bitcoin/test/functional/test_framework/wallet.py

80 lines
3.2 KiB
Python

#!/usr/bin/env python3
# Copyright (c) 2020 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""A limited-functionality wallet, which may replace a real wallet in tests"""
from decimal import Decimal
from test_framework.address import ADDRESS_BCRT1_P2WSH_OP_TRUE
from test_framework.messages import (
COIN,
COutPoint,
CTransaction,
CTxIn,
CTxInWitness,
CTxOut,
)
from test_framework.script import (
CScript,
OP_TRUE,
)
from test_framework.util import (
assert_equal,
hex_str_to_bytes,
satoshi_round,
)
class MiniWallet:
def __init__(self, test_node):
self._test_node = test_node
self._utxos = []
self._address = ADDRESS_BCRT1_P2WSH_OP_TRUE
self._scriptPubKey = hex_str_to_bytes(self._test_node.validateaddress(self._address)['scriptPubKey'])
def generate(self, num_blocks):
"""Generate blocks with coinbase outputs to the internal address, and append the outputs to the internal list"""
blocks = self._test_node.generatetoaddress(num_blocks, self._address)
for b in blocks:
cb_tx = self._test_node.getblock(blockhash=b, verbosity=2)['tx'][0]
self._utxos.append({'txid': cb_tx['txid'], 'vout': 0, 'value': cb_tx['vout'][0]['value']})
return blocks
def get_utxo(self, *, txid=''):
"""
Returns a utxo and marks it as spent (pops it from the internal list)
Args:
txid (string), optional: get the first utxo we find from a specific transaction
Note: Can be used to get the change output immediately after a send_self_transfer
"""
index = -1 # by default the last utxo
if txid:
utxo = next(filter(lambda utxo: txid == utxo['txid'], self._utxos))
index = self._utxos.index(utxo)
return self._utxos.pop(index)
def send_self_transfer(self, *, fee_rate=Decimal("0.003"), from_node, utxo_to_spend=None):
"""Create and send a tx with the specified fee_rate. Fee may be exact or at most one satoshi higher than needed."""
self._utxos = sorted(self._utxos, key=lambda k: k['value'])
utxo_to_spend = utxo_to_spend or self._utxos.pop() # Pick the largest utxo (if none provided) and hope it covers the fee
vsize = Decimal(96)
send_value = satoshi_round(utxo_to_spend['value'] - fee_rate * (vsize / 1000))
fee = utxo_to_spend['value'] - send_value
assert send_value > 0
tx = CTransaction()
tx.vin = [CTxIn(COutPoint(int(utxo_to_spend['txid'], 16), utxo_to_spend['vout']))]
tx.vout = [CTxOut(int(send_value * COIN), self._scriptPubKey)]
tx.wit.vtxinwit = [CTxInWitness()]
tx.wit.vtxinwit[0].scriptWitness.stack = [CScript([OP_TRUE])]
tx_hex = tx.serialize().hex()
txid = from_node.sendrawtransaction(tx_hex)
self._utxos.append({'txid': txid, 'vout': 0, 'value': send_value})
tx_info = from_node.getmempoolentry(txid)
assert_equal(tx_info['vsize'], vsize)
assert_equal(tx_info['fee'], fee)
return {'txid': txid, 'wtxid': tx_info['wtxid'], 'hex': tx_hex}