add placeholder for cached meta data reading

weed/filesys/dir.go

@@ -205,6 +205,10 @@ func (dir *Dir) Lookup(ctx context.Context, req *fuse.LookupRequest, resp *fuse.
 	fullFilePath := util.NewFullPath(dir.FullPath(), req.Name)
 	entry := dir.wfs.cacheGet(fullFilePath)
 
+	if dir.wfs.option.AsyncMetaDataCaching {
+
+	}
+
 	if entry == nil {
 		// glog.V(3).Infof("dir Lookup cache miss %s", fullFilePath)
 		entry, err = filer_pb.GetEntry(dir.wfs, fullFilePath)
@@ -244,6 +248,10 @@ func (dir *Dir) ReadDirAll(ctx context.Context) (ret []fuse.Dirent, err error) {
 
 	glog.V(3).Infof("dir ReadDirAll %s", dir.FullPath())
 
+	if dir.wfs.option.AsyncMetaDataCaching {
+
+	}
+
 	cacheTtl := 5 * time.Minute
 
 	readErr := filer_pb.ReadDirAllEntries(dir.wfs, util.FullPath(dir.FullPath()), "", func(entry *filer_pb.Entry, isLast bool) {

weed/filesys/wfs.go

@@ -44,6 +44,7 @@ type Option struct {
 
 	OutsideContainerClusterMode bool // whether the mount runs outside SeaweedFS containers
 	Cipher                      bool // whether encrypt data on volume server
+	AsyncMetaDataCaching        bool // whether asynchronously cache meta data
 
 }
 

weed/filesys/xattr.go

@@ -114,6 +114,10 @@ func (wfs *WFS) maybeLoadEntry(dir, name string) (entry *filer_pb.Entry, err err
 	}
 	// glog.V(3).Infof("read entry cache miss %s", fullpath)
 
+	if wfs.option.AsyncMetaDataCaching {
+
+	}
+
 	err = wfs.WithFilerClient(func(client filer_pb.SeaweedFilerClient) error {
 
 		request := &filer_pb.LookupDirectoryEntryRequest{