refactor: test/bench: dedup Build{Crediting,Spending}Transaction()

prototypes used in src/test/script_tests.cpp:
- CMutableTransaction BuildCreditingTransaction(const CScript& scriptPubKey, int nValue = 0);
- CMutableTransaction BuildSpendingTransaction(const CScript& scriptSig, const CScriptWitness& scriptWitness, const CTransaction& txCredit);

prototypes used in bench/verify_script.cpp:
- CMutableTransaction BuildCreditingTransaction(const CScript& scriptPubKey);
- CMutableTransaction BuildSpendingTransaction(const CScript& scriptSig, const CMutableTransaction& txCredit);

The more generic versions from the script tests are moved into a new file pair
transaction_utils.cpp/h and the calls are adapted accordingly in the
verify_script benchmark (passing the nValue of 1 explicitely for
BuildCreditingTransaction(), passing empty scriptWitness explicitely and
converting txCredit parameter to CTransaction in BuildSpendingTransaction()).

1 files changed, 39 insertions, 0 deletions

diff --git a/src/test/lib/transaction_utils.cpp b/src/test/lib/transaction_utils.cpp
new file mode 100644
index 0000000000..2619fb9006
--- /dev/null
+++ b/src/test/lib/transaction_utils.cpp
@@ -0,0 +1,39 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <test/lib/transaction_utils.h>
+
+CMutableTransaction BuildCreditingTransaction(const CScript& scriptPubKey, int nValue)
+{
+    CMutableTransaction txCredit;
+    txCredit.nVersion = 1;
+    txCredit.nLockTime = 0;
+    txCredit.vin.resize(1);
+    txCredit.vout.resize(1);
+    txCredit.vin[0].prevout.SetNull();
+    txCredit.vin[0].scriptSig = CScript() << CScriptNum(0) << CScriptNum(0);
+    txCredit.vin[0].nSequence = CTxIn::SEQUENCE_FINAL;
+    txCredit.vout[0].scriptPubKey = scriptPubKey;
+    txCredit.vout[0].nValue = nValue;
+
+    return txCredit;
+}
+
+CMutableTransaction BuildSpendingTransaction(const CScript& scriptSig, const CScriptWitness& scriptWitness, const CTransaction& txCredit)
+{
+    CMutableTransaction txSpend;
+    txSpend.nVersion = 1;
+    txSpend.nLockTime = 0;
+    txSpend.vin.resize(1);
+    txSpend.vout.resize(1);
+    txSpend.vin[0].scriptWitness = scriptWitness;
+    txSpend.vin[0].prevout.hash = txCredit.GetHash();
+    txSpend.vin[0].prevout.n = 0;
+    txSpend.vin[0].scriptSig = scriptSig;
+    txSpend.vin[0].nSequence = CTxIn::SEQUENCE_FINAL;
+    txSpend.vout[0].scriptPubKey = CScript();
+    txSpend.vout[0].nValue = txCredit.vout[0].nValue;
+
+    return txSpend;
+}