Refactor, add Object and Snapshot

cmd/khepri/cmd_backup.go

@@ -24,8 +24,9 @@ func hash(filename string) (khepri.ID, error) {
 	return h.Sum([]byte{}), nil
 }
 
-func archive_dir(repo *khepri.DirRepository, path string) (khepri.ID, error) {
+func archive_dir(repo *khepri.Repository, path string) (khepri.ID, error) {
 	log.Printf("archiving dir %q", path)
+
 	dir, err := os.Open(path)
 	if err != nil {
 		log.Printf("open(%q): %v\n", path, err)
@@ -81,7 +82,7 @@ func archive_dir(repo *khepri.DirRepository, path string) (khepri.ID, error) {
 	return id, nil
 }
 
-func commandBackup(repo *khepri.DirRepository, args []string) error {
+func commandBackup(repo *khepri.Repository, args []string) error {
 	if len(args) != 1 {
 		return errors.New("usage: backup dir")
 	}
@@ -93,7 +94,11 @@ func commandBackup(repo *khepri.DirRepository, args []string) error {
 		return err
 	}
 
-	fmt.Printf("%q archived as %v\n", target, id)
+	sn := repo.NewSnapshot(target)
+	sn.Tree = id
+	sn.Save()
+
+	fmt.Printf("%q archived as %v\n", target, sn.ID())
 
 	return nil
 }

cmd/khepri/cmd_list.go

@@ -8,7 +8,7 @@ import (
 	"github.com/fd0/khepri"
 )
 
-func commandList(repo *khepri.DirRepository, args []string) error {
+func commandList(repo *khepri.Repository, args []string) error {
 	if len(args) != 1 {
 		return errors.New("usage: list [blob|ref]")
 	}

cmd/khepri/cmd_restore.go

@@ -10,7 +10,7 @@ import (
 	"github.com/fd0/khepri"
 )
 
-func restore_file(repo *khepri.DirRepository, node khepri.Node, target string) error {
+func restore_file(repo *khepri.Repository, node khepri.Node, target string) error {
 	fmt.Printf("  restore file %q\n", target)
 
 	rd, err := repo.Get(khepri.TYPE_BLOB, node.Content)
@@ -47,7 +47,7 @@ func restore_file(repo *khepri.DirRepository, node khepri.Node, target string) e
 	return nil
 }
 
-func restore_dir(repo *khepri.DirRepository, id khepri.ID, target string) error {
+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)
 	if err != nil {
@@ -104,7 +104,7 @@ func restore_dir(repo *khepri.DirRepository, id khepri.ID, target string) error
 	return nil
 }
 
-func commandRestore(repo *khepri.DirRepository, args []string) error {
+func commandRestore(repo *khepri.Repository, args []string) error {
 	if len(args) != 2 {
 		return errors.New("usage: restore ID dir")
 	}

cmd/khepri/main.go

@@ -22,7 +22,7 @@ func errx(code int, format string, data ...interface{}) {
 	os.Exit(code)
 }
 
-type commandFunc func(*khepri.DirRepository, []string) error
+type commandFunc func(*khepri.Repository, []string) error
 
 var commands map[string]commandFunc
 
@@ -61,7 +61,7 @@ func main() {
 		errx(1, "unknown command: %q\n", cmd)
 	}
 
-	repo, err := khepri.NewDirRepository(Opts.Repo)
+	repo, err := khepri.NewRepository(Opts.Repo)
 
 	if err != nil {
 		errx(1, "unable to create/open repo: %v", err)

object.go

@@ -0,0 +1,119 @@
+package khepri
+
+import "os"
+
+type Object struct {
+	repo *Repository
+
+	id  ID
+	tpe Type
+
+	hw   HashingWriter
+	file *os.File
+}
+
+func (repo *Repository) NewObject(t Type) (*Object, error) {
+	obj := &Object{
+		repo: repo,
+		tpe:  t,
+	}
+
+	return obj, obj.open()
+}
+
+func (obj *Object) open() 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
+		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 {
+	if obj.file == nil || obj.hw == nil {
+		panic("object is not open")
+	}
+
+	obj.file.Close()
+
+	hash := obj.hw.Hash()
+
+	// 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
+	}
+
+	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

