Refactor

cmd/khepri/cmd_backup.go

@@ -24,7 +24,7 @@ func hash(filename string) (khepri.ID, error) {
 }
 
 func store_file(repo *khepri.Repository, path string) (khepri.ID, error) {
-	obj, err := repo.NewObject(khepri.TYPE_BLOB)
+	obj, idch, err := repo.Create(khepri.TYPE_BLOB)
 	if err != nil {
 		return nil, err
 	}
@@ -44,7 +44,7 @@ func store_file(repo *khepri.Repository, path string) (khepri.ID, error) {
 		return nil, err
 	}
 
-	return obj.ID(), nil
+	return <-idch, nil
 }
 
 func archive_dir(repo *khepri.Repository, path string) (khepri.ID, error) {
@@ -92,7 +92,7 @@ func archive_dir(repo *khepri.Repository, path string) (khepri.ID, error) {
 
 	log.Printf("  dir %q: %v entries", path, len(t.Nodes))
 
-	obj, err := repo.NewObject(khepri.TYPE_BLOB)
+	obj, idch, err := repo.Create(khepri.TYPE_BLOB)
 
 	if err != nil {
 		log.Printf("error creating object for tree: %v", err)
@@ -106,7 +106,7 @@ func archive_dir(repo *khepri.Repository, path string) (khepri.ID, error) {
 
 	obj.Close()
 
-	id := obj.ID()
+	id := <-idch
 	log.Printf("tree for %q saved at %s", path, id)
 
 	return id, nil
@@ -124,11 +124,15 @@ func commandBackup(repo *khepri.Repository, args []string) error {
 		return err
 	}
 
-	sn := repo.NewSnapshot(target)
+	sn := khepri.NewSnapshot(target)
 	sn.Tree = id
-	sn.Save()
+	snid, err := sn.Save(repo)
 
-	fmt.Printf("%q archived as %v\n", target, sn.ID())
+	if err != nil {
+		log.Printf("error saving snapshopt: %v", err)
+	}
+
+	fmt.Printf("%q archived as %v\n", target, snid)
 
 	return nil
 }

cmd/khepri/cmd_restore.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"os"
 	"path"
 
@@ -49,7 +50,7 @@ func restore_file(repo *khepri.Repository, node khepri.Node, target string) erro
 
 func restore_dir(repo *khepri.Repository, id khepri.ID, target string) error {
 	fmt.Printf("  restore dir %q\n", target)
-	rd, err := repo.Get(khepri.TYPE_REF, id)
+	rd, err := repo.Get(khepri.TYPE_BLOB, id)
 	if err != nil {
 		return err
 	}
@@ -121,7 +122,12 @@ func commandRestore(repo *khepri.Repository, args []string) error {
 		return err
 	}
 
-	err = restore_dir(repo, id, target)
+	sn, err := khepri.LoadSnapshot(repo, id)
+	if err != nil {
+		log.Fatalf("error loading snapshot %s", id)
+	}
+
+	err = restore_dir(repo, sn.Tree, target)
 	if err != nil {
 		return err
 	}

object.go

@@ -1,78 +1,60 @@
 package khepri
 
-import "os"
+import (
+	"io"
+	"os"
+)
 
-type Object struct {
+type createObject struct {
 	repo *Repository
 
-	id  ID
 	tpe Type
 
 	hw   HashingWriter
 	file *os.File
+
+	ch chan ID
 }
 
-func (repo *Repository) NewObject(t Type) (*Object, error) {
+func (repo *Repository) Create(t Type) (io.WriteCloser, <-chan ID, error) {
-	obj := &Object{
+	obj := &createObject{
 		repo: repo,
 		tpe:  t,
+		ch:   make(chan ID, 1),
 	}
 
-	return obj, obj.open()
+	// save contents to tempfile in repository, hash while writing
+	var err error
+	obj.file, err = obj.repo.tempFile()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// create hashing writer
+	obj.hw = NewHashingWriter(obj.file, obj.repo.hash)
+
+	return obj, obj.ch, nil
 }
 
-func (obj *Object) open() error {
+func (obj *createObject) Write(data []byte) (int, error) {
-	if obj.isFinal() {
-		panic("object is finalized")
-	}
-
-	if obj.isOpen() {
-		panic("object already open")
-	}
-
-	// create tempfile in repository
 	if obj.hw == nil {
-		// save contents to tempfile, hash while writing
+		panic("createObject: already closed!")
-		var err error
-		obj.file, err = obj.repo.tempFile()
-		if err != nil {
-			return err
-		}
-
-		// create hashing writer
-		obj.hw = NewHashingWriter(obj.file, obj.repo.hash)
-	}
-
-	return nil
-}
-
-func (obj *Object) isOpen() bool {
-	return obj.file != nil && obj.hw != nil
-}
-
-func (obj *Object) isFinal() bool {
-	return obj.id != nil
-}
-
-func (obj *Object) Write(data []byte) (int, error) {
-	if !obj.isOpen() {
-		panic("object not open")
 	}
 
 	return obj.hw.Write(data)
 }
 
-func (obj *Object) Close() error {
+func (obj *createObject) Close() error {
-	if obj.file == nil || obj.hw == nil {
+	if obj.hw == nil {
-		panic("object is not open")
+		panic("createObject: already closed!")
 	}
 
 	obj.file.Close()
 
