jam.utils.codec.composite.bit_sequences module

class jam.utils.codec.composite.bit_sequences.BitSequenceCodec(bit_length: int | None = None, bit_order: Literal['msb', 'lsb'] = 'msb')

Bases: Codec[Sequence[bool]]

Codec for encoding and decoding sequences of bits.

Bits are packed into octets (bytes) from least significant to most significant. IMP: It adds bit length encoded as a single byte at the beginning of the sequence ONLY if the bit length is not provided.

If dynamic length sequence:

• Initialise with None

• No need to pass bit length to decode_from

If fixed length sequence:

• Initialise with bit length

• Pass bit length to decode_from

__init__(bit_length: int | None = None, bit_order: Literal['msb', 'lsb'] = 'msb')

bit_length: int | None = None

bit_order: Literal['msb', 'lsb'] = 'msb'

encode_size(value: Sequence[bool]) → int

Calculate the number of bytes needed to encode the value.

encode_into(value: Sequence[bool], buffer: bytearray, offset: int = 0) → int

Encode the value into the provided buffer at the specified offset.

static decode_from(buffer: bytes | bytearray | memoryview, offset: int = 0, bit_length: int | None = None, bit_order: Literal['msb', 'lsb'] = 'msb') → Tuple[Sequence[bool], int]

Decode bit sequence from buffer.

Parameters:

• buffer – Source buffer

• offset – Starting offset

• bit_length – Expected number of bits (required)

Returns:

Tuple of (decoded bit list, bytes read)

Raises:

DecodeError – If buffer too small or bit_length not specified