Matteo Scandolo | a428586 | 2020-12-01 18:10:10 -0800 | [diff] [blame^] | 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 | "google.golang.org/protobuf/reflect/protoreflect" |
| 9 | ) |
| 10 | |
| 11 | // SetDefaults sets unpopulated scalar fields to their default values. |
| 12 | // Fields within a oneof are not set even if they have a default value. |
| 13 | // SetDefaults is recursively called upon any populated message fields. |
| 14 | func SetDefaults(m Message) { |
| 15 | if m != nil { |
| 16 | setDefaults(MessageReflect(m)) |
| 17 | } |
| 18 | } |
| 19 | |
| 20 | func setDefaults(m protoreflect.Message) { |
| 21 | fds := m.Descriptor().Fields() |
| 22 | for i := 0; i < fds.Len(); i++ { |
| 23 | fd := fds.Get(i) |
| 24 | if !m.Has(fd) { |
| 25 | if fd.HasDefault() && fd.ContainingOneof() == nil { |
| 26 | v := fd.Default() |
| 27 | if fd.Kind() == protoreflect.BytesKind { |
| 28 | v = protoreflect.ValueOf(append([]byte(nil), v.Bytes()...)) // copy the default bytes |
| 29 | } |
| 30 | m.Set(fd, v) |
| 31 | } |
| 32 | continue |
| 33 | } |
| 34 | } |
| 35 | |
| 36 | m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool { |
| 37 | switch { |
| 38 | // Handle singular message. |
| 39 | case fd.Cardinality() != protoreflect.Repeated: |
| 40 | if fd.Message() != nil { |
| 41 | setDefaults(m.Get(fd).Message()) |
| 42 | } |
| 43 | // Handle list of messages. |
| 44 | case fd.IsList(): |
| 45 | if fd.Message() != nil { |
| 46 | ls := m.Get(fd).List() |
| 47 | for i := 0; i < ls.Len(); i++ { |
| 48 | setDefaults(ls.Get(i).Message()) |
| 49 | } |
| 50 | } |
| 51 | // Handle map of messages. |
| 52 | case fd.IsMap(): |
| 53 | if fd.MapValue().Message() != nil { |
| 54 | ms := m.Get(fd).Map() |
| 55 | ms.Range(func(_ protoreflect.MapKey, v protoreflect.Value) bool { |
| 56 | setDefaults(v.Message()) |
| 57 | return true |
| 58 | }) |
| 59 | } |
| 60 | } |
| 61 | return true |
| 62 | }) |
| 63 | } |