Line data Source code
1 : // Copyright (c) 2012-2022 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 : #include <coins.h>
6 :
7 : #include <consensus/consensus.h>
8 : #include <logging.h>
9 : #include <random.h>
10 : #include <util/trace.h>
11 : #include <version.h>
12 :
13 0 : bool CCoinsView::GetCoin(const COutPoint &outpoint, Coin &coin) const { return false; }
14 0 : uint256 CCoinsView::GetBestBlock() const { return uint256(); }
15 0 : std::vector<uint256> CCoinsView::GetHeadBlocks() const { return std::vector<uint256>(); }
16 0 : bool CCoinsView::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock, bool erase) { return false; }
17 0 : std::unique_ptr<CCoinsViewCursor> CCoinsView::Cursor() const { return nullptr; }
18 :
19 0 : bool CCoinsView::HaveCoin(const COutPoint &outpoint) const
20 : {
21 0 : Coin coin;
22 0 : return GetCoin(outpoint, coin);
23 0 : }
24 :
25 42579 : CCoinsViewBacked::CCoinsViewBacked(CCoinsView *viewIn) : base(viewIn) { }
26 19256 : bool CCoinsViewBacked::GetCoin(const COutPoint &outpoint, Coin &coin) const { return base->GetCoin(outpoint, coin); }
27 0 : bool CCoinsViewBacked::HaveCoin(const COutPoint &outpoint) const { return base->HaveCoin(outpoint); }
28 5166 : uint256 CCoinsViewBacked::GetBestBlock() const { return base->GetBestBlock(); }
29 0 : std::vector<uint256> CCoinsViewBacked::GetHeadBlocks() const { return base->GetHeadBlocks(); }
30 21830 : void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; }
31 0 : bool CCoinsViewBacked::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock, bool erase) { return base->BatchWrite(mapCoins, hashBlock, erase); }
32 0 : std::unique_ptr<CCoinsViewCursor> CCoinsViewBacked::Cursor() const { return base->Cursor(); }
33 0 : size_t CCoinsViewBacked::EstimateSize() const { return base->EstimateSize(); }
34 :
35 54468 : CCoinsViewCache::CCoinsViewCache(CCoinsView* baseIn, bool deterministic) :
36 54468 : CCoinsViewBacked(baseIn), m_deterministic(deterministic),
37 27234 : cacheCoins(0, SaltedOutpointHasher(/*deterministic=*/deterministic), CCoinsMap::key_equal{}, &m_cache_coins_memory_resource)
38 54468 : {}
39 :
40 32095 : size_t CCoinsViewCache::DynamicMemoryUsage() const {
41 32095 : return memusage::DynamicUsage(cacheCoins) + cachedCoinsUsage;
42 : }
43 :
44 427907 : CCoinsMap::iterator CCoinsViewCache::FetchCoin(const COutPoint &outpoint) const {
45 427907 : CCoinsMap::iterator it = cacheCoins.find(outpoint);
46 427907 : if (it != cacheCoins.end())
47 309170 : return it;
48 118737 : Coin tmp;
49 118737 : if (!base->GetCoin(outpoint, tmp))
50 38512 : return cacheCoins.end();
51 80225 : CCoinsMap::iterator ret = cacheCoins.emplace(std::piecewise_construct, std::forward_as_tuple(outpoint), std::forward_as_tuple(std::move(tmp))).first;
52 80225 : if (ret->second.coin.IsSpent()) {
53 : // The parent only has an empty entry for this outpoint; we can consider our
54 : // version as fresh.
