minimal packfile support (#27)

resolves #9

.gitignore

@@ -1,4 +1,3 @@
-.idea
-.mygit
-test-dir
+/.idea
+/gitg
 

config.go

@@ -17,6 +17,7 @@ const (
 	DefaultBranchName         = "main"
 	DefaultEditor             = "vim"
 	DefaultPackedRefsFile     = "info/refs"
+	DefaultPackfileDirectory  = "pack"
 )
 
 var config Cnf
@@ -36,6 +37,7 @@ type (
 		RefsDirectory      string
 		RefsHeadsDirectory string
 		PackedRefsFile     string
+		PackfileDirectory  string
 		DefaultBranch      string
 		GitIgnore          []string
 		Editor             string
@@ -72,6 +74,7 @@ func Configure(opts ...Opt) error {
 		RefsDirectory:      DefaultRefsDirectory,
 		RefsHeadsDirectory: DefaultRefsHeadsDirectory,
 		PackedRefsFile:     DefaultPackedRefsFile,
+		PackfileDirectory:  DefaultPackfileDirectory,
 		DefaultBranch:      DefaultBranchName,
 		Editor:             DefaultEditor,
 		GitIgnore: []string{ //@todo read from .gitignore
@@ -130,6 +133,10 @@ func PackedRefsFile() string {
 	return filepath.Join(config.Path, config.GitDirectory, config.PackedRefsFile)
 }
 
+func ObjectPackfileDirectory() string {
+	return filepath.Join(config.Path, config.GitDirectory, config.ObjectsDirectory, config.PackfileDirectory)
+}
+
 func GitHeadPath() string {
 	return filepath.Join(config.Path, config.GitDirectory, config.HeadFile)
 }

fs.go

@@ -41,6 +41,7 @@ type (
 		Finfo     os.FileInfo
 	}
 	Sha struct {
+		set  bool
 		hash [20]byte
 	}
 	IndexStatus uint8
@@ -72,18 +73,34 @@ type (
 // NewSha creates a Sha from either a binary or hex encoded byte slice
 func NewSha(b []byte) (Sha, error) {
 	if len(b) == 40 {
-		s := Sha{}
+		s := Sha{set: true}
 		_, _ = hex.Decode(s.hash[:], b)
 		return s, nil
 	}
 	if len(b) == 20 {
-		s := Sha{}
+		s := Sha{set: true}
 		copy(s.hash[:], b)
 		return s, nil
 	}
 	return Sha{}, fmt.Errorf("invalid sha %s", b)
 }
 
+func ShaFromHexString(s string) (Sha, error) {
+	v, err := hex.DecodeString(s)
+	if err != nil {
+		return Sha{}, err
+	}
+	return NewSha(v)
+}
+
+func (s Sha) String() string {
+	return s.AsHexString()
+}
+
+func (s Sha) IsSet() bool {
+	return s.set
+}
+
 func (s Sha) AsHexString() string {
 	return hex.EncodeToString(s.hash[:])
 }

git/integration_test.go

@@ -224,8 +224,8 @@ func testCommit(t *testing.T, message []byte) []byte {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(sha) != 20 {
-		t.Errorf("expected sha len 20 got %d", len(sha))
+	if len(sha) != 40 {
+		t.Errorf("expected sha len 40 got %d", len(sha))
 	}
 	commitSha, err := g.NewSha(sha)
 	if err != nil {
@@ -234,7 +234,7 @@ func testCommit(t *testing.T, message []byte) []byte {
 	}
 
