Line data Source code
1 : // Copyright (c) 2012-2014 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 "memusage.h"
8 : #include "random.h"
9 :
10 : #include <assert.h>
11 :
12 : /**
13 : * calculate number of bytes for the bitmask, and its number of non-zero bytes
14 : * each bit in the bitmask represents the availability of one output, but the
15 : * availabilities of the first two outputs are encoded separately
16 : */
17 11028 : void CCoins::CalcMaskSize(unsigned int &nBytes, unsigned int &nNonzeroBytes) const {
18 11028 : unsigned int nLastUsedByte = 0;
19 22160 : for (unsigned int b = 0; 2+b*8 < vout.size(); b++) {
20 : bool fZero = true;
21 100 : for (unsigned int i = 0; i < 8 && 2+b*8+i < vout.size(); i++) {
22 200 : if (!vout[2+b*8+i].IsNull()) {
23 100 : fZero = false;
24 100 : continue;
25 : }
26 : }
27 52 : if (!fZero) {
28 52 : nLastUsedByte = b + 1;
29 52 : nNonzeroBytes++;
30 : }
31 : }
32 11028 : nBytes += nLastUsedByte;
33 11028 : }
34 :
35 7311 : bool CCoins::Spend(uint32_t nPos)
36 : {
37 21933 : if (nPos >= vout.size() || vout[nPos].IsNull())
38 : return false;
39 14622 : vout[nPos].SetNull();
40 7311 : Cleanup();
41 7311 : return true;
42 : }
43 :
44 16 : bool CCoinsView::GetCoins(const uint256 &txid, CCoins &coins) const { return false; }
45 0 : bool CCoinsView::HaveCoins(const uint256 &txid) const { return false; }
46 0 : uint256 CCoinsView::GetBestBlock() const { return uint256(); }
47 0 : bool CCoinsView::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return false; }
48 0 : bool CCoinsView::GetStats(CCoinsStats &stats) const { return false; }
49 :
50 :
51 41222 : CCoinsViewBacked::CCoinsViewBacked(CCoinsView *viewIn) : base(viewIn) { }
52 19258 : bool CCoinsViewBacked::GetCoins(const uint256 &txid, CCoins &coins) const { return base->GetCoins(txid, coins); }
53 0 : bool CCoinsViewBacked::HaveCoins(const uint256 &txid) const { return base->HaveCoins(txid); }
54 662 : uint256 CCoinsViewBacked::GetBestBlock() const { return base->GetBestBlock(); }
55 1148 : void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; }
56 130 : bool CCoinsViewBacked::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return base->BatchWrite(mapCoins, hashBlock); }
57 0 : bool CCoinsViewBacked::GetStats(CCoinsStats &stats) const { return base->GetStats(stats); }
58 :
59 19937 : CCoinsKeyHasher::CCoinsKeyHasher() : salt(GetRandHash()) {}
60 :
61 79748 : CCoinsViewCache::CCoinsViewCache(CCoinsView *baseIn) : CCoinsViewBacked(baseIn), hasModifier(false), cachedCoinsUsage(0) { }
62 :
63 59930 : CCoinsViewCache::~CCoinsViewCache()
64 : {
65 19937 : assert(!hasModifier);
66 20056 : }
67 :
68 38027 : size_t CCoinsViewCache::DynamicMemoryUsage() const {
69 76054 : return memusage::DynamicUsage(cacheCoins) + cachedCoinsUsage;
70 : }
71 :
72 513355 : CCoinsMap::const_iterator CCoinsViewCache::FetchCoins(const uint256 &txid) const {
73 1026710 : CCoinsMap::iterator it = cacheCoins.find(txid);
74 513355 : if (it != cacheCoins.end())
75 200365 : return it;
76 312990 : CCoins tmp;
77 312990 : if (!base->GetCoins(txid, tmp))
78 122341 : return cacheCoins.end();
79 953245 : CCoinsMap::iterator ret = cacheCoins.insert(std::make_pair(txid, CCoinsCacheEntry())).first;
80 190649 : tmp.swap(ret->second.coins);
81 190649 : if (ret->second.coins.IsPruned()) {
82 : // The parent only has an empty entry for this txid; we can consider our
83 : // version as fresh.
