1 files changed, 21 insertions, 71 deletions

diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index b043d1a70d..1ee23f7574 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -476,39 +476,6 @@ def find_output(node, txid, amount, *, blockhash=None):
     raise RuntimeError("find_output txid %s : %s not found" % (txid, str(amount)))
 
 
-# Helper to create at least "count" utxos
-# Pass in a fee that is sufficient for relay and mining new transactions.
-def create_confirmed_utxos(test_framework, fee, node, count, **kwargs):
-    to_generate = int(0.5 * count) + 101
-    while to_generate > 0:
-        test_framework.generate(node, min(25, to_generate), **kwargs)
-        to_generate -= 25
-    utxos = node.listunspent()
-    iterations = count - len(utxos)
-    addr1 = node.getnewaddress()
-    addr2 = node.getnewaddress()
-    if iterations <= 0:
-        return utxos
-    for _ in range(iterations):
-        t = utxos.pop()
-        inputs = []
-        inputs.append({"txid": t["txid"], "vout": t["vout"]})
-        outputs = {}
-        send_value = t['amount'] - fee
-        outputs[addr1] = satoshi_round(send_value / 2)
-        outputs[addr2] = satoshi_round(send_value / 2)
-        raw_tx = node.createrawtransaction(inputs, outputs)
-        signed_tx = node.signrawtransactionwithwallet(raw_tx)["hex"]
-        node.sendrawtransaction(signed_tx)
-
-    while (node.getmempoolinfo()['size'] > 0):
-        test_framework.generate(node, 1, **kwargs)
-
-    utxos = node.listunspent()
-    assert len(utxos) >= count
-    return utxos
-
-
 def chain_transaction(node, parent_txids, vouts, value, fee, num_outputs):
     """Build and send a transaction that spends the given inputs (specified
     by lists of parent_txid:vout each), with the desired total value and fee,
@@ -532,45 +499,33 @@ def chain_transaction(node, parent_txids, vouts, value, fee, num_outputs):
 
 
 # Create large OP_RETURN txouts that can be appended to a transaction
-# to make it large (helper for constructing large transactions).
+# to make it large (helper for constructing large transactions). The
+# total serialized size of the txouts is about 66k vbytes.
 def gen_return_txouts():
-    # Some pre-processing to create a bunch of OP_RETURN txouts to insert into transactions we create
-    # So we have big transactions (and therefore can't fit very many into each block)
-    # create one script_pubkey
-    script_pubkey = "6a4d0200"  # OP_RETURN OP_PUSH2 512 bytes
-    for _ in range(512):
-        script_pubkey = script_pubkey + "01"
-    # concatenate 128 txouts of above script_pubkey which we'll insert before the txout for change
-    txouts = []
     from .messages import CTxOut
-    txout = CTxOut()
-    txout.nValue = 0
-    txout.scriptPubKey = bytes.fromhex(script_pubkey)
-    for _ in range(128):
-        txouts.append(txout)
+    from .script import CScript, OP_RETURN
+    txouts = [CTxOut(nValue=0, scriptPubKey=CScript([OP_RETURN, b'\x01'*67437]))]
+    assert_equal(sum([len(txout.serialize()) for txout in txouts]), 67456)
     return txouts
 
 
 # Create a spend of each passed-in utxo, splicing in "txouts" to each raw
 # transaction to make it large.  See gen_return_txouts() above.
-def create_lots_of_big_transactions(node, txouts, utxos, num, fee):
-    addr = node.getnewaddress()
+def create_lots_of_big_transactions(mini_wallet, node, fee, tx_batch_size, txouts, utxos=None):
+    from .messages import COIN
+    fee_sats = int(fee * COIN)
     txids = []
-    from .messages import tx_from_hex
-    for _ in range(num):
-        t = utxos.pop()
-        inputs = [{"txid": t["txid"], "vout": t["vout"]}]
-        outputs = {}
-        change = t['amount'] - fee
-        outputs[addr] = satoshi_round(change)
-        rawtx = node.createrawtransaction(inputs, outputs)
-        tx = tx_from_hex(rawtx)
-        for txout in txouts:
-            tx.vout.append(txout)
-        newtx = tx.serialize().hex()
-        signresult = node.signrawtransactionwithwallet(newtx, None, "NONE")
-        txid = node.sendrawtransaction(signresult["hex"], 0)
-        txids.append(txid)
+    use_internal_utxos = utxos is None
+    for _ in range(tx_batch_size):
+        tx = mini_wallet.create_self_transfer(
+            utxo_to_spend=None if use_internal_utxos else utxos.pop(),
+            fee_rate=0,
+        )["tx"]
+        tx.vout[0].nValue -= fee_sats
+        tx.vout.extend(txouts)
+        res = node.testmempoolaccept([tx.serialize().hex()])[0]
+        assert_equal(res['fees']['base'], fee)
+        txids.append(node.sendrawtransaction(tx.serialize().hex()))
     return txids
 
 
@@ -578,13 +533,8 @@ def mine_large_block(test_framework, mini_wallet, node):
     # generate a 66k transaction,
     # and 14 of them is close to the 1MB block limit
     txouts = gen_return_txouts()
-    from .messages import COIN
-    fee = 100 * int(node.getnetworkinfo()["relayfee"] * COIN)
-    for _ in range(14):
-        tx = mini_wallet.create_self_transfer(from_node=node, fee_rate=0, mempool_valid=False)['tx']
-        tx.vout[0].nValue -= fee
-        tx.vout.extend(txouts)
-        mini_wallet.sendrawtransaction(from_node=node, tx_hex=tx.serialize().hex())
+    fee = 100 * node.getnetworkinfo()["relayfee"]
+    create_lots_of_big_transactions(mini_wallet, node, fee, 14, txouts)
     test_framework.generate(node, 1)