	"time"
 )

 type MemoryWriter struct {
+	storage *MemoryStorage
+
 	key        string
 	expiredAt  int64
-	m          map[uint64]*MemoryItem
-	locker     *sync.RWMutex
 	headerSize int64
 	bodySize   int64
 	status     int
@@ -20,12 +19,11 @@ type MemoryWriter struct {
 	endFunc func()
 }

-func NewMemoryWriter(m map[uint64]*MemoryItem, key string, expiredAt int64, status int, locker *sync.RWMutex, endFunc func()) *MemoryWriter {
+func NewMemoryWriter(memoryStorage *MemoryStorage, key string, expiredAt int64, status int, endFunc func()) *MemoryWriter {
 	w := &MemoryWriter{
-		m:         m,
+		storage:   memoryStorage,
 		key:       key,
 		expiredAt: expiredAt,
-		locker:    locker,
 		item: &MemoryItem{
 			ExpiredAt:  expiredAt,
 			ModifiedAt: time.Now().Unix(),
@@ -72,10 +70,17 @@ func (this *MemoryWriter) Close() error {
 		return nil
 	}

-	this.locker.Lock()
+	this.storage.locker.Lock()
 	this.item.IsDone = true
-	this.m[this.hash] = this.item
-	this.locker.Unlock()
+	this.storage.valuesMap[this.hash] = this.item
+	if this.storage.parentStorage != nil {
+		select {
+		case this.storage.dirtyChan <- this.key:
+		default:
+
+		}
+	}
+	this.storage.locker.Unlock()

 	return nil
 }
@@ -85,9 +90,9 @@ func (this *MemoryWriter) Discard() error {
 	// 需要在Locker之外
 	defer this.endFunc()

-	this.locker.Lock()
-	delete(this.m, this.hash)
-	this.locker.Unlock()
+	this.storage.locker.Lock()
+	delete(this.storage.valuesMap, this.hash)
+	this.storage.locker.Unlock()
 	return nil
 }

--- a/internal/const/vars.go
+++ b/internal/const/vars.go
@@ -0,0 +1,10 @@
+// Copyright 2021 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package teaconst
+
+var (
+	// 流量统计
+
+	InTrafficBytes  = uint64(0)
+	OutTrafficBytes = uint64(0)
+)
--- a/internal/nodes/client_conn.go
+++ b/internal/nodes/client_conn.go
@@ -4,6 +4,7 @@ package nodes

 import (
 	"github.com/TeaOSLab/EdgeCommon/pkg/nodeconfigs"
+	teaconst "github.com/TeaOSLab/EdgeNode/internal/const"
 	"github.com/TeaOSLab/EdgeNode/internal/events"
 	"github.com/TeaOSLab/EdgeNode/internal/monitor"
 	"github.com/iwind/TeaGo/maps"
@@ -12,10 +13,6 @@ import (
 	"time"
 )

-// 流量统计
-var inTrafficBytes = uint64(0)
-var outTrafficBytes = uint64(0)
-
 // 发送监控流量
 func init() {
 	events.On(events.EventStart, func() {
@@ -23,20 +20,20 @@ func init() {
 		go func() {
 			for range ticker.C {
 				// 加入到数据队列中
-				if inTrafficBytes > 0 {
+				if teaconst.InTrafficBytes > 0 {
 					monitor.SharedValueQueue.Add(nodeconfigs.NodeValueItemTrafficIn, maps.Map{
-						"total": inTrafficBytes,
+						"total": teaconst.InTrafficBytes,
 					})
 				}
-				if outTrafficBytes > 0 {
+				if teaconst.OutTrafficBytes > 0 {
 					monitor.SharedValueQueue.Add(nodeconfigs.NodeValueItemTrafficOut, maps.Map{
-						"total": outTrafficBytes,
+						"total": teaconst.OutTrafficBytes,
 					})
 				}

 				// 重置数据
-				atomic.StoreUint64(&inTrafficBytes, 0)
-				atomic.StoreUint64(&outTrafficBytes, 0)
+				atomic.StoreUint64(&teaconst.InTrafficBytes, 0)
+				atomic.StoreUint64(&teaconst.OutTrafficBytes, 0)
 			}
 		}()
 	})
@@ -63,7 +60,7 @@ func NewClientConn(conn net.Conn, quickClose bool) net.Conn {
 func (this *ClientConn) Read(b []byte) (n int, err error) {
 	n, err = this.rawConn.Read(b)
 	if n > 0 {
-		atomic.AddUint64(&inTrafficBytes, uint64(n))
+		atomic.AddUint64(&teaconst.InTrafficBytes, uint64(n))
 	}
 	return
 }
@@ -71,7 +68,7 @@ func (this *ClientConn) Read(b []byte) (n int, err error) {
 func (this *ClientConn) Write(b []byte) (n int, err error) {
 	n, err = this.rawConn.Write(b)
 	if n > 0 {
-		atomic.AddUint64(&outTrafficBytes, uint64(n))
+		atomic.AddUint64(&teaconst.OutTrafficBytes, uint64(n))
 	}
 	return
 }
--- a/internal/nodes/http_request_reverse_proxy.go
+++ b/internal/nodes/http_request_reverse_proxy.go
@@ -281,7 +281,7 @@ func (this *HTTPRequest) doReverseProxy() {

