1 files changed, 98 insertions, 0 deletions
diff --git a/modules/git/repo_index.go b/modules/git/repo_index.go
new file mode 100644
index 0000000000..4d26563a91
--- /dev/null
+++ b/modules/git/repo_index.go
@@ -0,0 +1,98 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"bytes"
+	"strings"
+)
+
+// ReadTreeToIndex reads a treeish to the index
+func (repo *Repository) ReadTreeToIndex(treeish string) error {
+	if len(treeish) != 40 {
+		res, err := NewCommand("rev-parse", treeish).RunInDir(repo.Path)
+		if err != nil {
+			return err
+		}
+		if len(res) > 0 {
+			treeish = res[:len(res)-1]
+		}
+	}
+	id, err := NewIDFromString(treeish)
+	if err != nil {
+		return err
+	}
+	return repo.readTreeToIndex(id)
+}
+
+func (repo *Repository) readTreeToIndex(id SHA1) error {
+	_, err := NewCommand("read-tree", id.String()).RunInDir(repo.Path)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// EmptyIndex empties the index
+func (repo *Repository) EmptyIndex() error {
+	_, err := NewCommand("read-tree", "--empty").RunInDir(repo.Path)
+	return err
+}
+
+// LsFiles checks if the given filenames are in the index
+func (repo *Repository) LsFiles(filenames ...string) ([]string, error) {
+	cmd := NewCommand("ls-files", "-z", "--")
+	for _, arg := range filenames {
+		if arg != "" {
+			cmd.AddArguments(arg)
+		}
+	}
+	res, err := cmd.RunInDirBytes(repo.Path)
+	if err != nil {
+		return nil, err
+	}
+	filelist := make([]string, 0, len(filenames))
+	for _, line := range bytes.Split(res, []byte{'\000'}) {
+		filelist = append(filelist, string(line))
+	}
+
+	return filelist, err
+}
+
+// RemoveFilesFromIndex removes given filenames from the index - it does not check whether they are present.
+func (repo *Repository) RemoveFilesFromIndex(filenames ...string) error {
+	cmd := NewCommand("update-index", "--remove", "-z", "--index-info")
+	stdout := new(bytes.Buffer)
+	stderr := new(bytes.Buffer)
+	buffer := new(bytes.Buffer)
+	for _, file := range filenames {
+		if file != "" {
+			buffer.WriteString("0 0000000000000000000000000000000000000000\t")
+			buffer.WriteString(file)
+			buffer.WriteByte('\000')
+		}
+	}
+	return cmd.RunInDirFullPipeline(repo.Path, stdout, stderr, bytes.NewReader(buffer.Bytes()))
+}
+
+// AddObjectToIndex adds the provided object hash to the index at the provided filename
+func (repo *Repository) AddObjectToIndex(mode string, object SHA1, filename string) error {
+	cmd := NewCommand("update-index", "--add", "--replace", "--cacheinfo", mode, object.String(), filename)
+	_, err := cmd.RunInDir(repo.Path)
+	return err
+}
+
+// WriteTree writes the current index as a tree to the object db and returns its hash
+func (repo *Repository) WriteTree() (*Tree, error) {
+	res, err := NewCommand("write-tree").RunInDir(repo.Path)
+	if err != nil {
+		return nil, err
+	}
+	id, err := NewIDFromString(strings.TrimSpace(res))
+	if err != nil {
+		return nil, err
+	}
+	return NewTree(repo, id), nil
+}