def set_tx(self, tx):
"""Reset the model to reflect tx."""
self.beginResetModel()
self.vin = []
for i in tx.vin:
self.vin.append(CMutableTxIn.from_txin(i))
self.endResetModel()
def as_tx(self):
sum_in = sum(prevtx.nValue for _, prevtx, _ in self.prevouts)
sig_size = sum(redeemer.spendbytes for _, _, redeemer in self.prevouts)
tx_size = (
4 + # version field
2 + # # of txins
len(self.prevouts) * 41 + # txins, excluding sigs
sig_size + # txins, sigs only
1 + # # of txouts
34 + # txout
4 # nLockTime field
)
feerate = int(self.proxy._call('estimatefee', 1) * COIN)
# satoshi's per KB
if feerate <= 0:
feerate = 10000
fees = int(tx_size * feerate / 1000)
tx = CMutableTransaction(
[CTxIn(outpoint, nSequence=0) for outpoint, _, _ in self.prevouts],
[CTxOut(sum_in - fees, self.payto.to_scriptPubKey())], 0)
for n, (_, _, redeemer) in enumerate(self.prevouts):
redeemer.mutate_spend(tx, n)
unsigned_tx = CTransaction.from_tx(tx)
for n, (_, _, redeemer) in enumerate(self.prevouts):
txin = CMutableTxIn.from_txin(tx.vin[n])
txin.scriptSig = redeemer.sign_spend(unsigned_tx, n)
tx.vin[n] = CTxIn.from_txin(txin)
print(b2x(tx.serialize()))
def set_tx(self, tx):
"""Reset the model to reflect tx."""
self.beginResetModel()
self.vin = []
for i in tx.vin:
self.vin.append(CMutableTxIn.from_txin(i))
self.endResetModel()
def as_tx(self):
sum_in = sum(prevtx.nValue for _,prevtx,_ in self.prevouts)
sig_size = sum(redeemer.spendbytes for _,_,redeemer in self.prevouts)
tx_size = (4 + # version field
2 + # # of txins
len(self.prevouts) * 41 + # txins, excluding sigs
sig_size + # txins, sigs only
1 + # # of txouts
34 + # txout
4 # nLockTime field
)
feerate = int(self.proxy._call('estimatefee', 1) * COIN)
# satoshi's per KB
if feerate <= 0:
feerate = 10000
fees = int(tx_size * feerate / 1000)
tx = CMutableTransaction(
[CTxIn(outpoint, nSequence=0)
for outpoint,_,_ in self.prevouts],
[CTxOut(sum_in - fees, self.payto.to_scriptPubKey())],
0)
for n,(_,_,redeemer) in enumerate(self.prevouts):
redeemer.mutate_spend(tx, n)
unsigned_tx = CTransaction.from_tx(tx)
for n,(_,_,redeemer) in enumerate(self.prevouts):
txin = CMutableTxIn.from_txin(tx.vin[n])
txin.scriptSig = redeemer.sign_spend(unsigned_tx, n)
tx.vin[n] = CTxIn.from_txin(txin)
print(b2x(tx.serialize()))
def bump_feerate(bitcoind, tx, feerate_add, prevouts_amount=None):
"""Bump the feerate of a CTransaction.
:param bitcoind: The bitcoind RPC connection, to access the wallet.
:param tx: The CTransaction which is to be bumped.
:param feerate_add: How much to increase the feerate, in sat/vbyte.
:param prevouts_amount: The sum of the value of all the consumed outputs.
:return: (CTransaction) The modified transaction.
"""
# Work on a copy
vin = [CMutableTxIn.from_txin(txin) for txin in tx.vin]
vout = [CMutableTxOut.from_txout(txout) for txout in tx.vout]
# FIXME: Add this to python-bitcoinlib
wit = CTxWitness([
CTxInWitness.from_txinwitness(txinwit) for txinwit in tx.wit.vtxinwit
])
mut_tx = CMutableTransaction(vin,
vout,
witness=wit,
nLockTime=tx.nLockTime,
nVersion=tx.nVersion)
fees = fees_to_add(bitcoind, mut_tx, feerate_add, prevouts_amount)
if bitcoind.getbalance() * COIN > fees:
return add_input(bitcoind, mut_tx, fees)
raise Exception("Could not bump fees, no suitable utxo available!")
def add_input(self, tx_input=None, input_index=None):
"""Add an input at input_index, or append one if input_index is None."""
if tx_input is None:
tx_input = CMutableTxIn()
elif tx_input.__class__ == CTxIn:
tx_input = CMutableTxIn.from_txin(tx_input)
if input_index is None:
input_index = len(self.vin)
self.beginInsertRows(QModelIndex(), input_index, input_index)
self.vin.insert(input_index, tx_input)
self.endInsertRows()
def add_input(self, tx_input=None, input_index=None):
"""Add an input at input_index, or append one if input_index is None."""
if tx_input is None:
tx_input = CMutableTxIn()
elif tx_input.__class__ == CTxIn:
tx_input = CMutableTxIn.from_txin(tx_input)
if input_index is None:
input_index = len(self.vin)
self.beginInsertRows(QModelIndex(), input_index, input_index)
self.vin.insert(input_index, tx_input)
self.endInsertRows()
def from_tx(cls, tx):
if not issubclass(tx.__class__, Transaction):
return super(Transaction, cls).from_tx(tx)
else:
kwfields = {}
for attr, _, _, default in transaction_fields:
if attr in ['vin', 'vout']:
continue
if hasattr(tx, attr):
kwfields[attr] = getattr(tx, attr)
vin = [CMutableTxIn.from_txin(txin) for txin in tx.vin]
vout = [CMutableTxOut.from_txout(txout) for txout in tx.vout]
kwfields['vin'] = vin
kwfields['vout'] = vout
return cls(kwfields=kwfields)
def bump_feerate(bitcoind, tx, feerate_add, prevouts_amount=None):
"""Bump the feerate of a CTransaction.
:param bitcoind: The bitcoind RPC connection, to access the wallet.
:param tx: The CTransaction which is to be bumped.
:param feerate_add: How much to increase the feerate, in sat/vbyte.
:param prevouts_amount: The sum of the value of all the consumed outputs.
:return: (CTransaction) The modified transaction.
"""
# Work on a copy
vin = [CMutableTxIn.from_txin(txin) for txin in tx.vin]
vout = [CMutableTxOut.from_txout(txout) for txout in tx.vout]
wit = CTxWitness([CTxInWitness.from_txinwitness(txinwit)
for txinwit in tx.wit.vtxinwit])
mut_tx = CMutableTransaction(vin, vout, witness=wit,
nLockTime=tx.nLockTime, nVersion=tx.nVersion)
fees = fees_to_add(bitcoind, mut_tx, feerate_add, prevouts_amount)
# No smart coin selection here, this is a demo
for coin in bitcoind.listunspent():
if coin["amount"] * Decimal(COIN) > fees and coin["spendable"]:
return add_input_output(bitcoind, mut_tx, coin, fees)
raise Exception("Could not bump fees, no suitable utxo!")
