test: refactor: move fill_mempool to new module mempool_util

This is needed to avoid circular dependencies in later commits.
Can be reviewed via `--color-moved=dimmed-zebra`.

test/functional/mempool_limit.py

@@ -6,14 +6,16 @@
 
 from decimal import Decimal
 
+from test_framework.mempool_util import (
+    fill_mempool,
+)
 from test_framework.p2p import P2PTxInvStore
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
     assert_fee_amount,
     assert_greater_than,
     assert_raises_rpc_error,
-    fill_mempool,
 )
 from test_framework.wallet import (
     COIN,

test/functional/p2p_1p1c_network.py

@@ -12,6 +12,9 @@
 from decimal import Decimal
 from math import ceil
 
+from test_framework.mempool_util import (
+    fill_mempool,
+)
 from test_framework.messages import (
     msg_tx,
 )
@@ -22,7 +25,6 @@
 from test_framework.util import (
     assert_equal,
     assert_greater_than,
-    fill_mempool,
 )
 from test_framework.wallet import (
     MiniWallet,

test/functional/p2p_opportunistic_1p1c.py

@@ -8,6 +8,9 @@
 
 from decimal import Decimal
 import time
+from test_framework.mempool_util import (
+    fill_mempool,
+)
 from test_framework.messages import (
     CInv,
     CTxInWitness,
@@ -24,7 +27,6 @@
 from test_framework.util import (
     assert_equal,
     assert_greater_than,
-    fill_mempool,
 )
 from test_framework.wallet import (
     MiniWallet,

test/functional/p2p_tx_download.py

@@ -8,6 +8,9 @@
 from decimal import Decimal
 import time
 
+from test_framework.mempool_util import (
+    fill_mempool,
+)
 from test_framework.messages import (
     CInv,
     MSG_TX,
@@ -24,7 +27,6 @@
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
-    fill_mempool,
 )
 from test_framework.wallet import MiniWallet
 

test/functional/rpc_packages.py

@@ -8,6 +8,9 @@
 import random
 
 from test_framework.blocktools import COINBASE_MATURITY
+from test_framework.mempool_util import (
+    fill_mempool,
+)
 from test_framework.messages import (
     MAX_BIP125_RBF_SEQUENCE,
     tx_from_hex,
@@ -18,7 +21,6 @@
     assert_equal,
     assert_fee_amount,
     assert_raises_rpc_error,
-    fill_mempool,
 )
 from test_framework.wallet import (
     DEFAULT_FEE,

test/functional/test_framework/mempool_util.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+# Copyright (c) 2024 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Helpful routines for mempool testing."""
+from decimal import Decimal
+
+from .util import (
+    assert_equal,
+    assert_greater_than,
+    create_lots_of_big_transactions,
+    gen_return_txouts,
+)
+
+
+def fill_mempool(test_framework, node, miniwallet):
+    """Fill mempool until eviction.
+
+    Allows for simpler testing of scenarios with floating mempoolminfee > minrelay
+    Requires -datacarriersize=100000 and
+   -maxmempool=5.
+    It will not ensure mempools become synced as it
+    is based on a single node and assumes -minrelaytxfee
+    is 1 sat/vbyte.
+    To avoid unintentional tx dependencies, it is recommended to use separate miniwallets for
+    mempool filling vs transactions in tests.
+    """
+    test_framework.log.info("Fill the mempool until eviction is triggered and the mempoolminfee rises")
+    txouts = gen_return_txouts()
+    relayfee = node.getnetworkinfo()['relayfee']
+
+    assert_equal(relayfee, Decimal('0.00001000'))
+
+    tx_batch_size = 1
+    num_of_batches = 75
+    # Generate UTXOs to flood the mempool
+    # 1 to create a tx initially that will be evicted from the mempool later
+    # 75 transactions each with a fee rate higher than the previous one
+    test_framework.generate(miniwallet, 1 + (num_of_batches * tx_batch_size))
+
+    # Mine COINBASE_MATURITY - 1 blocks so that the UTXOs are allowed to be spent
+    test_framework.generate(node, 100 - 1)
+
+    # Get all UTXOs up front to ensure none of the transactions spend from each other, as that may
+    # change their effective feerate and thus the order in which they are selected for eviction.
+    confirmed_utxos = [miniwallet.get_utxo(confirmed_only=True) for _ in range(num_of_batches * tx_batch_size + 1)]
+    assert_equal(len(confirmed_utxos), num_of_batches * tx_batch_size + 1)
+
+    test_framework.log.debug("Create a mempool tx that will be evicted")
+    tx_to_be_evicted_id = miniwallet.send_self_transfer(from_node=node, utxo_to_spend=confirmed_utxos[0], fee_rate=relayfee)["txid"]
+    del confirmed_utxos[0]
+
+    # Increase the tx fee rate to give the subsequent transactions a higher priority in the mempool
+    # The tx has an approx. vsize of 65k, i.e. multiplying the previous fee rate (in sats/kvB)
+    # by 130 should result in a fee that corresponds to 2x of that fee rate
+    base_fee = relayfee * 130
+
+    test_framework.log.debug("Fill up the mempool with txs with higher fee rate")
+    with node.assert_debug_log(["rolling minimum fee bumped"]):
+        for batch_of_txid in range(num_of_batches):
+            fee = (batch_of_txid + 1) * base_fee
+            utxos = confirmed_utxos[:tx_batch_size]
+            create_lots_of_big_transactions(miniwallet, node, fee, tx_batch_size, txouts, utxos)
+            del confirmed_utxos[:tx_batch_size]
+
+    test_framework.log.debug("The tx should be evicted by now")
+    # The number of transactions created should be greater than the ones present in the mempool
+    assert_greater_than(tx_batch_size * num_of_batches, len(node.getrawmempool()))
+    # Initial tx created should not be present in the mempool anymore as it had a lower fee rate
+    assert tx_to_be_evicted_id not in node.getrawmempool()
+
+    test_framework.log.debug("Check that mempoolminfee is larger than minrelaytxfee")
+    assert_equal(node.getmempoolinfo()['minrelaytxfee'], Decimal('0.00001000'))
+    assert_greater_than(node.getmempoolinfo()['mempoolminfee'], Decimal('0.00001000'))

