Refactor, add Object and Snapshot

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
+}