1. root dir has id of 0

2. only delete empty folders
3. correct listing files under a folder

go/filer/directory_in_map.go

@@ -28,8 +28,8 @@ type DirectoryManagerInMap struct {
 func (dm *DirectoryManagerInMap) NewDirectoryEntryInMap(parent *DirectoryEntryInMap, name string) (d *DirectoryEntryInMap) {
 	d = &DirectoryEntryInMap{Name: name, Parent: parent}
 	d.SubDirectories = make(map[string]*DirectoryEntryInMap)
-	d.Id = dm.max
 	dm.max++
+	d.Id = dm.max
 	parts := make([]string, 0)
 	for p := d; p != nil && p.Name != ""; p = p.Parent {
 		parts = append(parts, p.Name)

go/filer/filer_embedded.go

@@ -1,6 +1,7 @@
 package filer
 
 import (
+	"fmt"
 	"path/filepath"
 )
 
@@ -52,6 +53,13 @@ func (filer *FilerEmbedded) ListFiles(dirPath string, lastFileName string, limit
 	return filer.files.ListFiles(dirId, lastFileName, limit), nil
 }
 func (filer *FilerEmbedded) DeleteDirectory(dirPath string) (err error) {
+	dirId, e := filer.directories.FindDirectory(dirPath)
+	if e != nil {
+		return e
+	}
+	if len(filer.files.ListFiles(dirId, "", 1)) > 0 {
+		return fmt.Errorf("Fail to delete non-empty directory %s!", dirPath)
+	}
 	return filer.directories.DeleteDirectory(dirPath)
 }
 func (filer *FilerEmbedded) DeleteFile(filePath string) (fid string, err error) {

go/filer/filer_in_leveldb.go

@@ -50,20 +50,23 @@ func (fl *FileListInLevelDb) ListFiles(dirId DirectoryId, lastFileName string, l
 	glog.V(4).Infoln("directory", dirId, "lastFileName", lastFileName, "limit", limit)
 	dirKey := genKey(dirId, "")
 	iter := fl.db.NewIterator(&util.Range{Start: genKey(dirId, lastFileName)}, nil)
-	limitCounter := -1
+	limitCounter := 0
 	for iter.Next() {
+		key := iter.Key()
+		if !bytes.HasPrefix(key, dirKey) {
+			break
+		}
+		fileName := string(key[len(dirKey):])
+		if fileName == lastFileName {
+			continue
+		}
 		limitCounter++
 		if limit > 0 {
 			if limitCounter > limit {
 				break
 			}
 		}
-		key := iter.Key()
-		if !bytes.HasPrefix(key, dirKey) {
-			break
-		}
-		fileName := key[len(dirKey):]
-		files = append(files, FileEntry{Name: string(fileName), Id: FileId(string(iter.Value()))})
+		files = append(files, FileEntry{Name: fileName, Id: FileId(string(iter.Value()))})
 	}
 	iter.Release()
 	return