Branch data Line data Source code
1 : : // Copyright (c) 2009-2010 Satoshi Nakamoto
2 : : // Copyright (c) 2009-present 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_COINS_H
7 : : #define BITCOIN_COINS_H
8 : :
9 : : #include <compressor.h>
10 : : #include <core_memusage.h>
11 : : #include <memusage.h>
12 : : #include <primitives/transaction.h>
13 : : #include <serialize.h>
14 : : #include <support/allocators/pool.h>
15 : : #include <uint256.h>
16 : : #include <util/check.h>
17 : : #include <util/hasher.h>
18 : :
19 : : #include <cassert>
20 : : #include <cstdint>
21 : :
22 : : #include <functional>
23 : : #include <unordered_map>
24 : :
25 : : /**
26 : : * A UTXO entry.
27 : : *
28 : : * Serialized format:
29 : : * - VARINT((coinbase ? 1 : 0) | (height << 1))
30 : : * - the non-spent CTxOut (via TxOutCompression)
31 : : */
32 [ + - + - : 84611121 : class Coin
+ - + - +
- + - + -
- + - - +
- + - - +
- - + - +
- + - + -
+ + ][ + -
+ - + - +
- + - ][ +
+ + + # #
# # # # ]
[ + + + + ]
33 : : {
34 : : public:
35 : : //! unspent transaction output
36 : : CTxOut out;
37 : :
38 : : //! whether containing transaction was a coinbase
39 : : unsigned int fCoinBase : 1;
40 : :
41 : : //! at which height this containing transaction was included in the active block chain
42 : : uint32_t nHeight : 31;
43 : :
44 : : //! construct a Coin from a CTxOut and height/coinbase information.
45 [ + + ]: 61 : Coin(CTxOut&& outIn, int nHeightIn, bool fCoinBaseIn) : out(std::move(outIn)), fCoinBase(fCoinBaseIn), nHeight(nHeightIn) {}
46 [ + - ]: 19503997 : Coin(const CTxOut& outIn, int nHeightIn, bool fCoinBaseIn) : out(outIn), fCoinBase(fCoinBaseIn),nHeight(nHeightIn) {}
[ + + + + ]
47 : :
48 : 11916118 : void Clear() {
49 : 11916118 : out.SetNull();
50 : 11916118 : fCoinBase = false;
51 [ - + + + : 11916118 : nHeight = 0;
+ - ]
52 : 11848437 : }
53 : :
54 : : //! empty constructor
55 [ + - + - : 73600152 : Coin() : fCoinBase(false), nHeight(0) { }
# # # # #
# # # ][ +
- + - + -
- + - + +
+ ][ + - +
- + - ][ -
- - - +
- ]
56 : :
57 : 12205533 : bool IsCoinBase() const {
58 [ + + ]: 12205533 : return fCoinBase;
[ + + + + ]
59 : : }
60 : :
61 : : template<typename Stream>
62 : 297212 : void Serialize(Stream &s) const {
63 [ - + ]: 297212 : assert(!IsSpent());
64 : 297212 : uint32_t code = nHeight * uint32_t{2} + fCoinBase;
65 : 297212 : ::Serialize(s, VARINT(code));
66 : 297212 : ::Serialize(s, Using<TxOutCompression>(out));
67 : 297212 : }
68 : :
69 : : template<typename Stream>
70 : 317803 : void Unserialize(Stream &s) {
71 : 317803 : uint32_t code = 0;
72 : 317803 : ::Unserialize(s, VARINT(code));
73 : 317803 : nHeight = code >> 1;
74 : 317803 : fCoinBase = code & 1;
75 : 317803 : ::Unserialize(s, Using<TxOutCompression>(out));
76 : 317800 : }
77 : :
78 : : /** Either this coin never existed (see e.g. coinEmpty in coins.cpp), or it
79 : : * did exist and has been spent.
