1 files changed, 130 insertions, 0 deletions
diff --git a/packbuilder.go b/packbuilder.go
new file mode 100644
index 0000000..292604d
--- /dev/null
+++ b/packbuilder.go
@@ -0,0 +1,130 @@
+package git
+
+/*
+#cgo pkg-config: libgit2
+#include <git2.h>
+#include <git2/errors.h>
+#include <git2/pack.h>
+#include <stdlib.h>
+
+extern int _go_git_packbuilder_foreach(git_packbuilder *pb, void *payload);
+*/
+import "C"
+import (
+	"io"
+	"runtime"
+	"unsafe"
+)
+
+type Packbuilder struct {
+	ptr *C.git_packbuilder
+}
+
+func (repo *Repository) NewPackbuilder() (*Packbuilder, error) {
+	builder := &Packbuilder{}
+	ret := C.git_packbuilder_new(&builder.ptr, repo.ptr)
+	if ret != 0 {
+		return nil, LastError()
+	}
+	runtime.SetFinalizer(builder, (*Packbuilder).Free)
+	return builder, nil
+}
+
+func (pb *Packbuilder) Free() {
+	runtime.SetFinalizer(pb, nil)
+	C.git_packbuilder_free(pb.ptr)
+}
+
+func (pb *Packbuilder) Insert(id *Oid, name string) error {
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+	ret := C.git_packbuilder_insert(pb.ptr, id.toC(), cname)
+	if ret != 0 {
+		return LastError()
+	}
+	return nil
+}
+
+func (pb *Packbuilder) InsertCommit(id *Oid) error {
+	ret := C.git_packbuilder_insert_commit(pb.ptr, id.toC())
+	if ret != 0 {
+		return LastError()
+	}
+	return nil
+}
+
+func (pb *Packbuilder) InsertTree(id *Oid) error {
+	ret := C.git_packbuilder_insert_tree(pb.ptr, id.toC())
+	if ret != 0 {
+		return LastError()
+	}
+	return nil
+}
+
+func (pb *Packbuilder) ObjectCount() uint32 {
+	return uint32(C.git_packbuilder_object_count(pb.ptr))
+}
+
+func (pb *Packbuilder) WriteToFile(name string) error {
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+	ret := C.git_packbuilder_write(pb.ptr, cname, nil, nil)
+	if ret != 0 {
+		return LastError()
+	}
+	return nil
+}
+
+func (pb *Packbuilder) Write(w io.Writer) error {
+	ch, stop := pb.ForEach()
+	for slice := range ch {
+		_, err := w.Write(slice)
+		if err != nil {
+			close(stop)
+			return err
+		}
+	}
+	return nil
+}
+
+func (pb *Packbuilder) Written() uint32 {
+	return uint32(C.git_packbuilder_written(pb.ptr))
+}
+
+type packbuilderCbData struct {
+	ch chan<- []byte
+	stop <-chan bool
+}
+
+//export packbuilderForEachCb
+func packbuilderForEachCb(buf unsafe.Pointer, size C.size_t, payload unsafe.Pointer) int {
+	data := (*packbuilderCbData)(payload)
+	ch := data.ch
+	stop := data.stop
+
+	slice := C.GoBytes(buf, C.int(size))
+	select {
+	case <- stop:
+		return -1
+	case ch <- slice:
+	}
+
+	return 0
+}
+
+func (pb *Packbuilder) forEachWrap(data *packbuilderCbData) {
+	C._go_git_packbuilder_foreach(pb.ptr, unsafe.Pointer(data))
+	close(data.ch)
+}
+
+// Foreach sends the packfile as slices through the "data" channel. If
+// you want to stop the pack-building process (e.g. there's an error
+// writing to the output), close or write a value into the "stop"
+// channel.
+func (pb *Packbuilder) ForEach() (data <-chan []byte, stop chan<- bool) {
+	ch := make(chan []byte)
+	stop := make(chan bool)
+	data := packbuilderCbData{ch, stop}
+	go pb.forEachWrap(&data)
+	return ch, stop
+}