diff --git a/internal/caches/list_file_kv.go b/internal/caches/list_file_kv.go
index af743fe..d877e3b 100644
--- a/internal/caches/list_file_kv.go
+++ b/internal/caches/list_file_kv.go
@@ -78,7 +78,7 @@ func (this *KVFileList) Add(hash string, item *Item) error {
 }
 
 // Exist 检查内容是否存在
-func (this *KVFileList) Exist(hash string) (bool, error) {
+func (this *KVFileList) Exist(hash string) (bool, int64, error) {
 	return this.getStore(hash).ExistItem(hash)
 }
 
diff --git a/internal/caches/list_file_kv_store.go b/internal/caches/list_file_kv_store.go
index 4ca4f45..96b985e 100644
--- a/internal/caches/list_file_kv_store.go
+++ b/internal/caches/list_file_kv_store.go
@@ -90,23 +90,23 @@ func (this *KVListFileStore) AddItem(hash string, item *Item) error {
 	return this.itemsTable.Set(hash, item)
 }
 
-func (this *KVListFileStore) ExistItem(hash string) (bool, error) {
+func (this *KVListFileStore) ExistItem(hash string) (bool, int64, error) {
 	if !this.isReady() {
-		return false, nil
+		return false, -1, nil
 	}
 
 	item, err := this.itemsTable.Get(hash)
 	if err != nil {
 		if kvstore.IsNotFound(err) {
-			return false, nil
+			return false, -1, nil
 		}
-		return false, err
+		return false, -1, err
 	}
 	if item == nil {
-		return false, nil
+		return false, -1, nil
 	}
 
-	return item.ExpiresAt >= fasttime.Now().Unix(), nil
+	return item.ExpiresAt > fasttime.Now().Unix(), item.HeaderSize + item.BodySize, nil
 }
 
 func (this *KVListFileStore) ExistQuickItem(hash string) (bool, error) {
diff --git a/internal/caches/list_file_kv_test.go b/internal/caches/list_file_kv_test.go
index d84a59b..f2b1885 100644
--- a/internal/caches/list_file_kv_test.go
+++ b/internal/caches/list_file_kv_test.go
@@ -159,7 +159,7 @@ func TestKVFileList_Exist(t *testing.T) {
 		stringutil.Md5("123456"),
 		stringutil.Md5("654321"),
 	} {
-		b, err := list.Exist(hash)
+		b, _, err := list.Exist(hash)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -322,7 +322,7 @@ func BenchmarkKVFileList_Exist(b *testing.B) {
 
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {
-			_, existErr := list.Exist(stringutil.Md5(strconv.Itoa(rand.Int() % 2_000_000)))
+			_, _, existErr := list.Exist(stringutil.Md5(strconv.Itoa(rand.Int() % 2_000_000)))
 			if existErr != nil {
 				b.Fatal(existErr)
 			}
diff --git a/internal/caches/list_file_sqlite.go b/internal/caches/list_file_sqlite.go
index 64a59f3..043d513 100644
--- a/internal/caches/list_file_sqlite.go
+++ b/internal/caches/list_file_sqlite.go
@@ -130,26 +130,26 @@ func (this *SQLiteFileList) Add(hash string, item *Item) error {
 	return nil
 }
 
-func (this *SQLiteFileList) Exist(hash string) (bool, error) {
+func (this *SQLiteFileList) Exist(hash string) (bool, int64, error) {
 	var db = this.GetDB(hash)
 
 	if !db.IsReady() {
-		return false, nil
+		return false, -1, nil
 	}
 
 	// 如果Hash列表里不存在，那么必然不存在
 	if !db.hashMap.Exist(hash) {
-		return false, nil
+		return false, -1, nil
 	}
 
 	var item = this.memoryCache.Read(hash)
 	if item != nil {
-		return true, nil
+		return true, -1, nil
 	}
 
 	var row = db.existsByHashStmt.QueryRow(hash, time.Now().Unix())
 	if row.Err() != nil {
-		return false, nil
+		return false, -1, nil
 	}
 
 	var expiredAt int64
@@ -158,15 +158,15 @@ func (this *SQLiteFileList) Exist(hash string) (bool, error) {
 		if errors.Is(err, sql.ErrNoRows) {
 			err = nil
 		}
-		return false, err
+		return false, -1, err
 	}
 
