feat(inode): add inode struct

dir.go

@@ -22,8 +22,7 @@ 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
@@ -36,8 +35,6 @@ type Directory struct {
 	unixfsDir uio.Directory
 
 	modTime time.Time
-
-	name string
 }
 
 // NewDirectory constructs a new MFS directory.
@@ -51,11 +48,13 @@ func NewDirectory(ctx context.Context, name string, node ipld.Node, parent child
 	}
 
 	return &Directory{
-		dserv:     dserv,
+		inode: inode{
+			name:       name,
+			parent:     parent,
+			dagService: dserv,
+		},
 		ctx:       ctx,
-		name:      name,
 		unixfsDir: db,
-		parent:    parent,
 		childDirs: make(map[string]*Directory),
 		files:     make(map[string]*File),
 		modTime:   time.Now(),
@@ -108,7 +107,7 @@ 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
 	}
@@ -158,15 +157,15 @@ func (d *Directory) cacheNode(name string, nd ipld.Node) (FSNode, error) {
 
 		switch fsn.Type() {
 		case ft.TDirectory, ft.THAMTShard:
-			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 ft.TFile, ft.TRaw, ft.TSymlink:
-			nfi, err := NewFile(name, nd, d, d.dserv)
+			nfi, err := NewFile(name, nd, d, d.dagService)
 			if err != nil {
 				return nil, err
 			}
@@ -178,7 +177,7 @@ 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
 		}
@@ -308,7 +307,7 @@ 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
 	}
@@ -318,7 +317,7 @@ 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
 	}
@@ -356,7 +355,7 @@ 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
 	}
@@ -452,7 +451,7 @@ 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 +28,12 @@ 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: inode{
+			name:       name,
+			parent:     parent,
+			dagService: dserv,
+		},
+		node: node,
 	}
 	if node.Cid().Prefix().Version > 0 {
 		fi.RawLeaves = true
@@ -82,7 +81,7 @@ 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 +1,21 @@
+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 of this `inode` in the MFS path (the same value
+	// is also stored as the name of the DAG link).
+	name string
+
+	// parent directory of this `inode` (which may be the `Root`).
+	parent childCloser
+
+	// dagService used to store modifications made to the contents
+	// of the file or directory the `inode` belongs to.
+	dagService ipld.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
 	}