Merge pull request #645 from chrislusf/vasto_filer

merge back filer related refactoring

14 files changed, 166 insertions, 78 deletions

diff --git a/weed/command/mount_std.go b/weed/command/mount_std.go
index 0c36e488f..ef962e15b 100644
--- a/weed/command/mount_std.go
+++ b/weed/command/mount_std.go
@@ -59,27 +59,27 @@ func (WFS) Root() (fs.Node, error) {
 var fileIdMap = make(map[uint64]filer.FileId)
 
 type Dir struct {
-	Id        uint64
 	Path      string
 	DirentMap map[string]*fuse.Dirent
 }
 
 func (dir *Dir) Attr(context context.Context, attr *fuse.Attr) error {
-	attr.Inode = dir.Id
 	attr.Mode = os.ModeDir | 0555
 	return nil
 }
 
 func (dir *Dir) Lookup(ctx context.Context, name string) (fs.Node, error) {
-	if dirent, ok := dir.DirentMap[name]; ok {
-		if dirent.Type == fuse.DT_File {
-			return &File{Id: dirent.Inode, FileId: fileIdMap[dirent.Inode], Name: dirent.Name}, nil
+	if entry, err := filer.LookupDirectoryEntry(*mountOptions.filer, dir.Path, name); err == nil {
+		if !entry.Found {
+			return nil, fuse.ENOENT
+		}
+		if entry.FileId != "" {
+			return &File{FileId: filer.FileId(entry.FileId), Name: name}, nil
+		} else {
+			return &Dir{Path: path.Join(dir.Path, name)}, nil
 		}
-		return &Dir{
-			Id:   dirent.Inode,
-			Path: path.Join(dir.Path, dirent.Name),
-		}, nil
 	}
+
 	return nil, fuse.ENOENT
 }
 
@@ -90,17 +90,16 @@ func (dir *Dir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
 	}
 	if dirs, e := filer.ListDirectories(*mountOptions.filer, dir.Path); e == nil {
 		for _, d := range dirs.Directories {
-			dirId := uint64(d.Id)
-			dirent := fuse.Dirent{Inode: dirId, Name: d.Name, Type: fuse.DT_Dir}
+			dirent := fuse.Dirent{Name: string(d), Type: fuse.DT_Dir}
 			ret = append(ret, dirent)
-			dir.DirentMap[d.Name] = &dirent
+			dir.DirentMap[string(d)] = &dirent
 		}
 	}
 	if files, e := filer.ListFiles(*mountOptions.filer, dir.Path, ""); e == nil {
 		for _, f := range files.Files {
 			if fileId, e := storage.ParseFileId(string(f.Id)); e == nil {
 				fileInode := uint64(fileId.VolumeId)<<48 + fileId.Key
-				dirent := fuse.Dirent{Inode: fileInode, Name: f.Name, Type: fuse.DT_File}
+				dirent := fuse.Dirent{Name: f.Name, Type: fuse.DT_File}
 				ret = append(ret, dirent)
 				dir.DirentMap[f.Name] = &dirent
 				fileIdMap[fileInode] = f.Id
@@ -120,13 +119,11 @@ func (dir *Dir) Remove(ctx context.Context, req *fuse.RemoveRequest) error {
 }
 
 type File struct {
-	Id     uint64
 	FileId filer.FileId
 	Name   string
 }
 
 func (file *File) Attr(context context.Context, attr *fuse.Attr) error {
-	attr.Inode = file.Id
 	attr.Mode = 0444
 	ret, err := filer.GetFileSize(*mountOptions.filer, string(file.FileId))
 	if err == nil {
diff --git a/weed/filer/client_operations.go b/weed/filer/client_operations.go
index 95dd26396..057fb4c66 100644
--- a/weed/filer/client_operations.go
+++ b/weed/filer/client_operations.go
@@ -65,7 +65,7 @@ func GetFileContent(server string, fileId string) (ret *GetFileContentResult, er
 }
 
 type ListDirectoriesResult struct {
-	Directories []DirectoryEntry
+	Directories []DirectoryName
 	Error       string `json:"error,omitempty"`
 }
 
