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1 : : // Copyright (c) 2009-2010 Satoshi Nakamoto
2 : : // Copyright (c) 2009-2022 The Bitcoin Core developers
3 : : // Distributed under the MIT software license, see the accompanying
4 : : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 : :
6 : : #ifndef BITCOIN_TXMEMPOOL_H
7 : : #define BITCOIN_TXMEMPOOL_H
8 : :
9 : : #include <coins.h>
10 : : #include <consensus/amount.h>
11 : : #include <indirectmap.h>
12 : : #include <kernel/cs_main.h>
13 : : #include <kernel/mempool_entry.h> // IWYU pragma: export
14 : : #include <kernel/mempool_limits.h> // IWYU pragma: export
15 : : #include <kernel/mempool_options.h> // IWYU pragma: export
16 : : #include <kernel/mempool_removal_reason.h> // IWYU pragma: export
17 : : #include <policy/feerate.h>
18 : : #include <policy/packages.h>
19 : : #include <primitives/transaction.h>
20 : : #include <sync.h>
21 : : #include <util/epochguard.h>
22 : : #include <util/hasher.h>
23 : : #include <util/result.h>
24 : : #include <util/feefrac.h>
25 : :
26 : : #include <boost/multi_index/hashed_index.hpp>
27 : : #include <boost/multi_index/identity.hpp>
28 : : #include <boost/multi_index/indexed_by.hpp>
29 : : #include <boost/multi_index/ordered_index.hpp>
30 : : #include <boost/multi_index/sequenced_index.hpp>
31 : : #include <boost/multi_index/tag.hpp>
32 : : #include <boost/multi_index_container.hpp>
33 : :
34 : : #include <atomic>
35 : : #include <map>
36 : : #include <optional>
37 : : #include <set>
38 : : #include <string>
39 : : #include <string_view>
40 : : #include <utility>
41 : : #include <vector>
42 : :
43 : : class CChain;
44 : : class ValidationSignals;
45 : :
46 : : struct bilingual_str;
47 : :
48 : : /** Fake height value used in Coin to signify they are only in the memory pool (since 0.8) */
49 : : static const uint32_t MEMPOOL_HEIGHT = 0x7FFFFFFF;
50 : :
51 : : /**
52 : : * Test whether the LockPoints height and time are still valid on the current chain
53 : : */
54 : : bool TestLockPointValidity(CChain& active_chain, const LockPoints& lp) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
55 : :
56 : : // extracts a transaction hash from CTxMemPoolEntry or CTransactionRef
57 : : struct mempoolentry_txid
58 : : {
59 : : typedef uint256 result_type;
60 : 0 : result_type operator() (const CTxMemPoolEntry &entry) const
61 : : {
62 [ # # ][ # # : 0 : return entry.GetTx().GetHash();
# # # # #
# # # ]
63 : : }
64 : :
65 : : result_type operator() (const CTransactionRef& tx) const
66 : : {
67 : : return tx->GetHash();
68 : : }
69 : : };
70 : :
71 : : // extracts a transaction witness-hash from CTxMemPoolEntry or CTransactionRef
72 : : struct mempoolentry_wtxid
73 : : {
74 : : typedef uint256 result_type;
75 : 0 : result_type operator() (const CTxMemPoolEntry &entry) const
76 : : {
77 [ # # ][ # # : 0 : return entry.GetTx().GetWitnessHash();
# # # # #
# # # ]
78 : : }
79 : :
80 : : result_type operator() (const CTransactionRef& tx) const
81 : : {
82 : : return tx->GetWitnessHash();
83 : : }
84 : : };
85 : :
86 : :
87 : : /** \class CompareTxMemPoolEntryByDescendantScore
88 : : *
89 : : * Sort an entry by max(score/size of entry's tx, score/size with all descendants).
90 : : */
91 : : class CompareTxMemPoolEntryByDescendantScore
92 : : {
93 : : public:
94 : 0 : bool operator()(const CTxMemPoolEntry& a, const CTxMemPoolEntry& b) const
95 : : {
96 : 0 : double a_mod_fee, a_size, b_mod_fee, b_size;
97 : :
98 : 0 : GetModFeeAndSize(a, a_mod_fee, a_size);
99 : 0 : GetModFeeAndSize(b, b_mod_fee, b_size);
100 : :
101 : : // Avoid division by rewriting (a/b > c/d) as (a*d > c*b).
102 : 0 : double f1 = a_mod_fee * b_size;
103 : 0 : double f2 = a_size * b_mod_fee;
104 : :
105 [ # # ]: 0 : if (f1 == f2) {
106 : 0 : return a.GetTime() >= b.GetTime();
107 : : }
108 : 0 : return f1 < f2;
109 : : }
110 : :
111 : : // Return the fee/size we're using for sorting this entry.
112 : 0 : void GetModFeeAndSize(const CTxMemPoolEntry &a, double &mod_fee, double &size) const
113 : : {
114 : : // Compare feerate with descendants to feerate of the transaction, and
115 : : // return the fee/size for the max.
116 : 0 : double f1 = (double)a.GetModifiedFee() * a.GetSizeWithDescendants();
117 : 0 : double f2 = (double)a.GetModFeesWithDescendants() * a.GetTxSize();
118 : :
119 [ # # ]: 0 : if (f2 > f1) {
120 : 0 : mod_fee = a.GetModFeesWithDescendants();
121 : 0 : size = a.GetSizeWithDescendants();
122 : : } else {
123 : 0 : mod_fee = a.GetModifiedFee();
124 : 0 : size = a.GetTxSize();
125 : : }
126 : 0 : }
127 : : };
128 : :
129 : : /** \class CompareTxMemPoolEntryByScore
130 : : *
131 : : * Sort by feerate of entry (fee/size) in descending order
132 : : * This is only used for transaction relay, so we use GetFee()
133 : : * instead of GetModifiedFee() to avoid leaking prioritization
134 : : * information via the sort order.
