#!/usr/bin/env python3
# Copyright (c) 2021-2022 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Test logic for limiting mempool and package ancestors/descendants."""
from test_framework.blocktools import COINBASE_MATURITY
from test_framework.messages import (
WITNESS_SCALE_FACTOR,
)
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import (
assert_equal,
)
from test_framework.wallet import MiniWallet
# Decorator to
# 1) check that mempool is empty at the start of a subtest
# 2) run the subtest, which may submit some transaction(s) to the mempool and
# create a list of hex transactions
# 3) testmempoolaccept the package hex and check that it fails with the error
# "package-mempool-limits" for each tx
# 4) after mining a block, clearing the pre-submitted transactions from mempool,
# check that submitting the created package succeeds
def check_package_limits(func):
def func_wrapper(self, *args, **kwargs):
node = self.nodes[0]
assert_equal(0, node.getmempoolinfo()["size"])
package_hex = func(self, *args, **kwargs)
testres_error_expected = node.testmempoolaccept(rawtxs=package_hex)
assert_equal(len(testres_error_expected), len(package_hex))
for txres in testres_error_expected:
assert "package-mempool-limits" in txres["package-error"]
# Clear mempool and check that the package passes now
self.generate(node, 1)
assert all([res["allowed"] for res in node.testmempoolaccept(rawtxs=package_hex)])
return func_wrapper
class MempoolPackageLimitsTest(BitcoinTestFramework):
def set_test_params(self):
self.num_nodes = 1
self.setup_clean_chain = True
def run_test(self):
self.wallet = MiniWallet(self.nodes[0])
# Add enough mature utxos to the wallet so that all txs spend confirmed coins.
self.generate(self.wallet, COINBASE_MATURITY + 35)
self.test_chain_limits()
self.test_desc_count_limits()
self.test_desc_count_limits_2()
self.test_anc_count_limits()
self.test_anc_count_limits_2()
self.test_anc_count_limits_bushy()
# The node will accept (nonstandard) extra large OP_RETURN outputs
self.restart_node(0, extra_args=["-datacarriersize=100000"])
self.test_anc_size_limits()
self.test_desc_size_limits()
@check_package_limits
def test_chain_limits_helper(self, mempool_count, package_count):
node = self.nodes[0]
chain_hex = []
chaintip_utxo = self.wallet.send_self_transfer_chain(from_node=node, chain_length=mempool_count)[-1]["new_utxo"]
# in-package transactions
for _ in range(package_count):
tx = self.wallet.create_self_transfer(utxo_to_spend=chaintip_utxo)
chaintip_utxo = tx["new_utxo"]
chain_hex.append(tx["hex"])
return chain_hex
def test_chain_limits(self):
"""Create chains from mempool and package transactions that are longer than 25,
but only if both in-mempool and in-package transactions are considered together.
This checks that both mempool and in-package transactions are taken into account when
calculating ancestors/descendant limits.
"""
self.log.info("Check that in-package ancestors count for mempool ancestor limits")
# 24 transactions in the mempool and 2 in the package. The parent in the package has
# 24 in-mempool ancestors and 1 in-package descendant. The child has 0 direct parents
# in the mempool, but 25 in-mempool and in-package ancestors in total.
self.test_chain_limits_helper(24, 2)
# 2 transactions in the mempool and 24 in the package.
self.test_chain_limits_helper(2, 24)
# 13 transactions in the mempool and 13 in the package.
self.test_chain_limits_helper(13, 13)
@check_package_limits
def test_desc_count_limits(self):
"""Create an 'A' shaped package with 24 transactions in the mempool and 2 in the package:
M1
^ ^
M2a M2b
. .
. .
. .
M12a ^
^ M13b
^ ^
Pa Pb
The top ancestor in the package exceeds descendant limits but only if the in-mempool and in-package
descendants are all considered together (24 including in-mempool descendants and 26 including both
package transactions).