@@ -80,6 +80,23 @@ func ListDirectories(server string, directory string) (ret *ListDirectoriesResul
 	return nil, err
 }
 
+type LookupDirectoryEntryResult struct {
+	Found  bool
+	FileId string
+	Error  string `json:"error,omitempty"`
+}
+
+func LookupDirectoryEntry(server string, directory string, name string) (ret *LookupDirectoryEntryResult, err error) {
+	ret = new(LookupDirectoryEntryResult)
+	if err := call(server, ApiRequest{Command: "lookupDirectoryEntry", Directory: directory, FileName: name}, ret); err == nil {
+		if ret.Error != "" {
+			return nil, errors.New(ret.Error)
+		}
+		return ret, nil
+	}
+	return nil, err
+}
+
 func DeleteDirectoryOrFile(server string, path string, isDir bool) error {
 	destUrl := fmt.Sprintf("http://%s%s", server, path)
 	if isDir {
diff --git a/weed/filer/embedded_filer/directory.go b/weed/filer/embedded_filer/directory.go
index 4d4bd1c59..1ff725f28 100644
--- a/weed/filer/embedded_filer/directory.go
+++ b/weed/filer/embedded_filer/directory.go
@@ -5,11 +5,11 @@ import (
 )
 
 type DirectoryManager interface {
-	FindDirectory(dirPath string) (filer.DirectoryId, error)
-	ListDirectories(dirPath string) (dirs []filer.DirectoryEntry, err error)
-	MakeDirectory(currentDirPath string, dirName string) (filer.DirectoryId, error)
+	FindDirectory(dirPath string) (DirectoryId, error)
+	ListDirectories(dirPath string) (dirs []filer.DirectoryName, err error)
+	MakeDirectory(currentDirPath string, dirName string) (DirectoryId, error)
 	MoveUnderDirectory(oldDirPath string, newParentDirPath string) error
 	DeleteDirectory(dirPath string) error
 	//functions used by FUSE
-	FindDirectoryById(filer.DirectoryId, error)
+	FindDirectoryById(DirectoryId, error)
 }
diff --git a/weed/filer/embedded_filer/directory_in_map.go b/weed/filer/embedded_filer/directory_in_map.go
index e082bbf81..1266d3779 100644
--- a/weed/filer/embedded_filer/directory_in_map.go
+++ b/weed/filer/embedded_filer/directory_in_map.go
@@ -16,12 +16,14 @@ import (
 
 var writeLock sync.Mutex //serialize changes to dir.log
 
+type DirectoryId int32
+
 type DirectoryEntryInMap struct {
 	sync.Mutex
 	Name           string
 	Parent         *DirectoryEntryInMap
 	subDirectories map[string]*DirectoryEntryInMap
-	Id             filer.DirectoryId
+	Id             DirectoryId
 }
 
 func (de *DirectoryEntryInMap) getChild(dirName string) (*DirectoryEntryInMap, bool) {
@@ -45,18 +47,18 @@ func (de *DirectoryEntryInMap) hasChildren() bool {
 	defer de.Unlock()
 	return len(de.subDirectories) > 0
 }
-func (de *DirectoryEntryInMap) children() (dirNames []filer.DirectoryEntry) {
+func (de *DirectoryEntryInMap) children() (dirNames []filer.DirectoryName) {
 	de.Lock()
 	defer de.Unlock()
-	for k, v := range de.subDirectories {
-		dirNames = append(dirNames, filer.DirectoryEntry{Name: k, Id: v.Id})
+	for k, _ := range de.subDirectories {
+		dirNames = append(dirNames, filer.DirectoryName(k))
 	}
 	return dirNames
 }
 