55 0 : ret->second.flags = CCoinsCacheEntry::FRESH;
56 0 : }
57 80225 : cachedCoinsUsage += ret->second.coin.DynamicMemoryUsage();
58 80225 : return ret;
59 427907 : }
60 :
61 145909 : bool CCoinsViewCache::GetCoin(const COutPoint &outpoint, Coin &coin) const {
62 145909 : CCoinsMap::const_iterator it = FetchCoin(outpoint);
63 145909 : if (it != cacheCoins.end()) {
64 126653 : coin = it->second.coin;
65 126653 : return !coin.IsSpent();
66 : }
67 19256 : return false;
68 145909 : }
69 :
70 49517 : void CCoinsViewCache::AddCoin(const COutPoint &outpoint, Coin&& coin, bool possible_overwrite) {
71 49517 : assert(!coin.IsSpent());
72 49517 : if (coin.out.scriptPubKey.IsUnspendable()) return;
73 44258 : CCoinsMap::iterator it;
74 2 : bool inserted;
75 44258 : std::tie(it, inserted) = cacheCoins.emplace(std::piecewise_construct, std::forward_as_tuple(outpoint), std::tuple<>());
76 44258 : bool fresh = false;
77 44258 : if (!inserted) {
78 0 : cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage();
79 0 : }
80 44258 : if (!possible_overwrite) {
81 38999 : if (!it->second.coin.IsSpent()) {
82 0 : throw std::logic_error("Attempted to overwrite an unspent coin (when possible_overwrite is false)");
83 : }
84 : // If the coin exists in this cache as a spent coin and is DIRTY, then
85 : // its spentness hasn't been flushed to the parent cache. We're
86 : // re-adding the coin to this cache now but we can't mark it as FRESH.
87 : // If we mark it FRESH and then spend it before the cache is flushed
88 : // we would remove it from this cache and would never flush spentness
89 : // to the parent cache.
90 : //
91 : // Re-adding a spent coin can happen in the case of a re-org (the coin
92 : // is 'spent' when the block adding it is disconnected and then
93 : // re-added when it is also added in a newly connected block).
94 : //
95 : // If the coin doesn't exist in the current cache, or is spent but not
96 : // DIRTY, then it can be marked FRESH.
97 38999 : fresh = !(it->second.flags & CCoinsCacheEntry::DIRTY);
98 38999 : }
99 44258 : it->second.coin = std::move(coin);
100 44258 : it->second.flags |= CCoinsCacheEntry::DIRTY | (fresh ? CCoinsCacheEntry::FRESH : 0);
101 44258 : cachedCoinsUsage += it->second.coin.DynamicMemoryUsage();
102 : TRACE5(utxocache, add,
103 : outpoint.hash.data(),
104 : (uint32_t)outpoint.n,
105 : (uint32_t)it->second.coin.nHeight,
106 : (int64_t)it->second.coin.out.nValue,
107 : (bool)it->second.coin.IsCoinBase());
108 49517 : }
109 :
110 0 : void CCoinsViewCache::EmplaceCoinInternalDANGER(COutPoint&& outpoint, Coin&& coin) {
111 0 : cachedCoinsUsage += coin.DynamicMemoryUsage();
112 0 : cacheCoins.emplace(
113 : std::piecewise_construct,
114 0 : std::forward_as_tuple(std::move(outpoint)),
115 0 : std::forward_as_tuple(std::move(coin), CCoinsCacheEntry::DIRTY));
116 0 : }
117 :
118 8079 : void AddCoins(CCoinsViewCache& cache, const CTransaction &tx, int nHeight, bool check_for_overwrite) {
119 8079 : bool fCoinbase = tx.IsCoinBase();
120 8079 : const uint256& txid = tx.GetHash();
121 57596 : for (size_t i = 0; i < tx.vout.size(); ++i) {
122 49517 : bool overwrite = check_for_overwrite ? cache.HaveCoin(COutPoint(txid, i)) : fCoinbase;
123 : // Coinbase transactions can always be overwritten, in order to correctly
124 : // deal with the pre-BIP30 occurrences of duplicate coinbase transactions.
