1 files changed, 82 insertions, 0 deletions

diff --git a/storage/filesystem/internal/dotgit/dotgit.go b/storage/filesystem/internal/dotgit/dotgit.go
index 448f6a2..75c98ff 100644
--- a/storage/filesystem/internal/dotgit/dotgit.go
+++ b/storage/filesystem/internal/dotgit/dotgit.go
@@ -22,6 +22,8 @@ var (
 	ErrIdxNotFound = errors.New("idx file not found")
 	// ErrPackfileNotFound is returned by Packfile when the packfile is not found
 	ErrPackfileNotFound = errors.New("packfile not found")
+	// ErrObjfileNotFound is returned by Objectfile when the objectffile is not found
+	ErrObjfileNotFound = errors.New("object file not found")
 	// ErrConfigNotFound is returned by Config when the config is not found
 	ErrConfigNotFound = errors.New("config file not found")
 )
@@ -74,6 +76,10 @@ func (d *DotGit) Packfile() (fs.FS, string, error) {
 	packDir := d.fs.Join(d.path, "objects", "pack")
 	files, err := d.fs.ReadDir(packDir)
 	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, "", ErrPackfileNotFound
+		}
+
 		return nil, "", err
 	}
 
@@ -93,6 +99,10 @@ func (d *DotGit) Idxfile() (fs.FS, string, error) {
 	packDir := d.fs.Join(d.path, "objects", "pack")
 	files, err := d.fs.ReadDir(packDir)
 	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, "", ErrIdxNotFound
+		}
+
 		return nil, "", err
 	}
 
@@ -118,3 +128,75 @@ func (d *DotGit) Config() (fs.FS, string, error) {
 
 	return d.fs, configFile, nil
 }
+
+// Objectfiles returns a slice with the hashes of objects found under the
+// .git/objects/ directory.
+func (dg *DotGit) Objectfiles() (fs.FS, []core.Hash, error) {
+	objsDir := dg.fs.Join(dg.path, "objects")
+
+	files, err := dg.fs.ReadDir(objsDir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil, ErrObjfileNotFound
+		}
+
+		return nil, nil, err
+	}
+
+	var objects []core.Hash
+	for _, f := range files {
+		if f.IsDir() && len(f.Name()) == 2 && isHex(f.Name()) {
+			objDir := f.Name()
+			d, err := dg.fs.ReadDir(dg.fs.Join(objsDir, objDir))
+			if err != nil {
+				return nil, nil, err
+			}
+
+			for _, o := range d {
+				objects = append(objects, core.NewHash(objDir+o.Name()))
+			}
+		}
+	}
+
+	return dg.fs, objects, nil
+}
+
+func isHex(s string) bool {
+	for _, b := range []byte(s) {
+		if isNum(b) {
+			continue
+		}
+		if isHexAlpha(b) {
+			continue
+		}
+
+		return false
+	}
+
+	return true
+}
+
+func isNum(b byte) bool {
+	return b >= '0' && b <= '9'
+}
+
+func isHexAlpha(b byte) bool {
+	return b >= 'a' && b <= 'f' || b >= 'A' && b <= 'F'
+}
+
+// Objectfile returns the path of the object file for a given hash
+// *if the file exists*, otherwise returns an ErrObjfileNotFound error.
+func (d *DotGit) Objectfile(h core.Hash) (fs.FS, string, error) {
+	hash := h.String()
+	objFile := d.fs.Join(d.path, "objects", hash[0:2], hash[2:40])
+
+	if _, err := d.fs.Stat(objFile); err != nil {
+		if os.IsNotExist(err) {
+			return nil, "", ErrObjfileNotFound
+		}
+
+		return nil, "", err
+	}
+
+	return d.fs, objFile, nil
+}