test/functional/test_framework/util.py

@@ -496,65 +496,6 @@ def check_node_connections(*, node, num_in, num_out):
     assert_equal(info["connections_in"], num_in)
     assert_equal(info["connections_out"], num_out)
 
-def fill_mempool(test_framework, node, miniwallet):
-    """Fill mempool until eviction.
-
-    Allows for simpler testing of scenarios with floating mempoolminfee > minrelay
-    Requires -datacarriersize=100000 and
-   -maxmempool=5.
-    It will not ensure mempools become synced as it
-    is based on a single node and assumes -minrelaytxfee
-    is 1 sat/vbyte.
-    To avoid unintentional tx dependencies, it is recommended to use separate miniwallets for
-    mempool filling vs transactions in tests.
-    """
-    test_framework.log.info("Fill the mempool until eviction is triggered and the mempoolminfee rises")
-    txouts = gen_return_txouts()
-    relayfee = node.getnetworkinfo()['relayfee']
-
-    assert_equal(relayfee, Decimal('0.00001000'))
-
-    tx_batch_size = 1
-    num_of_batches = 75
-    # Generate UTXOs to flood the mempool
-    # 1 to create a tx initially that will be evicted from the mempool later
-    # 75 transactions each with a fee rate higher than the previous one
-    test_framework.generate(miniwallet, 1 + (num_of_batches * tx_batch_size))
-
-    # Mine COINBASE_MATURITY - 1 blocks so that the UTXOs are allowed to be spent
-    test_framework.generate(node, 100 - 1)
-
-    # Get all UTXOs up front to ensure none of the transactions spend from each other, as that may
-    # change their effective feerate and thus the order in which they are selected for eviction.
-    confirmed_utxos = [miniwallet.get_utxo(confirmed_only=True) for _ in range(num_of_batches * tx_batch_size + 1)]
-    assert_equal(len(confirmed_utxos), num_of_batches * tx_batch_size + 1)
-
-    test_framework.log.debug("Create a mempool tx that will be evicted")
-    tx_to_be_evicted_id = miniwallet.send_self_transfer(from_node=node, utxo_to_spend=confirmed_utxos[0], fee_rate=relayfee)["txid"]
-    del confirmed_utxos[0]
-
-    # Increase the tx fee rate to give the subsequent transactions a higher priority in the mempool
-    # The tx has an approx. vsize of 65k, i.e. multiplying the previous fee rate (in sats/kvB)
-    # by 130 should result in a fee that corresponds to 2x of that fee rate
-    base_fee = relayfee * 130
-
-    test_framework.log.debug("Fill up the mempool with txs with higher fee rate")
-    with node.assert_debug_log(["rolling minimum fee bumped"]):
-        for batch_of_txid in range(num_of_batches):
-            fee = (batch_of_txid + 1) * base_fee
-            utxos = confirmed_utxos[:tx_batch_size]
-            create_lots_of_big_transactions(miniwallet, node, fee, tx_batch_size, txouts, utxos)
-            del confirmed_utxos[:tx_batch_size]
-
-    test_framework.log.debug("The tx should be evicted by now")
-    # The number of transactions created should be greater than the ones present in the mempool
-    assert_greater_than(tx_batch_size * num_of_batches, len(node.getrawmempool()))
-    # Initial tx created should not be present in the mempool anymore as it had a lower fee rate
-    assert tx_to_be_evicted_id not in node.getrawmempool()
-
-    test_framework.log.debug("Check that mempoolminfee is larger than minrelaytxfee")
-    assert_equal(node.getmempoolinfo()['minrelaytxfee'], Decimal('0.00001000'))
-    assert_greater_than(node.getmempoolinfo()['mempoolminfee'], Decimal('0.00001000'))
 
 # Transaction/Block functions
 #############################