125 49517 : cache.AddCoin(COutPoint(txid, i), Coin(tx.vout[i], nHeight, fCoinbase), overwrite);
126 49517 : }
127 8079 : }
128 :
129 5398 : bool CCoinsViewCache::SpendCoin(const COutPoint &outpoint, Coin* moveout) {
130 5398 : CCoinsMap::iterator it = FetchCoin(outpoint);
131 5398 : if (it == cacheCoins.end()) return false;
132 5398 : cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage();
133 : TRACE5(utxocache, spent,
134 : outpoint.hash.data(),
135 : (uint32_t)outpoint.n,
136 : (uint32_t)it->second.coin.nHeight,
137 : (int64_t)it->second.coin.out.nValue,
138 : (bool)it->second.coin.IsCoinBase());
139 5398 : if (moveout) {
140 1089 : *moveout = std::move(it->second.coin);
141 1089 : }
142 5398 : if (it->second.flags & CCoinsCacheEntry::FRESH) {
143 733 : cacheCoins.erase(it);
144 733 : } else {
145 4665 : it->second.flags |= CCoinsCacheEntry::DIRTY;
146 4665 : it->second.coin.Clear();
147 : }
148 5398 : return true;
149 5398 : }
150 :
151 2 : static const Coin coinEmpty;
152 :
153 146594 : const Coin& CCoinsViewCache::AccessCoin(const COutPoint &outpoint) const {
154 146594 : CCoinsMap::const_iterator it = FetchCoin(outpoint);
155 146594 : if (it == cacheCoins.end()) {
156 0 : return coinEmpty;
157 : } else {
158 146594 : return it->second.coin;
159 : }
160 146594 : }
161 :
162 130006 : bool CCoinsViewCache::HaveCoin(const COutPoint &outpoint) const {
163 130006 : CCoinsMap::const_iterator it = FetchCoin(outpoint);
164 130006 : return (it != cacheCoins.end() && !it->second.coin.IsSpent());
165 : }
166 :
167 189807 : bool CCoinsViewCache::HaveCoinInCache(const COutPoint &outpoint) const {
168 189807 : CCoinsMap::const_iterator it = cacheCoins.find(outpoint);
169 189807 : return (it != cacheCoins.end() && !it->second.coin.IsSpent());
170 : }
171 :
172 28799 : uint256 CCoinsViewCache::GetBestBlock() const {
173 28799 : if (hashBlock.IsNull())
174 10426 : hashBlock = base->GetBestBlock();
175 28799 : return hashBlock;
176 : }
177 :
178 201 : void CCoinsViewCache::SetBestBlock(const uint256 &hashBlockIn) {
179 201 : hashBlock = hashBlockIn;
180 201 : }
181 :
182 201 : bool CCoinsViewCache::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlockIn, bool erase) {
183 401 : for (CCoinsMap::iterator it = mapCoins.begin();
184 401 : it != mapCoins.end();
185 200 : it = erase ? mapCoins.erase(it) : std::next(it)) {
186 : // Ignore non-dirty entries (optimization).
187 200 : if (!(it->second.flags & CCoinsCacheEntry::DIRTY)) {
188 0 : continue;
189 : }
190 200 : CCoinsMap::iterator itUs = cacheCoins.find(it->first);
191 200 : if (itUs == cacheCoins.end()) {
192 : // The parent cache does not have an entry, while the child cache does.
193 : // We can ignore it if it's both spent and FRESH in the child
194 200 : if (!(it->second.flags & CCoinsCacheEntry::FRESH && it->second.coin.IsSpent())) {
195 : // Create the coin in the parent cache, move the data up
196 : // and mark it as dirty.
197 200 : CCoinsCacheEntry& entry = cacheCoins[it->first];
198 200 : if (erase) {
199 : // The `move` call here is purely an optimization; we rely on the
200 : // `mapCoins.erase` call in the `for` expression to actually remove
201 : // the entry from the child map.