80 : : */
81 [ + - ]: 116044810 : bool IsSpent() const {
82 [ + + ][ + + : 115264971 : return out.IsNull();
+ + - + +
- + - + -
+ + + + +
+ + + + -
+ + + + +
+ + + -
+ ][ - - -
+ + - - +
- + ][ - +
+ + - + #
# # # ][ +
+ - + + +
+ - - + +
+ + + - +
- + + + -
+ ][ + + +
+ + + + +
+ + + + +
+ - + + +
+ + + + ]
83 : : }
84 : :
85 : 46007839 : size_t DynamicMemoryUsage() const {
86 [ - + + + : 46808792 : return memusage::DynamicUsage(out.scriptPubKey);
- + - + -
- - + + +
+ - + + +
+ - + + +
+ + + + +
+ - + - +
+ + + + -
+ ][ + + +
+ + + - +
- - + + +
+ + - + +
+ + + + +
+ + + + +
+ + + + +
+ + + + +
+ + ]
87 : : }
88 : : };
89 : :
90 : : struct CCoinsCacheEntry;
91 : : using CoinsCachePair = std::pair<const COutPoint, CCoinsCacheEntry>;
92 : :
93 : : /**
94 : : * A Coin in one level of the coins database caching hierarchy.
95 : : *
96 : : * A coin can either be:
97 : : * - unspent or spent (in which case the Coin object will be nulled out - see Coin.Clear())
98 : : * - DIRTY or not DIRTY
99 : : * - FRESH or not FRESH
100 : : *
101 : : * Out of these 2^3 = 8 states, only some combinations are valid:
102 : : * - unspent, FRESH, DIRTY (e.g. a new coin created in the cache)
103 : : * - unspent, not FRESH, DIRTY (e.g. a coin changed in the cache during a reorg)
104 : : * - unspent, not FRESH, not DIRTY (e.g. an unspent coin fetched from the parent cache)
105 : : * - spent, FRESH, not DIRTY (e.g. a spent coin fetched from the parent cache)
106 : : * - spent, not FRESH, DIRTY (e.g. a coin is spent and spentness needs to be flushed to the parent)
107 : : */
108 : : struct CCoinsCacheEntry
109 : : {
110 : : private:
111 : : /**
112 : : * These are used to create a doubly linked list of flagged entries.
113 : : * They are set in SetDirty, SetFresh, and unset in SetClean.
114 : : * A flagged entry is any entry that is either DIRTY, FRESH, or both.
115 : : *
116 : : * DIRTY entries are tracked so that only modified entries can be passed to
117 : : * the parent cache for batch writing. This is a performance optimization
118 : : * compared to giving all entries in the cache to the parent and having the
119 : : * parent scan for only modified entries.
120 : : *
121 : : * FRESH-but-not-DIRTY coins can not occur in practice, since that would
122 : : * mean a spent coin exists in the parent CCoinsView and not in the child
123 : : * CCoinsViewCache. Nevertheless, if a spent coin is retrieved from the
124 : : * parent cache, the FRESH-but-not-DIRTY coin will be tracked by the linked
125 : : * list and deleted when Sync or Flush is called on the CCoinsViewCache.
126 : : */
127 : : CoinsCachePair* m_prev{nullptr};
128 : : CoinsCachePair* m_next{nullptr};
129 : : uint8_t m_flags{0};
130 : :
131 : : //! Adding a flag requires a reference to the sentinel of the flagged pair linked list.
132 : 50888905 : static void AddFlags(uint8_t flags, CoinsCachePair& pair, CoinsCachePair& sentinel) noexcept
133 : : {
134 : 50888905 : Assume(flags & (DIRTY | FRESH));
135 : 50888905 : if (!pair.second.m_flags) {
136 : 31685577 : Assume(!pair.second.m_prev && !pair.second.m_next);
137 : 31685577 : pair.second.m_prev = sentinel.second.m_prev;
138 : 31685577 : pair.second.m_next = &sentinel;
139 : 31685577 : sentinel.second.m_prev = &pair;
140 : 31685577 : pair.second.m_prev->second.m_next = &pair;
141 : : }
142 : 50888905 : Assume(pair.second.m_prev && pair.second.m_next);
143 : 50888905 : pair.second.m_flags |= flags;
144 : : }
145 : :
146 : : public:
147 : : Coin coin; // The actual cached data.
