def test_skip_binary_search_if_total_not_enough(self):
fee = utxo(CENT).get_estimator(self.ledger).fee
big_pool = self.estimates(utxo(CENT + fee) for _ in range(100))
selector = CoinSelector(big_pool, 101 * CENT, 0)
self.assertEqual(selector.select(), [])
self.assertEqual(selector.tries, 0) # Never tried.
# check happy path
selector = CoinSelector(big_pool, 100 * CENT, 0)
self.assertEqual(len(selector.select()), 100)
self.assertEqual(selector.tries, 201)
def test_random_draw(self):
utxo_pool = self.estimates(utxo(2 * CENT), utxo(3 * CENT),
utxo(4 * CENT))
selector = CoinSelector(utxo_pool, CENT, 0, '\x00')
match = selector.select()
self.assertEqual([2 * CENT], [c.txo.amount for c in match])
self.assertFalse(selector.exact_match)
def test_exact_match(self):
fee = utxo(CENT).get_estimator(self.ledger).fee
utxo_pool = self.estimates(utxo(CENT + fee), utxo(CENT),
utxo(CENT - fee))
selector = CoinSelector(utxo_pool, CENT, 0)
match = selector.select()
self.assertEqual([CENT + fee], [c.txo.amount for c in match])
self.assertTrue(selector.exact_match)
async def get_spendable_utxos(self, amount: int, funding_accounts):
async with self._utxo_reservation_lock:
txos = await self.get_effective_amount_estimators(funding_accounts)
fee = self.transaction_class.output_class.pay_pubkey_hash(COIN, NULL_HASH32).get_fee(self)
selector = CoinSelector(amount, fee)
spendables = selector.select(txos, self.coin_selection_strategy)
if spendables:
await self.reserve_outputs(s.txo for s in spendables)
return spendables
def test_prefer_confirmed_strategy(self):
utxo_pool = self.estimates(
utxo(11 * CENT, height=5),
utxo(11 * CENT, height=0),
utxo(11 * CENT, height=-2),
utxo(11 * CENT, height=5),
)
selector = CoinSelector(utxo_pool, 20 * CENT, 0)
match = selector.select("prefer_confirmed")
self.assertEqual([5, 5], [c.txo.tx_ref.height for c in match])
def test_pick(self):
utxo_pool = self.estimates(
utxo(1 * CENT),
utxo(1 * CENT),
utxo(3 * CENT),
utxo(5 * CENT),
utxo(10 * CENT),
)
selector = CoinSelector(utxo_pool, 3 * CENT, 0)
match = selector.select()
self.assertEqual([5 * CENT], [c.txo.amount for c in match])
def test_branch_and_bound_coin_selection(self):
self.ledger.fee_per_byte = 0
utxo_pool = self.estimates(
utxo(1 * CENT),
utxo(2 * CENT),
utxo(3 * CENT),
utxo(4 * CENT)
)
# Select 1 Cent
self.assertListEqual([1 * CENT], search(utxo_pool, 1 * CENT, 0.5 * CENT))
# Select 2 Cent
self.assertListEqual([2 * CENT], search(utxo_pool, 2 * CENT, 0.5 * CENT))
# Select 5 Cent
self.assertListEqual([3 * CENT, 2 * CENT], search(utxo_pool, 5 * CENT, 0.5 * CENT))
# Select 11 Cent, not possible
self.assertListEqual([], search(utxo_pool, 11 * CENT, 0.5 * CENT))
# Select 10 Cent
utxo_pool += self.estimates(utxo(5 * CENT))
self.assertListEqual(
[4 * CENT, 3 * CENT, 2 * CENT, 1 * CENT],
search(utxo_pool, 10 * CENT, 0.5 * CENT)
)
# Negative effective value
# Select 10 Cent but have 1 Cent not be possible because too small
# TODO: bitcoin has [5, 3, 2]
self.assertListEqual(
[4 * CENT, 3 * CENT, 2 * CENT, 1 * CENT],
search(utxo_pool, 10 * CENT, 5000)
)
# Select 0.25 Cent, not possible
self.assertListEqual(search(utxo_pool, 0.25 * CENT, 0.5 * CENT), [])
# Iteration exhaustion test
utxo_pool, target = self.make_hard_case(17)
selector = CoinSelector(target, 0)
self.assertListEqual(selector.select(utxo_pool, 'branch_and_bound'), [])
self.assertEqual(selector.tries, MAXIMUM_TRIES) # Should exhaust
utxo_pool, target = self.make_hard_case(14)
self.assertIsNotNone(search(utxo_pool, target, 0)) # Should not exhaust
# Test same value early bailout optimization
utxo_pool = self.estimates([
utxo(7 * CENT),
utxo(7 * CENT),
utxo(7 * CENT),
utxo(7 * CENT),
utxo(2 * CENT)
] + [utxo(5 * CENT)]*50000)
self.assertListEqual(
[7 * CENT, 7 * CENT, 7 * CENT, 7 * CENT, 2 * CENT],
search(utxo_pool, 30 * CENT, 5000)
)
# Select 1 Cent with pool of only greater than 5 Cent
utxo_pool = self.estimates(utxo(i * CENT) for i in range(5, 21))
for _ in range(100):
self.assertListEqual(search(utxo_pool, 1 * CENT, 2 * CENT), [])