aboutsummaryrefslogtreecommitdiff
path: root/src/coins.cpp
blob: b45fc76338183d027d525861a7bb51bd25237899 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
// Copyright (c) 2012-2016 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "coins.h"

#include "consensus/consensus.h"
#include "memusage.h"
#include "random.h"

#include <assert.h>

bool CCoinsView::GetCoin(const COutPoint &outpoint, Coin &coin) const { return false; }
bool CCoinsView::HaveCoin(const COutPoint &outpoint) const { return false; }
uint256 CCoinsView::GetBestBlock() const { return uint256(); }
bool CCoinsView::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return false; }
CCoinsViewCursor *CCoinsView::Cursor() const { return 0; }


CCoinsViewBacked::CCoinsViewBacked(CCoinsView *viewIn) : base(viewIn) { }
bool CCoinsViewBacked::GetCoin(const COutPoint &outpoint, Coin &coin) const { return base->GetCoin(outpoint, coin); }
bool CCoinsViewBacked::HaveCoin(const COutPoint &outpoint) const { return base->HaveCoin(outpoint); }
uint256 CCoinsViewBacked::GetBestBlock() const { return base->GetBestBlock(); }
void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; }
bool CCoinsViewBacked::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return base->BatchWrite(mapCoins, hashBlock); }
CCoinsViewCursor *CCoinsViewBacked::Cursor() const { return base->Cursor(); }
size_t CCoinsViewBacked::EstimateSize() const { return base->EstimateSize(); }

SaltedOutpointHasher::SaltedOutpointHasher() : k0(GetRand(std::numeric_limits<uint64_t>::max())), k1(GetRand(std::numeric_limits<uint64_t>::max())) {}

CCoinsViewCache::CCoinsViewCache(CCoinsView *baseIn) : CCoinsViewBacked(baseIn), cachedCoinsUsage(0) {}

size_t CCoinsViewCache::DynamicMemoryUsage() const {
    return memusage::DynamicUsage(cacheCoins) + cachedCoinsUsage;
}

CCoinsMap::iterator CCoinsViewCache::FetchCoin(const COutPoint &outpoint) const {
    CCoinsMap::iterator it = cacheCoins.find(outpoint);
    if (it != cacheCoins.end())
        return it;
    Coin tmp;
    if (!base->GetCoin(outpoint, tmp))
        return cacheCoins.end();
    CCoinsMap::iterator ret = cacheCoins.emplace(std::piecewise_construct, std::forward_as_tuple(outpoint), std::forward_as_tuple(std::move(tmp))).first;
    if (ret->second.coin.IsSpent()) {
        // The parent only has an empty entry for this outpoint; we can consider our
        // version as fresh.
        ret->second.flags = CCoinsCacheEntry::FRESH;
    }
    cachedCoinsUsage += ret->second.coin.DynamicMemoryUsage();
    return ret;
}

bool CCoinsViewCache::GetCoin(const COutPoint &outpoint, Coin &coin) const {
    CCoinsMap::const_iterator it = FetchCoin(outpoint);
    if (it != cacheCoins.end()) {
        coin = it->second.coin;
        return true;
    }
    return false;
}

void CCoinsViewCache::AddCoin(const COutPoint &outpoint, Coin&& coin, bool possible_overwrite) {
    assert(!coin.IsSpent());
    if (coin.out.scriptPubKey.IsUnspendable()) return;
    CCoinsMap::iterator it;
    bool inserted;
    std::tie(it, inserted) = cacheCoins.emplace(std::piecewise_construct, std::forward_as_tuple(outpoint), std::tuple<>());
    bool fresh = false;
    if (!inserted) {
        cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage();
    }
    if (!possible_overwrite) {
        if (!it->second.coin.IsSpent()) {
            throw std::logic_error("Adding new coin that replaces non-pruned entry");
        }
        fresh = !(it->second.flags & CCoinsCacheEntry::DIRTY);
    }
    it->second.coin = std::move(coin);
    it->second.flags |= CCoinsCacheEntry::DIRTY | (fresh ? CCoinsCacheEntry::FRESH : 0);
    cachedCoinsUsage += it->second.coin.DynamicMemoryUsage();
}

void AddCoins(CCoinsViewCache& cache, const CTransaction &tx, int nHeight) {
    bool fCoinbase = tx.IsCoinBase();
    const uint256& txid = tx.GetHash();
    for (size_t i = 0; i < tx.vout.size(); ++i) {
        // Pass fCoinbase as the possible_overwrite flag to AddCoin, in order to correctly
        // deal with the pre-BIP30 occurrences of duplicate coinbase transactions.
        cache.AddCoin(COutPoint(txid, i), Coin(tx.vout[i], nHeight, fCoinbase), fCoinbase);
    }
}

void CCoinsViewCache::SpendCoin(const COutPoint &outpoint, Coin* moveout) {
    CCoinsMap::iterator it = FetchCoin(outpoint);
    if (it == cacheCoins.end()) return;
    cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage();
    if (moveout) {
        *moveout = std::move(it->second.coin);
    }
    if (it->second.flags & CCoinsCacheEntry::FRESH) {
        cacheCoins.erase(it);
    } else {
        it->second.flags |= CCoinsCacheEntry::DIRTY;
        it->second.coin.Clear();
    }
}

static const Coin coinEmpty;

const Coin& CCoinsViewCache::AccessCoin(const COutPoint &outpoint) const {
    CCoinsMap::const_iterator it = FetchCoin(outpoint);
    if (it == cacheCoins.end()) {
        return coinEmpty;
    } else {
        return it->second.coin;
    }
}