135 : : */
136 : : class CompareTxMemPoolEntryByScore
137 : : {
138 : : public:
139 : 0 : bool operator()(const CTxMemPoolEntry& a, const CTxMemPoolEntry& b) const
140 : : {
141 : 0 : double f1 = (double)a.GetFee() * b.GetTxSize();
142 : 0 : double f2 = (double)b.GetFee() * a.GetTxSize();
143 [ # # ]: 0 : if (f1 == f2) {
144 : 0 : return b.GetTx().GetHash() < a.GetTx().GetHash();
145 : : }
146 : 0 : return f1 > f2;
147 : : }
148 : : };
149 : :
150 : : class CompareTxMemPoolEntryByEntryTime
151 : : {
152 : : public:
153 : 0 : bool operator()(const CTxMemPoolEntry& a, const CTxMemPoolEntry& b) const
154 : : {
155 : 0 : return a.GetTime() < b.GetTime();
156 : : }
157 : : };
158 : :
159 : : /** \class CompareTxMemPoolEntryByAncestorScore
160 : : *
161 : : * Sort an entry by min(score/size of entry's tx, score/size with all ancestors).
162 : : */
163 : : class CompareTxMemPoolEntryByAncestorFee
164 : : {
165 : : public:
166 : : template<typename T>
167 : 0 : bool operator()(const T& a, const T& b) const
168 : : {
169 : : double a_mod_fee, a_size, b_mod_fee, b_size;
170 : :
171 : 0 : GetModFeeAndSize(a, a_mod_fee, a_size);
172 : 0 : GetModFeeAndSize(b, b_mod_fee, b_size);
173 : :
174 : : // Avoid division by rewriting (a/b > c/d) as (a*d > c*b).
175 : 0 : double f1 = a_mod_fee * b_size;
176 : 0 : double f2 = a_size * b_mod_fee;
177 : :
178 [ # # ]: 0 : if (f1 == f2) {
179 : 0 : return a.GetTx().GetHash() < b.GetTx().GetHash();
180 : : }
181 : 0 : return f1 > f2;
182 : : }
183 : :
184 : : // Return the fee/size we're using for sorting this entry.
185 : : template <typename T>
186 : 0 : void GetModFeeAndSize(const T &a, double &mod_fee, double &size) const
187 : : {
188 : : // Compare feerate with ancestors to feerate of the transaction, and
189 : : // return the fee/size for the min.
190 : 0 : double f1 = (double)a.GetModifiedFee() * a.GetSizeWithAncestors();
191 : 0 : double f2 = (double)a.GetModFeesWithAncestors() * a.GetTxSize();
192 : :
193 [ # # ]: 0 : if (f1 > f2) {
194 : 0 : mod_fee = a.GetModFeesWithAncestors();
195 : 0 : size = a.GetSizeWithAncestors();
196 : : } else {
197 : 0 : mod_fee = a.GetModifiedFee();
198 : 0 : size = a.GetTxSize();
199 : : }
200 : 0 : }
201 : : };
202 : :
203 : : // Multi_index tag names
204 : : struct descendant_score {};
205 : : struct entry_time {};
206 : : struct ancestor_score {};
207 : : struct index_by_wtxid {};
208 : :
209 : : /**
210 : : * Information about a mempool transaction.
211 : : */
212 [ # # ][ # # : 0 : struct TxMempoolInfo
# # # # #
# # # #
# ][ # # #
# # # #
# ]
213 : : {
214 : : /** The transaction itself */
215 : : CTransactionRef tx;
216 : :
217 : : /** Time the transaction entered the mempool. */
218 : : std::chrono::seconds m_time;
219 : :
220 : : /** Fee of the transaction. */
221 : : CAmount fee;
222 : :
223 : : /** Virtual size of the transaction. */
224 : : int32_t vsize;
225 : :
226 : : /** The fee delta. */
227 : : int64_t nFeeDelta;
228 : : };
229 : :
230 : : /**
231 : : * CTxMemPool stores valid-according-to-the-current-best-chain transactions
232 : : * that may be included in the next block.
233 : : *
234 : : * Transactions are added when they are seen on the network (or created by the
235 : : * local node), but not all transactions seen are added to the pool. For
236 : : * example, the following new transactions will not be added to the mempool:
237 : : * - a transaction which doesn't meet the minimum fee requirements.
238 : : * - a new transaction that double-spends an input of a transaction already in
239 : : * the pool where the new transaction does not meet the Replace-By-Fee
240 : : * requirements as defined in doc/policy/mempool-replacements.md.
241 : : * - a non-standard transaction.
242 : : *
243 : : * CTxMemPool::mapTx, and CTxMemPoolEntry bookkeeping:
244 : : *
245 : : * mapTx is a boost::multi_index that sorts the mempool on 5 criteria:
246 : : * - transaction hash (txid)
247 : : * - witness-transaction hash (wtxid)
248 : : * - descendant feerate [we use max(feerate of tx, feerate of tx with all descendants)]
249 : : * - time in mempool
250 : : * - ancestor feerate [we use min(feerate of tx, feerate of tx with all unconfirmed ancestors)]
251 : : *
252 : : * Note: the term "descendant" refers to in-mempool transactions that depend on
253 : : * this one, while "ancestor" refers to in-mempool transactions that a given
254 : : * transaction depends on.
255 : : *
256 : : * In order for the feerate sort to remain correct, we must update transactions
257 : : * in the mempool when new descendants arrive. To facilitate this, we track
258 : : * the set of in-mempool direct parents and direct children in mapLinks. Within
259 : : * each CTxMemPoolEntry, we track the size and fees of all descendants.