148 : :
149 : : enum Flags {
150 : : /**
151 : : * DIRTY means the CCoinsCacheEntry is potentially different from the
152 : : * version in the parent cache. Failure to mark a coin as DIRTY when
153 : : * it is potentially different from the parent cache will cause a
154 : : * consensus failure, since the coin's state won't get written to the
155 : : * parent when the cache is flushed.
156 : : */
157 : : DIRTY = (1 << 0),
158 : : /**
159 : : * FRESH means the parent cache does not have this coin or that it is a
160 : : * spent coin in the parent cache. If a FRESH coin in the cache is
161 : : * later spent, it can be deleted entirely and doesn't ever need to be
162 : : * flushed to the parent. This is a performance optimization. Marking a
163 : : * coin as FRESH when it exists unspent in the parent cache will cause a
164 : : * consensus failure, since it might not be deleted from the parent
165 : : * when this cache is flushed.
166 : : */
167 : : FRESH = (1 << 1),
168 : : };
169 : :
170 : 60292437 : CCoinsCacheEntry() noexcept = default;
171 : 6049 : explicit CCoinsCacheEntry(Coin&& coin_) noexcept : coin(std::move(coin_)) {}
172 : 60298806 : ~CCoinsCacheEntry()
173 : : {
174 : 120597612 : SetClean();
175 : 60298806 : }
176 : :
177 [ + - + + : 63044870 : static void SetDirty(CoinsCachePair& pair, CoinsCachePair& sentinel) noexcept { AddFlags(DIRTY, pair, sentinel); }
+ + + + +
- + + +
+ ][ + - #
# # # # #
# # # # ]
[ + - + +
+ + + + +
- + + +
+ ]
178 [ + - + - : 19529612 : static void SetFresh(CoinsCachePair& pair, CoinsCachePair& sentinel) noexcept { AddFlags(FRESH, pair, sentinel); }
- + + - ]
[ + + # #
# # # # ]
179 : :
180 : 60356907 : void SetClean() noexcept
181 : : {
182 [ + + ][ + - : 60298812 : if (!m_flags) return;
- + + - -
- ]
183 : 32211741 : m_next->second.m_prev = m_prev;
184 : 32211741 : m_prev->second.m_next = m_next;
185 : 32211741 : m_flags = 0;
186 : 32211741 : m_prev = m_next = nullptr;
187 : : }
188 [ + - + - : 20723764 : bool IsDirty() const noexcept { return m_flags & DIRTY; }
+ - + - +
- + - + -
+ - + - +
- + - ][ +
+ - - + +
- + # # #
# # # # #
# # # # #
# ][ + + +
+ + + +
+ ]
189 [ + + + + : 12985276 : bool IsFresh() const noexcept { return m_flags & FRESH; }
+ + + + +
+ ][ + + +
+ + + + +
+ + ]
190 : :
191 : : //! Only call Next when this entry is DIRTY, FRESH, or both
192 : 1423890 : CoinsCachePair* Next() const noexcept
193 : : {
194 : 1423891 : Assume(m_flags);
195 [ + + + - : 1085200 : return m_next;
+ - + - +
- + - + -
+ - + - +
- + - + -
+ - + - +
- + - + -
+ - + - +
- + - + -
+ - + - ]
[ - + ]
196 : : }
197 : :
198 : : //! Only call Prev when this entry is DIRTY, FRESH, or both
199 : 194697 : CoinsCachePair* Prev() const noexcept
200 : : {
201 : 194697 : Assume(m_flags);
202 [ + - + - : 97368 : return m_prev;
+ - + - +
- + - + -
+ - + - +
- + - + -
+ - + - +
- + - + -
+ - + - +
- ]
[ - + - + ]
203 : : }
204 : :
205 : : //! Only use this for initializing the linked list sentinel
206 : 526164 : void SelfRef(CoinsCachePair& pair) noexcept
207 : : {
208 : 526164 : Assume(&pair.second == this);
209 : 526164 : m_prev = &pair;
210 : 526164 : m_next = &pair;
211 : : // Set sentinel to DIRTY so we can call Next on it
212 [ + - + - : 526164 : m_flags = DIRTY;
+ - ][ + -
# # # # ]
213 : : }
214 : : };
215 : :
216 : : /**
217 : : * PoolAllocator's MAX_BLOCK_SIZE_BYTES parameter here uses sizeof the data, and adds the size
218 : : * of 4 pointers. We do not know the exact node size used in the std::unordered_node implementation
219 : : * because it is implementation defined. Most implementations have an overhead of 1 or 2 pointers,
220 : : * so nodes can be connected in a linked list, and in some cases the hash value is stored as well.
