From 140f362428d07ba130c4797b346e1bc2b8777b78 Mon Sep 17 00:00:00 2001
From: Axel Wagner <mail+git2go@merovius.de>
Date: Thu, 16 May 2013 13:56:07 +0200
Subject: [PATCH 1/3] Add support for git_packbuilder

---
 packbuilder.go | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++
 wrapper.c      |  6 +++
 2 files changed, 105 insertions(+)
 create mode 100644 packbuilder.go

diff --git a/packbuilder.go b/packbuilder.go
new file mode 100644
index 0000000..40b2c81
--- /dev/null
+++ b/packbuilder.go
@@ -0,0 +1,99 @@
+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 (
+	"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)
+	if ret != 0 {
+		return LastError()
+	}
+	return nil
+}
+
+func (pb *Packbuilder) Written() uint32 {
+	return uint32(C.git_packbuilder_written(pb.ptr))
+}
+
+//export packbuilderForEachCb
+func packbuilderForEachCb(buf unsafe.Pointer, size C.size_t, payload unsafe.Pointer) int {
+	ch := *(*chan []byte)(payload)
+
+	slice := C.GoBytes(buf, C.int(size))
+	ch <- slice
+	return 0
+}
+
+func (pb *Packbuilder) forEachWrap(ch chan []byte) {
+	C._go_git_packbuilder_foreach(pb.ptr, unsafe.Pointer(&ch))
+	close(ch)
+}
+
+func (pb *Packbuilder) ForEach() chan []byte {
+	ch := make(chan []byte, 0)
+	go pb.forEachWrap(ch)
+	return ch
+}
diff --git a/wrapper.c b/wrapper.c
index 13478cb..67f34fd 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -1,6 +1,7 @@
 #include "_cgo_export.h"
 #include "git2.h"
 #include "git2/submodule.h"
+#include "git2/pack.h"
 
 typedef int (*gogit_submodule_cbk)(git_submodule *sm, const char *name, void *payload);
 
@@ -14,4 +15,9 @@ int _go_git_treewalk(git_tree *tree, git_treewalk_mode mode, void *ptr)
 	return git_tree_walk(tree, mode, (git_treewalk_cb)&CallbackGitTreeWalk, ptr);
 }
 
+int _go_git_packbuilder_foreach(git_packbuilder *pb, void *payload)
+{
+    return git_packbuilder_foreach(pb, (git_packbuilder_foreach_cb)&packbuilderForEachCb, payload);
+}
+
 /* EOF */

From 1da989e28b04807fb9781c3198769630ccb9a0fd Mon Sep 17 00:00:00 2001
From: Axel Wagner <mail+git2go@merovius.de>
Date: Thu, 16 May 2013 14:02:22 +0200
Subject: [PATCH 2/3] Add Write(w io.Writer) to packbuilder

This wraps (*packbuilder).ForEach(), making it possible to write the
pack easiliy to a tcp-connection, a HTTP-Body or the like.
---
 packbuilder.go | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/packbuilder.go b/packbuilder.go
index 40b2c81..6228e12 100644
--- a/packbuilder.go
+++ b/packbuilder.go
@@ -74,6 +74,17 @@ func (pb *Packbuilder) WriteToFile(name string) error {
 	return nil
 }
 
+func (pb *Packbuilder) Write(w io.Writer) error {
+	ch := pb.Foreach()
+	for _, slice := range ch {
+		_, err := w.Write(slice)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func (pb *Packbuilder) Written() uint32 {
 	return uint32(C.git_packbuilder_written(pb.ptr))
 }

From 3a1bbbdf9dcdf88c909ea9df127f32b126d38547 Mon Sep 17 00:00:00 2001
From: Axel Wagner <mail+git2go@merovius.de>
Date: Thu, 16 May 2013 16:53:21 +0200
Subject: [PATCH 3/3] Correct some errors from 1da989e

---
 packbuilder.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/packbuilder.go b/packbuilder.go
index 6228e12..8cc03bd 100644
--- a/packbuilder.go
+++ b/packbuilder.go
@@ -13,6 +13,7 @@ import "C"
 import (
 	"runtime"
 	"unsafe"
+	"io"
 )
 
 type Packbuilder struct {
@@ -75,8 +76,8 @@ func (pb *Packbuilder) WriteToFile(name string) error {
 }
 
 func (pb *Packbuilder) Write(w io.Writer) error {
-	ch := pb.Foreach()
-	for _, slice := range ch {
+	ch := pb.ForEach()
+	for slice := range ch {
 		_, err := w.Write(slice)
 		if err != nil {
 			return err