feat(inode): add inode struct

dir.go

@@ -23,8 +23,7 @@ var ErrInvalidChild = errors.New("invalid child node")
 var ErrDirExists = errors.New("directory already has entry by that name")
 
 type Directory struct {
-	dserv  ipld.DAGService
-	parent childCloser
+	*inode
 
 	childDirs map[string]*Directory
 	files     map[string]*File
@@ -37,8 +36,6 @@ type Directory struct {
 	unixfsDir uio.Directory
 
 	modTime time.Time
-
-	name string
 }
 
 // NewDirectory constructs a new MFS directory.
@@ -52,11 +49,9 @@ func NewDirectory(ctx context.Context, name string, node ipld.Node, parent child
 	}
 
 	return &Directory{
-		dserv:     dserv,
+		inode:     NewInode(name, parent, dserv),
 		ctx:       ctx,
-		name:      name,
 		unixfsDir: db,
-		parent:    parent,
 		childDirs: make(map[string]*Directory),
 		files:     make(map[string]*File),
 		modTime:   time.Now(),
@@ -109,7 +104,7 @@ func (d *Directory) flushCurrentNode() (*dag.ProtoNode, error) {
 		return nil, err
 	}
 
-	err = d.dserv.Add(d.ctx, nd)
+	err = d.dagService.Add(d.ctx, nd)
 	if err != nil {
 		return nil, err
 	}
@@ -159,15 +154,15 @@ func (d *Directory) cacheNode(name string, nd ipld.Node) (FSNode, error) {
 
 		switch fsn.Type() {
 		case ufspb.Data_Directory, ufspb.Data_HAMTShard:
-			ndir, err := NewDirectory(d.ctx, name, nd, d, d.dserv)
+			ndir, err := NewDirectory(d.ctx, name, nd, d, d.dagService)
 			if err != nil {
 				return nil, err
 			}
 
 			d.childDirs[name] = ndir
 			return ndir, nil
 		case ufspb.Data_File, ufspb.Data_Raw, ufspb.Data_Symlink:
-			nfi, err := NewFile(name, nd, d, d.dserv)
+			nfi, err := NewFile(name, nd, d, d.dagService)
 			if err != nil {
 				return nil, err
 			}
@@ -179,7 +174,7 @@ func (d *Directory) cacheNode(name string, nd ipld.Node) (FSNode, error) {
 			return nil, ErrInvalidChild
 		}
 	case *dag.RawNode:
-		nfi, err := NewFile(name, nd, d, d.dserv)
+		nfi, err := NewFile(name, nd, d, d.dagService)
 		if err != nil {
 			return nil, err
 		}
@@ -309,7 +304,7 @@ func (d *Directory) Mkdir(name string) (*Directory, error) {
 	ndir := ft.EmptyDirNode()
 	ndir.SetCidBuilder(d.GetCidBuilder())
 
-	err = d.dserv.Add(d.ctx, ndir)
+	err = d.dagService.Add(d.ctx, ndir)
 	if err != nil {
 		return nil, err
 	}
@@ -319,7 +314,7 @@ func (d *Directory) Mkdir(name string) (*Directory, error) {
 		return nil, err
 	}
 
-	dirobj, err := NewDirectory(d.ctx, name, ndir, d, d.dserv)
+	dirobj, err := NewDirectory(d.ctx, name, ndir, d, d.dagService)
 	if err != nil {
 		return nil, err
 	}
@@ -357,7 +352,7 @@ func (d *Directory) AddChild(name string, nd ipld.Node) error {
 		return ErrDirExists
 	}
 
-	err = d.dserv.Add(d.ctx, nd)
+	err = d.dagService.Add(d.ctx, nd)
 	if err != nil {
 		return err
 	}
@@ -453,7 +448,7 @@ func (d *Directory) GetNode() (ipld.Node, error) {
 		return nil, err
 	}
 
-	err = d.dserv.Add(d.ctx, nd)
+	err = d.dagService.Add(d.ctx, nd)
 	if err != nil {
 		return nil, err
 	}

fd.go

@@ -122,7 +122,7 @@ func (fi *fileDescriptor) flushUp(fullsync bool) error {
 		return err
 	}
 
-	err = fi.inode.dserv.Add(context.TODO(), nd)
+	err = fi.inode.dagService.Add(context.TODO(), nd)
 	if err != nil {
 		return err
 	}

file.go

@@ -14,13 +14,10 @@ import (
 )
 
 type File struct {
-	parent childCloser
-
-	name string
+	*inode
 
 	desclock sync.RWMutex
 
-	dserv  ipld.DAGService
 	node   ipld.Node
 	nodelk sync.Mutex
 
@@ -31,10 +28,8 @@ type File struct {
 // Cid version is non-zero RawLeaves will be enabled.
 func NewFile(name string, node ipld.Node, parent childCloser, dserv ipld.DAGService) (*File, error) {
 	fi := &File{
-		dserv:  dserv,
-		parent: parent,
-		name:   name,
-		node:   node,
+		inode: NewInode(name, parent, dserv),
+		node:  node,
 	}
 	if node.Cid().Prefix().Version > 0 {
 		fi.RawLeaves = true
@@ -82,7 +77,7 @@ func (fi *File) Open(flags int, sync bool) (FileDescriptor, error) {
 		return nil, fmt.Errorf("mode not supported")
 	}
 
-	dmod, err := mod.NewDagModifier(context.TODO(), node, fi.dserv, chunker.DefaultSplitter)
+	dmod, err := mod.NewDagModifier(context.TODO(), node, fi.dagService, chunker.DefaultSplitter)
 	if err != nil {
 		return nil, err
 	}

inode.go

@@ -0,0 +1,23 @@
+package mfs
+
+import (
+	ipld "github.com/ipfs/go-ipld-format"
+)
+
+// inode abstracts the common characteristics of the MFS `File`
+// and `Directory`. All of its attributes are initialized at
+// creation.
+type inode struct {
+	name       string
+	parent     childCloser
+	dagService ipld.DAGService
+}
+
+// NewInode creates a new `inode` structure and return it's pointer.
+func NewInode(name string, parent childCloser, dagService ipld.DAGService) *inode {
+	return &inode{
+		name:       name,
+		parent:     parent,
+		dagService: dagService,
+	}
+}

mfs_test.go

@@ -555,7 +555,7 @@ func actorMakeFile(d *Directory) error {
 	}
 
 	name := randomName()
-	f, err := NewFile(name, dag.NodeWithData(ft.FilePBData(nil, 0)), d, d.dserv)
+	f, err := NewFile(name, dag.NodeWithData(ft.FilePBData(nil, 0)), d, d.dagService)
 	if err != nil {
 		return err
 	}

system.go

@@ -145,7 +145,7 @@ func (kr *Root) FlushMemFree(ctx context.Context) error {
 // closeChild implements the childCloser interface, and signals to the publisher that
 // there are changes ready to be published.
 func (kr *Root) closeChild(name string, nd ipld.Node, sync bool) error {
-	err := kr.GetDirectory().dserv.Add(context.TODO(), nd)
+	err := kr.GetDirectory().dagService.Add(context.TODO(), nd)
 	if err != nil {
 		return err
 	}