正文
源码阅读 etherum-transactions.py
提示：扫一扫查出行【扫一扫了解最新限行尾号】
复制提示
交易(transaction.py)的结构:
fields = [
('nonce', big_endian_int),
('gasprice', big_endian_int),
('startgas', big_endian_int),
('to', utils.address),
('value', big_endian_int),
('data', binary),
('v', big_endian_int),
('r', big_endian_int),
('s', big_endian_int),
]
__init__方法：
to参数初始化：to = utils.normalize_address(to, allow_blank=True)
关于上面的normalize_address方法
def normalize_address(x, allow_blank=False):
if is_numeric(x):
return int_to_addr(x)
if allow_blank and x in {'', b''}:
return b''
if len(x) in (42, 50) and x[:2] in {'0x', b'0x'}://如果前两个字符问0x，截取从第三个字符开始的所有字符串
x = x[2:]
if len(x) in (40, 48):
x = decode_hex(x)
if len(x) == 24:
assert len(x) == 24 and sha3(x[:20])[:4] == x[-4:] //比较哈希值
x = x[:20]
if len(x) != 20:
raise Exception("Invalid address format: %r" % x)
return x
回到transactions.py方法：
使用父类构造方法初始化
super(Transaction, self).__init__(nonce, gasprice, startgas, to, value, data, v, r, s)
通过gas 判断交易是否合法：
if self.gasprice >= TT256 or self.startgas >= TT256 or \
self.value >= TT256 or self.nonce >= TT256:
raise InvalidTransaction("Values way too high!")
if self.startgas < self.intrinsic_gas_used:
raise InvalidTransaction("Startgas too low")
def sender(self)方法：通过签名和公钥验证账号合法性
def sender(self): if not self._sender:
# Determine sender
if self.v:
if self.r >= N or self.s >= N or self.v < 27 or self.v > 28 \
or self.r == 0 or self.s == 0:
raise InvalidTransaction("Invalid signature values!")
log.debug('recovering sender')
rlpdata = rlp.encode(self, UnsignedTransaction)
rawhash = utils.sha3(rlpdata) pk = PublicKey(flags=ALL_FLAGS)
try:
pk.public_key = pk.ecdsa_recover(
rawhash,
pk.ecdsa_recoverable_deserialize(
zpad(utils.bytearray_to_bytestr(int_to_32bytearray(self.r)), 32) + zpad(utils.bytearray_to_bytestr(int_to_32bytearray(self.s)), 32),
self.v - 27
),
raw=True
)
pub = pk.serialize(compressed=False)
except Exception:
raise InvalidTransaction("Invalid signature values (x^3+7 is non-residue)") if pub[1:] == b"\x00" * 32:
raise InvalidTransaction("Invalid signature (zero privkey cannot sign)")
pub = encode_pubkey(pub, 'bin')
self._sender = utils.sha3(pub[1:])[-20:]
assert self.sender == self._sender
else:
self._sender = 0
return self._sender
sender的setter函数：
@sender.setter
def sender(self, value):
self._sender = value
def intrinsic_gas_used(self)方法：
@property
def intrinsic_gas_used(self):
#计算0位数量
num_zero_bytes = str_to_bytes(self.data).count(ascii_chr(0))
#计算非0位数量
num_non_zero_bytes = len(self.data) - num_zero_bytes
return (opcodes.GTXCOST
+ opcodes.GTXDATAZERO * num_zero_bytes
+ opcodes.GTXDATANONZERO * num_non_zero_bytes)