 type DirectoryManagerInMap struct {
 	Root      *DirectoryEntryInMap
-	max       filer.DirectoryId
+	max       DirectoryId
 	logFile   *os.File
 	isLoading bool
 }
@@ -113,7 +115,7 @@ func (dm *DirectoryManagerInMap) processEachLine(line string) error {
 		if pe != nil {
 			return pe
 		}
-		if e := dm.loadDirectory(parts[1], filer.DirectoryId(v)); e != nil {
+		if e := dm.loadDirectory(parts[1], DirectoryId(v)); e != nil {
 			return e
 		}
 	case "mov":
@@ -172,7 +174,7 @@ func (dm *DirectoryManagerInMap) findDirectory(dirPath string) (*DirectoryEntryI
 	}
 	return dir, nil
 }
-func (dm *DirectoryManagerInMap) FindDirectory(dirPath string) (filer.DirectoryId, error) {
+func (dm *DirectoryManagerInMap) findDirectoryId(dirPath string) (DirectoryId, error) {
 	d, e := dm.findDirectory(dirPath)
 	if e == nil {
 		return d.Id, nil
@@ -180,7 +182,7 @@ func (dm *DirectoryManagerInMap) FindDirectory(dirPath string) (filer.DirectoryI
 	return dm.Root.Id, e
 }
 
-func (dm *DirectoryManagerInMap) loadDirectory(dirPath string, dirId filer.DirectoryId) error {
+func (dm *DirectoryManagerInMap) loadDirectory(dirPath string, dirId DirectoryId) error {
 	dirPath = CleanFilePath(dirPath)
 	if dirPath == "/" {
 		return nil
@@ -248,7 +250,7 @@ func (dm *DirectoryManagerInMap) makeDirectory(dirPath string) (dir *DirectoryEn
 	return dir, created
 }
 
-func (dm *DirectoryManagerInMap) MakeDirectory(dirPath string) (filer.DirectoryId, error) {
+func (dm *DirectoryManagerInMap) MakeDirectory(dirPath string) (DirectoryId, error) {
 	dir, _ := dm.makeDirectory(dirPath)
 	return dir.Id, nil
 }
@@ -275,7 +277,7 @@ func (dm *DirectoryManagerInMap) MoveUnderDirectory(oldDirPath string, newParent
 	return nil
 }
 