"""
node = self.nodes[0]
self.log.info("Check that in-mempool and in-package descendants are calculated properly in packages")
# Top parent in mempool, M1
m1_utxos = self.wallet.send_self_transfer_multi(from_node=node, num_outputs=2)['new_utxos']
package_hex = []
# Chain A (M2a... M12a)
chain_a_tip_utxo = self.wallet.send_self_transfer_chain(from_node=node, chain_length=11, utxo_to_spend=m1_utxos[0])[-1]["new_utxo"]
# Pa
pa_hex = self.wallet.create_self_transfer(utxo_to_spend=chain_a_tip_utxo)["hex"]
package_hex.append(pa_hex)
# Chain B (M2b... M13b)
chain_b_tip_utxo = self.wallet.send_self_transfer_chain(from_node=node, chain_length=12, utxo_to_spend=m1_utxos[1])[-1]["new_utxo"]
# Pb
pb_hex = self.wallet.create_self_transfer(utxo_to_spend=chain_b_tip_utxo)["hex"]
package_hex.append(pb_hex)
assert_equal(24, node.getmempoolinfo()["size"])
assert_equal(2, len(package_hex))
return package_hex
@check_package_limits
def test_desc_count_limits_2(self):
"""Create a Package with 24 transaction in mempool and 2 transaction in package:
M1
^ ^
M2 ^
. ^
. ^
. ^
M24 ^
^
P1
^
P2
P1 has M1 as a mempool ancestor, P2 has no in-mempool ancestors, but when
combined P2 has M1 as an ancestor and M1 exceeds descendant_limits(23 in-mempool
descendants + 2 in-package descendants, a total of 26 including itself).
"""
node = self.nodes[0]
package_hex = []
# M1
m1_utxos = self.wallet.send_self_transfer_multi(from_node=node, num_outputs=2)['new_utxos']
# Chain M2...M24
self.wallet.send_self_transfer_chain(from_node=node, chain_length=23, utxo_to_spend=m1_utxos[0])[-1]["new_utxo"]
# P1
p1_tx = self.wallet.create_self_transfer(utxo_to_spend=m1_utxos[1])
package_hex.append(p1_tx["hex"])
# P2
p2_tx = self.wallet.create_self_transfer(utxo_to_spend=p1_tx["new_utxo"])
package_hex.append(p2_tx["hex"])
assert_equal(24, node.getmempoolinfo()["size"])
assert_equal(2, len(package_hex))
return package_hex
@check_package_limits
def test_anc_count_limits(self):
"""Create a 'V' shaped chain with 24 transactions in the mempool and 3 in the package:
M1a M1b
^ ^
M2a M2b
. .
. .
. .
M12a M12b
^ ^
Pa Pb
^ ^
Pc
The lowest descendant, Pc, exceeds ancestor limits, but only if the in-mempool
and in-package ancestors are all considered together.
"""
node = self.nodes[0]
package_hex = []
pc_parent_utxos = []
self.log.info("Check that in-mempool and in-package ancestors are calculated properly in packages")
# Two chains of 13 transactions each
for _ in range(2):
chain_tip_utxo = self.wallet.send_self_transfer_chain(from_node=node, chain_length=12)[-1]["new_utxo"]
# Save the 13th transaction for the package
tx = self.wallet.create_self_transfer(utxo_to_spend=chain_tip_utxo)
package_hex.append(tx["hex"])
pc_parent_utxos.append(tx["new_utxo"])
# Child Pc
pc_hex = self.wallet.create_self_transfer_multi(utxos_to_spend=pc_parent_utxos)["hex"]
package_hex.append(pc_hex)
assert_equal(24, node.getmempoolinfo()["size"])
assert_equal(3, len(package_hex))
return package_hex
@check_package_limits
def test_anc_count_limits_2(self):
"""Create a 'Y' shaped chain with 24 transactions in the mempool and 2 in the package:
M1a M1b
^ ^
M2a M2b
. .
. .
. .
M12a M12b
^ ^
Pc
^
Pd
The lowest descendant, Pd, exceeds ancestor limits, but only if the in-mempool
and in-package ancestors are all considered together.
"""
node = self.nodes[0]
pc_parent_utxos = []
self.log.info("Check that in-mempool and in-package ancestors are calculated properly in packages")
# Two chains of 12 transactions each
for _ in range(2):
chaintip_utxo = self.wallet.send_self_transfer_chain(from_node=node, chain_length=12)[-1]["new_utxo"]
# last 2 transactions will be the parents of Pc
pc_parent_utxos.append(chaintip_utxo)
# Child Pc
pc_tx = self.wallet.create_self_transfer_multi(utxos_to_spend=pc_parent_utxos)
# Child Pd
pd_tx = self.wallet.create_self_transfer(utxo_to_spend=pc_tx["new_utxos"][0])
assert_equal(24, node.getmempoolinfo()["size"])
return [pc_tx["hex"], pd_tx["hex"]]
@check_package_limits
def test_anc_count_limits_bushy(self):
"""Create a tree with 20 transactions in the mempool and 6 in the package:
M1...M4 M5...M8 M9...M12 M13...M16 M17...M20
^ ^ ^ ^ ^ (each with 4 parents)
P0 P1 P2 P3 P4
^ ^ ^ ^ ^ (5 parents)
PC
Where M(4i+1)...M+(4i+4) are the parents of Pi and P0, P1, P2, P3, and P4 are the parents of PC.