 	closeErr := resp.Body.Close()
 	if closeErr != nil {
-		if !this.canIgnore(err) {
+		if !this.canIgnore(closeErr) {
 			remotelogs.Warn("HTTP_REQUEST_REVERSE_PROXY", closeErr.Error())
 		}
 	}
--- a/internal/nodes/node_status_executor.go
+++ b/internal/nodes/node_status_executor.go
@@ -68,8 +68,8 @@ func (this *NodeStatusExecutor) update() {
 	status.ConnectionCount = sharedListenerManager.TotalActiveConnections()
 	status.CacheTotalDiskSize = caches.SharedManager.TotalDiskSize()
 	status.CacheTotalMemorySize = caches.SharedManager.TotalMemorySize()
-	status.TrafficInBytes = inTrafficBytes
-	status.TrafficOutBytes = outTrafficBytes
+	status.TrafficInBytes = teaconst.InTrafficBytes
+	status.TrafficOutBytes = teaconst.OutTrafficBytes

 	// 记录监控数据
 	monitor.SharedValueQueue.Add(nodeconfigs.NodeValueItemConnections, maps.Map{
--- a/internal/utils/free_hours_manager.go
+++ b/internal/utils/free_hours_manager.go
@@ -0,0 +1,172 @@
+// Copyright 2021 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package utils
+
+import (
+	teaconst "github.com/TeaOSLab/EdgeNode/internal/const"
+	"github.com/TeaOSLab/EdgeNode/internal/events"
+	"sort"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+var SharedFreeHoursManager = NewFreeHoursManager()
+
+func init() {
+	events.On(events.EventLoaded, func() {
+		go SharedFreeHoursManager.Start()
+	})
+}
+
+// FreeHoursManager 计算节点空闲时间
+// 以便于我们在空闲时间执行高强度的任务，如果清理缓存等
+type FreeHoursManager struct {
+	dayTrafficMap map[int][24]uint64 // day => [ traffic bytes ]
+	lastBytes     uint64
+
+	freeHours []int
+	count     int
+
+	locker sync.Mutex
+}
+
+func NewFreeHoursManager() *FreeHoursManager {
+	return &FreeHoursManager{dayTrafficMap: map[int][24]uint64{}, count: 3}
+}
+
+func (this *FreeHoursManager) Start() {
+	var ticker = time.NewTicker(30 * time.Minute)
+	for range ticker.C {
+		this.Update(atomic.LoadUint64(&teaconst.InTrafficBytes))
+	}
+}
+
+func (this *FreeHoursManager) Update(bytes uint64) {
+	if this.count <= 0 {
+		this.count = 3
+	}
+
+	if this.lastBytes == 0 {
+		this.lastBytes = bytes
+	} else {
+		// 记录流量
+		var deltaBytes = bytes - this.lastBytes
+		var now = time.Now()
+		var day = now.Day()
+		var hour = now.Hour()
+		traffic, ok := this.dayTrafficMap[day]
+		if ok {
+			traffic[hour] += deltaBytes
+		} else {
+			var traffic = [24]uint64{}
+			traffic[hour] += deltaBytes
+			this.dayTrafficMap[day] = traffic
+		}
+
+		this.lastBytes = bytes
+
+		// 计算空闲时间
+		var result = [24]uint64{}
+		var hasData = false
+		for trafficDay, trafficArray := range this.dayTrafficMap {
+			// 当天的不算
+			if trafficDay == day {
+				continue
+			}
+
+			// 查看最近5天的
+			if (day > trafficDay && day-trafficDay <= 5) || (day < trafficDay && trafficDay-day >= 26) {
+				var weights = this.sortUintArrayWeights(trafficArray)
+				for k, v := range weights {
+					result[k] += v
+				}
+				hasData = true
+			}
+		}
+		if hasData {
+			var freeHours = this.sortUintArrayIndexes(result)
+			this.locker.Lock()
+			this.freeHours = freeHours[:this.count] // 取前N个小时作为空闲时间
+			this.locker.Unlock()
+		}
+	}
+}
+
+func (this *FreeHoursManager) IsFreeHour() bool {
+	this.locker.Lock()
+	defer this.locker.Unlock()
+
+	if len(this.freeHours) == 0 {
+		return false
+	}
+
+	var hour = time.Now().Hour()
+	for _, h := range this.freeHours {
