This question is related to this one and this one. I'm trying to store data in the blockchain inside the transaction data field:
The second question offers a solution using a contract but is it possible to use only the transaction field. In pyethapp it is defined as follows:
class Transaction(rlp.Serializable):
"""
A transaction is stored as:
[nonce, gasprice, startgas, to, value, data, v, r, s]
nonce is the number of transactions already sent by that account, encoded
in binary form (eg. 0 -> '', 7 -> '\x07', 1000 -> '\x03\xd8').
(v,r,s) is the raw Electrum-style signature of the transaction without the
signature made with the private key corresponding to the sending account,
with 0 <= v <= 3. From an Electrum-style signature (65 bytes) it is
possible to extract the public key, and thereby the address, directly.
A valid transaction is one where:
(i) the signature is well-formed (ie. 0 <= v <= 3, 0 <= r < P, 0 <= s < N,
0 <= r < P - N if v >= 2), and
(ii) the sending account has enough funds to pay the fee and the value.
"""
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),
]
_sender = None
def __init__(self, nonce, gasprice, startgas, to, value, data, v=0, r=0, s=0):
self.data = None
to = utils.normalize_address(to, allow_blank=True)
assert len(to) == 20 or len(to) == 0
super(Transaction, self).__init__(nonce, gasprice, startgas, to, value, data, v, r, s)
self.logs = []
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")
log.debug('deserialized tx', tx=encode_hex(self.hash)[:8])
I'm not sure whether the field has an upper bound in terms of size.
How much data can be stored within a transaction?
