READ THE CODE

Inside Bitcoin

The code behind the network, with room to understand it.

Stable release v32.1bitcoin/bitcoin · f0de87f04062 ↗3,020 source files · 47.5 MB stored on the server340 file guides

Release published 2026-10-28 · Snapshot fetched 2026-11-01. Latest stable release at fetch time; development branches and Git history are excluded. Only the selected code window and visible folders load here.

5,120 bytes · SHA-256 41ad7a7243ecc92e… · View upstream ↗

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_POLICY_RBF_H
6#define BITCOIN_POLICY_RBF_H
7
8#include <consensus/amount.h>
9#include <primitives/transaction.h>
10#include <sync.h>
11#include <txmempool.h>
12#include <util/feefrac.h>
13
14#include <compare>
15#include <cstddef>
16#include <cstdint>
17#include <optional>
18#include <set>
19#include <string>
20
21class CFeeRate;
22class uint256;
23
24/** Maximum number of unique clusters that can be affected by an RBF (Rule #5);
25 * see GetEntriesForConflicts() */
26inline constexpr uint32_t MAX_REPLACEMENT_CANDIDATES{100};
27
28/** The rbf state of unconfirmed transactions */
29enum class RBFTransactionState {
30    /** Unconfirmed tx that does not signal rbf and is not in the mempool */
31    UNKNOWN,
32    /** Either this tx or a mempool ancestor signals rbf */
33    REPLACEABLE_BIP125,
34    /** Neither this tx nor a mempool ancestor signals rbf */
35    FINAL,
36};
37
38enum class DiagramCheckError {
39    /** Unable to calculate due to topology or other reason */
40    UNCALCULABLE,
41    /** New diagram wasn't strictly superior  */
42    FAILURE,
43};
44
45/**
46 * Determine whether an unconfirmed transaction is signaling opt-in to RBF
47 * according to BIP 125
48 * This involves checking sequence numbers of the transaction, as well
49 * as the sequence numbers of all in-mempool ancestors.
50 *
51 * @param tx   The unconfirmed transaction
52 * @param pool The mempool, which may contain the tx
53 *
54 * @return     The rbf state
55 */
56RBFTransactionState IsRBFOptIn(const CTransaction& tx, const CTxMemPool& pool) EXCLUSIVE_LOCKS_REQUIRED(pool.cs);
57RBFTransactionState IsRBFOptInEmptyMempool(const CTransaction& tx);
58
59/** Get all descendants of iters_conflicting. Checks that there are no more than
60 * MAX_REPLACEMENT_CANDIDATES distinct clusters affected.
61 *
62 * @param[in]   iters_conflicting   The set of iterators to mempool entries.
63 * @param[out]  all_conflicts       Populated with all the mempool entries that would be replaced,
64 *                                  which includes iters_conflicting and all entries' descendants.
65 *                                  Not cleared at the start; any existing mempool entries will
66 *                                  remain in the set.
67 * @returns an error message if the number of affected clusters would exceed MAX_REPLACEMENT_CANDIDATES, std::nullopt otherwise
68 */
69std::optional<std::string> GetEntriesForConflicts(const CTransaction& tx, CTxMemPool& pool,
70                                                  const CTxMemPool::setEntries& iters_conflicting,
71                                                  CTxMemPool::setEntries& all_conflicts)
72    EXCLUSIVE_LOCKS_REQUIRED(pool.cs);
73
74/** Check the intersection between two sets of transactions (a set of mempool entries and a set of
75 * txids) to make sure they are disjoint.
76 * @param[in]   ancestors           Set of mempool entries corresponding to ancestors of the
77 *                                  replacement transactions.
78 * @param[in]   direct_conflicts    Set of txids corresponding to the mempool conflicts
79 *                                  (candidates to be replaced).
80 * @param[in]   txid                Transaction ID, included in the error message if violation occurs.
81 * @returns error message if the sets intersect, std::nullopt if they are disjoint.
82 */
83std::optional<std::string> EntriesAndTxidsDisjoint(const CTxMemPool::setEntries& ancestors,
84                                                   const std::set<Txid>& direct_conflicts,
85                                                   const Txid& txid);
86
87/** The replacement transaction must pay more fees than the original transactions. The additional
88 * fees must pay for the replacement's bandwidth at or above the incremental relay feerate.
89 * @param[in]   original_fees       Total modified fees of original transaction(s).
90 * @param[in]   replacement_fees    Total modified fees of replacement transaction(s).
91 * @param[in]   replacement_vsize   Total virtual size of replacement transaction(s).
92 * @param[in]   relay_fee           The node's minimum feerate for transaction relay.
93 * @param[in]   txid                Transaction ID, included in the error message if violation occurs.
94 * @returns error string if fees are insufficient, otherwise std::nullopt.
95 */
96std::optional<std::string> PaysForRBF(CAmount original_fees,
97                                      CAmount replacement_fees,
98                                      size_t replacement_vsize,
99                                      CFeeRate relay_fee,
100                                      const Txid& txid);
101
102/**
103 * The replacement transaction must improve the feerate diagram of the mempool.
104 * @param[in]   changeset           The changeset containing proposed additions/removals
105 * @returns error type and string if mempool diagram doesn't improve, otherwise std::nullopt.
106 */
107std::optional<std::pair<DiagramCheckError, std::string>> ImprovesFeerateDiagram(CTxMemPool::ChangeSet& changeset);
108
109#endif // BITCOIN_POLICY_RBF_H
110

