Wrap more objects with CGo

Author: vmarkovtsev

cshared/README.md

@@ -72,8 +72,8 @@ and it is the responsibility of the other side to `free()` it or it will leak
 otherwise.
 
 Another tricky part is in `c_std_map_get_str_str` and similar places
-where you need to return `*C.char` from an unaddressed array accessed under
+where you need to return `*C.char` from an unaddressable array accessed under
 a pseudonym type through reflection. The only way I've found working
-is using `reflect.Copy` to byte slice (copy) and then conversion to
-`string` (copy), then `C.CString` (copy) and finally another (copy) on the
-receiving side because the latter must be `free()`-d. Extremely efficient.
+is using `reflect.Copy` to byte slice (copy), then `CBytes` (copy) and
+finally another (copy) on the receiving side because the latter must be
+`free()`-d.

cshared/blame_cshared.go

@@ -0,0 +1,51 @@
+// +build ignore
+package main
+
+import (
+	"C"
+
+	"gopkg.in/src-d/go-git.v3"
+)
+
+//export c_Blame_get_Path
+func c_Blame_get_Path(b uint64) *C.char {
+	obj, ok := GetObject(Handle(b))
+	if !ok {
+		return nil
+	}
+	blame := obj.(*git.Blame)
+	return C.CString(blame.Path)
+}
+
+//export c_Blame_get_Rev
+func c_Blame_get_Rev(b uint64) *C.char {
+	obj, ok := GetObject(Handle(b))
+	if !ok {
+		return nil
+	}
+	blame := obj.(*git.Blame)
+	return CBytes(blame.Rev[:])
+}
+
+
+//export c_Blame_get_Lines_len
+func c_Blame_get_Lines_len(b uint64) int {
+	obj, ok := GetObject(Handle(b))
+	if !ok {
+		return 0
+	}
+	blame := obj.(*git.Blame)
+	return len(blame.Lines)
+}
+
+//export c_Blame_get_Lines_item
+func c_Blame_get_Lines_item(b uint64, i int) {
+	obj, ok := GetObject(Handle(b))
+	if !ok {
+		return
+	}
+	blame := obj.(*git.Blame)
+	line := blame.Lines[i]
+	_ = line
+}
+

cshared/commit_cshared.go

@@ -4,6 +4,8 @@ package main
 import (
 	"C"
 	"io"
+	"reflect"
+	"unsafe"
 
 	"gopkg.in/src-d/go-git.v3"
 	"gopkg.in/src-d/go-git.v3/core"
@@ -16,7 +18,7 @@ func c_Commit_get_Hash(c uint64) *C.char {
 		return nil
 	}
 	commit := obj.(*git.Commit)
-	return C.CString(string(commit.Hash[:]))
+	return CBytes(commit.Hash[:])
 }
 
 //export c_Commit_get_Author
@@ -142,6 +144,43 @@ func c_Commit_String(c uint64) *C.char {
 	return C.CString(commit.String())
 }
 
+//export c_Commit_References
+func c_Commit_References(c uint64, path string) (*C.char, int, int, *C.char) {
+	obj, ok := GetObject(Handle(c))
+	if !ok {
+		return nil, 0, ErrorCodeNotFound, C.CString(MessageNotFound)
+	}
+	commit := obj.(*git.Commit)
+	refs, err := commit.References(CopyString(path))
+	if err != nil {
+		return nil, 0, ErrorCodeInternal, C.CString(err.Error())
+	}
+	handles := make([]uint64, len(refs))
+	for i, c := range(refs) {
+		handles[i] = uint64(RegisterObject(c))
+	}
+	size := 8 * len(handles)
+	dest := C.malloc(C.size_t(size))
+	header := (*reflect.SliceHeader)(unsafe.Pointer(&handles))
+	header.Len *= 8
+	copy((*[1<<30]byte)(dest)[:], *(*[]byte)(unsafe.Pointer(header)))
+	return (*C.char)(dest), size / 8, ErrorCodeSuccess, nil
+}
+
+//export c_Commit_Blame
+func c_Commit_Blame(c uint64, path string) (uint64, int, *C.char) {
+	obj, ok := GetObject(Handle(c))
+	if !ok {
+		return IH, ErrorCodeNotFound, C.CString(MessageNotFound)
+	}
+	commit := obj.(*git.Commit)
+	blame, err := commit.Blame(CopyString(path))
+	if err != nil {
+		return IH, ErrorCodeInternal, C.CString(err.Error())
+	}
+	return uint64(RegisterObject(blame)), ErrorCodeSuccess, nil
+}
+
 //export c_NewCommitIter
 func c_NewCommitIter(r uint64, iter uint64) uint64 {
 	obj, ok := GetObject(Handle(r))