84 50054 : ret->second.flags = CCoinsCacheEntry::FRESH;
85 : }
86 190649 : cachedCoinsUsage += ret->second.coins.DynamicMemoryUsage();
87 190649 : return ret;
88 : }
89 :
90 256796 : bool CCoinsViewCache::GetCoins(const uint256 &txid, CCoins &coins) const {
91 256796 : CCoinsMap::const_iterator it = FetchCoins(txid);
92 513592 : if (it != cacheCoins.end()) {
93 177310 : coins = it->second.coins;
94 177310 : return true;
95 : }
96 : return false;
97 : }
98 :
99 71383 : CCoinsModifier CCoinsViewCache::ModifyCoins(const uint256 &txid) {
100 71383 : assert(!hasModifier);
101 356915 : std::pair<CCoinsMap::iterator, bool> ret = cacheCoins.insert(std::make_pair(txid, CCoinsCacheEntry()));
102 71383 : size_t cachedCoinUsage = 0;
103 71383 : if (ret.second) {
104 108820 : if (!base->GetCoins(txid, ret.first->second.coins)) {
105 : // The parent view does not have this entry; mark it as fresh.
106 23670 : ret.first->second.coins.Clear();
107 23670 : ret.first->second.flags = CCoinsCacheEntry::FRESH;
108 30740 : } else if (ret.first->second.coins.IsPruned()) {
109 : // The parent view only has a pruned entry for this; mark it as fresh.
110 5112 : ret.first->second.flags = CCoinsCacheEntry::FRESH;
111 : }
112 : } else {
113 16973 : cachedCoinUsage = ret.first->second.coins.DynamicMemoryUsage();
114 : }
115 : // Assume that whenever ModifyCoins is called, the entry will be modified.
116 71383 : ret.first->second.flags |= CCoinsCacheEntry::DIRTY;
117 71383 : return CCoinsModifier(*this, ret.first, cachedCoinUsage);
118 : }
119 :
120 227198 : const CCoins* CCoinsViewCache::AccessCoins(const uint256 &txid) const {
121 252322 : CCoinsMap::const_iterator it = FetchCoins(txid);
122 504644 : if (it == cacheCoins.end()) {
123 : return NULL;
124 : } else {
125 212375 : return &it->second.coins;
126 : }
127 : }
128 :
129 4237 : bool CCoinsViewCache::HaveCoins(const uint256 &txid) const {
130 4237 : CCoinsMap::const_iterator it = FetchCoins(txid);
131 : // We're using vtx.empty() instead of IsPruned here for performance reasons,
132 : // as we only care about the case where a transaction was replaced entirely
133 : // in a reorganization (which wipes vout entirely, as opposed to spending
134 : // which just cleans individual outputs).
135 11132 : return (it != cacheCoins.end() && !it->second.coins.vout.empty());
136 : }
137 :
138 33183 : uint256 CCoinsViewCache::GetBestBlock() const {
139 66366 : if (hashBlock.IsNull())
140 8246 : hashBlock = base->GetBestBlock();
141 33183 : return hashBlock;
142 : }
143 :
144 16636 : void CCoinsViewCache::SetBestBlock(const uint256 &hashBlockIn) {
145 16636 : hashBlock = hashBlockIn;
146 16636 : }
147 :
148 5694 : bool CCoinsViewCache::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlockIn) {
149 5694 : assert(!hasModifier);
150 193376 : for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end();) {
151 181988 : if (it->second.flags & CCoinsCacheEntry::DIRTY) { // Ignore non-dirty entries (optimization).
152 107870 : CCoinsMap::iterator itUs = cacheCoins.find(it->first);
153 53935 : if (itUs == cacheCoins.end()) {
154 18108 : if (!it->second.coins.IsPruned()) {
155 : // The parent cache does not have an entry, while the child
156 : // cache does have (a non-pruned) one. Move the data up, and
157 : // mark it as fresh (if the grandparent did have it, we
158 : // would have pulled it in at first GetCoins).
159 18108 : assert(it->second.flags & CCoinsCacheEntry::FRESH);
160 36216 : CCoinsCacheEntry& entry = cacheCoins[it->first];
161 18108 : entry.coins.swap(it->second.coins);
162 18108 : cachedCoinsUsage += entry.coins.DynamicMemoryUsage();
163 18108 : entry.flags = CCoinsCacheEntry::DIRTY | CCoinsCacheEntry::FRESH;
164 : }
165 : } else {
166 46248 : if ((itUs->second.flags & CCoinsCacheEntry::FRESH) && it->second.coins.IsPruned()) {
167 : // The grandparent does not have an entry, and the child is
168 : // modified and being pruned. This means we can just delete
169 : // it from the parent.