202 200 : entry.coin = std::move(it->second.coin);
203 200 : } else {
204 0 : entry.coin = it->second.coin;
205 : }
206 200 : cachedCoinsUsage += entry.coin.DynamicMemoryUsage();
207 200 : entry.flags = CCoinsCacheEntry::DIRTY;
208 : // We can mark it FRESH in the parent if it was FRESH in the child
209 : // Otherwise it might have just been flushed from the parent's cache
210 : // and already exist in the grandparent
211 200 : if (it->second.flags & CCoinsCacheEntry::FRESH) {
212 0 : entry.flags |= CCoinsCacheEntry::FRESH;
213 0 : }
214 200 : }
215 200 : } else {
216 : // Found the entry in the parent cache
217 0 : if ((it->second.flags & CCoinsCacheEntry::FRESH) && !itUs->second.coin.IsSpent()) {
218 : // The coin was marked FRESH in the child cache, but the coin
219 : // exists in the parent cache. If this ever happens, it means
220 : // the FRESH flag was misapplied and there is a logic error in
221 : // the calling code.
222 0 : throw std::logic_error("FRESH flag misapplied to coin that exists in parent cache");
223 : }
224 :
225 0 : if ((itUs->second.flags & CCoinsCacheEntry::FRESH) && it->second.coin.IsSpent()) {
226 : // The grandparent cache does not have an entry, and the coin
227 : // has been spent. We can just delete it from the parent cache.
228 0 : cachedCoinsUsage -= itUs->second.coin.DynamicMemoryUsage();
229 0 : cacheCoins.erase(itUs);
230 0 : } else {
231 : // A normal modification.
232 0 : cachedCoinsUsage -= itUs->second.coin.DynamicMemoryUsage();
233 0 : if (erase) {
234 : // The `move` call here is purely an optimization; we rely on the
235 : // `mapCoins.erase` call in the `for` expression to actually remove
236 : // the entry from the child map.
237 0 : itUs->second.coin = std::move(it->second.coin);
238 0 : } else {
239 0 : itUs->second.coin = it->second.coin;
240 27234 : }
241 0 : cachedCoinsUsage += itUs->second.coin.DynamicMemoryUsage();
242 0 : itUs->second.flags |= CCoinsCacheEntry::DIRTY;
243 : // NOTE: It isn't safe to mark the coin as FRESH in the parent
244 27234 : // cache. If it already existed and was spent in the parent
245 : // cache then marking it FRESH would prevent that spentness
246 : // from being flushed to the grandparent.
247 : }
248 : }
249 200 : }
250 201 : hashBlock = hashBlockIn;
251 201 : return true;
252 0 : }
253 :
254 201 : bool CCoinsViewCache::Flush() {
255 201 : bool fOk = base->BatchWrite(cacheCoins, hashBlock, /*erase=*/true);
256 201 : if (fOk) {
257 201 : if (!cacheCoins.empty()) {
258 : /* BatchWrite must erase all cacheCoins elements when erase=true. */
259 0 : throw std::logic_error("Not all cached coins were erased");
260 : }
261 201 : ReallocateCache();
262 201 : }
263 201 : cachedCoinsUsage = 0;
264 201 : return fOk;
265 0 : }
266 :
267 0 : bool CCoinsViewCache::Sync()
268 : {
269 0 : bool fOk = base->BatchWrite(cacheCoins, hashBlock, /*erase=*/false);
270 : // Instead of clearing `cacheCoins` as we would in Flush(), just clear the
271 : // FRESH/DIRTY flags of any coin that isn't spent.