 	// read object
-	c, err := g.ReadCommit(commitSha.AsHexBytes())
+	c, err := g.ReadCommit(commitSha)
 	if err != nil {
 		t.Error(err)
 		return sha

git/restore.go

@@ -47,7 +47,7 @@ func Restore(path string, staged bool) error {
 		// this should not happen
 		return errors.New("index did not return file for some reason")
 	}
-	obj, err := g.ReadObject(file.Sha.AsHexBytes())
+	obj, err := g.ReadObject(file.Sha)
 	if err != nil {
 		return err
 	}

git/status.go

@@ -9,25 +9,10 @@ import (
 // Status currently displays the file statuses comparing the working directory
 // to the index and the index to the last commit (if any).
 func Status(o io.Writer) error {
-	var err error
-	// index
-	idx, err := g.ReadIndex()
+	files, err := g.CurrentStatus()
 	if err != nil {
 		return err
 	}
-
-	commitSha, err := g.LastCommit()
-	if err != nil {
-		// @todo error types to check for e.g no previous commits as source of error
-		return err
-	}
-
-	files, err := g.Status(idx, commitSha)
-
-	if err != nil {
-		return err
-	}
-
 	for _, v := range files.Files() {
 		if v.IdxStatus == g.IndexNotUpdated && v.WdStatus == g.WDIndexAndWorkingTreeMatch {
 			continue
@@ -36,6 +21,5 @@ func Status(o io.Writer) error {
 			return err
 		}
 	}
-
 	return nil
 }

git/switch.go

@@ -23,7 +23,7 @@ func SwitchBranch(name string) error {
 		return err
 	}
 
-	if commitSha == nil {
+	if !commitSha.IsSet() {
 		return fmt.Errorf("fatal: invalid reference: %s", name)
 	}
 
@@ -97,7 +97,7 @@ func SwitchBranch(name string) error {
 	idx = g.NewIndex()
 
 	for _, v := range commitFiles {
-		obj, err := g.ReadObject(v.Sha.AsHexBytes())
+		obj, err := g.ReadObject(v.Sha)
 		if err != nil {
 			return err
 		}

index.go

@@ -241,27 +241,6 @@ func fromIndexItemP(p *indexItemP) *Finfo {
 	return f
 }
 
-// Status returns a FileSet containing all files from commit, index and working directory
-// with the corresponding status.
-func Status(idx *Index, commitSha []byte) (*FileSet, error) {
-	var commitFiles []*File
-	var err error
-	if commitSha != nil {
-		commitFiles, err = CommittedFiles(commitSha)
-		if err != nil {
-			return nil, err
-		}
-	}
-	files := NewFileSet(commitFiles)
-	files.MergeFromIndex(NewFileSet(idx.Files()))
-	workingDirectoryFiles, err := Ls(Path())
-	if err != nil {
-		return nil, err
-	}
-	files.MergeFromWD(NewFileSet(workingDirectoryFiles))
-	return files, nil
-}
-
 // FsStatus returns a FileSet containing all files from the index and working directory
 // with the corresponding status.
 func FsStatus(path string) (*FileSet, error) {

object.go

@@ -32,7 +32,7 @@ type (
 	Commit     struct {
 		Sha            []byte
 		Tree           []byte
-		Parents        [][]byte
+		Parents        []Sha
 		Author         string
 		AuthorEmail    string
 		AuthoredTime   time.Time
@@ -67,7 +67,7 @@ func (c Commit) String() string {
 	o += fmt.Sprintf("commit: %s\n", string(c.Sha))
 	o += fmt.Sprintf("tree: %s\n", string(c.Tree))
 	for _, v := range c.Parents {
-		o += fmt.Sprintf("parent: %s\n", string(v))
+		o += fmt.Sprintf("parent: %s\n", v.AsHexString())
 	}
 	o += fmt.Sprintf("%s <%s> %s\n", c.Author, c.AuthorEmail, c.AuthoredTime.String())
 	o += fmt.Sprintf("%s <%s> %s\n", c.Committer, c.CommitterEmail, c.CommittedTime.String())
@@ -131,10 +131,21 @@ func (o *Object) FlattenTree() []*File {
 	return objFiles
 }
 
