Joey Armstrong | 903c69d | 2024-02-01 19:46:39 -0500 | [diff] [blame] | 1 | package internal |
| 2 | |
| 3 | import ( |
| 4 | "reflect" |
| 5 | |
| 6 | "github.com/golang/protobuf/proto" |
| 7 | ) |
| 8 | |
| 9 | var typeOfBytes = reflect.TypeOf([]byte(nil)) |
| 10 | |
| 11 | // GetUnrecognized fetches the bytes of unrecognized fields for the given message. |
| 12 | func GetUnrecognized(msg proto.Message) []byte { |
| 13 | val := reflect.Indirect(reflect.ValueOf(msg)) |
| 14 | u := val.FieldByName("XXX_unrecognized") |
| 15 | if u.IsValid() && u.Type() == typeOfBytes { |
| 16 | return u.Interface().([]byte) |
| 17 | } |
| 18 | |
| 19 | // Fallback to reflection for API v2 messages |
| 20 | get, _, _, ok := unrecognizedGetSetMethods(val) |
| 21 | if !ok { |
| 22 | return nil |
| 23 | } |
| 24 | |
| 25 | return get.Call([]reflect.Value(nil))[0].Convert(typeOfBytes).Interface().([]byte) |
| 26 | } |
| 27 | |
| 28 | // SetUnrecognized adds the given bytes to the unrecognized fields for the given message. |
| 29 | func SetUnrecognized(msg proto.Message, data []byte) { |
| 30 | val := reflect.Indirect(reflect.ValueOf(msg)) |
| 31 | u := val.FieldByName("XXX_unrecognized") |
| 32 | if u.IsValid() && u.Type() == typeOfBytes { |
| 33 | // Just store the bytes in the unrecognized field |
| 34 | ub := u.Interface().([]byte) |
| 35 | ub = append(ub, data...) |
| 36 | u.Set(reflect.ValueOf(ub)) |
| 37 | return |
| 38 | } |
| 39 | |
| 40 | // Fallback to reflection for API v2 messages |
| 41 | get, set, argType, ok := unrecognizedGetSetMethods(val) |
| 42 | if !ok { |
| 43 | return |
| 44 | } |
| 45 | |
| 46 | existing := get.Call([]reflect.Value(nil))[0].Convert(typeOfBytes).Interface().([]byte) |
| 47 | if len(existing) > 0 { |
| 48 | data = append(existing, data...) |
| 49 | } |
| 50 | set.Call([]reflect.Value{reflect.ValueOf(data).Convert(argType)}) |
| 51 | } |
| 52 | |
| 53 | func unrecognizedGetSetMethods(val reflect.Value) (get reflect.Value, set reflect.Value, argType reflect.Type, ok bool) { |
| 54 | // val could be an APIv2 message. We use reflection to interact with |
| 55 | // this message so that we don't have a hard dependency on the new |
| 56 | // version of the protobuf package. |
| 57 | refMethod := val.MethodByName("ProtoReflect") |
| 58 | if !refMethod.IsValid() { |
| 59 | if val.CanAddr() { |
| 60 | refMethod = val.Addr().MethodByName("ProtoReflect") |
| 61 | } |
| 62 | if !refMethod.IsValid() { |
| 63 | return |
| 64 | } |
| 65 | } |
| 66 | refType := refMethod.Type() |
| 67 | if refType.NumIn() != 0 || refType.NumOut() != 1 { |
| 68 | return |
| 69 | } |
| 70 | ref := refMethod.Call([]reflect.Value(nil)) |
| 71 | getMethod, setMethod := ref[0].MethodByName("GetUnknown"), ref[0].MethodByName("SetUnknown") |
| 72 | if !getMethod.IsValid() || !setMethod.IsValid() { |
| 73 | return |
| 74 | } |
| 75 | getType := getMethod.Type() |
| 76 | setType := setMethod.Type() |
| 77 | if getType.NumIn() != 0 || getType.NumOut() != 1 || setType.NumIn() != 1 || setType.NumOut() != 0 { |
| 78 | return |
| 79 | } |
| 80 | arg := setType.In(0) |
| 81 | if !arg.ConvertibleTo(typeOfBytes) || getType.Out(0) != arg { |
| 82 | return |
| 83 | } |
| 84 | |
| 85 | return getMethod, setMethod, arg, true |
| 86 | } |