-	hash := obj.hw.Hash()
+	id := ID(obj.hw.Hash())
+	obj.ch <- id
 
 	// move file to final name using hash of contents
-	id := ID(hash)
 	err := obj.repo.renameFile(obj.file, obj.tpe, id)
 	if err != nil {
 		return err
@@ -80,40 +62,5 @@ func (obj *Object) Close() error {
 
 	obj.hw = nil
 	obj.file = nil
-
-	obj.id = id
-	return nil
-}
-
-func (obj *Object) ID() ID {
-	if !obj.isFinal() {
-		panic("object not finalized")
-	}
-
-	return obj.id
-}
-
-func (obj *Object) Type() Type {
-	return obj.tpe
-}
-
-func (obj *Object) Remove() error {
-	if obj.id != nil {
-		return obj.repo.Remove(obj.tpe, obj.id)
-	}
-
-	if obj.file != nil {
-		file := obj.file
-		obj.hw = nil
-		obj.file = nil
-
-		err := file.Close()
-		if err != nil {
-			return err
-		}
-
-		return os.Remove(file.Name())
-	}
-
 	return nil
 }

object_test.go

@@ -16,16 +16,18 @@ func TestObjects(t *testing.T) {
 	}()
 
 	for _, test := range TestStrings {
-		obj, err := repo.NewObject(khepri.TYPE_BLOB)
+		obj, ch, err := repo.Create(khepri.TYPE_BLOB)
 		ok(t, err)
 
 		_, err = obj.Write([]byte(test.data))
 		ok(t, err)
 
-		obj.Close()
+		err = obj.Close()
+		ok(t, err)
+
 		id, err := khepri.ParseID(test.id)
 		ok(t, err)
 
-		equals(t, id, obj.ID())
+		equals(t, id, <-ch)
 	}
 }

repository.go

@@ -151,7 +151,7 @@ func (r *Repository) Test(t Type, id ID) (bool, error) {
 }
 
 // Get returns a reader for the content stored under the given ID.
-func (r *Repository) Get(t Type, id ID) (io.Reader, error) {
+func (r *Repository) Get(t Type, id ID) (io.ReadCloser, error) {
 	// try to open file
 	file, err := os.Open(r.filename(t, id))
 	if err != nil {

repository_test.go

@@ -75,7 +75,7 @@ func TestRepository(t *testing.T) {
 	// add files
 	for _, test := range TestStrings {
 		// store string in repository
-		obj, err := repo.NewObject(test.t)
+		obj, id_ch, err := repo.Create(test.t)
 		ok(t, err)
 
 		_, err = obj.Write([]byte(test.data))
@@ -84,7 +84,7 @@ func TestRepository(t *testing.T) {
 		err = obj.Close()
 		ok(t, err)
 
-		id := obj.ID()
+		id := <-id_ch
 		equals(t, test.id, id.String())
 
 		// try to get it out again

snapshot.go

@@ -15,14 +15,11 @@ type Snapshot struct {
 	Username string    `json:"username,omitempty"`
 	UID      string    `json:"uid,omitempty"`
 	GID      string    `json:"gid,omitempty"`
-	id       ID
-	repo     *Repository
 }
 
-func (repo *Repository) NewSnapshot(dir string) *Snapshot {
+func NewSnapshot(dir string) *Snapshot {
 	sn := &Snapshot{
 		Dir:  dir,
-		repo: repo,
 		Time: time.Now(),
 	}
 
@@ -41,31 +38,43 @@ func (repo *Repository) NewSnapshot(dir string) *Snapshot {
 	return sn
 }
 
-func (sn *Snapshot) Save() error {
+func (sn *Snapshot) Save(repo *Repository) (ID, error) {
 	if sn.Tree == nil {
 		panic("Snapshot.Save() called with nil tree id")
 	}
 
-	obj, err := sn.repo.NewObject(TYPE_REF)
+	obj, id_ch, err := repo.Create(TYPE_REF)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	enc := json.NewEncoder(obj)
 	err = enc.Encode(sn)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	err = obj.Close()
 	if err != nil {
-		return err
+		return nil, err
 	}
 
-	sn.id = obj.ID()
+	return <-id_ch, nil
-	return nil
 }
 
-func (sn *Snapshot) ID() ID {
+func LoadSnapshot(repo *Repository, id ID) (*Snapshot, error) {
-	return sn.id
+	rd, err := repo.Get(TYPE_REF, id)
+	if err != nil {
+		return nil, err
+	}
+
+	dec := json.NewDecoder(rd)
+	sn := &Snapshot{}
+	err = dec.Decode(sn)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return sn, nil
 }

snapshot_test.go

@@ -16,11 +16,12 @@ func TestSnapshot(t *testing.T) {
 		ok(t, err)
 	}()
 
-	sn := repo.NewSnapshot("/home/foobar")
+	sn := khepri.NewSnapshot("/home/foobar")
 	sn.Tree, err = khepri.ParseID("c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2")
 	ok(t, err)
 	sn.Time, err = time.Parse(time.RFC3339Nano, "2014-08-03T17:49:05.378595539+02:00")
 	ok(t, err)
 
-	ok(t, sn.Save())
+	_, err = sn.Save(repo)
+	ok(t, err)
 }