private static TypeActivator ClassActivator(Type expectedType)
{
var constructors =
expectedType.GetConstructors(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic)
.Where(c => c.IsDefined(typeof(ConstructorAttribute), true))
.ToList();
if (constructors.Count == 0)
{
throw new DeserializationException(
$"No constructors found for {expectedType} found with MaxMind.Db.Constructor attribute");
}
if (constructors.Count > 1)
{
throw new DeserializationException(
$"More than one constructor found for {expectedType} found with MaxMind.Db/Constructor attribute");
}
var constructor = constructors[0];
var parameters = constructor.GetParameters();
var paramNameTypes = new Dictionary <Key, ParameterInfo>();
var injectables = new Dictionary <string, ParameterInfo>();
var networkParams = new List <ParameterInfo>();
var alwaysCreated = new List <ParameterInfo>();
foreach (var param in parameters)
{
var injectableAttribute = param.GetCustomAttributes <InjectAttribute>().FirstOrDefault();
if (injectableAttribute != null)
{
injectables.Add(injectableAttribute.ParameterName, param);
}
var networkAttribute = param.GetCustomAttributes <NetworkAttribute>().FirstOrDefault();
if (networkAttribute != null)
{
networkParams.Add(param);
}
var paramAttribute = param.GetCustomAttributes <ParameterAttribute>().FirstOrDefault();
string?name;
if (paramAttribute != null)
{
name = paramAttribute.ParameterName;
if (paramAttribute.AlwaysCreate)
{
alwaysCreated.Add(param);
}
}
else
{
name = param.Name;
if (name == null)
{
throw new DeserializationException("Unexpected null parameter name");
}
}
var bytes = Encoding.UTF8.GetBytes(name);
paramNameTypes.Add(new Key(new ArrayBuffer(bytes), 0, bytes.Length), param);
}
var activator = ReflectionUtil.CreateActivator(constructor);
var clsConstructor = new TypeActivator(activator, paramNameTypes, injectables, networkParams, alwaysCreated);
return(clsConstructor);
}