260 : : *
261 : : * Usually when a new transaction is added to the mempool, it has no in-mempool
262 : : * children (because any such children would be an orphan). So in
263 : : * addUnchecked(), we:
264 : : * - update a new entry's setMemPoolParents to include all in-mempool parents
265 : : * - update the new entry's direct parents to include the new tx as a child
266 : : * - update all ancestors of the transaction to include the new tx's size/fee
267 : : *
268 : : * When a transaction is removed from the mempool, we must:
269 : : * - update all in-mempool parents to not track the tx in setMemPoolChildren
270 : : * - update all ancestors to not include the tx's size/fees in descendant state
271 : : * - update all in-mempool children to not include it as a parent
272 : : *
273 : : * These happen in UpdateForRemoveFromMempool(). (Note that when removing a
274 : : * transaction along with its descendants, we must calculate that set of
275 : : * transactions to be removed before doing the removal, or else the mempool can
276 : : * be in an inconsistent state where it's impossible to walk the ancestors of
277 : : * a transaction.)
278 : : *
279 : : * In the event of a reorg, the assumption that a newly added tx has no
280 : : * in-mempool children is false. In particular, the mempool is in an
281 : : * inconsistent state while new transactions are being added, because there may
282 : : * be descendant transactions of a tx coming from a disconnected block that are
283 : : * unreachable from just looking at transactions in the mempool (the linking
284 : : * transactions may also be in the disconnected block, waiting to be added).
285 : : * Because of this, there's not much benefit in trying to search for in-mempool
286 : : * children in addUnchecked(). Instead, in the special case of transactions
287 : : * being added from a disconnected block, we require the caller to clean up the
288 : : * state, to account for in-mempool, out-of-block descendants for all the
289 : : * in-block transactions by calling UpdateTransactionsFromBlock(). Note that
290 : : * until this is called, the mempool state is not consistent, and in particular
291 : : * mapLinks may not be correct (and therefore functions like
292 : : * CalculateMemPoolAncestors() and CalculateDescendants() that rely
293 : : * on them to walk the mempool are not generally safe to use).
294 : : *
295 : : * Computational limits:
296 : : *
297 : : * Updating all in-mempool ancestors of a newly added transaction can be slow,
298 : : * if no bound exists on how many in-mempool ancestors there may be.
299 : : * CalculateMemPoolAncestors() takes configurable limits that are designed to
300 : : * prevent these calculations from being too CPU intensive.
301 : : *
302 : : */
303 : : class CTxMemPool
304 : : {
305 : : protected:
306 : : std::atomic<unsigned int> nTransactionsUpdated{0}; //!< Used by getblocktemplate to trigger CreateNewBlock() invocation
307 : :
308 : : uint64_t totalTxSize GUARDED_BY(cs){0}; //!< sum of all mempool tx's virtual sizes. Differs from serialized tx size since witness data is discounted. Defined in BIP 141.
309 : : CAmount m_total_fee GUARDED_BY(cs){0}; //!< sum of all mempool tx's fees (NOT modified fee)
310 : : uint64_t cachedInnerUsage GUARDED_BY(cs){0}; //!< sum of dynamic memory usage of all the map elements (NOT the maps themselves)
311 : :
312 : : mutable int64_t lastRollingFeeUpdate GUARDED_BY(cs){GetTime()};
313 : : mutable bool blockSinceLastRollingFeeBump GUARDED_BY(cs){false};
314 : : mutable double rollingMinimumFeeRate GUARDED_BY(cs){0}; //!< minimum fee to get into the pool, decreases exponentially
315 : : mutable Epoch m_epoch GUARDED_BY(cs){};
316 : :
317 : : // In-memory counter for external mempool tracking purposes.
318 : : // This number is incremented once every time a transaction
319 : : // is added or removed from the mempool for any reason.
320 : : mutable uint64_t m_sequence_number GUARDED_BY(cs){1};
321 : :
322 : : void trackPackageRemoved(const CFeeRate& rate) EXCLUSIVE_LOCKS_REQUIRED(cs);
323 : :
324 : : bool m_load_tried GUARDED_BY(cs){false};
325 : :
326 : : CFeeRate GetMinFee(size_t sizelimit) const;
327 : :
328 : : public:
329 : :
330 : : static const int ROLLING_FEE_HALFLIFE = 60 * 60 * 12; // public only for testing
331 : :
332 : : struct CTxMemPoolEntry_Indices final : boost::multi_index::indexed_by<
333 : : // sorted by txid
334 : : boost::multi_index::hashed_unique<mempoolentry_txid, SaltedTxidHasher>,
335 : : // sorted by wtxid
336 : : boost::multi_index::hashed_unique<
337 : : boost::multi_index::tag<index_by_wtxid>,
338 : : mempoolentry_wtxid,
339 : : SaltedTxidHasher
340 : : >,
341 : : // sorted by fee rate
342 : : boost::multi_index::ordered_non_unique<
343 : : boost::multi_index::tag<descendant_score>,
344 : : boost::multi_index::identity<CTxMemPoolEntry>,
345 : : CompareTxMemPoolEntryByDescendantScore
346 : : >,
347 : : // sorted by entry time
348 : : boost::multi_index::ordered_non_unique<
349 : : boost::multi_index::tag<entry_time>,
350 : : boost::multi_index::identity<CTxMemPoolEntry>,
351 : : CompareTxMemPoolEntryByEntryTime
352 : : >,
353 : : // sorted by fee rate with ancestors
354 : : boost::multi_index::ordered_non_unique<
355 : : boost::multi_index::tag<ancestor_score>,
356 : : boost::multi_index::identity<CTxMemPoolEntry>,
357 : : CompareTxMemPoolEntryByAncestorFee
358 : : >
359 : : >
360 : : {};
361 : : typedef boost::multi_index_container<
362 : : CTxMemPoolEntry,
363 : : CTxMemPoolEntry_Indices
364 : : > indexed_transaction_set;
365 : :
366 : : /**
367 : : * This mutex needs to be locked when accessing `mapTx` or other members
368 : : * that are guarded by it.