src/wallet/receive.cpp

src/wallet/coinselection.cpp

src/consensus/validation.h

src/primitives/transaction.cpp

src/script/descriptor.cpp

src/bitcoin-cli.cpp

src/rpc/blockchain.cpp

src/rpc/rawtransaction.cpp

src/init.cpp

src/crypto/sha256.cpp

src/consensus/merkle.h

src/consensus/tx_check.h

src/consensus/tx_verify.h

src/policy/feerate.h

src/policy/feerate.cpp

src/primitives/transaction_identifier.h

src/chainparamsbase.h

src/chainparamsbase.cpp

src/util/moneystr.cpp

src/crypto/ripemd160.h

src/crypto/sha1.h

src/crypto/sha512.h

src/crypto/hmac_sha256.h

src/crypto/hmac_sha512.h

src/crypto/hmac_sha256.cpp

src/crypto/hmac_sha512.cpp

src/crypto/hkdf_sha256_32.h

src/crypto/hkdf_sha256_32.cpp

src/support/cleanse.h

src/support/cleanse.cpp

src/crypto/siphash.cpp

src/crypto/muhash.h

src/crypto/chacha20.h

src/crypto/poly1305.h

src/crypto/chacha20poly1305.h

src/crypto/chacha20poly1305.cpp

src/util/chaintype.cpp

src/util/obfuscation.h

src/util/byte_units.h

src/util/overflow.h

src/blockencodings.cpp

src/net_permissions.cpp

src/policy/packages.cpp

src/policy/rbf.cpp

src/policy/truc_policy.cpp

src/policy/ephemeral_policy.cpp

src/policy/settings.cpp

src/policy/policy.cpp

src/node/transaction.cpp

src/node/coin.cpp

src/rpc/client.cpp

src/rpc/external_signer.cpp

src/rpc/request.cpp

src/rpc/server_util.cpp

src/rpc/fees.cpp

src/rpc/output_script.cpp

src/rpc/rawtransaction_util.cpp

src/rpc/rawtransaction_util.h

src/rpc/register.h

src/rpc/request.h

src/rpc/server_util.h

src/rpc/protocol.h

src/rpc/server.h

src/rpc/signmessage.cpp

src/rpc/txoutproof.cpp

src/rpc/util.cpp

src/rpc/util.h

src/wallet/rpc/addresses.cpp

src/wallet/rpc/backup.cpp

src/wallet/rpc/coins.cpp

src/wallet/rpc/encrypt.cpp

src/wallet/rpc/signmessage.cpp

src/wallet/rpc/util.cpp

src/wallet/rpc/util.h

src/wallet/coincontrol.cpp

src/wallet/coincontrol.h

src/wallet/context.cpp

src/wallet/context.h

src/wallet/crypter.cpp

src/wallet/crypter.h

src/wallet/db.cpp

src/wallet/export.cpp

src/wallet/external_signer_scriptpubkeyman.cpp

src/wallet/rpc/spend.cpp

src/wallet/rpc/transactions.cpp

src/wallet/rpc/wallet.cpp

src/wallet/feebumper.cpp

src/wallet/feebumper.h

src/index/base.h

src/index/base.cpp

src/index/txindex.h

src/index/txindex.cpp

src/index/txindex_key.h

src/index/txospenderindex.h

src/index/txospenderindex.cpp

src/index/blockfilterindex.h

src/index/blockfilterindex.cpp

src/index/coinstatsindex.h

src/index/coinstatsindex.cpp

src/index/db_key.h

src/index/disktxpos.h

src/kernel/chain.cpp

src/kernel/chain.h

src/kernel/checks.cpp

src/kernel/checks.h

src/kernel/context.cpp

src/kernel/context.h

src/kernel/cs_main.cpp

src/kernel/cs_main.h

src/kernel/disconnected_transactions.cpp

src/kernel/disconnected_transactions.h

src/kernel/mempool_removal_reason.cpp

src/kernel/mempool_removal_reason.h

src/kernel/coinstats.cpp

src/kernel/coinstats.h

src/kernel/chainparams.cpp

src/kernel/chainparams.h

src/wallet/sqlite.cpp

src/wallet/sqlite.h

src/wallet/transaction.cpp

src/wallet/transaction.h

src/wallet/dump.cpp

src/wallet/dump.h

src/wallet/init.cpp

src/wallet/walletutil.cpp

src/wallet/walletutil.h

src/wallet/wallettool.cpp

