aboutsummaryrefslogtreecommitdiff
path: root/src/coins.cpp
blob: e76d8c7ef2dc9bce7f68fec06d75725c22dc82c5 (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
// Copyright (c) 2012-2013 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "coins.h"

#include "random.h"

#include <assert.h>

// calculate number of bytes for the bitmask, and its number of non-zero bytes
// each bit in the bitmask represents the availability of one output, but the
// availabilities of the first two outputs are encoded separately
void CCoins::CalcMaskSize(unsigned int &nBytes, unsigned int &nNonzeroBytes) const {
    unsigned int nLastUsedByte = 0;
    for (unsigned int b = 0; 2+b*8 < vout.size(); b++) {
        bool fZero = true;
        for (unsigned int i = 0; i < 8 && 2+b*8+i < vout.size(); i++) {
            if (!vout[2+b*8+i].IsNull()) {
                fZero = false;
                continue;
            }
        }
        if (!fZero) {
            nLastUsedByte = b + 1;
            nNonzeroBytes++;
        }
    }
    nBytes += nLastUsedByte;
}

bool CCoins::Spend(const COutPoint &out, CTxInUndo &undo) {
    if (out.n >= vout.size())
        return false;
    if (vout[out.n].IsNull())
        return false;
    undo = CTxInUndo(vout[out.n]);
    vout[out.n].SetNull();
    Cleanup();
    if (vout.size() == 0) {
        undo.nHeight = nHeight;
        undo.fCoinBase = fCoinBase;
        undo.nVersion = this->nVersion;
    }
    return true;
}

bool CCoins::Spend(int nPos) {
    CTxInUndo undo;
    COutPoint out(0, nPos);
    return Spend(out, undo);
}


bool CCoinsView::GetCoins(const uint256 &txid, CCoins &coins) { return false; }
bool CCoinsView::SetCoins(const uint256 &txid, const CCoins &coins) { return false; }
bool CCoinsView::HaveCoins(const uint256 &txid) { return false; }
uint256 CCoinsView::GetBestBlock() { return uint256(0); }
bool CCoinsView::SetBestBlock(const uint256 &hashBlock) { return false; }
bool CCoinsView::BatchWrite(const CCoinsMap &mapCoins, const uint256 &hashBlock) { return false; }
bool CCoinsView::GetStats(CCoinsStats &stats) { return false; }


CCoinsViewBacked::CCoinsViewBacked(CCoinsView &viewIn) : base(&viewIn) { }
bool CCoinsViewBacked::GetCoins(const uint256 &txid, CCoins &coins) { return base->GetCoins(txid, coins); }
bool CCoinsViewBacked::SetCoins(const uint256 &txid, const CCoins &coins) { return base->SetCoins(txid, coins); }
bool CCoinsViewBacked::HaveCoins(const uint256 &txid) { return base->HaveCoins(txid); }
uint256 CCoinsViewBacked::GetBestBlock() { return base->GetBestBlock(); }
bool CCoinsViewBacked::SetBestBlock(const uint256 &hashBlock) { return base->SetBestBlock(hashBlock); }
void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; }
bool CCoinsViewBacked::BatchWrite(const CCoinsMap &mapCoins, const uint256 &hashBlock) { return base->BatchWrite(mapCoins, hashBlock); }
bool CCoinsViewBacked::GetStats(CCoinsStats &stats) { return base->GetStats(stats); }

CCoinsKeyHasher::CCoinsKeyHasher() : salt(GetRandHash()) {}

CCoinsViewCache::CCoinsViewCache(CCoinsView &baseIn, bool fDummy) : CCoinsViewBacked(baseIn), hashBlock(0) { }

bool CCoinsViewCache::GetCoins(const uint256 &txid, CCoins &coins) {
    if (cacheCoins.count(txid)) {
        coins = cacheCoins[txid];
        return true;
    }
    if (base->GetCoins(txid, coins)) {
        cacheCoins[txid] = coins;
        return true;
    }
    return false;
}

CCoinsMap::iterator CCoinsViewCache::FetchCoins(const uint256 &txid) {
    CCoinsMap::iterator it = cacheCoins.find(txid);
    if (it != cacheCoins.end())
        return it;
    CCoins tmp;
    if (!base->GetCoins(txid,tmp))
        return cacheCoins.end();
    CCoinsMap::iterator ret = cacheCoins.insert(it, std::make_pair(txid, CCoins()));
    tmp.swap(ret->second);
    return ret;
}

CCoins &CCoinsViewCache::GetCoins(const uint256 &txid) {
    CCoinsMap::iterator it = FetchCoins(txid);
    assert(it != cacheCoins.end());
    return it->second;
}

bool CCoinsViewCache::SetCoins(const uint256 &txid, const CCoins &coins) {
    cacheCoins[txid] = coins;
    return true;
}

bool CCoinsViewCache::HaveCoins(const uint256 &txid) {
    return FetchCoins(txid) != cacheCoins.end();
}

uint256 CCoinsViewCache::GetBestBlock() {
    if (hashBlock == uint256(0))
        hashBlock = base->GetBestBlock();
    return hashBlock;
}

bool CCoinsViewCache::SetBestBlock(const uint256 &hashBlockIn) {
    hashBlock = hashBlockIn;
    return true;
}

bool CCoinsViewCache::BatchWrite(const CCoinsMap &mapCoins, const uint256 &hashBlockIn) {
    for (CCoinsMap::const_iterator it = mapCoins.begin(); it != mapCoins.end(); it++)
        cacheCoins[it->first] = it->second;
    hashBlock = hashBlockIn;
    return true;
}

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

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

const CTxOut &CCoinsViewCache::GetOutputFor(const CTxIn& input)
{
    const CCoins &coins = GetCoins(input.prevout.hash);
    assert(coins.IsAvailable(input.prevout.n));
    return coins.vout[input.prevout.n];
}

int64_t CCoinsViewCache::GetValueIn(const CTransaction& tx)
{
    if (tx.IsCoinBase())
        return 0;

    int64_t nResult = 0;
    for (unsigned int i = 0; i < tx.vin.size(); i++)
        nResult += GetOutputFor(tx.vin[i]).nValue;

    return nResult;
}

bool CCoinsViewCache::HaveInputs(const CTransaction& tx)
{
    if (!tx.IsCoinBase()) {
        // first check whether information about the prevout hash is available
        for (unsigned int i = 0; i < tx.vin.size(); i++) {
            const COutPoint &prevout = tx.vin[i].prevout;
            if (!HaveCoins(prevout.hash))
                return false;
        }

        // then check whether the actual outputs are available
        for (unsigned int i = 0; i < tx.vin.size(); i++) {
            const COutPoint &prevout = tx.vin[i].prevout;
            const CCoins &coins = GetCoins(prevout.hash);
            if (!coins.IsAvailable(prevout.n))
                return false;
        }
    }
    return true;
}

double CCoinsViewCache::GetPriority(const CTransaction &tx, int nHeight)
{
    if (tx.IsCoinBase())
        return 0.0;
    double dResult = 0.0;
    BOOST_FOREACH(const CTxIn& txin, tx.vin)
    {
        const CCoins &coins = GetCoins(txin.prevout.hash);
        if (!coins.IsAvailable(txin.prevout.n)) continue;
        if (coins.nHeight < nHeight) {
            dResult += coins.vout[txin.prevout.n].nValue * (nHeight-coins.nHeight);
        }
    }
    return tx.ComputePriority(dResult);
}