369 : : *
370 : : * @par Consistency guarantees
371 : : * By design, it is guaranteed that:
372 : : * 1. Locking both `cs_main` and `mempool.cs` will give a view of mempool
373 : : * that is consistent with current chain tip (`ActiveChain()` and
374 : : * `CoinsTip()`) and is fully populated. Fully populated means that if the
375 : : * current active chain is missing transactions that were present in a
376 : : * previously active chain, all the missing transactions will have been
377 : : * re-added to the mempool and should be present if they meet size and
378 : : * consistency constraints.
379 : : * 2. Locking `mempool.cs` without `cs_main` will give a view of a mempool
380 : : * consistent with some chain that was active since `cs_main` was last
381 : : * locked, and that is fully populated as described above. It is ok for
382 : : * code that only needs to query or remove transactions from the mempool
383 : : * to lock just `mempool.cs` without `cs_main`.
384 : : *
385 : : * To provide these guarantees, it is necessary to lock both `cs_main` and
386 : : * `mempool.cs` whenever adding transactions to the mempool and whenever
387 : : * changing the chain tip. It's necessary to keep both mutexes locked until
388 : : * the mempool is consistent with the new chain tip and fully populated.
389 : : */
390 : : mutable RecursiveMutex cs;
391 : : indexed_transaction_set mapTx GUARDED_BY(cs);
392 : :
393 : : using txiter = indexed_transaction_set::nth_index<0>::type::const_iterator;
394 : : std::vector<CTransactionRef> txns_randomized GUARDED_BY(cs); //!< All transactions in mapTx, in random order
395 : :
396 : : typedef std::set<txiter, CompareIteratorByHash> setEntries;
397 : :
398 : : using Limits = kernel::MemPoolLimits;
399 : :
400 : : uint64_t CalculateDescendantMaximum(txiter entry) const EXCLUSIVE_LOCKS_REQUIRED(cs);
401 : : private:
402 : : typedef std::map<txiter, setEntries, CompareIteratorByHash> cacheMap;
403 : :
404 : :
405 : : void UpdateParent(txiter entry, txiter parent, bool add) EXCLUSIVE_LOCKS_REQUIRED(cs);
406 : : void UpdateChild(txiter entry, txiter child, bool add) EXCLUSIVE_LOCKS_REQUIRED(cs);
407 : :
408 : : std::vector<indexed_transaction_set::const_iterator> GetSortedDepthAndScore() const EXCLUSIVE_LOCKS_REQUIRED(cs);
409 : :
410 : : /**
411 : : * Track locally submitted transactions to periodically retry initial broadcast.
412 : : */
413 : : std::set<uint256> m_unbroadcast_txids GUARDED_BY(cs);
414 : :
415 : :
416 : : /**
417 : : * Helper function to calculate all in-mempool ancestors of staged_ancestors and apply ancestor
418 : : * and descendant limits (including staged_ancestors themselves, entry_size and entry_count).
419 : : *
420 : : * @param[in] entry_size Virtual size to include in the limits.
421 : : * @param[in] entry_count How many entries to include in the limits.
422 : : * @param[in] staged_ancestors Should contain entries in the mempool.
423 : : * @param[in] limits Maximum number and size of ancestors and descendants
424 : : *
425 : : * @return all in-mempool ancestors, or an error if any ancestor or descendant limits were hit
426 : : */
427 : : util::Result<setEntries> CalculateAncestorsAndCheckLimits(int64_t entry_size,
428 : : size_t entry_count,
429 : : CTxMemPoolEntry::Parents &staged_ancestors,
430 : : const Limits& limits
431 : : ) const EXCLUSIVE_LOCKS_REQUIRED(cs);
432 : :
433 : : public:
434 : : indirectmap<COutPoint, const CTransaction*> mapNextTx GUARDED_BY(cs);
435 : : std::map<uint256, CAmount> mapDeltas GUARDED_BY(cs);
436 : :
437 : : using Options = kernel::MemPoolOptions;
438 : :
439 : : const Options m_opts;
440 : :
441 : : /** Create a new CTxMemPool.
442 : : * Sanity checks will be off by default for performance, because otherwise
443 : : * accepting transactions becomes O(N^2) where N is the number of transactions
444 : : * in the pool.
445 : : */
446 : : explicit CTxMemPool(Options opts, bilingual_str& error);
447 : :
448 : : /**
449 : : * If sanity-checking is turned on, check makes sure the pool is
450 : : * consistent (does not contain two transactions that spend the same inputs,
451 : : * all inputs are in the mapNextTx array). If sanity-checking is turned off,
452 : : * check does nothing.
453 : : */
454 : : void check(const CCoinsViewCache& active_coins_tip, int64_t spendheight) const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
455 : :
456 : : // addUnchecked must updated state for all ancestors of a given transaction,
457 : : // to track size/count of descendant transactions. First version of
458 : : // addUnchecked can be used to have it call CalculateMemPoolAncestors(), and
459 : : // then invoke the second version.
460 : : // Note that addUnchecked is ONLY called from ATMP outside of tests
461 : : // and any other callers may break wallet's in-mempool tracking (due to
462 : : // lack of CValidationInterface::TransactionAddedToMempool callbacks).
463 : : void addUnchecked(const CTxMemPoolEntry& entry) EXCLUSIVE_LOCKS_REQUIRED(cs, cs_main);
464 : : void addUnchecked(const CTxMemPoolEntry& entry, setEntries& setAncestors) EXCLUSIVE_LOCKS_REQUIRED(cs, cs_main);
465 : :
466 : : void removeRecursive(const CTransaction& tx, MemPoolRemovalReason reason) EXCLUSIVE_LOCKS_REQUIRED(cs);
467 : : /** After reorg, filter the entries that would no longer be valid in the next block, and update
468 : : * the entries' cached LockPoints if needed. The mempool does not have any knowledge of
469 : : * consensus rules. It just applies the callable function and removes the ones for which it
470 : : * returns true.
