1 files changed, 99 insertions, 0 deletions
diff --git a/indexer.go b/indexer.go
new file mode 100644
index 0000000..d1b9372
--- /dev/null
+++ b/indexer.go
@@ -0,0 +1,99 @@
+package git
+
+/*
+#include <git2.h>
+
+extern const git_oid * git_indexer_hash(const git_indexer *idx);
+extern int git_indexer_append(git_indexer *idx, const void *data, size_t size, git_transfer_progress *stats);
+extern int git_indexer_commit(git_indexer *idx, git_transfer_progress *stats);
+extern int _go_git_indexer_new(git_indexer **out, const char *path, unsigned int mode, git_odb *odb, void *progress_cb_payload);
+extern void git_indexer_free(git_indexer *idx);
+*/
+import "C"
+import (
+	"reflect"
+	"runtime"
+	"unsafe"
+)
+
+// Indexer can post-process packfiles and create an .idx file for efficient
+// lookup.
+type Indexer struct {
+	ptr             *C.git_indexer
+	stats           C.git_transfer_progress
+	callbacks       RemoteCallbacks
+	callbacksHandle unsafe.Pointer
+}
+
+// NewIndexer creates a new indexer instance.
+func NewIndexer(packfilePath string, odb *Odb, callback TransferProgressCallback) (indexer *Indexer, err error) {
+	indexer = new(Indexer)
+
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	var odbPtr *C.git_odb = nil
+	if odb != nil {
+		odbPtr = odb.ptr
+	}
+
+	indexer.callbacks.TransferProgressCallback = callback
+	indexer.callbacksHandle = pointerHandles.Track(&indexer.callbacks)
+
+	cstr := C.CString(packfilePath)
+	defer C.free(unsafe.Pointer(cstr))
+
+	ret := C._go_git_indexer_new(&indexer.ptr, cstr, 0, odbPtr, indexer.callbacksHandle)
+	runtime.KeepAlive(odb)
+	if ret < 0 {
+		pointerHandles.Untrack(indexer.callbacksHandle)
+		return nil, MakeGitError(ret)
+	}
+
+	runtime.SetFinalizer(indexer, (*Indexer).Free)
+	return indexer, nil
+}
+
+// Write adds data to the indexer.
+func (indexer *Indexer) Write(data []byte) (int, error) {
+	header := (*reflect.SliceHeader)(unsafe.Pointer(&data))
+	ptr := unsafe.Pointer(header.Data)
+	size := C.size_t(header.Len)
+
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	ret := C.git_indexer_append(indexer.ptr, ptr, size, &indexer.stats)
+	runtime.KeepAlive(indexer)
+	if ret < 0 {
+		return 0, MakeGitError(ret)
+	}
+
+	return len(data), nil
+}
+
+// Commit finalizes the pack and index. It resolves any pending deltas and
+// writes out the index file.
+//
+// It also returns the packfile's hash. A packfile's name is derived from the
+// sorted hashing of all object names.
+func (indexer *Indexer) Commit() (*Oid, error) {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	ret := C.git_indexer_commit(indexer.ptr, &indexer.stats)
+	if ret < 0 {
+		return nil, MakeGitError(ret)
+	}
+
+	id := newOidFromC(C.git_indexer_hash(indexer.ptr))
+	runtime.KeepAlive(indexer)
+	return id, nil
+}
+
+// Free frees the indexer and its resources.
+func (indexer *Indexer) Free() {
+	pointerHandles.Untrack(indexer.callbacksHandle)
+	runtime.SetFinalizer(indexer, nil)
+	C.git_indexer_free(indexer.ptr)
+}