def consume_length_prefix(rlp, start):
"""Read a length prefix from an RLP string.
:param rlp: the rlp string to read from
:param start: the position at which to start reading
:returns: a tuple ``(type, length, end)``, where ``type`` is either ``str``
or ``list`` depending on the type of the following payload,
``length`` is the length of the payload in bytes, and ``end`` is
the position of the first payload byte in the rlp string
"""
b0 = safe_ord(rlp[start])
if b0 < 128: # single byte
return (str, 1, start)
elif b0 < 128 + 56: # short string
return (str, b0 - 128, start + 1)
elif b0 < 192: # long string
ll = b0 - 128 - 56 + 1
l_idx = big_endian_to_int(rlp[start + 1:start + 1 + ll])
return (str, l_idx, start + 1 + ll)
elif b0 < 192 + 56: # short list
return (list, b0 - 192, start + 1)
else: # long list
ll = b0 - 192 - 56 + 1
l_idx = big_endian_to_int(rlp[start + 1:start + 1 + ll])
return (list, l_idx, start + 1 + ll)
def __hash__(self):
return utils.big_endian_to_int(str_to_bytes(self.__repr__()))
def __hash__(self):
return utils.big_endian_to_int(str_to_bytes(self.__repr__()))