471 : : * @param[in] filter_final_and_mature Predicate that checks the relevant validation rules
472 : : * and updates an entry's LockPoints.
473 : : * */
474 : : void removeForReorg(CChain& chain, std::function<bool(txiter)> filter_final_and_mature) EXCLUSIVE_LOCKS_REQUIRED(cs, cs_main);
475 : : void removeConflicts(const CTransaction& tx) EXCLUSIVE_LOCKS_REQUIRED(cs);
476 : : void removeForBlock(const std::vector<CTransactionRef>& vtx, unsigned int nBlockHeight) EXCLUSIVE_LOCKS_REQUIRED(cs);
477 : :
478 : : bool CompareDepthAndScore(const uint256& hasha, const uint256& hashb, bool wtxid=false);
479 : : bool isSpent(const COutPoint& outpoint) const;
480 : : unsigned int GetTransactionsUpdated() const;
481 : : void AddTransactionsUpdated(unsigned int n);
482 : : /**
483 : : * Check that none of this transactions inputs are in the mempool, and thus
484 : : * the tx is not dependent on other mempool transactions to be included in a block.
485 : : */
486 : : bool HasNoInputsOf(const CTransaction& tx) const EXCLUSIVE_LOCKS_REQUIRED(cs);
487 : :
488 : : /** Affect CreateNewBlock prioritisation of transactions */
489 : : void PrioritiseTransaction(const uint256& hash, const CAmount& nFeeDelta);
490 : : void ApplyDelta(const uint256& hash, CAmount &nFeeDelta) const EXCLUSIVE_LOCKS_REQUIRED(cs);
491 : : void ClearPrioritisation(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs);
492 : :
493 : : struct delta_info {
494 : : /** Whether this transaction is in the mempool. */
495 : : const bool in_mempool;
496 : : /** The fee delta added using PrioritiseTransaction(). */
497 : : const CAmount delta;
498 : : /** The modified fee (base fee + delta) of this entry. Only present if in_mempool=true. */
499 : : std::optional<CAmount> modified_fee;
500 : : /** The prioritised transaction's txid. */
501 : : const uint256 txid;
502 : : };
503 : : /** Return a vector of all entries in mapDeltas with their corresponding delta_info. */
504 : : std::vector<delta_info> GetPrioritisedTransactions() const EXCLUSIVE_LOCKS_REQUIRED(!cs);
505 : :
506 : : /** Get the transaction in the pool that spends the same prevout */
507 : : const CTransaction* GetConflictTx(const COutPoint& prevout) const EXCLUSIVE_LOCKS_REQUIRED(cs);
508 : :
509 : : /** Returns an iterator to the given hash, if found */
510 : : std::optional<txiter> GetIter(const uint256& txid) const EXCLUSIVE_LOCKS_REQUIRED(cs);
511 : :
512 : : /** Translate a set of hashes into a set of pool iterators to avoid repeated lookups.
513 : : * Does not require that all of the hashes correspond to actual transactions in the mempool,
514 : : * only returns the ones that exist. */
515 : : setEntries GetIterSet(const std::set<Txid>& hashes) const EXCLUSIVE_LOCKS_REQUIRED(cs);
516 : :
517 : : /** Translate a list of hashes into a list of mempool iterators to avoid repeated lookups.
518 : : * The nth element in txids becomes the nth element in the returned vector. If any of the txids
519 : : * don't actually exist in the mempool, returns an empty vector. */
520 : : std::vector<txiter> GetIterVec(const std::vector<uint256>& txids) const EXCLUSIVE_LOCKS_REQUIRED(cs);
521 : :
522 : : /** Remove a set of transactions from the mempool.
523 : : * If a transaction is in this set, then all in-mempool descendants must
524 : : * also be in the set, unless this transaction is being removed for being
525 : : * in a block.
526 : : * Set updateDescendants to true when removing a tx that was in a block, so
527 : : * that any in-mempool descendants have their ancestor state updated.
528 : : */
529 : : void RemoveStaged(setEntries& stage, bool updateDescendants, MemPoolRemovalReason reason) EXCLUSIVE_LOCKS_REQUIRED(cs);
530 : :
531 : : /** UpdateTransactionsFromBlock is called when adding transactions from a
532 : : * disconnected block back to the mempool, new mempool entries may have
533 : : * children in the mempool (which is generally not the case when otherwise
534 : : * adding transactions).
535 : : * @post updated descendant state for descendants of each transaction in
536 : : * vHashesToUpdate (excluding any child transactions present in
537 : : * vHashesToUpdate, which are already accounted for). Updated state
538 : : * includes add fee/size information for such descendants to the
539 : : * parent and updated ancestor state to include the parent.
540 : : *
541 : : * @param[in] vHashesToUpdate The set of txids from the
542 : : * disconnected block that have been accepted back into the mempool.
543 : : */
544 : : void UpdateTransactionsFromBlock(const std::vector<uint256>& vHashesToUpdate) EXCLUSIVE_LOCKS_REQUIRED(cs, cs_main) LOCKS_EXCLUDED(m_epoch);
545 : :
546 : : /**
547 : : * Try to calculate all in-mempool ancestors of entry.
548 : : * (these are all calculated including the tx itself)
549 : : *
550 : : * @param[in] entry CTxMemPoolEntry of which all in-mempool ancestors are calculated
551 : : * @param[in] limits Maximum number and size of ancestors and descendants
552 : : * @param[in] fSearchForParents Whether to search a tx's vin for in-mempool parents, or look
553 : : * up parents from mapLinks. Must be true for entries not in
554 : : * the mempool
555 : : *
556 : : * @return all in-mempool ancestors, or an error if any ancestor or descendant limits were hit
557 : : */
558 : : util::Result<setEntries> CalculateMemPoolAncestors(const CTxMemPoolEntry& entry,
559 : : const Limits& limits,
560 : : bool fSearchForParents = true) const EXCLUSIVE_LOCKS_REQUIRED(cs);
561 : :
562 : : /**
563 : : * Same as CalculateMemPoolAncestors, but always returns a (non-optional) setEntries.
