proto: support message_set_wire_format
MessageSets are a deprecated proto1 feature, long since superseded by
extensions. Add disabled-by-default support behind flags.Proto1Legacy.
Change-Id: I7d3ace07f3b0efd59673034f3dc633b908345a88
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185538
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/internal/impl/codec_message.go b/internal/impl/codec_message.go
index 2b8b047..e43c812 100644
--- a/internal/impl/codec_message.go
+++ b/internal/impl/codec_message.go
@@ -5,9 +5,11 @@
package impl
import (
+ "fmt"
"reflect"
"sort"
+ "google.golang.org/protobuf/internal/encoding/messageset"
"google.golang.org/protobuf/internal/encoding/wire"
pref "google.golang.org/protobuf/reflect/protoreflect"
piface "google.golang.org/protobuf/runtime/protoiface"
@@ -77,6 +79,21 @@
mi.orderedCoderFields = append(mi.orderedCoderFields, cf)
mi.coderFields[cf.num] = cf
}
+ if messageset.IsMessageSet(mi.PBType.Descriptor()) {
+ if !mi.extensionOffset.IsValid() {
+ panic(fmt.Sprintf("%v: MessageSet with no extensions field", mi.PBType.FullName()))
+ }
+ cf := &coderFieldInfo{
+ num: messageset.FieldItem,
+ offset: si.extensionOffset,
+ isPointer: true,
+ funcs: makeMessageSetFieldCoder(mi),
+ }
+ mi.orderedCoderFields = append(mi.orderedCoderFields, cf)
+ mi.coderFields[cf.num] = cf
+ // Invalidate the extension offset, since the field codec handles extensions.
+ mi.extensionOffset = invalidOffset
+ }
sort.Slice(mi.orderedCoderFields, func(i, j int) bool {
return mi.orderedCoderFields[i].num < mi.orderedCoderFields[j].num
})
diff --git a/internal/impl/codec_messageset.go b/internal/impl/codec_messageset.go
new file mode 100644
index 0000000..073c4dc
--- /dev/null
+++ b/internal/impl/codec_messageset.go
@@ -0,0 +1,119 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style.
+// license that can be found in the LICENSE file.
+
+package impl
+
+import (
+ "sort"
+
+ "google.golang.org/protobuf/internal/encoding/messageset"
+ "google.golang.org/protobuf/internal/encoding/wire"
+ "google.golang.org/protobuf/internal/errors"
+ "google.golang.org/protobuf/internal/flags"
+)
+
+func makeMessageSetFieldCoder(mi *MessageInfo) pointerCoderFuncs {
+ return pointerCoderFuncs{
+ size: func(p pointer, tagsize int, opts marshalOptions) int {
+ return sizeMessageSet(mi, p, tagsize, opts)
+ },
+ marshal: func(b []byte, p pointer, wiretag uint64, opts marshalOptions) ([]byte, error) {
+ return marshalMessageSet(mi, b, p, wiretag, opts)
+ },
+ unmarshal: func(b []byte, p pointer, wtyp wire.Type, opts unmarshalOptions) (int, error) {
+ return unmarshalMessageSet(mi, b, p, wtyp, opts)
+ },
+ }
+}
+
+func sizeMessageSet(mi *MessageInfo, p pointer, tagsize int, opts marshalOptions) (n int) {
+ ext := *p.Extensions()
+ if ext == nil {
+ return 0
+ }
+ for _, x := range ext {
+ xi := mi.extensionFieldInfo(x.GetType())
+ if xi.funcs.size == nil {
+ continue
+ }
+ num, _ := wire.DecodeTag(xi.wiretag)
+ n += messageset.SizeField(num)
+ n += xi.funcs.size(x.GetValue(), wire.SizeTag(messageset.FieldMessage), opts)
+ }
+ return n
+}
+
+func marshalMessageSet(mi *MessageInfo, b []byte, p pointer, wiretag uint64, opts marshalOptions) ([]byte, error) {
+ if !flags.Proto1Legacy {
+ return b, errors.New("no support for message_set_wire_format")
+ }
+ ext := *p.Extensions()
+ if ext == nil {
+ return b, nil
+ }
+ switch len(ext) {
+ case 0:
+ return b, nil
+ case 1:
+ // Fast-path for one extension: Don't bother sorting the keys.
+ for _, x := range ext {
+ var err error
+ b, err = marshalMessageSetField(mi, b, x, opts)
+ if err != nil {
+ return b, err
+ }
+ }
+ return b, nil
+ default:
+ // Sort the keys to provide a deterministic encoding.
+ // Not sure this is required, but the old code does it.
+ keys := make([]int, 0, len(ext))
+ for k := range ext {
+ keys = append(keys, int(k))
+ }
+ sort.Ints(keys)
+ for _, k := range keys {
+ var err error
+ b, err = marshalMessageSetField(mi, b, ext[int32(k)], opts)
+ if err != nil {
+ return b, err
+ }
+ }
+ return b, nil
+ }
+}
+
+func marshalMessageSetField(mi *MessageInfo, b []byte, x ExtensionField, opts marshalOptions) ([]byte, error) {
+ xi := mi.extensionFieldInfo(x.GetType())
+ num, _ := wire.DecodeTag(xi.wiretag)
+ b = messageset.AppendFieldStart(b, num)
+ b, err := xi.funcs.marshal(b, x.GetValue(), wire.EncodeTag(messageset.FieldMessage, wire.BytesType), opts)
+ if err != nil {
+ return b, err
+ }
+ b = messageset.AppendFieldEnd(b)
+ return b, nil
+}
+
+func unmarshalMessageSet(mi *MessageInfo, b []byte, p pointer, wtyp wire.Type, opts unmarshalOptions) (int, error) {
+ if !flags.Proto1Legacy {
+ return 0, errors.New("no support for message_set_wire_format")
+ }
+ if wtyp != wire.StartGroupType {
+ return 0, errUnknown
+ }
+ ep := p.Extensions()
+ if *ep == nil {
+ *ep = make(map[int32]ExtensionField)
+ }
+ ext := *ep
+ num, v, n, err := messageset.ConsumeFieldValue(b, true)
+ if err != nil {
+ return 0, err
+ }
+ if _, err := mi.unmarshalExtension(v, num, wire.BytesType, ext, opts); err != nil {
+ return 0, err
+ }
+ return n, nil
+}