Merge #13309: Directly operate with CMutableTransaction in SignSignature

6b8b63af1461dc11ffd813401e2c36fa44656715 Generic TransactionSignatureCreator works with both CTransaction and CMutableTransaction (Martin Ankerl)

Pull request description:

  Refactored `TransactionSignatureCreator` into a templated `GenericTransactionSignatureCreator` that works with both `CMutableTransaction` and `CTransaction`.

  The advantage is that now in `SignSignature`, the `MutableTransactionSignatureCreator` can now operate directly with the `CMutableTransaction` without the need to copy the data into a `CTransaction`.

  Running all unit tests brings a very noticable speedup on my machine:

      48.4 sec before this change
      36.4 sec with this change
      --------
      12.0 seconds saved

  running only `--run_test=transaction_tests/test_big_witness_transaction`:

      16.7 sec before this change
       5.9 sec with this change
      --------
      10.8 seconds saved

  This relates to my first attempt with the const_cast hack #13202, and to the slow unit test issue #10026.

  Also see #13050 which modifies the tests but not the production code (like this PR) to get a speedup.

Tree-SHA512: 2cff0e9699f484f26120a40e431a24c8bc8f9e780fd89cb0ecf20c5be3eab6c43f9c359cde244abd9f3620d06c7c354e3b9dd3da41fa2ca1ac1e09386fea25fb

1 files changed, 4 insertions, 11 deletions

diff --git a/src/script/sign.h b/src/script/sign.h
index cf3651c1de..a10366dcd1 100644
--- a/src/script/sign.h
+++ b/src/script/sign.h
@@ -37,26 +37,19 @@ public:
 };
 
 /** A signature creator for transactions. */
-class TransactionSignatureCreator : public BaseSignatureCreator {
-    const CTransaction* txTo;
+class MutableTransactionSignatureCreator : public BaseSignatureCreator {
+    const CMutableTransaction* txTo;
     unsigned int nIn;
     int nHashType;
     CAmount amount;
-    const TransactionSignatureChecker checker;
+    const MutableTransactionSignatureChecker checker;
 
 public:
-    TransactionSignatureCreator(const CTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, int nHashTypeIn=SIGHASH_ALL);
+    MutableTransactionSignatureCreator(const CMutableTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, int nHashTypeIn = SIGHASH_ALL);
     const BaseSignatureChecker& Checker() const override { return checker; }
     bool CreateSig(const SigningProvider& provider, std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode, SigVersion sigversion) const override;
 };
 
-class MutableTransactionSignatureCreator : public TransactionSignatureCreator {
-    CTransaction tx;
-
-public:
-    MutableTransactionSignatureCreator(const CMutableTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, int nHashTypeIn) : TransactionSignatureCreator(&tx, nInIn, amountIn, nHashTypeIn), tx(*txToIn) {}
-};
-
 /** A signature creator that just produces 72-byte empty signatures. */
 extern const BaseSignatureCreator& DUMMY_SIGNATURE_CREATOR;