-func (dm *DirectoryManagerInMap) ListDirectories(dirPath string) (dirNames []filer.DirectoryEntry, err error) {
+func (dm *DirectoryManagerInMap) ListDirectories(dirPath string) (dirNames []filer.DirectoryName, err error) {
 	d, e := dm.findDirectory(dirPath)
 	if e != nil {
 		return dirNames, e
diff --git a/weed/filer/embedded_filer/directory_test.go b/weed/filer/embedded_filer/directory_test.go
index c8b3f1f30..b70164a14 100644
--- a/weed/filer/embedded_filer/directory_test.go
+++ b/weed/filer/embedded_filer/directory_test.go
@@ -19,17 +19,17 @@ func TestDirectory(t *testing.T) {
 	dm.MakeDirectory("/a/b/e/f")
 	dm.MakeDirectory("/a/b/e/f/g")
 	dm.MoveUnderDirectory("/a/b/e/f/g", "/a/b", "t")
-	if _, err := dm.FindDirectory("/a/b/e/f/g"); err == nil {
+	if _, err := dm.findDirectoryId("/a/b/e/f/g"); err == nil {
 		t.Fatal("/a/b/e/f/g should not exist any more after moving")
 	}
-	if _, err := dm.FindDirectory("/a/b/t"); err != nil {
+	if _, err := dm.findDirectoryId("/a/b/t"); err != nil {
 		t.Fatal("/a/b/t should exist after moving")
 	}
-	if _, err := dm.FindDirectory("/a/b/g"); err == nil {
+	if _, err := dm.findDirectoryId("/a/b/g"); err == nil {
 		t.Fatal("/a/b/g should not exist after moving")
 	}
 	dm.MoveUnderDirectory("/a/b/e/f", "/a/b", "")
-	if _, err := dm.FindDirectory("/a/b/f"); err != nil {
+	if _, err := dm.findDirectoryId("/a/b/f"); err != nil {
 		t.Fatal("/a/b/g should not exist after moving")
 	}
 	dm.MakeDirectory("/a/b/g/h/i")
diff --git a/weed/filer/embedded_filer/filer_embedded.go b/weed/filer/embedded_filer/filer_embedded.go
index 4a335058b..d6ab3c70a 100644
--- a/weed/filer/embedded_filer/filer_embedded.go
+++ b/weed/filer/embedded_filer/filer_embedded.go
@@ -45,27 +45,37 @@ func (filer *FilerEmbedded) CreateFile(filePath string, fid string) (err error)
 }
 func (filer *FilerEmbedded) FindFile(filePath string) (fid string, err error) {
 	dir, file := filepath.Split(filePath)
-	dirId, e := filer.directories.FindDirectory(dir)
+	return filer.findFileEntry(dir, file)
+}
+func (filer *FilerEmbedded) findFileEntry(parentPath string, fileName string) (fid string, err error) {
+	dirId, e := filer.directories.findDirectoryId(parentPath)
 	if e != nil {
 		return "", e
 	}
-	return filer.files.FindFile(dirId, file)
+	return filer.files.FindFile(dirId, fileName)
 }
-func (filer *FilerEmbedded) FindDirectory(dirPath string) (dirId filer.DirectoryId, err error) {
-	return filer.directories.FindDirectory(dirPath)
+
+func (filer *FilerEmbedded) LookupDirectoryEntry(dirPath string, name string) (found bool, fileId string, err error) {
+	if _, err = filer.directories.findDirectory(filepath.Join(dirPath, name)); err == nil {
+		return true, "", nil
+	}
+	if fileId, err = filer.findFileEntry(dirPath, name); err == nil {
+		return true, fileId, nil
+	}
+	return false, "", err
 }
-func (filer *FilerEmbedded) ListDirectories(dirPath string) (dirs []filer.DirectoryEntry, err error) {
+func (filer *FilerEmbedded) ListDirectories(dirPath string) (dirs []filer.DirectoryName, err error) {
 	return filer.directories.ListDirectories(dirPath)
 }
 func (filer *FilerEmbedded) ListFiles(dirPath string, lastFileName string, limit int) (files []filer.FileEntry, err error) {
-	dirId, e := filer.directories.FindDirectory(dirPath)
+	dirId, e := filer.directories.findDirectoryId(dirPath)
 	if e != nil {
 		return nil, e
 	}
 	return filer.files.ListFiles(dirId, lastFileName, limit), nil
 }
 func (filer *FilerEmbedded) DeleteDirectory(dirPath string, recursive bool) (err error) {
-	dirId, e := filer.directories.FindDirectory(dirPath)
+	dirId, e := filer.directories.findDirectoryId(dirPath)
 	if e != nil {
 		return e
 	}
@@ -74,7 +84,7 @@ func (filer *FilerEmbedded) DeleteDirectory(dirPath string, recursive bool) (err
 			return fmt.Errorf("Fail to delete directory %s: %d sub directories found!", dirPath, len(sub_dirs))
 		}
 		for _, sub := range sub_dirs {
-			if delete_sub_err := filer.DeleteDirectory(filepath.Join(dirPath, sub.Name), recursive); delete_sub_err != nil {
+			if delete_sub_err := filer.DeleteDirectory(filepath.Join(dirPath, string(sub)), recursive); delete_sub_err != nil {
 				return delete_sub_err
 			}
 		}
@@ -108,7 +118,7 @@ func (filer *FilerEmbedded) DeleteDirectory(dirPath string, recursive bool) (err
 
 func (filer *FilerEmbedded) DeleteFile(filePath string) (fid string, err error) {
 	dir, file := filepath.Split(filePath)
-	dirId, e := filer.directories.FindDirectory(dir)
+	dirId, e := filer.directories.findDirectoryId(dir)
 	if e != nil {
 		return "", e
 	}
@@ -126,8 +136,8 @@ func (filer *FilerEmbedded) Move(fromPath string, toPath string) error {
 	filer.mvMutex.Lock()
 	defer filer.mvMutex.Unlock()
 
