jam.utils.codec.primitives.nulls module

Null codec implementation for JAM protocol.

Implements encoding and decoding of null values according to the JAM specification. Null values are encoded as an empty byte sequence.

class jam.utils.codec.primitives.nulls.NullCodec[source]

Bases: Codec[None]

Codec for null values.

Null values are encoded as empty byte sequences. This is the simplest possible codec as it doesn’t actually write any bytes.

Examples

>>> codec = NullCodec()
>>> encoded = codec.encode(None)
>>> assert encoded == b""
>>> decoded, size = codec.decode_from(b"")
>>> assert decoded is None
>>> assert size == 0

encode_size(value: None) → int[source]

Calculate encoded size for null value.

Parameters:: value – Must be None
Returns:: Always returns 0
Raises:: EncodeError – If value is not None

encode_into(value: None, buffer: bytearray, offset: int = 0) → int[source]

Encode a null value into the provided buffer.

Parameters:

value – Must be None
buffer – Destination buffer
offset – Starting position in buffer

Returns:

Always returns 0

Raises:

EncodeError – If value is not None

static decode_from(buffer: bytes | bytearray | memoryview, offset: int = 0) → Tuple[None, int][source]

Decode a null value from the provided buffer.

Parameters:

buffer – Source buffer
offset – Starting position in buffer

Returns:

Tuple of (None, 0)