bool CCoinsViewCache::HaveCoin(const COutPoint &outpoint) const {
    CCoinsMap::const_iterator it = FetchCoin(outpoint);
    return (it != cacheCoins.end() && !it->second.coin.IsSpent());
}

bool CCoinsViewCache::HaveCoinInCache(const COutPoint &outpoint) const {
    CCoinsMap::const_iterator it = cacheCoins.find(outpoint);
    return it != cacheCoins.end();
}

uint256 CCoinsViewCache::GetBestBlock() const {
    if (hashBlock.IsNull())
        hashBlock = base->GetBestBlock();
    return hashBlock;
}

void CCoinsViewCache::SetBestBlock(const uint256 &hashBlockIn) {
    hashBlock = hashBlockIn;
}

bool CCoinsViewCache::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlockIn) {
    for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end();) {
        if (it->second.flags & CCoinsCacheEntry::DIRTY) { // Ignore non-dirty entries (optimization).
            CCoinsMap::iterator itUs = cacheCoins.find(it->first);
            if (itUs == cacheCoins.end()) {
                // The parent cache does not have an entry, while the child does
                // We can ignore it if it's both FRESH and pruned in the child
                if (!(it->second.flags & CCoinsCacheEntry::FRESH && it->second.coin.IsSpent())) {
                    // Otherwise we will need to create it in the parent
                    // and move the data up and mark it as dirty
                    CCoinsCacheEntry& entry = cacheCoins[it->first];
                    entry.coin = std::move(it->second.coin);
                    cachedCoinsUsage += entry.coin.DynamicMemoryUsage();
                    entry.flags = CCoinsCacheEntry::DIRTY;
                    // We can mark it FRESH in the parent if it was FRESH in the child
                    // Otherwise it might have just been flushed from the parent's cache
                    // and already exist in the grandparent
                    if (it->second.flags & CCoinsCacheEntry::FRESH)
                        entry.flags |= CCoinsCacheEntry::FRESH;
                }
            } else {
                // Assert that the child cache entry was not marked FRESH if the
                // parent cache entry has unspent outputs. If this ever happens,
                // it means the FRESH flag was misapplied and there is a logic
                // error in the calling code.
                if ((it->second.flags & CCoinsCacheEntry::FRESH) && !itUs->second.coin.IsSpent())
                    throw std::logic_error("FRESH flag misapplied to cache entry for base transaction with spendable outputs");

                // Found the entry in the parent cache
                if ((itUs->second.flags & CCoinsCacheEntry::FRESH) && it->second.coin.IsSpent()) {
                    // The grandparent does not have an entry, and the child is
                    // modified and being pruned. This means we can just delete
                    // it from the parent.
                    cachedCoinsUsage -= itUs->second.coin.DynamicMemoryUsage();
                    cacheCoins.erase(itUs);
                } else {
                    // A normal modification.
                    cachedCoinsUsage -= itUs->second.coin.DynamicMemoryUsage();
                    itUs->second.coin = std::move(it->second.coin);
                    cachedCoinsUsage += itUs->second.coin.DynamicMemoryUsage();
                    itUs->second.flags |= CCoinsCacheEntry::DIRTY;
                    // NOTE: It is possible the child has a FRESH flag here in
                    // the event the entry we found in the parent is pruned. But
                    // we must not copy that FRESH flag to the parent as that
                    // pruned state likely still needs to be communicated to the
                    // grandparent.
                }
            }
        }
        CCoinsMap::iterator itOld = it++;
        mapCoins.erase(itOld);
    }
    hashBlock = hashBlockIn;
    return true;
}

bool CCoinsViewCache::Flush() {
    bool fOk = base->BatchWrite(cacheCoins, hashBlock);
    cacheCoins.clear();
    cachedCoinsUsage = 0;
    return fOk;
}

void CCoinsViewCache::Uncache(const COutPoint& hash)
{
    CCoinsMap::iterator it = cacheCoins.find(hash);
    if (it != cacheCoins.end() && it->second.flags == 0) {
        cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage();
        cacheCoins.erase(it);
    }
}

unsigned int CCoinsViewCache::GetCacheSize() const {
    return cacheCoins.size();
}

CAmount CCoinsViewCache::GetValueIn(const CTransaction& tx) const
{
    if (tx.IsCoinBase())
        return 0;

    CAmount nResult = 0;
    for (unsigned int i = 0; i < tx.vin.size(); i++)
        nResult += AccessCoin(tx.vin[i].prevout).out.nValue;

    return nResult;
}

bool CCoinsViewCache::HaveInputs(const CTransaction& tx) const
{
    if (!tx.IsCoinBase()) {
        for (unsigned int i = 0; i < tx.vin.size(); i++) {
            if (!HaveCoin(tx.vin[i].prevout)) {
                return false;
            }
        }
    }
    return true;
}

static const size_t MAX_OUTPUTS_PER_BLOCK = MAX_BLOCK_BASE_SIZE /  ::GetSerializeSize(CTxOut(), SER_NETWORK, PROTOCOL_VERSION); // TODO: merge with similar definition in undo.h.

const Coin& AccessByTxid(const CCoinsViewCache& view, const uint256& txid)
{
    COutPoint iter(txid, 0);
    while (iter.n < MAX_OUTPUTS_PER_BLOCK) {
        const Coin& alternate = view.AccessCoin(iter);
        if (!alternate.IsSpent()) return alternate;
        ++iter.n;
    }
    return coinEmpty;
}