-	if _, dir_err := filer.FindDirectory(fromPath); dir_err == nil {
-		if _, err := filer.FindDirectory(toPath); err == nil {
+	if _, dir_err := filer.directories.findDirectoryId(fromPath); dir_err == nil {
+		if _, err := filer.directories.findDirectoryId(toPath); err == nil {
 			// move folder under an existing folder
 			return filer.directories.MoveUnderDirectory(fromPath, toPath, "")
 		}
@@ -135,7 +145,7 @@ func (filer *FilerEmbedded) Move(fromPath string, toPath string) error {
 		return filer.directories.MoveUnderDirectory(fromPath, filepath.Dir(toPath), filepath.Base(toPath))
 	}
 	if fid, file_err := filer.DeleteFile(fromPath); file_err == nil {
-		if _, err := filer.FindDirectory(toPath); err == nil {
+		if _, err := filer.directories.findDirectoryId(toPath); err == nil {
 			// move file under an existing folder
 			return filer.CreateFile(filepath.Join(toPath, filepath.Base(fromPath)), fid)
 		}
diff --git a/weed/filer/embedded_filer/files_in_leveldb.go b/weed/filer/embedded_filer/files_in_leveldb.go
index c40d7adaf..bde41d8a2 100644
--- a/weed/filer/embedded_filer/files_in_leveldb.go
+++ b/weed/filer/embedded_filer/files_in_leveldb.go
@@ -28,7 +28,7 @@ func NewFileListInLevelDb(dir string) (fl *FileListInLevelDb, err error) {
 	return
 }
 
-func genKey(dirId filer.DirectoryId, fileName string) []byte {
+func genKey(dirId DirectoryId, fileName string) []byte {
 	ret := make([]byte, 0, 4+len(fileName))
 	for i := 3; i >= 0; i-- {
 		ret = append(ret, byte(dirId>>(uint(i)*8)))
@@ -37,11 +37,11 @@ func genKey(dirId filer.DirectoryId, fileName string) []byte {
 	return ret
 }
 
-func (fl *FileListInLevelDb) CreateFile(dirId filer.DirectoryId, fileName string, fid string) (err error) {
+func (fl *FileListInLevelDb) CreateFile(dirId DirectoryId, fileName string, fid string) (err error) {
 	glog.V(4).Infoln("directory", dirId, "fileName", fileName, "fid", fid)
 	return fl.db.Put(genKey(dirId, fileName), []byte(fid), nil)
 }
-func (fl *FileListInLevelDb) DeleteFile(dirId filer.DirectoryId, fileName string) (fid string, err error) {
+func (fl *FileListInLevelDb) DeleteFile(dirId DirectoryId, fileName string) (fid string, err error) {
 	if fid, err = fl.FindFile(dirId, fileName); err != nil {
 		if err == leveldb.ErrNotFound {
 			return "", nil
@@ -51,7 +51,7 @@ func (fl *FileListInLevelDb) DeleteFile(dirId filer.DirectoryId, fileName string
 	err = fl.db.Delete(genKey(dirId, fileName), nil)
 	return fid, err
 }
-func (fl *FileListInLevelDb) FindFile(dirId filer.DirectoryId, fileName string) (fid string, err error) {
+func (fl *FileListInLevelDb) FindFile(dirId DirectoryId, fileName string) (fid string, err error) {
 	data, e := fl.db.Get(genKey(dirId, fileName), nil)
 	if e == leveldb.ErrNotFound {
 		return "", filer.ErrNotFound
@@ -60,7 +60,7 @@ func (fl *FileListInLevelDb) FindFile(dirId filer.DirectoryId, fileName string)
 	}
 	return string(data), nil
 }
-func (fl *FileListInLevelDb) ListFiles(dirId filer.DirectoryId, lastFileName string, limit int) (files []filer.FileEntry) {
+func (fl *FileListInLevelDb) ListFiles(dirId DirectoryId, lastFileName string, limit int) (files []filer.FileEntry) {
 	glog.V(4).Infoln("directory", dirId, "lastFileName", lastFileName, "limit", limit)
 	dirKey := genKey(dirId, "")
 	iter := fl.db.NewIterator(&util.Range{Start: genKey(dirId, lastFileName)}, nil)
diff --git a/weed/filer/filer.go b/weed/filer/filer.go
index 5d5acb68d..8f6344975 100644
--- a/weed/filer/filer.go
+++ b/weed/filer/filer.go
@@ -11,12 +11,7 @@ type FileEntry struct {
 	Id   FileId `json:"fid,omitempty"`
 }
 
-type DirectoryId int32
-
-type DirectoryEntry struct {
-	Name string //dir name without path
-	Id   DirectoryId
-}
+type DirectoryName string
 
 type Filer interface {
 	CreateFile(fullFileName string, fid string) (err error)
@@ -24,11 +19,11 @@ type Filer interface {
 	DeleteFile(fullFileName string) (fid string, err error)
 