272 0 : for (auto it = cacheCoins.begin(); it != cacheCoins.end(); ) {
273 0 : if (it->second.coin.IsSpent()) {
274 0 : cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage();
275 0 : it = cacheCoins.erase(it);
276 0 : } else {
277 0 : it->second.flags = 0;
278 0 : ++it;
279 : }
280 : }
281 0 : return fOk;
282 : }
283 :
284 104434 : void CCoinsViewCache::Uncache(const COutPoint& hash)
285 : {
286 104434 : CCoinsMap::iterator it = cacheCoins.find(hash);
287 104434 : if (it != cacheCoins.end() && it->second.flags == 0) {
288 17914 : cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage();
289 : TRACE5(utxocache, uncache,
290 : hash.hash.data(),
291 : (uint32_t)hash.n,
292 : (uint32_t)it->second.coin.nHeight,
293 : (int64_t)it->second.coin.out.nValue,
294 : (bool)it->second.coin.IsCoinBase());
295 17914 : cacheCoins.erase(it);
296 17914 : }
297 104434 : }
298 :
299 16148 : unsigned int CCoinsViewCache::GetCacheSize() const {
300 16148 : return cacheCoins.size();
301 : }
302 :
303 7867 : bool CCoinsViewCache::HaveInputs(const CTransaction& tx) const
304 : {
305 7867 : if (!tx.IsCoinBase()) {
306 36658 : for (unsigned int i = 0; i < tx.vin.size(); i++) {
307 28791 : if (!HaveCoin(tx.vin[i].prevout)) {
308 0 : return false;
309 : }
310 28791 : }
311 7867 : }
312 7867 : return true;
313 7867 : }
314 :
315 201 : void CCoinsViewCache::ReallocateCache()
316 : {
317 : // Cache should be empty when we're calling this.
318 201 : assert(cacheCoins.size() == 0);
319 201 : cacheCoins.~CCoinsMap();
320 201 : m_cache_coins_memory_resource.~CCoinsMapMemoryResource();
321 201 : ::new (&m_cache_coins_memory_resource) CCoinsMapMemoryResource{};
322 201 : ::new (&cacheCoins) CCoinsMap{0, SaltedOutpointHasher{/*deterministic=*/m_deterministic}, CCoinsMap::key_equal{}, &m_cache_coins_memory_resource};
323 201 : }
324 :
325 0 : void CCoinsViewCache::SanityCheck() const
326 : {
327 0 : size_t recomputed_usage = 0;
328 0 : for (const auto& [_, entry] : cacheCoins) {
329 0 : unsigned attr = 0;
330 0 : if (entry.flags & CCoinsCacheEntry::DIRTY) attr |= 1;
331 0 : if (entry.flags & CCoinsCacheEntry::FRESH) attr |= 2;
332 0 : if (entry.coin.IsSpent()) attr |= 4;
333 : // Only 5 combinations are possible.
334 0 : assert(attr != 2 && attr != 4 && attr != 7);
335 :
336 : // Recompute cachedCoinsUsage.
337 0 : recomputed_usage += entry.coin.DynamicMemoryUsage();
338 : }
339 0 : assert(recomputed_usage == cachedCoinsUsage);
340 0 : }
341 :
342 2 : static const size_t MIN_TRANSACTION_OUTPUT_WEIGHT = WITNESS_SCALE_FACTOR * ::GetSerializeSize(CTxOut(), PROTOCOL_VERSION);
343 2 : static const size_t MAX_OUTPUTS_PER_BLOCK = MAX_BLOCK_WEIGHT / MIN_TRANSACTION_OUTPUT_WEIGHT;
344 :
345 0 : const Coin& AccessByTxid(const CCoinsViewCache& view, const uint256& txid)
346 : {
347 0 : COutPoint iter(txid, 0);
348 0 : while (iter.n < MAX_OUTPUTS_PER_BLOCK) {
349 0 : const Coin& alternate = view.AccessCoin(iter);
350 0 : if (!alternate.IsSpent()) return alternate;
351 0 : ++iter.n;
352 : }
353 0 : return coinEmpty;
354 0 : }
355 :
356 19256 : bool CCoinsViewErrorCatcher::GetCoin(const COutPoint &outpoint, Coin &coin) const {
357 : try {
358 19256 : return CCoinsViewBacked::GetCoin(outpoint, coin);
359 0 : } catch(const std::runtime_error& e) {
360 0 : for (const auto& f : m_err_callbacks) {
361 0 : f();
362 : }
363 0 : LogPrintf("Error reading from database: %s\n", e.what());
364 : // Starting the shutdown sequence and returning false to the caller would be
365 : // interpreted as 'entry not found' (as opposed to unable to read data), and
366 : // could lead to invalid interpretation. Just exit immediately, as we can't
367 : // continue anyway, and all writes should be atomic.
368 0 : std::abort();
369 0 : }
370 0 : }
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