@@ -0,0 +1,31 @@
+package khepri_test
+
+import (
+	"testing"
+
+	"github.com/fd0/khepri"
+)
+
+func TestObjects(t *testing.T) {
+	repo, err := setupRepo()
+	ok(t, err)
+
+	defer func() {
+		err = teardownRepo(repo)
+		ok(t, err)
+	}()
+
+	for _, test := range TestStrings {
+		obj, err := repo.NewObject(khepri.TYPE_BLOB)
+		ok(t, err)
+
+		_, err = obj.Write([]byte(test.data))
+		ok(t, err)
+
+		obj.Close()
+		id, err := khepri.ParseID(test.id)
+		ok(t, err)
+
+		equals(t, id, obj.ID())
+	}
+}

repository.go

@@ -31,7 +31,7 @@ func (n Name) Encode() string {
 	return url.QueryEscape(string(n))
 }
 
-type DirRepository struct {
+type Repository struct {
 	path string
 	hash func() hash.Hash
 }
@@ -66,8 +66,8 @@ func (t Type) String() string {
 }
 
 // NewDirRepository creates a new dir-baked repository at the given path.
-func NewDirRepository(path string) (*DirRepository, error) {
+func NewRepository(path string) (*Repository, error) {
-	d := &DirRepository{
+	d := &Repository{
 		path: path,
 		hash: sha256.New,
 	}
@@ -81,7 +81,7 @@ func NewDirRepository(path string) (*DirRepository, error) {
 	return d, nil
 }
 
-func (r *DirRepository) create() error {
+func (r *Repository) create() error {
 	dirs := []string{
 		r.path,
 		path.Join(r.path, blobPath),
@@ -100,28 +100,28 @@ func (r *DirRepository) create() error {
 }
 
 // SetHash changes the hash function used for deriving IDs. Default is SHA256.
-func (r *DirRepository) SetHash(h func() hash.Hash) {
+func (r *Repository) SetHash(h func() hash.Hash) {
 	r.hash = h
 }
 
 // Path returns the directory used for this repository.
-func (r *DirRepository) Path() string {
+func (r *Repository) Path() string {
 	return r.path
 }
 
 // Return temp directory in correct directory for this repository.
-func (r *DirRepository) tempFile() (*os.File, error) {
+func (r *Repository) tempFile() (*os.File, error) {
 	return ioutil.TempFile(path.Join(r.path, tempPath), "temp-")
 }
 
 // Rename temp file to final name according to type and ID.
-func (r *DirRepository) renameFile(file *os.File, t Type, id ID) error {
+func (r *Repository) renameFile(file *os.File, t Type, id ID) error {
 	filename := path.Join(r.dir(t), id.String())
 	return os.Rename(file.Name(), filename)
 }
 
 // Put saves content and returns the ID.
-func (r *DirRepository) Put(t Type, reader io.Reader) (ID, error) {
+func (r *Repository) Put(t Type, reader io.Reader) (ID, error) {
 	// save contents to tempfile, hash while writing
 	file, err := r.tempFile()
 	if err != nil {
@@ -150,7 +150,7 @@ func (r *DirRepository) Put(t Type, reader io.Reader) (ID, error) {
 }
 
 // Construct directory for given Type.
-func (r *DirRepository) dir(t Type) string {
+func (r *Repository) dir(t Type) string {
 	switch t {
 	case TYPE_BLOB:
 		return path.Join(r.path, blobPath)
@@ -162,12 +162,12 @@ func (r *DirRepository) dir(t Type) string {
 }
 
 // Construct path for given Type and ID.
-func (r *DirRepository) filename(t Type, id ID) string {
+func (r *Repository) filename(t Type, id ID) string {
 	return path.Join(r.dir(t), id.String())
 }
 
 // PutFile saves a file's content to the repository and returns the ID.
-func (r *DirRepository) PutFile(path string) (ID, error) {
+func (r *Repository) PutFile(path string) (ID, error) {
 	f, err := os.Open(path)
 	defer f.Close()
 	if err != nil {
@@ -178,7 +178,7 @@ func (r *DirRepository) PutFile(path string) (ID, error) {
 }
 
 // PutRaw saves a []byte's content to the repository and returns the ID.
-func (r *DirRepository) PutRaw(t Type, buf []byte) (ID, error) {
+func (r *Repository) PutRaw(t Type, buf []byte) (ID, error) {
 	// save contents to tempfile, hash while writing
 	file, err := r.tempFile()
 	if err != nil {
@@ -206,7 +206,7 @@ func (r *DirRepository) PutRaw(t Type, buf []byte) (ID, error) {
 }
 
