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)
def make_hard_case(self, utxos):
target = 0
utxo_pool = []
for i in range(utxos):
amount = 1 << (utxos + i)
target += amount
utxo_pool.append(utxo(amount))
utxo_pool.append(utxo(amount + (1 << (utxos - 1 - i))))
return self.estimates(utxo_pool), target
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_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_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_confirmed_strategies(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),
)
match = CoinSelector(20*CENT, 0).select(utxo_pool, "only_confirmed")
self.assertListEqual([5, 5], [c.txo.tx_ref.height for c in match])
match = CoinSelector(25*CENT, 0).select(utxo_pool, "only_confirmed")
self.assertListEqual([], [c.txo.tx_ref.height for c in match])
match = CoinSelector(20*CENT, 0).select(utxo_pool, "prefer_confirmed")
self.assertListEqual([5, 5], [c.txo.tx_ref.height for c in match])
match = CoinSelector(25*CENT, 0, '\x00').select(utxo_pool, "prefer_confirmed")
self.assertListEqual([5, 0, -2], [c.txo.tx_ref.height 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.assertEqual([1 * CENT], search(utxo_pool, 1 * CENT, 0.5 * CENT))
# Select 2 Cent
self.assertEqual([2 * CENT], search(utxo_pool, 2 * CENT, 0.5 * CENT))
# Select 5 Cent
self.assertEqual([3 * CENT, 2 * CENT],
search(utxo_pool, 5 * CENT, 0.5 * CENT))
# Select 11 Cent, not possible
self.assertEqual([], search(utxo_pool, 11 * CENT, 0.5 * CENT))
# Select 10 Cent
utxo_pool += self.estimates(utxo(5 * CENT))
self.assertEqual([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.assertEqual([4 * CENT, 3 * CENT, 2 * CENT, 1 * CENT],
search(utxo_pool, 10 * CENT, 5000))
# Select 0.25 Cent, not possible
self.assertEqual(search(utxo_pool, 0.25 * CENT, 0.5 * CENT), [])
# Iteration exhaustion test
utxo_pool, target = self.make_hard_case(17)
selector = CoinSelector(utxo_pool, target, 0)
self.assertEqual(selector.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.assertEqual([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.assertEqual(search(utxo_pool, 1 * CENT, 2 * CENT), [])