def serialize(self, val):
if (
not isinstance(val, Iterable) or
isinstance(val, (bytes, bytearray, str))
):
raise SerializationError(
'Can only serialize Iterable objects, except Dictionaries',
val
)
if self.empty and len(val) != 0:
raise ValueError(
"Empty List Sedes cannot serialize non-empty Iterables"
)
serialized_iterable_string = b"".join(
self.element_sedes.serialize(element) for element in val
)
if len(serialized_iterable_string) >= 2 ** (LIST_PREFIX_LENGTH * 8):
raise SerializationError(
'List too long to fit into {} bytes after serialization'.format(LIST_PREFIX_LENGTH),
val
)
serialized_len = len(serialized_iterable_string).to_bytes(LIST_PREFIX_LENGTH, 'big')
return serialized_len + serialized_iterable_string
def serialize(self, val):
if not isinstance(val, bytes):
raise SerializationError('Hash should be of type bytes', val)
if len(val) != self.num_bytes:
raise SerializationError(
"Can only serialize values of {} bytes".format(self.num_bytes),
val)
return val
def serialize(self, value: int) -> bytes:
if value < 0:
raise SerializationError(
f"Can only serialize non-negative integers, got {value}", )
try:
return value.to_bytes(self.size, "little")
except OverflowError:
raise SerializationError(
f"{value} is too large to be serialized in {self.size * 8} bits"
)
def serialize_content(self,
value: Sequence[TSerializableElement]) -> bytes:
if isinstance(value, (bytes, bytearray, str)):
raise SerializationError("Can not serialize strings as tuples")
if len(value) != self.length:
raise SerializationError(
f"Cannot serialize {len(value)} elements as {self.length}-tuple"
)
return b"".join(
self.element_sedes.serialize(element) for element in value)
def serialize(self, val):
if not isinstance(val, (bytes, bytearray)):
raise SerializationError(
"Can only serialize bytes or bytearray objects", val)
object_len = len(val)
if object_len >= 2**(BYTES_PREFIX_LENGTH * 8):
raise SerializationError(
f'Object too long for its length to fit into {BYTES_PREFIX_LENGTH} bytes'
f'after serialization', val)
# Convert the length of bytes to a 4 bytes value
object_len_bytes = object_len.to_bytes(BYTES_PREFIX_LENGTH, 'big')
return object_len_bytes + val
def serialize(self, value: BytesOrByteArray) -> bytes:
if len(value) != self.length:
raise SerializationError(
f"Cannot serialize length {len(value)} byte-string as bytes{self.length}"
)
return value
def serialize(self, value: Sequence[bool]) -> bytes:
if len(value) != self.bit_count:
raise SerializationError(
f"Cannot serialize length {len(value)} bit array as Bitvector[{self.bit_count}]"
)
return bytes(
get_serialized_bytearray(value, self.bit_count, extra_byte=False))
def _validate_emptiness(value: Iterable[TSerializable]) -> None:
try:
first(value)
except StopIteration:
pass
else:
raise SerializationError("Can only serialize empty Iterables")
def serialize(self, val):
if isinstance(val, bool) or not isinstance(val, int):
raise SerializationError(
'As per specified sedes object, can only serialize non-negative integer values',
val)
if val < 0:
raise SerializationError(
'As per specified sedes object, can only serialize non-negative integer values',
val)
try:
serialized_obj = val.to_bytes(self.num_bytes, 'big')
except OverflowError as err:
raise SerializationError('As per specified sedes object, %s' % err,
val)
return serialized_obj
def serialize_content(self, value: Iterable[TSerializable]) -> bytes:
if isinstance(value, (bytes, bytearray, str)):
raise SerializationError("Can not serialize strings as lists")
if self.empty:
self._validate_emptiness(value)
return b"".join(
self.element_sedes.serialize(element) for element in value)
def serialize(self, obj):
if not isinstance(obj, bool):
raise SerializationError('Can only serialize boolean values', obj)
if obj is False:
return b'\x00'
elif obj is True:
return b'\x01'
else:
raise Exception("Invariant: no other options for boolean values")
def serialize(self, value: Sequence[bool]) -> bytes:
len_value = len(value)
if len_value > self.max_bit_count:
raise SerializationError(
f"Cannot serialize length {len_value} bit array as Bitlist[{self.max_bit_count}]"
)
serialized_bytearray = get_serialized_bytearray(value,
len_value,
extra_byte=True)
serialized_bytearray[len_value // 8] |= 1 << (len_value % 8)
return bytes(serialized_bytearray)
def serialize(cls, obj):
# Make sure that the obj is instance of class before serializing
if not isinstance(obj, cls):
raise SerializationError(
f"Can only serialize objects which are instances of {cls.__name__} class",
obj
)
serialized_string = b"".join(
field_sedes.serialize(getattr(obj, field_name))
for field_name, field_sedes in cls._meta.fields
)
if len(serialized_string) >= MAX_LEN_SERIALIZED_CONTAINER_OBJECT:
raise SerializationError(
f'Container too long to fit into {CONTAINER_PREFIX_LENGTH} bytes'
f'after serialization',
obj
)
serialized_len = len(serialized_string).to_bytes(CONTAINER_PREFIX_LENGTH, 'big')
return serialized_len + serialized_string
def validate_content_size(content: bytes) -> None:
if len(content) >= MAX_CONTENT_SIZE:
raise SerializationError(
f"Content size is too large to be encoded in a {SIZE_PREFIX_SIZE} byte prefix",
)
def serialize_content(self, value: BytesOrByteArray) -> bytes:
if len(value) != self.size:
raise SerializationError(
f"Cannot serialize {len(value)} bytes as bytes{self.size}")
return value
def serialize(self, value: TSerializable) -> bytes:
serialized_content = self.serialize_content(value)
if len(serialized_content) != self.size:
raise SerializationError(
f"Cannot serialize {value} in {self.size} bytes")
return serialized_content
def validate_content_length(self, content: bytes) -> None:
if len(content) >= self.max_content_length:
raise SerializationError(
f"Content is too big to be encoded in prefix of {self.length_bytes} bytes",
)
def serialize(self, value: Sequence[TSerializable]):
if len(value):
raise SerializationError("Cannot serialize non-empty sequence using `EmptyList` sedes")
return b''
def _validate_serializable(self, value: Any) -> None:
if len(value) != self.length:
raise SerializationError(
f"Length mismatch. Cannot serialize value with length "
f"{len(value)} as {self.length}-tuple")
def serialize_element_for_tree(self, index: int, byte_value: int) -> bytes:
if not 0 <= byte_value < 256:
raise SerializationError(
f"Cannot serialize byte as its value {byte_value} is invalid")
return bytes((byte_value, ))
def serialize_content(self, value: BytesOrByteArray) -> bytes:
if len(value) != self.length:
raise SerializationError(
f"Can only serialize values of exactly {self.length} bytes, got"
f"{encode_hex(value)} which is {len(value)} bytes.")
return value
def serialize(self, value: bytes) -> bytes:
if len(value) != 1:
raise SerializationError(
f"The `Byte` sedes can only serialize single bytes. Got: {value!r}"
)
return value
def _validate_serializable(self, value: Sequence[Any]) -> bytes:
if len(value) != len(self.field_sedes):
raise SerializationError(
f"Incorrect element count: Expected: {len(self.field_sedes)} / Got: {len(value)}"
)
