ProtoBuf distorts byte array during deserialization (added 0 added)

Question

I am using ProtoBuf.NET to serialize / deserialize some classes. I find that when deserializing I get a corrupted byte [] (extra 0). Before asking, yes, I need the * WithLengthPrefix () versions of the ProtoBuf API, since the ProtoBuf part is at the beginning of the user stream :)

Anyway, I see

Original object is (JSON depiction): {"ByteArray":"M+B6q+PXNuF8P5hl","ByteArray2":"DmErxVQ2y87IypSRcfxcWA==","K":2,"V ":1.0} Protobuf: Raw Hex (42 bytes): 29-2A-20-0A-0C-33-E0-7A-AB-E3-D7-36-E1-7C-3F-98-65-12-10-0E-61-2B-C5-54-36-CB-CE -C8-CA-94-91-71-FC-5C-58-08-02-15-00-00-80-3F Regenerated object is (JSON depiction): {"ByteArray":"AAAAAAAAAAAAAAAAM+B6q+PXNuF8P5hl","ByteArray2":"DmErxVQ2y87IypSRcf xcWA==","K":2,"V":1.0} 

The optional AAA*A in the ByteArray element is basically hex 0x00 in base64.

Application logic is similar to

 static void Main(string[] args) { var parent = new Parent(); parent.Init(); Console.WriteLine("\nOriginal object is (JSON depiction):"); Console.WriteLine(JsonConvert.SerializeObject(parent)); using (var ms = new MemoryStream()) { Serializer.SerializeWithLengthPrefix(ms, parent, PrefixStyle.Base128); byte[] bytes2 = ms.ToArray(); var hex2 = BitConverter.ToString(bytes2); Console.WriteLine("\nProtobuf: Hex ({0} bytes):\n{1}", bytes2.Length, hex2); ms.Seek(0, SeekOrigin.Begin); var backFirst = Serializer.DeserializeWithLengthPrefix<Parent>(ms,PrefixStyle.Base128); Console.WriteLine("\nRegenerated object is (JSON depiction):"); Console.WriteLine(JsonConvert.SerializeObject(backFirst)); } } 

DTO Classes

 [DataContract] [ProtoContract] internal class Parent : Child { [DataMember(Name = "ByteArray", Order = 10)] [ProtoMember(1)] public byte[] ByteArray { get; set; } [DataMember(Name = "ByteArray2", Order = 30, EmitDefaultValue = false)] [ProtoMember(2)] public byte[] ByteArray2 { get; set; } public Parent() { ByteArray = new byte[12]; } internal void Init(bool bindRow = false) { base.Init(); var rng = new RNGCryptoServiceProvider(); rng.GetBytes(ByteArray); ByteArray2 = new byte[16]; rng.GetBytes(ByteArray2); } } [DataContract] [ProtoContract] [ProtoInclude(5, typeof(Parent))] public class Child { [DataMember(Name = "K", Order = 100)] [ProtoMember(1)] public Int32 K { get; set; } [DataMember(Name = "V", Order = 110)] [ProtoMember(2)] public float V { get; set; } internal void Init() { K = 2; V = 1.0f; } } 

I see that when I move ByteArray = new byte[12] from the form the Parent constructor into Init() , ProtoBuf works fine. However, we have application logic that prevents this in the real version (compared to the one you see above).

Are we doing something wrong or is this a bug in ProtoBuf?

Answer 1

Here we go:

 public Parent() { ByteArray = new byte[12]; } 

Note: protobuf is designed (by Google) to be both incremental and integrated. Where append / merge is a synonym (for lists / arrays, etc.) With "append".

Two options (both possible through attributes):

• disable constructor: [ProtoContract(SkipConstructor = true)]
• disable add: [ProtoMember(1, OverwriteList = true)]

There are other options, but these are the ones I lean on.

You notice that the initialization of the array is different from the real code, but: I can not comment on the code that I do not see.