private const int MaxFieldId = 536870911; // 2^29-1
static GrpcMarshaller()
{
// https://github.com/protobuf-net/protobuf-net/wiki/Getting-Started#inheritance
var baseType = typeof(T).BaseType;
if (baseType != typeof(object))
{
RegisterSubType(typeof(T));
}
if (typeof(T).IsGenericType)
{
foreach (var argType in typeof(T).GenericTypeArguments)
{
GrpcConfig.Register(argType);
}
}
}
private static void RegisterSubType(Type type)
{
if (GrpcConfig.IgnoreTypeModel(type))
{
return;
}
var baseMetaType = GrpcConfig.Register(type.BaseType);
// need to generate predictable fieldIds, allow specifying with [Id(n)] or use MurmurHash2 hash function % 2^29-1,
var idAttr = type.FirstAttribute <IdAttribute>();
var fieldId = idAttr?.Id ?? Math.Abs(unchecked ((int)MurmurHash2.Hash(GetTypeName(type))));
fieldId = fieldId % MaxFieldId;
if (fieldId == default || (idAttr == null && fieldId < 50)) // min = 1, avoid hash conflicts with real field ids
{
fieldId += 50;
}