1 // Copyright 2019 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4 5 package proto
6 7 import (
8 "fmt"
9 10 "google.golang.org/protobuf/reflect/protoreflect"
11 )
12 13 // Reset clears every field in the message.
14 // The resulting message shares no observable memory with its previous state
15 // other than the memory for the message itself.
16 func Reset(m Message) {
17 if mr, ok := m.(interface{ Reset() }); ok && hasProtoMethods {
18 mr.Reset()
19 return
20 }
21 resetMessage(m.ProtoReflect())
22 }
23 24 func resetMessage(m protoreflect.Message) {
25 if !m.IsValid() {
26 panic(fmt.Sprintf("cannot reset invalid %v message", m.Descriptor().FullName()))
27 }
28 29 // Clear all known fields.
30 fds := m.Descriptor().Fields()
31 for i := 0; i < fds.Len(); i++ {
32 m.Clear(fds.Get(i))
33 }
34 35 // Clear extension fields.
36 m.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
37 m.Clear(fd)
38 return true
39 })
40 41 // Clear unknown fields.
42 m.SetUnknown(nil)
43 }
44