git: Add function to generate tar file from repo

Changes

1 changed files (+136/-0)

• git/git.go
  • @@ -1,8 +1,13 @@
    package git import ( + "archive/tar" "fmt" + "io" + "io/fs" + "path" "sort" + "time" "github.com/go-git/go-git/v5" "github.com/go-git/go-git/v5/plumbing"
  • @@ -15,6 +20,16 @@ h plumbing.Hash
    } type TagList []*object.Tag + + // infoWrapper wraps the property of a TreeEntry so it can export fs.FileInfo + // to tar WriteHeader + type infoWrapper struct { + name string + size int64 + mode fs.FileMode + modTime time.Time + isDir bool + } func (self TagList) Len() int { return len(self)
  • @@ -154,3 +169,124 @@ }
    } return "", fmt.Errorf("unable to find main branch") } + + // WriteTar writes itself from a tree into a binary tar file format. + // prefix is root folder to be appended. + func (g *GitRepo) WriteTar(w io.Writer, prefix string) error { + tw := tar.NewWriter(w) + defer tw.Close() + + c, err := g.r.CommitObject(g.h) + if err != nil { + return fmt.Errorf("commit object: %w", err) + } + + tree, err := c.Tree() + if err != nil { + return err + } + + walker := object.NewTreeWalker(tree, true, nil) + defer walker.Close() + + name, entry, err := walker.Next() + for ; err == nil; name, entry, err = walker.Next() { + info, err := newInfoWrapper(name, prefix, &entry, tree) + if err != nil { + return err + } + + header, err := tar.FileInfoHeader(info, "") + if err != nil { + return err + } + + err = tw.WriteHeader(header) + if err != nil { + return err + } + + if !info.IsDir() { + file, err := tree.File(name) + if err != nil { + return err + } + + reader, err := file.Blob.Reader() + if err != nil { + return err + } + + _, err = io.Copy(tw, reader) + if err != nil { + reader.Close() + return err + } + reader.Close() + } + } + + return nil + } + + func newInfoWrapper( + name string, + prefix string, + entry *object.TreeEntry, + tree *object.Tree, + ) (*infoWrapper, error) { + var ( + size int64 + mode fs.FileMode + isDir bool + ) + + if entry.Mode.IsFile() { + file, err := tree.TreeEntryFile(entry) + if err != nil { + return nil, err + } + mode = fs.FileMode(file.Mode) + + size, err = tree.Size(name) + if err != nil { + return nil, err + } + } else { + isDir = true + mode = fs.ModeDir | fs.ModePerm + } + + fullname := path.Join(prefix, name) + return &infoWrapper{ + name: fullname, + size: size, + mode: mode, + modTime: time.Unix(0, 0), + isDir: isDir, + }, nil + } + + func (i *infoWrapper) Name() string { + return i.name + } + + func (i *infoWrapper) Size() int64 { + return i.size + } + + func (i *infoWrapper) Mode() fs.FileMode { + return i.mode + } + + func (i *infoWrapper) ModTime() time.Time { + return i.modTime + } + + func (i *infoWrapper) IsDir() bool { + return i.isDir + } + + func (i *infoWrapper) Sys() any { + return nil + }