def streamable(cls: Any):
"""
This is a decorator for class definitions. It applies the strictdataclass decorator,
which checks all types at construction. It also defines a simple serialization format,
and adds parse, from bytes, stream, and __bytes__ methods.
Serialization format:
- Each field is serialized in order, by calling from_bytes/__bytes__.
- For Lists, there is a 4 byte prefix for the list length.
- For Optionals, there is a one byte prefix, 1 iff object is present, 0 iff not.
All of the constituents must have parse/from_bytes, and stream/__bytes__ and therefore
be of fixed size. For example, int cannot be a constituent since it is not a fixed size,
whereas uint32 can be.
Furthermore, a get_hash() member is added, which performs a serialization and a sha256.
This class is used for deterministic serialization and hashing, for consensus critical
objects such as the block header.
Make sure to use the Streamable class as a parent class when using the streamable decorator,
as it will allow linters to recognize the methods that are added by the decorator. Also,
use the @dataclass(frozen=True) decorator as well, for linters to recognize constructor
arguments.
"""
cls1 = strictdataclass(cls)
return type(cls.__name__, (cls1, Streamable), {})
def cbor_message(cls: Any) -> Type:
"""
Decorator, converts a class into a strictdataclass, which checks all arguments to make sure
they are the right type.
"""
cls1 = strictdataclass(cls=cls)
return type(cls.__name__, (cls1, ), {"__cbor_message__": True})