Index: Add OpenIndex

This lets you persist an index at an arbitrary location.

index.go

@@ -96,6 +96,24 @@ func NewIndex() (*Index, error) {
 	return &Index{ptr: ptr}, nil
 }
 
+// OpenIndex creates a new index at the given path. If the file does
+// not exist it will be created when Write() is called.
+func OpenIndex(path string) (*Index, error) {
+	var ptr *C.git_index
+
+	var cpath = C.CString(path)
+	defer C.free(unsafe.Pointer(cpath))
+
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	if err := C.git_index_open(&ptr, cpath); err < 0 {
+		return nil, MakeGitError(err)
+	}
+
+	return &Index{ptr: ptr}, nil
+}
+
 // Add adds or replaces the given entry to the index, making a copy of
 // the data
 func (v *Index) Add(entry *IndexEntry) error {

index_test.go

@@ -2,6 +2,7 @@ package git
 
 import (
 	"io/ioutil"
+	"os"
 	"runtime"
 	"testing"
 )
@@ -148,6 +149,29 @@ func TestIndexAddAllCallback(t *testing.T) {
 	}
 }
 
+func TestIndexOpen(t *testing.T) {
+	repo := createTestRepo(t)
+	defer cleanupTestRepo(t, repo)
+
+	path := repo.Workdir() + "/heyindex"
+
+	_, err := os.Stat(path)
+	if !os.IsNotExist(err) {
+		t.Fatal("new index file already exists")
+	}
+
+	idx, err := OpenIndex(path)
+	checkFatal(t, err)
+
+	err = idx.Write()
+	checkFatal(t, err)
+
+	_, err = os.Stat(path)
+	if os.IsNotExist(err) {
+		t.Fatal("new index file did not get written")
+	}
+}
+
 func checkFatal(t *testing.T, err error) {
 	if err == nil {
 		return