The opt-in replacement sequence-number boundary

1// Copyright (c) 2016-present The Bitcoin Core developers
2// Distributed under the MIT software license, see the accompanying
3// file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5#ifndef BITCOIN_UTIL_RBF_H
6#define BITCOIN_UTIL_RBF_H
7
8#include <cstdint>
9
10class CTransaction;
11
12inline constexpr uint32_t MAX_BIP125_RBF_SEQUENCE{0xfffffffd};
13
14/** Check whether the sequence numbers on this transaction are signaling opt-in to replace-by-fee,
15 * according to BIP 125.  Allow opt-out of transaction replacement by setting nSequence >
16 * MAX_BIP125_RBF_SEQUENCE (SEQUENCE_FINAL-2) on all inputs.
17*
18* SEQUENCE_FINAL-1 is picked to still allow use of nLockTime by non-replaceable transactions. All
19* inputs rather than just one is for the sake of multi-party protocols, where we don't want a single
20* party to be able to disable replacement by opting out in their own input. */
21bool SignalsOptInRBF(const CTransaction& tx);
22
23#endif // BITCOIN_UTIL_RBF_H
24