Converting Stream to String and back

Question

I want to serialize objects to strings, and back.

We use protobuf-net to turn an object into a Stream and back, successfully.

However, Stream to string and back... not so successful. After going through StreamToString and StringToStream, the new Streamisn't deserialized by protobuf-net; it raises an Arithmetic Operation resulted in an Overflow exception. If we deserialize the original stream, it works.

Our methods:

public static string StreamToString(Stream stream)
{
    stream.Position = 0;
    using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
    {
        return reader.ReadToEnd();
    }
}

public static Stream StringToStream(string src)
{
    byte[] byteArray = Encoding.UTF8.GetBytes(src);
    return new MemoryStream(byteArray);
}

Our example code using these two:

MemoryStream stream = new MemoryStream();
Serializer.Serialize<SuperExample>(stream, test);
stream.Position = 0;
string strout = StreamToString(stream);
MemoryStream result = (MemoryStream)StringToStream(strout);
var other = Serializer.Deserialize<SuperExample>(result);

Answer 1

This is so common but so profoundly wrong. Protobuf data is not string data. It certainly isn't ASCII. You are using the encoding backwards. A text encoding transfers:

• an arbitrary string to formatted bytes
• formatted bytes to the original string

You do not have "formatted bytes". You have arbitrary bytes. You need to use something like a base-n (commonly: base-64) encode. This transfers

• arbitrary bytes to a formatted string
• a formatted string to the original bytes

Look at Convert.ToBase64String and Convert.FromBase64String.