221 : : * Using an additional sizeof(void*)*4 for MAX_BLOCK_SIZE_BYTES should thus be sufficient so that
222 : : * all implementations can allocate the nodes from the PoolAllocator.
223 : : */
224 : : using CCoinsMap = std::unordered_map<COutPoint,
225 : : CCoinsCacheEntry,
226 : : SaltedOutpointHasher,
227 : : std::equal_to<COutPoint>,
228 : : PoolAllocator<CoinsCachePair,
229 : : sizeof(CoinsCachePair) + sizeof(void*) * 4>>;
230 : :
231 : : using CCoinsMapMemoryResource = CCoinsMap::allocator_type::ResourceType;
232 : :
233 : : /** Cursor for iterating over CoinsView state */
234 : : class CCoinsViewCursor
235 : : {
236 : : public:
237 : 1194 : CCoinsViewCursor(const uint256 &hashBlockIn): hashBlock(hashBlockIn) {}
238 : 1194 : virtual ~CCoinsViewCursor() = default;
239 : :
240 : : virtual bool GetKey(COutPoint &key) const = 0;
241 : : virtual bool GetValue(Coin &coin) const = 0;
242 : :
243 : : virtual bool Valid() const = 0;
244 : : virtual void Next() = 0;
245 : :
246 : : //! Get best block at the time this cursor was created
247 : : const uint256 &GetBestBlock() const { return hashBlock; }
248 : : private:
249 : : uint256 hashBlock;
250 : : };
251 : :
252 : : /**
253 : : * Cursor for iterating over the linked list of flagged entries in CCoinsViewCache.
254 : : *
255 : : * This is a helper struct to encapsulate the diverging logic between a non-erasing
256 : : * CCoinsViewCache::Sync and an erasing CCoinsViewCache::Flush. This allows the receiver
257 : : * of CCoinsView::BatchWrite to iterate through the flagged entries without knowing
258 : : * the caller's intent.
259 : : *
260 : : * However, the receiver can still call CoinsViewCacheCursor::WillErase to see if the
261 : : * caller will erase the entry after BatchWrite returns. If so, the receiver can
262 : : * perform optimizations such as moving the coin out of the CCoinsCachEntry instead
263 : : * of copying it.
264 : : */
265 : : struct CoinsViewCacheCursor
266 : : {
267 : : //! If will_erase is not set, iterating through the cursor will erase spent coins from the map,
268 : : //! and other coins will be unflagged (removing them from the linked list).
269 : : //! If will_erase is set, the underlying map and linked list will not be modified,
270 : : //! as the caller is expected to wipe the entire map anyway.
271 : : //! This is an optimization compared to erasing all entries as the cursor iterates them when will_erase is set.
272 : : //! Calling CCoinsMap::clear() afterwards is faster because a CoinsCachePair cannot be coerced back into a
273 : : //! CCoinsMap::iterator to be erased, and must therefore be looked up again by key in the CCoinsMap before being erased.