src/wallet/wallettool.h

src/wallet/export.h

src/wallet/migrate.cpp

src/wallet/migrate.h

src/wallet/db.h

src/wallet/walletdb.cpp

src/wallet/interfaces.cpp

src/wallet/scriptpubkeyman.cpp

src/wallet/scriptpubkeyman.h

src/kernel/bitcoinkernel.cpp

src/kernel/bitcoinkernel.h

src/kernel/bitcoinkernel_wrapper.h

src/node/chainstate.cpp

src/node/chainstate.h

src/node/blockstorage.cpp

src/node/blockstorage.h

src/node/mempool_persist.cpp

src/node/mempool_persist.h

src/node/utxo_snapshot.cpp

src/node/utxo_snapshot.h

src/node/kernel_notifications.cpp

src/node/kernel_notifications.h

src/node/blockmanager_args.cpp

src/kernel/blockmanager_opts.h

src/util/expected.cpp

src/policy/settings.h

src/util/types.h

src/kernel/messagestartchars.h

src/kernel/warning.h

src/util/exception.h

src/common/license_info.h

src/node/coins_view_args.h

src/node/database_args.h

src/util/batchpriority.h

src/util/ui_change_type.h

src/node/coins_view_args.cpp

src/node/peerman_args.h

src/util/serfloat.h

src/node/blockmanager_args.h

src/node/database_args.cpp

src/util/overloaded.h

src/interfaces/types.h

src/node/chainstatemanager_args.h

src/node/minisketchwrapper.h

src/util/macros.h

src/util/syserror.h

src/common/run_command.h

src/util/bytevectorhash.cpp

src/node/mempool_persist_args.cpp

src/util/exec.h

src/util/rbf.h

src/crypto/hex_base.h

src/node/mempool_persist_args.h

src/interfaces/echo.h

src/util/any.h

src/util/batchpriority.cpp

src/util/threadnames.h

src/node/coin.h

src/node/mempool_args.h

src/util/asmap.h

src/util/bytevectorhash.h

src/node/context.cpp

src/util/insert.h

src/util/readwritefile.h

src/node/peerman_args.cpp

src/node/interface_ui.cpp

src/interfaces/handler.h

src/node/mining_args.h

src/util/hasher.cpp

src/common/init.h

src/kernel/mempool_limits.h

src/common/system.h

src/crypto/sha3.h

src/util/threadinterrupt.cpp

src/node/protocol_version.h

src/util/exception.cpp

src/common/messages.h

src/node/connection_types.cpp

src/util/bip32.h

src/common/license_info.cpp

src/util/stdmutex.h

src/common/run_command.cpp

src/util/check.cpp

src/util/golombrice.h

src/node/types.h

src/node/timeoffsets.h

src/util/readwritefile.cpp

src/util/fastrange.h

src/util/signalinterrupt.h

src/util/task_runner.h

src/util/syserror.cpp

src/common/interfaces.cpp

src/common/types.h

src/util/threadinterrupt.h

src/kernel/chainstatemanager_opts.h

src/node/psbt.h

src/policy/ephemeral_policy.h

src/util/trace.h

src/common/url.cpp

src/kernel/mempool_options.h

src/util/serfloat.cpp

src/kernel/notifications_interface.h

src/node/timeoffsets.cpp

src/node/warnings.cpp

src/util/hash_type.h

src/crypto/hex_base.cpp

src/node/eviction.h

src/util/tokenbucket.h

src/crypto/aes.h

src/common/pcp.h

src/util/feefrac.cpp

src/node/transaction.h

src/util/threadnames.cpp

src/common/signmessage.h

src/util/exec.cpp

src/util/signalinterrupt.cpp

Independent explanations by MyBitcoinExplorer. Not affiliated with or endorsed by Bitcoin Core. Guides are educational and do not replace the source or its tests.

Bitcoin Core source © its contributors, distributed under the MIT license. Original notices and bundled third-party licenses are retained in the source tree.