564 : : * Should only be used when it is assumed CalculateMemPoolAncestors would not fail. If
565 : : * CalculateMemPoolAncestors does unexpectedly fail, an empty setEntries is returned and the
566 : : * error is logged to BCLog::MEMPOOL with level BCLog::Level::Error. In debug builds, failure
567 : : * of CalculateMemPoolAncestors will lead to shutdown due to assertion failure.
568 : : *
569 : : * @param[in] calling_fn_name Name of calling function so we can properly log the call site
570 : : *
571 : : * @return a setEntries corresponding to the result of CalculateMemPoolAncestors or an empty
572 : : * setEntries if it failed
573 : : *
574 : : * @see CTXMemPool::CalculateMemPoolAncestors()
575 : : */
576 : : setEntries AssumeCalculateMemPoolAncestors(
577 : : std::string_view calling_fn_name,
578 : : const CTxMemPoolEntry &entry,
579 : : const Limits& limits,
580 : : bool fSearchForParents = true) const EXCLUSIVE_LOCKS_REQUIRED(cs);
581 : :
582 : : /** Collect the entire cluster of connected transactions for each transaction in txids.
583 : : * All txids must correspond to transaction entries in the mempool, otherwise this returns an
584 : : * empty vector. This call will also exit early and return an empty vector if it collects 500 or
585 : : * more transactions as a DoS protection. */
586 : : std::vector<txiter> GatherClusters(const std::vector<uint256>& txids) const EXCLUSIVE_LOCKS_REQUIRED(cs);
587 : :
588 : : /** Calculate all in-mempool ancestors of a set of transactions not already in the mempool and
589 : : * check ancestor and descendant limits. Heuristics are used to estimate the ancestor and
590 : : * descendant count of all entries if the package were to be added to the mempool. The limits
591 : : * are applied to the union of all package transactions. For example, if the package has 3
592 : : * transactions and limits.ancestor_count = 25, the union of all 3 sets of ancestors (including the
593 : : * transactions themselves) must be <= 22.
594 : : * @param[in] package Transaction package being evaluated for acceptance
595 : : * to mempool. The transactions need not be direct
596 : : * ancestors/descendants of each other.
597 : : * @param[in] total_vsize Sum of virtual sizes for all transactions in package.
598 : : * @returns {} or the error reason if a limit is hit.
599 : : */
600 : : util::Result<void> CheckPackageLimits(const Package& package,
601 : : int64_t total_vsize) const EXCLUSIVE_LOCKS_REQUIRED(cs);
602 : :
603 : : /** Populate setDescendants with all in-mempool descendants of hash.
604 : : * Assumes that setDescendants includes all in-mempool descendants of anything
605 : : * already in it. */
606 : : void CalculateDescendants(txiter it, setEntries& setDescendants) const EXCLUSIVE_LOCKS_REQUIRED(cs);
607 : :
608 : : /** The minimum fee to get into the mempool, which may itself not be enough
609 : : * for larger-sized transactions.
610 : : * The m_incremental_relay_feerate policy variable is used to bound the time it
611 : : * takes the fee rate to go back down all the way to 0. When the feerate
612 : : * would otherwise be half of this, it is set to 0 instead.
613 : : */
614 : 0 : CFeeRate GetMinFee() const {
615 [ # # ]: 0 : return GetMinFee(m_opts.max_size_bytes);
616 : : }
617 : :
618 : : /** Remove transactions from the mempool until its dynamic size is <= sizelimit.
619 : : * pvNoSpendsRemaining, if set, will be populated with the list of outpoints
620 : : * which are not in mempool which no longer have any spends in this mempool.
621 : : */
622 : : void TrimToSize(size_t sizelimit, std::vector<COutPoint>* pvNoSpendsRemaining = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs);
623 : :
624 : : /** Expire all transaction (and their dependencies) in the mempool older than time. Return the number of removed transactions. */
625 : : int Expire(std::chrono::seconds time) EXCLUSIVE_LOCKS_REQUIRED(cs);
626 : :
627 : : /**
628 : : * Calculate the ancestor and descendant count for the given transaction.
629 : : * The counts include the transaction itself.
630 : : * When ancestors is non-zero (ie, the transaction itself is in the mempool),
631 : : * ancestorsize and ancestorfees will also be set to the appropriate values.