-	if expiredAt < fasttime.Now().Unix() {
-		return false, nil
+	if expiredAt <= fasttime.Now().Unix() {
+		return false, -1, nil
 	}
 
 	this.memoryCache.Write(hash, zero.Zero{}, this.maxExpiresAtForMemoryCache(expiredAt))
-	return true, nil
+	return true, -1, nil
 }
 
 func (this *SQLiteFileList) ExistQuick(hash string) (isReady bool, found bool) {
diff --git a/internal/caches/list_file_sqlite_test.go b/internal/caches/list_file_sqlite_test.go
index 6106844..7e53985 100644
--- a/internal/caches/list_file_sqlite_test.go
+++ b/internal/caches/list_file_sqlite_test.go
@@ -140,7 +140,7 @@ func TestFileList_Exist(t *testing.T) {
 	}()
 	{
 		var hash = stringutil.Md5("123456")
-		exists, err := list.Exist(hash)
+		exists, _, err := list.Exist(hash)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -148,7 +148,7 @@ func TestFileList_Exist(t *testing.T) {
 	}
 	{
 		var hash = stringutil.Md5("http://edge.teaos.cn/1234561")
-		exists, err := list.Exist(hash)
+		exists, _, err := list.Exist(hash)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -208,7 +208,7 @@ func TestFileList_Exist_Many_DB(t *testing.T) {
 					countLocker.Unlock()
 
 					var list = listSlice[rands.Int(0, len(listSlice)-1)]
-					_, _ = list.Exist(hash)
+					_, _, _ = list.Exist(hash)
 				default:
 					return
 				}
@@ -442,6 +442,6 @@ func BenchmarkFileList_Exist(b *testing.B) {
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		_, _ = list.Exist("f0eb5b87e0b0041f3917002c0707475f" + types.String(i))
+		_, _, _ = list.Exist("f0eb5b87e0b0041f3917002c0707475f" + types.String(i))
 	}
 }
diff --git a/internal/caches/list_interface.go b/internal/caches/list_interface.go
index 0e93ab7..644033a 100644
--- a/internal/caches/list_interface.go
+++ b/internal/caches/list_interface.go
@@ -13,7 +13,7 @@ type ListInterface interface {
 	Add(hash string, item *Item) error
 
 	// Exist 检查内容是否存在
-	Exist(hash string) (bool, error)
+	Exist(hash string) (ok bool, size int64, err error)
 
 	// CleanPrefix 清除某个前缀的缓存
 	CleanPrefix(prefix string) error
diff --git a/internal/caches/list_memory.go b/internal/caches/list_memory.go
index ec631ed..7033837 100644
--- a/internal/caches/list_memory.go
+++ b/internal/caches/list_memory.go
@@ -89,21 +89,21 @@ func (this *MemoryList) Add(hash string, item *Item) error {
 	return nil
 }
 
-func (this *MemoryList) Exist(hash string) (bool, error) {
+func (this *MemoryList) Exist(hash string) (bool, int64, error) {
 	this.locker.RLock()
 	defer this.locker.RUnlock()
 
 	prefix := this.prefix(hash)
 	itemMap, ok := this.itemMaps[prefix]
 	if !ok {
-		return false, nil
+		return false, -1, nil
 	}
 	item, ok := itemMap[hash]
 	if !ok {
-		return false, nil
+		return false, -1, nil
 	}
 
-	return !item.IsExpired(), nil
+	return !item.IsExpired(), -1, nil
 }
 
 // CleanPrefix 根据前缀进行清除
diff --git a/internal/caches/list_memory_test.go b/internal/caches/list_memory_test.go
index 578bca6..9dcf5f8 100644
--- a/internal/caches/list_memory_test.go
+++ b/internal/caches/list_memory_test.go
@@ -317,7 +317,7 @@ func BenchmarkMemoryList(b *testing.B) {
 
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {
-			_, _ = list.Exist(types.String("a" + types.String(rands.Int(1, 10000))))
+			_, _, _ = list.Exist(types.String("a" + types.String(rands.Int(1, 10000))))
 			_ = list.Add("a"+types.String(rands.Int(1, 100000)), &caches.Item{})
 			_, _ = list.Purge(1000, func(hash string) error {
 				return nil
diff --git a/internal/caches/reader_file_mmap.go b/internal/caches/reader_file_mmap.go
index 4a26537..1c8b93c 100644
--- a/internal/caches/reader_file_mmap.go
+++ b/internal/caches/reader_file_mmap.go
@@ -6,23 +6,12 @@ package caches
 import (
 	"errors"
 	"io"
-	"os"
 )
 
-func IsValidForMMAP(fp *os.File) (ok bool, stat os.FileInfo) {
-	// stub
-	return
-}
-
 type MMAPFileReader struct {
 	FileReader
 }
 
-func NewMMAPFileReader(fp *os.File, stat os.FileInfo) (*MMAPFileReader, error) {
-	// stub
-	return &MMAPFileReader{}, errors.New("not implemented")
-}
-
 func (this *MMAPFileReader) CopyBodyTo(writer io.Writer) (int, error) {
 	// stub
 	return 0, errors.New("not implemented")
diff --git a/internal/caches/storage_file.go b/internal/caches/storage_file.go
index 7f64a9f..88bf73d 100644
--- a/internal/caches/storage_file.go
+++ b/internal/caches/storage_file.go
@@ -304,7 +304,12 @@ func (this *FileStorage) Init() error {
 		} else if totalSize > 1*sizes.K {
 			sizeMB = fmt.Sprintf("%.3f K", float64(totalSize)/float64(sizes.K))
 		}
-		remotelogs.Println("CACHE", "init policy "+types.String(this.policy.Id)+" from '"+this.options.Dir+"', cost: "+fmt.Sprintf("%.2f", cost)+" ms, size: "+sizeMB)
+
+		var mmapTag = "disabled"
+		if this.options.EnableMMAP {
+			mmapTag = "enabled"
+		}
+		remotelogs.Println("CACHE", "init policy "+types.String(this.policy.Id)+" from '"+this.options.Dir+"', cost: "+fmt.Sprintf("%.2f", cost)+" ms, size: "+sizeMB+", mmap: "+mmapTag)
 	}()
 