+		if h == hour {
+			return true
+		}
+	}
+	return false
+}
+
+// 对数组进行排序，并返回权重
+func (this *FreeHoursManager) sortUintArrayWeights(arr [24]uint64) [24]uint64 {
+	var l = []map[string]interface{}{}
+	for k, v := range arr {
+		l = append(l, map[string]interface{}{
+			"k": k,
+			"v": v,
+		})
+	}
+	sort.Slice(l, func(i, j int) bool {
+		var m1 = l[i]
+		var v1 = m1["v"].(uint64)
+
+		var m2 = l[j]
+		var v2 = m2["v"].(uint64)
+
+		return v1 < v2
+	})
+
+	var result = [24]uint64{}
+	for k, v := range l {
+		if k < this.count {
+			k = 0
+		} else {
+			k = 1
+		}
+		result[v["k"].(int)] = v["v"].(uint64)
+	}
+
+	return result
+}
+
+// 对数组进行排序，并返回索引
+func (this *FreeHoursManager) sortUintArrayIndexes(arr [24]uint64) [24]int {
+	var l = []map[string]interface{}{}
+	for k, v := range arr {
+		l = append(l, map[string]interface{}{
+			"k": k,
+			"v": v,
+		})
+	}
+	sort.Slice(l, func(i, j int) bool {
+		var m1 = l[i]
+		var v1 = m1["v"].(uint64)
+
+		var m2 = l[j]
+		var v2 = m2["v"].(uint64)
+
+		return v1 < v2
+	})
+
+	var result = [24]int{}
+	var i = 0
+	for _, v := range l {
+		result[i] = v["k"].(int)
+		i++
+	}
+
+	return result
+}
--- a/internal/utils/free_hours_manager_test.go
+++ b/internal/utils/free_hours_manager_test.go
@@ -0,0 +1,49 @@
+// Copyright 2021 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package utils
+
+import (
+	"testing"
+	"time"
+)
+
+func TestFreeHoursManager_Update(t *testing.T) {
+	var manager = NewFreeHoursManager()
+	manager.Update(111)
+
+	manager.dayTrafficMap[1] = [24]uint64{1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 1}
+	manager.dayTrafficMap[2] = [24]uint64{0, 0, 1, 0, 1, 1, 1, 0, 0}
+	manager.dayTrafficMap[3] = [24]uint64{0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1}
+	manager.dayTrafficMap[4] = [24]uint64{0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1}
+	manager.dayTrafficMap[5] = [24]uint64{0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1}
+	manager.dayTrafficMap[6] = [24]uint64{0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1}
+	manager.dayTrafficMap[7] = [24]uint64{}
+	manager.dayTrafficMap[8] = [24]uint64{}
+	manager.dayTrafficMap[9] = [24]uint64{}
+	manager.dayTrafficMap[10] = [24]uint64{1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}
+	manager.dayTrafficMap[11] = [24]uint64{1}
+	manager.dayTrafficMap[12] = [24]uint64{1}
+	manager.dayTrafficMap[13] = [24]uint64{1}
+	manager.dayTrafficMap[14] = [24]uint64{}
+	manager.dayTrafficMap[15] = [24]uint64{}
+	manager.dayTrafficMap[16] = [24]uint64{}
+	manager.dayTrafficMap[25] = [24]uint64{}
+	manager.dayTrafficMap[26] = [24]uint64{}
+	manager.dayTrafficMap[27] = [24]uint64{}
+	manager.dayTrafficMap[28] = [24]uint64{}
+	manager.dayTrafficMap[29] = [24]uint64{}
+	manager.dayTrafficMap[30] = [24]uint64{}
+	manager.dayTrafficMap[31] = [24]uint64{}
+
+	var before = time.Now()
+	manager.Update(222)
+	t.Log(manager.freeHours)
+	t.Log(manager.IsFreeHour())
+	t.Log(time.Since(before).Seconds()*1000, "ms")
+}
+
+func TestFreeHoursManager_SortArray(t *testing.T) {
+	var manager = NewFreeHoursManager()
+	t.Log(manager.sortUintArrayWeights([24]uint64{0, 1, 2, 3, 4, 5, 6, 7, 8, 109, 10, 11, 12, 130, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23}))
+	t.Log(manager.sortUintArrayIndexes([24]uint64{1, 2, 3, 5, 4, 0, 100}))
+}