274 : 147860 : CoinsViewCacheCursor(CoinsCachePair& sentinel LIFETIMEBOUND,
275 : : CCoinsMap& map LIFETIMEBOUND,
276 : : bool will_erase) noexcept
277 [ + - ]: 147860 : : m_sentinel(sentinel), m_map(map), m_will_erase(will_erase) {}
278 : :
279 : 147860 : inline CoinsCachePair* Begin() const noexcept { return m_sentinel.second.Next(); }
280 [ + + ]: 1228567 : inline CoinsCachePair* End() const noexcept { return &m_sentinel; }
281 : :
282 : : //! Return the next entry after current, possibly erasing current
283 : 1080707 : inline CoinsCachePair* NextAndMaybeErase(CoinsCachePair& current) noexcept
284 : : {
285 : 1080707 : const auto next_entry{current.second.Next()};
286 : : // If we are not going to erase the cache, we must still erase spent entries.
287 : : // Otherwise, clear the state of the entry.
288 [ + + ]: 1080707 : if (!m_will_erase) {
289 [ + + ]: 82716 : if (current.second.coin.IsSpent()) {
290 [ - + - - ]: 24621 : assert(current.second.coin.DynamicMemoryUsage() == 0); // scriptPubKey was already cleared in SpendCoin
291 : 24621 : m_map.erase(current.first);
292 : : } else {
293 [ + - ]: 58095 : current.second.SetClean();
294 : : }
295 : : }
296 : 1080707 : return next_entry;
297 : : }
298 : :
299 [ + + + + : 470822 : inline bool WillErase(CoinsCachePair& current) const noexcept { return m_will_erase || current.second.coin.IsSpent(); }
+ + + + ]
300 : : private:
301 : : CoinsCachePair& m_sentinel;
302 : : CCoinsMap& m_map;
303 : : bool m_will_erase;
304 : : };
305 : :
306 : : /** Abstract view on the open txout dataset. */
307 [ + - + - : 604579 : class CCoinsView
+ - ]
308 : : {
309 : : public:
310 : : //! Retrieve the Coin (unspent transaction output) for a given outpoint.
311 : : virtual std::optional<Coin> GetCoin(const COutPoint& outpoint) const;
312 : :
313 : : //! Just check whether a given outpoint is unspent.
314 : : virtual bool HaveCoin(const COutPoint &outpoint) const;
315 : :
316 : : //! Retrieve the block hash whose state this CCoinsView currently represents
317 : : virtual uint256 GetBestBlock() const;
318 : :
319 : : //! Retrieve the range of blocks that may have been only partially written.
320 : : //! If the database is in a consistent state, the result is the empty vector.
321 : : //! Otherwise, a two-element vector is returned consisting of the new and
322 : : //! the old block hash, in that order.
323 : : virtual std::vector<uint256> GetHeadBlocks() const;
324 : :
325 : : //! Do a bulk modification (multiple Coin changes + BestBlock change).
326 : : //! The passed cursor is used to iterate through the coins.
327 : : virtual bool BatchWrite(CoinsViewCacheCursor& cursor, const uint256& hashBlock);
328 : :
329 : : //! Get a cursor to iterate over the whole state
330 : : virtual std::unique_ptr<CCoinsViewCursor> Cursor() const;
331 : :
332 : : //! As we use CCoinsViews polymorphically, have a virtual destructor
333 : 191 : virtual ~CCoinsView() = default;
334 : :
335 : : //! Estimate database size (0 if not implemented)
336 : 0 : virtual size_t EstimateSize() const { return 0; }
337 : : };
338 : :
339 : :
340 : : /** CCoinsView backed by another CCoinsView */
341 : 0 : class CCoinsViewBacked : public CCoinsView
342 : : {
343 : : protected:
344 : : CCoinsView *base;
345 : :
346 : : public:
347 : : CCoinsViewBacked(CCoinsView *viewIn);
348 : : std::optional<Coin> GetCoin(const COutPoint& outpoint) const override;
349 : : bool HaveCoin(const COutPoint &outpoint) const override;
350 : : uint256 GetBestBlock() const override;
351 : : std::vector<uint256> GetHeadBlocks() const override;
352 : : void SetBackend(CCoinsView &viewIn);
353 : : bool BatchWrite(CoinsViewCacheCursor& cursor, const uint256 &hashBlock) override;
354 : : std::unique_ptr<CCoinsViewCursor> Cursor() const override;
355 : : size_t EstimateSize() const override;
356 : : };
357 : :
358 : :
359 : : /** CCoinsView that adds a memory cache for transactions to another CCoinsView */
360 : : class CCoinsViewCache : public CCoinsViewBacked
361 : : {
362 : : private:
363 : : const bool m_deterministic;
364 : :
365 : : protected:
366 : : /**
367 : : * Make mutable so that we can "fill the cache" even from Get-methods
368 : : * declared as "const".