P0... P4 individually only have 4 parents each, and PC has no in-mempool parents. But
combined, PC has 25 in-mempool and in-package parents.
"""
node = self.nodes[0]
package_hex = []
pc_parent_utxos = []
for _ in range(5): # Make package transactions P0 ... P4
pc_grandparent_utxos = []
for _ in range(4): # Make mempool transactions M(4i+1)...M(4i+4)
pc_grandparent_utxos.append(self.wallet.send_self_transfer(from_node=node)["new_utxo"])
# Package transaction Pi
pi_tx = self.wallet.create_self_transfer_multi(utxos_to_spend=pc_grandparent_utxos)
package_hex.append(pi_tx["hex"])
pc_parent_utxos.append(pi_tx["new_utxos"][0])
# Package transaction PC
pc_hex = self.wallet.create_self_transfer_multi(utxos_to_spend=pc_parent_utxos)["hex"]
package_hex.append(pc_hex)
assert_equal(20, node.getmempoolinfo()["size"])
assert_equal(6, len(package_hex))
return package_hex
@check_package_limits
def test_anc_size_limits(self):
"""Test Case with 2 independent transactions in the mempool and a parent + child in the
package, where the package parent is the child of both mempool transactions (30KvB each):
A B
^ ^
C
^
D
The lowest descendant, D, exceeds ancestor size limits, but only if the in-mempool
and in-package ancestors are all considered together.
"""
node = self.nodes[0]
parent_utxos = []
target_vsize = 30_000
high_fee = 10 * target_vsize # 10 sats/vB
target_weight = target_vsize * WITNESS_SCALE_FACTOR
self.log.info("Check that in-mempool and in-package ancestor size limits are calculated properly in packages")
# Mempool transactions A and B
for _ in range(2):
bulked_tx = self.wallet.create_self_transfer(target_weight=target_weight)
self.wallet.sendrawtransaction(from_node=node, tx_hex=bulked_tx["hex"])
parent_utxos.append(bulked_tx["new_utxo"])
# Package transaction C
pc_tx = self.wallet.create_self_transfer_multi(utxos_to_spend=parent_utxos, fee_per_output=high_fee, target_weight=target_weight)
# Package transaction D
pd_tx = self.wallet.create_self_transfer(utxo_to_spend=pc_tx["new_utxos"][0], target_weight=target_weight)
assert_equal(2, node.getmempoolinfo()["size"])
return [pc_tx["hex"], pd_tx["hex"]]
@check_package_limits
def test_desc_size_limits(self):
"""Create 3 mempool transactions and 2 package transactions (21KvB each):
Ma
^ ^
Mb Mc
^ ^
Pd Pe
The top ancestor in the package exceeds descendant size limits but only if the in-mempool
and in-package descendants are all considered together.
"""
node = self.nodes[0]
target_vsize = 21_000
high_fee = 10 * target_vsize # 10 sats/vB
target_weight = target_vsize * WITNESS_SCALE_FACTOR
self.log.info("Check that in-mempool and in-package descendant sizes are calculated properly in packages")
# Top parent in mempool, Ma
ma_tx = self.wallet.create_self_transfer_multi(num_outputs=2, fee_per_output=high_fee // 2, target_weight=target_weight)
self.wallet.sendrawtransaction(from_node=node, tx_hex=ma_tx["hex"])
package_hex = []
for j in range(2): # Two legs (left and right)
# Mempool transaction (Mb and Mc)
mempool_tx = self.wallet.create_self_transfer(utxo_to_spend=ma_tx["new_utxos"][j], target_weight=target_weight)
self.wallet.sendrawtransaction(from_node=node, tx_hex=mempool_tx["hex"])
# Package transaction (Pd and Pe)
package_tx = self.wallet.create_self_transfer(utxo_to_spend=mempool_tx["new_utxo"], target_weight=target_weight)
package_hex.append(package_tx["hex"])
assert_equal(3, node.getmempoolinfo()["size"])
assert_equal(2, len(package_hex))
return package_hex
if __name__ == "__main__":
MempoolPackageLimitsTest().main()