632 : : */
633 : : void GetTransactionAncestry(const uint256& txid, size_t& ancestors, size_t& descendants, size_t* ancestorsize = nullptr, CAmount* ancestorfees = nullptr) const;
634 : :
635 : : /**
636 : : * @returns true if an initial attempt to load the persisted mempool was made, regardless of
637 : : * whether the attempt was successful or not
638 : : */
639 : : bool GetLoadTried() const;
640 : :
641 : : /**
642 : : * Set whether or not an initial attempt to load the persisted mempool was made (regardless
643 : : * of whether the attempt was successful or not)
644 : : */
645 : : void SetLoadTried(bool load_tried);
646 : :
647 : 0 : unsigned long size() const
648 : : {
649 : 0 : LOCK(cs);
650 [ # # ]: 0 : return mapTx.size();
651 : 0 : }
652 : :
653 : 0 : uint64_t GetTotalTxSize() const EXCLUSIVE_LOCKS_REQUIRED(cs)
654 : : {
655 : 0 : AssertLockHeld(cs);
656 [ # # ]: 0 : return totalTxSize;
657 : : }
658 : :
659 : 0 : CAmount GetTotalFee() const EXCLUSIVE_LOCKS_REQUIRED(cs)
660 : : {
661 : 0 : AssertLockHeld(cs);
662 [ # # ]: 0 : return m_total_fee;
663 : : }
664 : :
665 : 0 : bool exists(const GenTxid& gtxid) const
666 : : {
667 : 0 : LOCK(cs);
668 [ # # ]: 0 : if (gtxid.IsWtxid()) {
669 [ # # ]: 0 : return (mapTx.get<index_by_wtxid>().count(gtxid.GetHash()) != 0);
670 : : }
671 [ # # ]: 0 : return (mapTx.count(gtxid.GetHash()) != 0);
672 : 0 : }
673 : :
674 : : const CTxMemPoolEntry* GetEntry(const Txid& txid) const LIFETIMEBOUND EXCLUSIVE_LOCKS_REQUIRED(cs);
675 : :
676 : : CTransactionRef get(const uint256& hash) const;
677 : 0 : txiter get_iter_from_wtxid(const uint256& wtxid) const EXCLUSIVE_LOCKS_REQUIRED(cs)
678 : : {
679 : 0 : AssertLockHeld(cs);
680 : 0 : return mapTx.project<0>(mapTx.get<index_by_wtxid>().find(wtxid));
681 : : }
682 : : TxMempoolInfo info(const GenTxid& gtxid) const;
683 : :
684 : : /** Returns info for a transaction if its entry_sequence < last_sequence */
685 : : TxMempoolInfo info_for_relay(const GenTxid& gtxid, uint64_t last_sequence) const;
686 : :
687 : : std::vector<CTxMemPoolEntryRef> entryAll() const EXCLUSIVE_LOCKS_REQUIRED(cs);
688 : : std::vector<TxMempoolInfo> infoAll() const;
689 : :
690 : : size_t DynamicMemoryUsage() const;
691 : :
692 : : /** Adds a transaction to the unbroadcast set */
693 : 0 : void AddUnbroadcastTx(const uint256& txid)
694 : : {
695 : 0 : LOCK(cs);
696 : : // Sanity check the transaction is in the mempool & insert into
697 : : // unbroadcast set.
698 [ # # # # : 0 : if (exists(GenTxid::Txid(txid))) m_unbroadcast_txids.insert(txid);
# # ]
699 : 0 : };
700 : :
701 : : /** Removes a transaction from the unbroadcast set */
702 : : void RemoveUnbroadcastTx(const uint256& txid, const bool unchecked = false);
703 : :
704 : : /** Returns transactions in unbroadcast set */
705 : 0 : std::set<uint256> GetUnbroadcastTxs() const
706 : : {
707 : 0 : LOCK(cs);
708 [ # # # # ]: 0 : return m_unbroadcast_txids;
709 : 0 : }
710 : :
711 : : /** Returns whether a txid is in the unbroadcast set */
712 : 0 : bool IsUnbroadcastTx(const uint256& txid) const EXCLUSIVE_LOCKS_REQUIRED(cs)
713 : : {
714 : 0 : AssertLockHeld(cs);
715 [ # # ]: 0 : return m_unbroadcast_txids.count(txid) != 0;
716 : : }
717 : :
718 : : /** Guards this internal counter for external reporting */
719 : 0 : uint64_t GetAndIncrementSequence() const EXCLUSIVE_LOCKS_REQUIRED(cs) {
720 [ # # # # ]: 0 : return m_sequence_number++;
[ # # # # ]
721 : : }
722 : :
723 : 0 : uint64_t GetSequence() const EXCLUSIVE_LOCKS_REQUIRED(cs) {
724 [ # # ]: 0 : return m_sequence_number;
725 : : }
726 : :
727 : : /**
728 : : * Calculate the sorted chunks for the old and new mempool relating to the
729 : : * clusters that would be affected by a potential replacement transaction.
730 : : * (replacement_fees, replacement_vsize) values are gathered from a
731 : : * proposed set of replacement transactions that are considered as a single
732 : : * chunk, and represent their complete cluster. In other words, they have no
733 : : * in-mempool ancestors.
734 : : *
735 : : * @param[in] replacement_fees Package fees
736 : : * @param[in] replacement_vsize Package size (must be greater than 0)
737 : : * @param[in] direct_conflicts All transactions that would be removed directly by
738 : : * having a conflicting input with a proposed transaction
739 : : * @param[in] all_conflicts All transactions that would be removed
740 : : * @return old and new diagram pair respectively, or an error string if the conflicts don't match a calculable topology
741 : : */
742 : : util::Result<std::pair<std::vector<FeeFrac>, std::vector<FeeFrac>>> CalculateChunksForRBF(CAmount replacement_fees, int64_t replacement_vsize, const setEntries& direct_conflicts, const setEntries& all_conflicts) EXCLUSIVE_LOCKS_REQUIRED(cs);
743 : :
744 : : /* Check that all direct conflicts are in a cluster size of two or less. Each
745 : : * direct conflict may be in a separate cluster.
746 : : */
747 : : std::optional<std::string> CheckConflictTopology(const setEntries& direct_conflicts);
748 : :
749 : : private:
750 : : /** UpdateForDescendants is used by UpdateTransactionsFromBlock to update
751 : : * the descendants for a single transaction that has been added to the
752 : : * mempool but may have child transactions in the mempool, eg during a
753 : : * chain reorg.
754 : : *
755 : : * @pre CTxMemPoolEntry::m_children is correct for the given tx and all
756 : : * descendants.
757 : : * @pre cachedDescendants is an accurate cache where each entry has all
758 : : * descendants of the corresponding key, including those that should
759 : : * be removed for violation of ancestor limits.
760 : : * @post if updateIt has any non-excluded descendants, cachedDescendants has
761 : : * a new cache line for updateIt.
762 : : * @post descendants_to_remove has a new entry for any descendant which exceeded
763 : : * ancestor limits relative to updateIt.