369 : : */
370 : : mutable uint256 hashBlock;
371 : : mutable CCoinsMapMemoryResource m_cache_coins_memory_resource{};
372 : : /* The starting sentinel of the flagged entry circular doubly linked list. */
373 : : mutable CoinsCachePair m_sentinel;
374 : : mutable CCoinsMap cacheCoins;
375 : :
376 : : /* Cached dynamic memory usage for the inner Coin objects. */
377 : : mutable size_t cachedCoinsUsage{0};
378 : :
379 : : public:
380 : : CCoinsViewCache(CCoinsView *baseIn, bool deterministic = false);
381 : :
382 : : /**
383 : : * By deleting the copy constructor, we prevent accidentally using it when one intends to create a cache on top of a base cache.
384 : : */
385 : : CCoinsViewCache(const CCoinsViewCache &) = delete;
386 : :
387 : : // Standard CCoinsView methods
388 : : std::optional<Coin> GetCoin(const COutPoint& outpoint) const override;
389 : : bool HaveCoin(const COutPoint &outpoint) const override;
390 : : uint256 GetBestBlock() const override;
391 : : void SetBestBlock(const uint256 &hashBlock);
392 : : bool BatchWrite(CoinsViewCacheCursor& cursor, const uint256 &hashBlock) override;
393 : 0 : std::unique_ptr<CCoinsViewCursor> Cursor() const override {
394 [ # # ]: 0 : throw std::logic_error("CCoinsViewCache cursor iteration not supported.");
395 : : }
396 : :
397 : : /**
398 : : * Check if we have the given utxo already loaded in this cache.
399 : : * The semantics are the same as HaveCoin(), but no calls to
400 : : * the backing CCoinsView are made.
401 : : */
402 : : bool HaveCoinInCache(const COutPoint &outpoint) const;
403 : :
404 : : /**
405 : : * Return a reference to Coin in the cache, or coinEmpty if not found. This is
406 : : * more efficient than GetCoin.
407 : : *
408 : : * Generally, do not hold the reference returned for more than a short scope.
409 : : * While the current implementation allows for modifications to the contents
410 : : * of the cache while holding the reference, this behavior should not be relied
411 : : * on! To be safe, best to not hold the returned reference through any other
412 : : * calls to this cache.
413 : : */
414 : : const Coin& AccessCoin(const COutPoint &output) const;
415 : :
416 : : /**
417 : : * Add a coin. Set possible_overwrite to true if an unspent version may
418 : : * already exist in the cache.
419 : : */
420 : : void AddCoin(const COutPoint& outpoint, Coin&& coin, bool possible_overwrite);
421 : :
422 : : /**
423 : : * Emplace a coin into cacheCoins without performing any checks, marking
424 : : * the emplaced coin as dirty.
425 : : *
426 : : * NOT FOR GENERAL USE. Used only when loading coins from a UTXO snapshot.
427 : : * @sa ChainstateManager::PopulateAndValidateSnapshot()
428 : : */
429 : : void EmplaceCoinInternalDANGER(COutPoint&& outpoint, Coin&& coin);
430 : :
431 : : /**
432 : : * Spend a coin. Pass moveto in order to get the deleted data.
433 : : * If no unspent output exists for the passed outpoint, this call
434 : : * has no effect.
435 : : */
436 : : bool SpendCoin(const COutPoint &outpoint, Coin* moveto = nullptr);
437 : :
438 : : /**
439 : : * Push the modifications applied to this cache to its base and wipe local state.
440 : : * Failure to call this method or Sync() before destruction will cause the changes
441 : : * to be forgotten.