 	//Optional functions. embedded filer support these
-	FindDirectory(dirPath string) (dirId DirectoryId, err error)
-	ListDirectories(dirPath string) (dirs []DirectoryEntry, err error)
+	ListDirectories(dirPath string) (dirs []DirectoryName, err error)
 	ListFiles(dirPath string, lastFileName string, limit int) (files []FileEntry, err error)
 	DeleteDirectory(dirPath string, recursive bool) (err error)
 	Move(fromPath string, toPath string) (err error)
+	LookupDirectoryEntry(dirPath string, name string) (found bool, fileId string, err error)
 }
 
 var ErrNotFound = errors.New("filer: no entry is found in filer store")
diff --git a/weed/filer/flat_namespace/flat_namespace_filer.go b/weed/filer/flat_namespace/flat_namespace_filer.go
index f5e17b621..4173c41ee 100644
--- a/weed/filer/flat_namespace/flat_namespace_filer.go
+++ b/weed/filer/flat_namespace/flat_namespace_filer.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 
 	"github.com/chrislusf/seaweedfs/weed/filer"
+	"path/filepath"
 )
 
 type FlatNamespaceFiler struct {
@@ -28,10 +29,13 @@ func (filer *FlatNamespaceFiler) CreateFile(fullFileName string, fid string) (er
 func (filer *FlatNamespaceFiler) FindFile(fullFileName string) (fid string, err error) {
 	return filer.store.Get(fullFileName)
 }
-func (filer *FlatNamespaceFiler) FindDirectory(dirPath string) (dirId filer.DirectoryId, err error) {
-	return 0, ErrNotImplemented
+func (filer *FlatNamespaceFiler) LookupDirectoryEntry(dirPath string, name string) (found bool, fileId string, err error) {
+	if fileId, err = filer.FindFile(filepath.Join(dirPath, name)); err == nil {
+		return true, fileId, nil
+	}
+	return false, "", err
 }
-func (filer *FlatNamespaceFiler) ListDirectories(dirPath string) (dirs []filer.DirectoryEntry, err error) {
+func (filer *FlatNamespaceFiler) ListDirectories(dirPath string) (dirs []filer.DirectoryName, err error) {
 	return nil, ErrNotImplemented
 }
 func (filer *FlatNamespaceFiler) ListFiles(dirPath string, lastFileName string, limit int) (files []filer.FileEntry, err error) {
diff --git a/weed/filer/postgres_store/postgres_native.go b/weed/filer/postgres_store/postgres_native.go
index 12b5015cf..61bd4210c 100644
--- a/weed/filer/postgres_store/postgres_native.go
+++ b/weed/filer/postgres_store/postgres_native.go
@@ -14,6 +14,8 @@ import (
 	"strings"
 )
 
+type DirectoryId int32
+
 func databaseExists(db *sql.DB, databaseName string) (bool, error) {
 	sqlStatement := "SELECT datname from pg_database WHERE datname='%s'"
 	row := db.QueryRow(fmt.Sprintf(sqlStatement, databaseName))
@@ -293,13 +295,13 @@ func (s *PostgresStore) delete(uriPath string) error {
 	return nil
 }
 
-func (s *PostgresStore) lookupDirectory(dirPath string) (filer.DirectoryId, string, error) {
+func (s *PostgresStore) lookupDirectory(dirPath string) (DirectoryId, string, error) {
 	directoryRoot, directoryName := s.mySplitPath(dirPath)
 
 	sqlStatement := fmt.Sprintf("SELECT id, directoryroot, directoryname FROM %s WHERE directoryRoot=$1 AND directoryName=$2", directoriesTableName)
 
 	row := s.db.QueryRow(sqlStatement, directoryRoot, directoryName)
-	var id filer.DirectoryId
+	var id DirectoryId
 	var dirRoot string
 	var dirName string
 	err := row.Scan(&id, &dirRoot, &dirName)
@@ -312,7 +314,7 @@ func (s *PostgresStore) lookupDirectory(dirPath string) (filer.DirectoryId, stri
 	return id, filepath.Join(dirRoot, dirName), err
 }
 