 	// 初始化list
@@ -360,14 +365,27 @@ func (this *FileStorage) openReader(key string, allowMemory bool, useStale bool,
 	hash, path, _ := this.keyPath(key)
 
 	// 检查文件记录是否已过期
+	var estimatedSize int64
 	if !useStale {
-		exists, err := this.list.Exist(hash)
+		exists, filesize, err := this.list.Exist(hash)
 		if err != nil {
 			return nil, err
 		}
 		if !exists {
 			return nil, ErrNotFound
 		}
+		estimatedSize = filesize
+	}
+
+	// 尝试通过MMAP读取
+	if estimatedSize > 0 {
+		reader, err := this.tryMMAPReader(isPartial, estimatedSize, path)
+		if err != nil {
+			return nil, err
+		}
+		if reader != nil {
+			return reader, nil
+		}
 	}
 
 	var isOk = false
@@ -404,22 +422,10 @@ func (this *FileStorage) openReader(key string, allowMemory bool, useStale bool,
 		partialFileReader.openFileCache = openFileCache
 		reader = partialFileReader
 	} else {
-		var options = this.options // copy
-		if options != nil && options.EnableMMAP {
-			if isValid, stat := IsValidForMMAP(fp); isValid {
-				reader, err = NewMMAPFileReader(fp, stat)
-				if err != nil {
-					return nil, err
-				}
-			}
-		}
-
-		if reader == nil {
-			var fileReader = NewFileReader(fp)
-			fileReader.openFile = openFile
-			fileReader.openFileCache = openFileCache
-			reader = fileReader
-		}
+		var fileReader = NewFileReader(fp)
+		fileReader.openFile = openFile
+		fileReader.openFileCache = openFileCache
+		reader = fileReader
 	}
 
 	err = reader.Init()
@@ -562,7 +568,7 @@ func (this *FileStorage) openWriter(key string, expiredAt int64, status int, hea
 	var partialRanges *PartialRanges
 	if isPartial {
 		// 数据库中是否存在
-		existsCacheItem, _ := this.list.Exist(hash)
+		existsCacheItem, _, _ := this.list.Exist(hash)
 		if existsCacheItem {
 			readerFp, err := os.OpenFile(tmpPath, os.O_RDONLY, 0444)
 			if err == nil {
diff --git a/internal/caches/storage_file_ext.go b/internal/caches/storage_file_ext.go
new file mode 100644
index 0000000..9fc6b29
--- /dev/null
+++ b/internal/caches/storage_file_ext.go
@@ -0,0 +1,9 @@
+// Copyright 2024 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
+//go:build !plus
+
+package caches
+
+func (this *FileStorage) tryMMAPReader(isPartial bool, estimatedSize int64, path string) (Reader, error) {
+	// stub
+	return nil, nil
+}
diff --git a/internal/caches/storage_memory.go b/internal/caches/storage_memory.go
index 262dbd7..3b8b469 100644
--- a/internal/caches/storage_memory.go
+++ b/internal/caches/storage_memory.go
@@ -128,7 +128,7 @@ func (this *MemoryStorage) OpenReader(key string, useStale bool, isPartial bool)
 	var hash = this.hash(key)
 
 	// check if exists in list
-	exists, _ := this.list.Exist(types.String(hash))
+	exists, _, _ := this.list.Exist(types.String(hash))
 	if !exists {
 		return nil, ErrNotFound
 	}
@@ -212,7 +212,7 @@ func (this *MemoryStorage) openWriter(key string, expiresAt int64, status int, h
 	item, ok := this.valuesMap[hash]
 	if ok && !item.IsExpired() {
 		var hashString = types.String(hash)
-		exists, _ := this.list.Exist(hashString)
+		exists, _, _ := this.list.Exist(hashString)
 		if !exists {
 			// remove from values map
 			delete(this.valuesMap, hash)
@@ -546,7 +546,7 @@ func (this *MemoryStorage) flushItem(key string) {
 	}
 
 	// 检查是否在列表中，防止未加入列表时就开始flush
-	isInList, err := this.list.Exist(types.String(hash))
+	isInList, _, err := this.list.Exist(types.String(hash))
 	if err != nil {
 		remotelogs.Error("CACHE", "flush items failed: "+err.Error())
 		return