442 : : * If false is returned, the state of this cache (and its backing view) will be undefined.
443 : : */
444 : : bool Flush();
445 : :
446 : : /**
447 : : * Push the modifications applied to this cache to its base while retaining
448 : : * the contents of this cache (except for spent coins, which we erase).
449 : : * Failure to call this method or Flush() before destruction will cause the changes
450 : : * to be forgotten.
451 : : * If false is returned, the state of this cache (and its backing view) will be undefined.
452 : : */
453 : : bool Sync();
454 : :
455 : : /**
456 : : * Removes the UTXO with the given outpoint from the cache, if it is
457 : : * not modified.
458 : : */
459 : : void Uncache(const COutPoint &outpoint);
460 : :
461 : : //! Calculate the size of the cache (in number of transaction outputs)
462 : : unsigned int GetCacheSize() const;
463 : :
464 : : //! Calculate the size of the cache (in bytes)
465 : : size_t DynamicMemoryUsage() const;
466 : :
467 : : //! Check whether all prevouts of the transaction are present in the UTXO set represented by this view
468 : : bool HaveInputs(const CTransaction& tx) const;
469 : :
470 : : //! Force a reallocation of the cache map. This is required when downsizing
471 : : //! the cache because the map's allocator may be hanging onto a lot of
472 : : //! memory despite having called .clear().
473 : : //!
474 : : //! See: https://stackoverflow.com/questions/42114044/how-to-release-unordered-map-memory
475 : : void ReallocateCache();
476 : :
477 : : //! Run an internal sanity check on the cache data structure. */
478 : : void SanityCheck() const;
479 : :
480 : : private:
481 : : /**
482 : : * @note this is marked const, but may actually append to `cacheCoins`, increasing
483 : : * memory usage.
484 : : */
485 : : CCoinsMap::iterator FetchCoin(const COutPoint &outpoint) const;
486 : : };
487 : :
488 : : //! Utility function to add all of a transaction's outputs to a cache.
489 : : //! When check is false, this assumes that overwrites are only possible for coinbase transactions.
490 : : //! When check is true, the underlying view may be queried to determine whether an addition is
491 : : //! an overwrite.
492 : : // TODO: pass in a boolean to limit these possible overwrites to known
493 : : // (pre-BIP34) cases.
494 : : void AddCoins(CCoinsViewCache& cache, const CTransaction& tx, int nHeight, bool check = false);
495 : :
496 : : //! Utility function to find any unspent output with a given txid.
497 : : //! This function can be quite expensive because in the event of a transaction
498 : : //! which is not found in the cache, it can cause up to MAX_OUTPUTS_PER_BLOCK
499 : : //! lookups to database, so it should be used with care.
500 : : const Coin& AccessByTxid(const CCoinsViewCache& cache, const Txid& txid);
501 : :
502 : : /**
503 : : * This is a minimally invasive approach to shutdown on LevelDB read errors from the
504 : : * chainstate, while keeping user interface out of the common library, which is shared
505 : : * between bitcoind, and bitcoin-qt and non-server tools.
506 : : *
507 : : * Writes do not need similar protection, as failure to write is handled by the caller.
508 : : */
509 : : class CCoinsViewErrorCatcher final : public CCoinsViewBacked
510 : : {
511 : : public:
512 [ + - ]: 1241 : explicit CCoinsViewErrorCatcher(CCoinsView* view) : CCoinsViewBacked(view) {}
513 : :
514 : 1021 : void AddReadErrCallback(std::function<void()> f) {
515 [ + - ]: 1021 : m_err_callbacks.emplace_back(std::move(f));
516 : 1021 : }
517 : :
518 : : std::optional<Coin> GetCoin(const COutPoint& outpoint) const override;
519 : : bool HaveCoin(const COutPoint &outpoint) const override;
520 : :
521 : : private:
522 : : /** A list of callbacks to execute upon leveldb read error. */
523 : : std::vector<std::function<void()>> m_err_callbacks;
524 : :
525 : : };
526 : :
527 : : #endif // BITCOIN_COINS_H
|