-func (s *PostgresStore) findDirectories(dirPath string, limit int) (dirs []filer.DirectoryEntry, err error) {
+func (s *PostgresStore) findDirectories(dirPath string, limit int) (dirs []filer.DirectoryName, err error) {
 	sqlStatement := fmt.Sprintf("SELECT id, directoryroot, directoryname FROM %s WHERE directoryRoot=$1 AND directoryName != '' ORDER BY id LIMIT $2", directoriesTableName)
 	rows, err := s.db.Query(sqlStatement, dirPath, limit)
 
@@ -323,7 +325,7 @@ func (s *PostgresStore) findDirectories(dirPath string, limit int) (dirs []filer
 	if rows != nil {
 		defer rows.Close()
 		for rows.Next() {
-			var id filer.DirectoryId
+			var id DirectoryId
 			var directoryRoot string
 			var directoryName string
 
@@ -331,7 +333,7 @@ func (s *PostgresStore) findDirectories(dirPath string, limit int) (dirs []filer
 			if scanErr != nil {
 				err = scanErr
 			}
-			dirs = append(dirs, filer.DirectoryEntry{Name: (directoryName), Id: id})
+			dirs = append(dirs, filer.DirectoryName(directoryName))
 		}
 	}
 	return
@@ -344,7 +346,7 @@ func (s *PostgresStore) safeToDeleteDirectory(dirPath string, recursive bool) bo
 	sqlStatement := fmt.Sprintf("SELECT id FROM %s WHERE directoryRoot LIKE $1 LIMIT 1", directoriesTableName)
 	row := s.db.QueryRow(sqlStatement, dirPath+"%")
 
-	var id filer.DirectoryId
+	var id DirectoryId
 	err := row.Scan(&id)
 	if err != nil {
 		if err == sql.ErrNoRows {
diff --git a/weed/filer/postgres_store/postgres_store.go b/weed/filer/postgres_store/postgres_store.go
index e0aa2a02f..854793f6a 100644
--- a/weed/filer/postgres_store/postgres_store.go
+++ b/weed/filer/postgres_store/postgres_store.go
@@ -10,6 +10,7 @@ import (
 
 	_ "github.com/lib/pq"
 	_ "path/filepath"
+	"path/filepath"
 )
 
 const (
@@ -74,6 +75,17 @@ func (s *PostgresStore) FindFile(fullFilePath string) (fid string, err error) {
 	return fid, err
 }
 
+func (s *PostgresStore) LookupDirectoryEntry(dirPath string, name string) (found bool, fileId string, err error) {
+	fullPath := filepath.Join(dirPath, name)
+	if fileId, err = s.FindFile(fullPath); err == nil {
+		return true, fileId, nil
+	}
+	if _, _, err := s.lookupDirectory(fullPath); err == nil {
+		return true, "", err
+	}
+	return false, "", err
+}
+
 func (s *PostgresStore) DeleteFile(fullFilePath string) (fid string, err error) {
 	if err != nil {
 		return "", fmt.Errorf("PostgresStore Delete operation can not parse file path %s: err is %v", fullFilePath, err)
@@ -90,14 +102,9 @@ func (s *PostgresStore) DeleteFile(fullFilePath string) (fid string, err error)
 	}
 }
 
-func (s *PostgresStore) FindDirectory(dirPath string) (dirId filer.DirectoryId, err error) {
-	dirId, _, err = s.lookupDirectory(dirPath)
-	return dirId, err
-}
-
-func (s *PostgresStore) ListDirectories(dirPath string) (dirs []filer.DirectoryEntry, err error) {
+func (s *PostgresStore) ListDirectories(dirPath string) (dirs []filer.DirectoryName, err error) {
 