cshared/file_cshared.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"C"
+
+	"gopkg.in/src-d/go-git.v3"
+)
+
+//export c_File_get_Name
+func c_File_get_Name(f uint64) *C.char {
+	obj, ok := GetObject(Handle(f))
+	if !ok {
+		return nil
+	}
+	file := obj.(*git.File)
+	return C.CString(file.Name)
+}
+
+//export c_File_get_Mode
+func c_File_get_Mode(f uint64) uint32 {
+	obj, ok := GetObject(Handle(f))
+	if !ok {
+		return 0
+	}
+	file := obj.(*git.File)
+	return uint32(file.Mode)
+}
+
+//export c_NewFileIter
+func c_NewFileIter(r uint64, t uint64) uint64 {
+	obj, ok := GetObject(Handle(r))
+	if !ok {
+		return IH
+	}
+	repo := obj.(*git.Repository)
+	obj, ok = GetObject(Handle(t))
+	if !ok {
+		return IH
+	}
+	tree := obj.(*git.Tree)
+	iter := git.NewFileIter(repo, tree)
+	return uint64(RegisterObject(iter))
+}
+
+//export c_FileIter_Next
+func c_FileIter_Next(i uint64) (uint64, int, *C.char) {
+	obj, ok := GetObject(Handle(i))
+	if !ok {
+		return IH, ErrorCodeNotFound, C.CString(MessageNotFound)
+	}
+	iter := obj.(*git.FileIter)
+	file, err := iter.Next()
+	if err != nil {
+		return IH, ErrorCodeInternal, C.CString(err.Error())
+	}
+	return uint64(RegisterObject(file)), ErrorCodeSuccess, nil
+}
+
+//export c_FileIter_Close
+func c_FileIter_Close(i uint64) {
+	obj, ok := GetObject(Handle(i))
+	if !ok {
+		return
+	}
+	iter := obj.(*git.FileIter)
+	iter.Close()
+}

cshared/objects.go

@@ -140,6 +140,13 @@ func CopyString(str string) string {
 	return string(buf)
 }
 
+// https://github.com/golang/go/issues/14838
+func CBytes(bytes []byte) *C.char {
+	ptr := C.malloc(C.size_t(len(bytes)))
+	copy((*[1<<30]byte)(ptr)[:], bytes)
+	return (*C.char)(ptr)
+}
+
 func SafeIsNil(v reflect.Value) bool {
   defer func() { recover() }()
   return v.IsNil()

cshared/objects_cshared.go

@@ -54,7 +54,7 @@ func c_Blob_get_Hash(b uint64) *C.char {
 		return nil
 	}
 	blob := obj.(*git.Blob)
-	return C.CString(string(blob.Hash[:]))
+	return CBytes(blob.Hash[:])
 }
 
 //export c_Blob_Size

cshared/remote_cshared.go

@@ -130,7 +130,7 @@ func c_Remote_Head(r uint64) (*C.char, int, *C.char) {
 	if err != nil {
 		return nil, ErrorCodeInternal, C.CString(err.Error())
 	}
-	return C.CString(string(hash[:])), ErrorCodeSuccess, nil
+	return CBytes(hash[:]), ErrorCodeSuccess, nil
 }
 
 //export c_Remote_Fetch
@@ -177,7 +177,7 @@ func c_Remote_Ref(r uint64, refName string) (*C.char, int, *C.char) {
 	if err != nil {
 		return nil, ErrorCodeInternal, C.CString(err.Error())
 	}
-	return C.CString(string(hash[:])), ErrorCodeSuccess, nil
+	return CBytes(hash[:]), ErrorCodeSuccess, nil
 }
 
 //export c_Remote_Refs

cshared/std_cshared.go

@@ -28,7 +28,7 @@ func c_std_map_get_str_str(m uint64, key string) *C.char {
 	    val.Type().Elem().Kind() == reflect.Uint8 {
 		arr := make([]byte, val.Len(), val.Len())
 		reflect.Copy(reflect.ValueOf(arr), val)
-		return C.CString(string(arr))
+		return CBytes(arr)
 	}
 	return C.CString(val.String())
 }