170 2792 : cachedCoinsUsage -= itUs->second.coins.DynamicMemoryUsage();
171 2792 : cacheCoins.erase(itUs);
172 : } else {
173 : // A normal modification.
174 33035 : cachedCoinsUsage -= itUs->second.coins.DynamicMemoryUsage();
175 66070 : itUs->second.coins.swap(it->second.coins);
176 33035 : cachedCoinsUsage += itUs->second.coins.DynamicMemoryUsage();
177 33035 : itUs->second.flags |= CCoinsCacheEntry::DIRTY;
178 : }
179 : }
180 : }
181 363976 : CCoinsMap::iterator itOld = it++;
182 : mapCoins.erase(itOld);
183 : }
184 5694 : hashBlock = hashBlockIn;
185 5694 : return true;
186 : }
187 :
188 5892 : bool CCoinsViewCache::Flush() {
189 5892 : bool fOk = base->BatchWrite(cacheCoins, hashBlock);
190 5892 : cacheCoins.clear();
191 5892 : cachedCoinsUsage = 0;
192 5892 : return fOk;
193 : }
194 :
195 5709 : unsigned int CCoinsViewCache::GetCacheSize() const {
196 5709 : return cacheCoins.size();
197 : }
198 :
199 9736 : const CTxOut &CCoinsViewCache::GetOutputFor(const CTxIn& input) const
200 : {
201 19472 : const CCoins* coins = AccessCoins(input.prevout.hash);
202 19472 : assert(coins && coins->IsAvailable(input.prevout.n));
203 19472 : return coins->vout[input.prevout.n];
204 : }
205 :
206 3635 : CAmount CCoinsViewCache::GetValueIn(const CTransaction& tx) const
207 : {
208 3635 : if (tx.IsCoinBase())
209 : return 0;
210 :
211 : CAmount nResult = 0;
212 13349 : for (unsigned int i = 0; i < tx.vin.size(); i++)
213 9714 : nResult += GetOutputFor(tx.vin[i]).nValue;
214 :
215 3635 : return nResult;
216 : }
217 :
218 10334 : bool CCoinsViewCache::HaveInputs(const CTransaction& tx) const
219 : {
220 10334 : if (!tx.IsCoinBase()) {
221 38992 : for (unsigned int i = 0; i < tx.vin.size(); i++) {
222 28714 : const COutPoint &prevout = tx.vin[i].prevout;
223 28714 : const CCoins* coins = AccessCoins(prevout.hash);
224 28691 : if (!coins || !coins->IsAvailable(prevout.n)) {
225 : return false;
226 : }
227 : }
228 : }
229 : return true;
230 : }
231 :
232 557 : double CCoinsViewCache::GetPriority(const CTransaction &tx, int nHeight) const
233 : {
234 557 : if (tx.IsCoinBase())
235 : return 0.0;
236 557 : double dResult = 0.0;
237 8971 : BOOST_FOREACH(const CTxIn& txin, tx.vin)
238 : {
239 2062 : const CCoins* coins = AccessCoins(txin.prevout.hash);
240 1031 : assert(coins);
241 2062 : if (!coins->IsAvailable(txin.prevout.n)) continue;
242 1031 : if (coins->nHeight < nHeight) {
243 1408 : dResult += coins->vout[txin.prevout.n].nValue * (nHeight-coins->nHeight);
244 : }
245 : }
246 557 : return tx.ComputePriority(dResult);
247 : }
248 :
249 71383 : CCoinsModifier::CCoinsModifier(CCoinsViewCache& cache_, CCoinsMap::iterator it_, size_t usage) : cache(cache_), it(it_), cachedCoinUsage(usage) {
250 71383 : assert(!cache.hasModifier);
251 71383 : cache.hasModifier = true;
252 0 : }
253 :
254 71383 : CCoinsModifier::~CCoinsModifier()
255 : {
256 71383 : assert(cache.hasModifier);
257 71383 : cache.hasModifier = false;
258 142766 : it->second.coins.Cleanup();
259 71383 : cache.cachedCoinsUsage -= cachedCoinUsage; // Subtract the old usage
260 177448 : if ((it->second.flags & CCoinsCacheEntry::FRESH) && it->second.coins.IsPruned()) {
261 7128 : cache.cacheCoins.erase(it);
262 : } else {
263 : // If the coin still exists after the modification, add the new usage
264 135638 : cache.cachedCoinsUsage += it->second.coins.DynamicMemoryUsage();
265 : }
266 71383 : }
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