-	dirs, err = s.findDirectories(dirPath, 20)
+	dirs, err = s.findDirectories(dirPath, 1000)
 
 	glog.V(3).Infof("Postgres ListDirs = found %d directories under %s", len(dirs), dirPath)
 
diff --git a/weed/filer/vasto_store/design.txt b/weed/filer/vasto_store/design.txt
new file mode 100644
index 000000000..99faa29d6
--- /dev/null
+++ b/weed/filer/vasto_store/design.txt
@@ -0,0 +1,45 @@
+There are two main components of a filer: directories and files.
+
+My previous approach was to use some sequance number to generate directoryId.
+However, this is not scalable. The id generation itself is a bottleneck.
+It needs careful locking and deduplication checking to get a directoryId.
+
+In a second design, each directory is deterministically mapped to UUID version 3,
+which uses MD5 to map a tuple of <uuid, name> to a version 3 UUID.
+However, this UUID3 approach is logically the same as storing the full path.
+
+Storing the full path is the simplest design.
+
+separator is a special byte, 0x00.
+
+When writing a file:
+  <file parent full path, separator, file name> => fildId, file properties
+For folders:
+  The filer breaks the directory path into folders.
+  for each folder:
+    if it is not in cache:
+	  check whether the folder is created in the KVS, if not:
+        set <folder parent full path, separator, folder name> => directory properties
+	if no permission for the folder:
+	  break
+	  
+
+The filer caches the most recently used folder permissions with a TTL.
+  So any folder permission change needs to wait TTL interval to take effect.
+
+
+
+When listing the directory:
+  prefix scan of using (the folder full path + separator) as the prefix
+
+The downside:
+	1. Rename a folder will need to recursively process all sub folders and files.
+	2. Move   a folder will need to recursively process all sub folders and files.
+So these operations are not allowed if the folder is not empty.
+
+Allowing:
+	1. Rename a file
+	2. Move a file to a different folder
+	3. Delete an empty folder
+
+
diff --git a/weed/server/filer_server_handlers_api.go b/weed/server/filer_server_handlers_api.go
index f07aab88a..93a0dd751 100644
--- a/weed/server/filer_server_handlers_api.go
+++ b/weed/server/filer_server_handlers_api.go
@@ -21,6 +21,13 @@ func (fs *FilerServer) apiHandler(w http.ResponseWriter, r *http.Request) {
 		writeJsonError(w, r, http.StatusInternalServerError, err)
 	}
 	switch apiRequest.Command {
+	case "lookupDirectoryEntry":
+		res := filer.LookupDirectoryEntryResult{}
+		res.Found, res.FileId, err = fs.filer.LookupDirectoryEntry(apiRequest.Directory, apiRequest.FileName)
+		if err != nil {
+			res.Error = err.Error()
+		}
+		writeJsonQuiet(w, r, http.StatusOK, res)
 	case "listDirectories":
 		res := filer.ListDirectoriesResult{}
 		res.Directories, err = fs.filer.ListDirectories(apiRequest.Directory)
@@ -30,7 +37,7 @@ func (fs *FilerServer) apiHandler(w http.ResponseWriter, r *http.Request) {
 		writeJsonQuiet(w, r, http.StatusOK, res)
 	case "listFiles":
 		res := filer.ListFilesResult{}
-		res.Files, err = fs.filer.ListFiles(apiRequest.Directory, apiRequest.FileName, 100)
+		res.Files, err = fs.filer.ListFiles(apiRequest.Directory, apiRequest.FileName, 1000)
 		if err != nil {
 			res.Error = err.Error()
 		}
diff --git a/weed/server/filer_ui/templates.go b/weed/server/filer_ui/templates.go
index 6f4f7ce86..b6a8a1878 100644
--- a/weed/server/filer_ui/templates.go
+++ b/weed/server/filer_ui/templates.go
@@ -28,15 +28,17 @@ var StatusTpl = template.Must(template.New("status").Parse(`<!DOCTYPE html>
 				{{$path := .Path }}
 				{{ range $dirs_index, $dir := .Directories }}
 				<li>
-					<a href=		{{ print $path  $dir.Name  "/"}} >
-						{{ $dir.Name }}
+					<a href={{ print $path  $dir  "/"}} >
+						{{ $dir }}
 					</a>
 				</li>
 				{{ end }}
 
 				{{ range $file_index, $file := .Files }}
 				<li>
+					<a href={{ print $path  $file.Name}} >
 					{{ $file.Name }}
+					</a>
 				</li>
 				{{ end }}
 			</ul>