6b8b63af14 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
36fc8052f6