-func ReadObject(sha []byte) (*Object, error) {
+func ReadObject(sha Sha) (*Object, error) {
 	var err error
-	o := &Object{Sha: sha}
-	o.ReadCloser = ObjectReadCloser(sha)
+	var o *Object
+
+	// check if a loose file or in a packfile
+	if _, err := os.Stat(filepath.Join(ObjectPath(), string(sha.AsHexBytes()[0:2]), string(sha.AsHexBytes()[2:]))); err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return lookupInPackfiles(sha)
+		} else {
+			return nil, err
+		}
+	}
+
+	o = &Object{Sha: sha.AsHexBytes()}
+	o.ReadCloser = ObjectReadCloser(sha.AsHexBytes())
 	z, err := o.ReadCloser()
 	if err != nil {
 		return o, err
@@ -159,6 +170,7 @@ func ReadObject(sha []byte) (*Object, error) {
 		return nil, fmt.Errorf("unknown %s", string(header[0]))
 	}
 	o.Length, err = strconv.Atoi(string(header[1][:len(header[1])-1]))
+
 	return o, err
 }
 
@@ -175,18 +187,25 @@ func ObjectReadCloser(sha []byte) func() (io.ReadCloser, error) {
 }
 
 // ReadObjectTree reads an object from the object store
-func ReadObjectTree(sha []byte) (*Object, error) {
+func ReadObjectTree(sha Sha) (*Object, error) {
 	obj, err := ReadObject(sha)
 	if err != nil {
 		return nil, err
 	}
+	if obj == nil {
+		return nil, fmt.Errorf("object %s not found", sha.AsHexString())
+	}
 	switch obj.Typ {
 	case ObjectTypeCommit:
 		commit, err := readCommit(obj)
 		if err != nil {
 			return obj, err
 		}
-		co, err := ReadObjectTree(commit.Tree)
+		sha, err := NewSha(commit.Tree)
+		if err != nil {
+			return obj, err
+		}
+		co, err := ReadObjectTree(sha)
 		if err != nil {
 			return nil, err
 		}
@@ -198,7 +217,11 @@ func ReadObjectTree(sha []byte) (*Object, error) {
 			return nil, err
 		}
 		for _, v := range tree.Items {
-			o, err := ReadObjectTree(v.Sha)
+			sha, err := NewSha(v.Sha)
+			if err != nil {
+				return obj, err
+			}
+			o, err := ReadObjectTree(sha)
 			if err != nil {
 				return nil, err
 			}
@@ -283,7 +306,7 @@ func ReadHeadBytes(r io.ReadCloser, obj *Object) error {
 	return nil
 }
 
-func ReadCommit(sha []byte) (*Commit, error) {
+func ReadCommit(sha Sha) (*Commit, error) {
 	o, err := ReadObject(sha)
 	if err != nil {
 		return nil, err
@@ -326,7 +349,11 @@ func readCommit(obj *Object) (*Commit, error) {
 		}
 		// can be parent
 		if t == "parent" {
-			c.Parents = append(c.Parents, p[1])
+			sha, err := NewSha(p[1])
+			if err != nil {
+				return nil, err
+			}
+			c.Parents = append(c.Parents, sha)
 			continue
 		}
 		if c.Author == "" {
@@ -408,7 +435,7 @@ func readCommitter(b []byte, c *Commit) error {
 	return nil
 }
 
-func CommittedFiles(sha []byte) ([]*File, error) {
+func CommittedFiles(sha Sha) ([]*File, error) {
 	obj, err := ReadObjectTree(sha)
 	if err != nil {
 		return nil, err
@@ -529,13 +556,17 @@ func WriteCommit(c *Commit) ([]byte, error) {
 		c.Message,
 	))
 	header := []byte(fmt.Sprintf("commit %d%s", len(content), string(byte(0))))
-	sha, err := WriteObject(header, content, "", ObjectPath())
+	b, err := WriteObject(header, content, "", ObjectPath())
 	if err != nil {
 		return nil, err
 	}
 	branch, err := CurrentBranch()
 	if err != nil {
 		return nil, err
 	}
-	return sha, UpdateBranchHead(branch, sha)
+	sha, err := NewSha(b)
+	if err != nil {
+		return nil, err
+	}
+	return sha.AsHexBytes(), UpdateBranchHead(branch, sha)
 }