 // Test returns true if the given ID exists in the repository.
-func (r *DirRepository) Test(t Type, id ID) (bool, error) {
+func (r *Repository) Test(t Type, id ID) (bool, error) {
 	// try to open file
 	file, err := os.Open(r.filename(t, id))
 	defer func() {
@@ -224,7 +224,7 @@ func (r *DirRepository) Test(t Type, id ID) (bool, error) {
 }
 
 // Get returns a reader for the content stored under the given ID.
-func (r *DirRepository) Get(t Type, id ID) (io.Reader, error) {
+func (r *Repository) Get(t Type, id ID) (io.Reader, error) {
 	// try to open file
 	file, err := os.Open(r.filename(t, id))
 	if err != nil {
@@ -235,14 +235,14 @@ func (r *DirRepository) Get(t Type, id ID) (io.Reader, error) {
 }
 
 // Remove removes the content stored at ID.
-func (r *DirRepository) Remove(t Type, id ID) error {
+func (r *Repository) Remove(t Type, id ID) error {
 	return os.Remove(r.filename(t, id))
 }
 
 type IDs []ID
 
 // Lists all objects of a given type.
-func (r *DirRepository) ListIDs(t Type) (IDs, error) {
+func (r *Repository) ListIDs(t Type) (IDs, error) {
 	// TODO: use os.Open() and d.Readdirnames() instead of Glob()
 	pattern := path.Join(r.dir(t), "*")
 

repository_test.go

@@ -25,13 +25,13 @@ var TestStrings = []struct {
 	{"4e54d2c721cbdb730f01b10b62dec622962b36966ec685880effa63d71c808f2", khepri.TYPE_BLOB, "foo/../../baz"},
 }
 
-func setupRepo() (*khepri.DirRepository, error) {
+func setupRepo() (*khepri.Repository, error) {
 	tempdir, err := ioutil.TempDir("", "khepri-test-")
 	if err != nil {
 		return nil, err
 	}
 
-	repo, err := khepri.NewDirRepository(tempdir)
+	repo, err := khepri.NewRepository(tempdir)
 	if err != nil {
 		return nil, err
 	}
@@ -39,7 +39,7 @@ func setupRepo() (*khepri.DirRepository, error) {
 	return repo, nil
 }
 
-func teardownRepo(repo *khepri.DirRepository) error {
+func teardownRepo(repo *khepri.Repository) error {
 	if !*testCleanup {
 		fmt.Fprintf(os.Stderr, "leaving repository at %s\n", repo.Path())
 		return nil

snapshot.go

@@ -0,0 +1,71 @@
+package khepri
+
+import (
+	"encoding/json"
+	"os"
+	"os/user"
+	"time"
+)
+
+type Snapshot struct {
+	Time     time.Time `json:"time"`
+	Tree     ID        `json:"tree"`
+	Dir      string    `json:"dir"`
+	Hostname string    `json:"hostname,omitempty"`
+	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 {
+	sn := &Snapshot{
+		Dir:  dir,
+		repo: repo,
+		Time: time.Now(),
+	}
+
+	hn, err := os.Hostname()
+	if err == nil {
+		sn.Hostname = hn
+	}
+
+	usr, err := user.Current()
+	if err == nil {
+		sn.Username = usr.Username
+		sn.UID = usr.Uid
+		sn.GID = usr.Gid
+	}
+
+	return sn
+}
+
+func (sn *Snapshot) Save() error {
+	if sn.Tree == nil {
+		panic("Snapshot.Save() called with nil tree id")
+	}
+
+	obj, err := sn.repo.NewObject(TYPE_REF)
+	if err != nil {
+		return err
+	}
+
+	enc := json.NewEncoder(obj)
+	err = enc.Encode(sn)
+	if err != nil {
+		return err
+	}
+
+	err = obj.Close()
+	if err != nil {
+		return err
+	}
+
+	sn.id = obj.ID()
+	return nil
+}
+
+func (sn *Snapshot) ID() ID {
+	return sn.id
+}

snapshot_test.go

@@ -0,0 +1,26 @@
+package khepri_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/fd0/khepri"
+)
+
+func TestSnapshot(t *testing.T) {
+	repo, err := setupRepo()
+	ok(t, err)
+
+	defer func() {
+		err = teardownRepo(repo)
+		ok(t, err)
+	}()
+
+	sn := repo.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())
+}