764 : : *
765 : : * @param[in] updateIt the entry to update for its descendants
766 : : * @param[in,out] cachedDescendants a cache where each line corresponds to all
767 : : * descendants. It will be updated with the descendants of the transaction
768 : : * being updated, so that future invocations don't need to walk the same
769 : : * transaction again, if encountered in another transaction chain.
770 : : * @param[in] setExclude the set of descendant transactions in the mempool
771 : : * that must not be accounted for (because any descendants in setExclude
772 : : * were added to the mempool after the transaction being updated and hence
773 : : * their state is already reflected in the parent state).
774 : : * @param[out] descendants_to_remove Populated with the txids of entries that
775 : : * exceed ancestor limits. It's the responsibility of the caller to
776 : : * removeRecursive them.
777 : : */
778 : : void UpdateForDescendants(txiter updateIt, cacheMap& cachedDescendants,
779 : : const std::set<uint256>& setExclude, std::set<uint256>& descendants_to_remove) EXCLUSIVE_LOCKS_REQUIRED(cs);
780 : : /** Update ancestors of hash to add/remove it as a descendant transaction. */
781 : : void UpdateAncestorsOf(bool add, txiter hash, setEntries &setAncestors) EXCLUSIVE_LOCKS_REQUIRED(cs);
782 : : /** Set ancestor state for an entry */
783 : : void UpdateEntryForAncestors(txiter it, const setEntries &setAncestors) EXCLUSIVE_LOCKS_REQUIRED(cs);
784 : : /** For each transaction being removed, update ancestors and any direct children.
785 : : * If updateDescendants is true, then also update in-mempool descendants'
786 : : * ancestor state. */
787 : : void UpdateForRemoveFromMempool(const setEntries &entriesToRemove, bool updateDescendants) EXCLUSIVE_LOCKS_REQUIRED(cs);
788 : : /** Sever link between specified transaction and direct children. */
789 : : void UpdateChildrenForRemoval(txiter entry) EXCLUSIVE_LOCKS_REQUIRED(cs);
790 : :
791 : : /** Before calling removeUnchecked for a given transaction,
792 : : * UpdateForRemoveFromMempool must be called on the entire (dependent) set
793 : : * of transactions being removed at the same time. We use each
794 : : * CTxMemPoolEntry's setMemPoolParents in order to walk ancestors of a
795 : : * given transaction that is removed, so we can't remove intermediate
796 : : * transactions in a chain before we've updated all the state for the
797 : : * removal.
798 : : */
799 : : void removeUnchecked(txiter entry, MemPoolRemovalReason reason) EXCLUSIVE_LOCKS_REQUIRED(cs);
800 : : public:
801 : : /** visited marks a CTxMemPoolEntry as having been traversed
802 : : * during the lifetime of the most recently created Epoch::Guard
803 : : * and returns false if we are the first visitor, true otherwise.
804 : : *
805 : : * An Epoch::Guard must be held when visited is called or an assert will be
806 : : * triggered.
807 : : *
808 : : */
809 : 0 : bool visited(const txiter it) const EXCLUSIVE_LOCKS_REQUIRED(cs, m_epoch)
810 : : {
811 : 0 : return m_epoch.visited(it->m_epoch_marker);
812 : : }
813 : :
814 : : bool visited(std::optional<txiter> it) const EXCLUSIVE_LOCKS_REQUIRED(cs, m_epoch)
815 : : {
816 : : assert(m_epoch.guarded()); // verify guard even when it==nullopt
817 : : return !it || visited(*it);
818 : : }
819 : : };
820 : :
821 : : /**
822 : : * CCoinsView that brings transactions from a mempool into view.
823 : : * It does not check for spendings by memory pool transactions.
824 : : * Instead, it provides access to all Coins which are either unspent in the
825 : : * base CCoinsView, are outputs from any mempool transaction, or are
826 : : * tracked temporarily to allow transaction dependencies in package validation.
827 : : * This allows transaction replacement to work as expected, as you want to
828 : : * have all inputs "available" to check signatures, and any cycles in the
829 : : * dependency graph are checked directly in AcceptToMemoryPool.
830 : : * It also allows you to sign a double-spend directly in
831 : : * signrawtransactionwithkey and signrawtransactionwithwallet,
832 : : * as long as the conflicting transaction is not yet confirmed.
833 : : */
834 : : class CCoinsViewMemPool : public CCoinsViewBacked
835 : : {
836 : : /**
837 : : * Coins made available by transactions being validated. Tracking these allows for package
838 : : * validation, since we can access transaction outputs without submitting them to mempool.
839 : : */
840 : : std::unordered_map<COutPoint, Coin, SaltedOutpointHasher> m_temp_added;
841 : :
842 : : /**
843 : : * Set of all coins that have been fetched from mempool or created using PackageAddTransaction
844 : : * (not base). Used to track the origin of a coin, see GetNonBaseCoins().
845 : : */
846 : : mutable std::unordered_set<COutPoint, SaltedOutpointHasher> m_non_base_coins;
847 : : protected:
848 : : const CTxMemPool& mempool;
849 : :
850 : : public:
851 : : CCoinsViewMemPool(CCoinsView* baseIn, const CTxMemPool& mempoolIn);
852 : : /** GetCoin, returning whether it exists and is not spent. Also updates m_non_base_coins if the
853 : : * coin is not fetched from base. */
854 : : bool GetCoin(const COutPoint &outpoint, Coin &coin) const override;
855 : : /** Add the coins created by this transaction. These coins are only temporarily stored in
856 : : * m_temp_added and cannot be flushed to the back end. Only used for package validation. */
857 : : void PackageAddTransaction(const CTransactionRef& tx);
858 : : /** Get all coins in m_non_base_coins. */
859 : 0 : std::unordered_set<COutPoint, SaltedOutpointHasher> GetNonBaseCoins() const { return m_non_base_coins; }
860 : : /** Clear m_temp_added and m_non_base_coins. */
861 : : void Reset();
862 : : };
863 : : #endif // BITCOIN_TXMEMPOOL_H
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