private AnyClass ReadInstance(int index)
{
Debug.Assert(index > 0);
if (index > 1)
{
if (_instanceMap != null && _instanceMap.Count > index - 2)
{
return(_instanceMap[index - 2]);
}
throw new InvalidDataException($"could not find index {index} in {nameof(_instanceMap)}");
}
if (++_classGraphDepth > Communicator.ClassGraphDepthMax)
{
throw new InvalidDataException("maximum class graph depth reached");
}
InstanceData?previousCurrent = Push(InstanceType.Class);
Debug.Assert(_current != null);
AnyClass?instance = null;
do
{
// Read the slice header.
string?typeIdOpt = ReadSliceHeaderIntoCurrent();
// We cannot read the indirection table at this point as it may reference the new instance that is
// not created yet.
IClassFactory?factory = null;
if (typeIdOpt is string typeId)
{
Debug.Assert(_current.SliceCompactId == null);
factory = Communicator.FindClassFactory(typeId);
}
else if (_current.SliceCompactId is int compactId)
{
factory = Communicator.FindClassFactory(compactId);
}
if (factory != null)
{
instance = factory.Read(this);
}
else if (SkipSlice()) // Slice off what we don't understand.
{
instance = new UnknownSlicedClass(this);
}
}while (instance == null);
Pop(previousCurrent);
--_classGraphDepth;
return(instance);
}