litecoin/src/txdb.cpp
Warren Togami e30d65c009 Litecoin: Disable PoW Sanity check while loading block index from disk.
We use the sha256 hash for the block index for performance reasons, which is recorded for later use.
CheckProofOfWork() uses the scrypt hash which is discarded after a block is accepted.
While it is technically feasible to verify the PoW, doing so takes several minutes as it
requires recomputing every PoW hash during every Litecoin startup.
We opt instead to simply trust the data that is on your local disk.
2016-11-17 18:30:26 -08:00

222 lines
7.7 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2015 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 "txdb.h"
#include "chainparams.h"
#include "hash.h"
#include "pow.h"
#include "uint256.h"
#include <stdint.h>
#include <boost/thread.hpp>
using namespace std;
static const char DB_COINS = 'c';
static const char DB_BLOCK_FILES = 'f';
static const char DB_TXINDEX = 't';
static const char DB_BLOCK_INDEX = 'b';
static const char DB_BEST_BLOCK = 'B';
static const char DB_FLAG = 'F';
static const char DB_REINDEX_FLAG = 'R';
static const char DB_LAST_BLOCK = 'l';
CCoinsViewDB::CCoinsViewDB(size_t nCacheSize, bool fMemory, bool fWipe) : db(GetDataDir() / "chainstate", nCacheSize, fMemory, fWipe, true)
{
}
bool CCoinsViewDB::GetCoins(const uint256 &txid, CCoins &coins) const {
return db.Read(make_pair(DB_COINS, txid), coins);
}
bool CCoinsViewDB::HaveCoins(const uint256 &txid) const {
return db.Exists(make_pair(DB_COINS, txid));
}
uint256 CCoinsViewDB::GetBestBlock() const {
uint256 hashBestChain;
if (!db.Read(DB_BEST_BLOCK, hashBestChain))
return uint256();
return hashBestChain;
}
bool CCoinsViewDB::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) {
CDBBatch batch(db);
size_t count = 0;
size_t changed = 0;
for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end();) {
if (it->second.flags & CCoinsCacheEntry::DIRTY) {
if (it->second.coins.IsPruned())
batch.Erase(make_pair(DB_COINS, it->first));
else
batch.Write(make_pair(DB_COINS, it->first), it->second.coins);
changed++;
}
count++;
CCoinsMap::iterator itOld = it++;
mapCoins.erase(itOld);
}
if (!hashBlock.IsNull())
batch.Write(DB_BEST_BLOCK, hashBlock);
LogPrint("coindb", "Committing %u changed transactions (out of %u) to coin database...\n", (unsigned int)changed, (unsigned int)count);
return db.WriteBatch(batch);
}
CBlockTreeDB::CBlockTreeDB(size_t nCacheSize, bool fMemory, bool fWipe) : CDBWrapper(GetDataDir() / "blocks" / "index", nCacheSize, fMemory, fWipe) {
}
bool CBlockTreeDB::ReadBlockFileInfo(int nFile, CBlockFileInfo &info) {
return Read(make_pair(DB_BLOCK_FILES, nFile), info);
}
bool CBlockTreeDB::WriteReindexing(bool fReindexing) {
if (fReindexing)
return Write(DB_REINDEX_FLAG, '1');
else
return Erase(DB_REINDEX_FLAG);
}
bool CBlockTreeDB::ReadReindexing(bool &fReindexing) {
fReindexing = Exists(DB_REINDEX_FLAG);
return true;
}
bool CBlockTreeDB::ReadLastBlockFile(int &nFile) {
return Read(DB_LAST_BLOCK, nFile);
}
CCoinsViewCursor *CCoinsViewDB::Cursor() const
{
CCoinsViewDBCursor *i = new CCoinsViewDBCursor(const_cast<CDBWrapper*>(&db)->NewIterator(), GetBestBlock());
/* It seems that there are no "const iterators" for LevelDB. Since we
only need read operations on it, use a const-cast to get around
that restriction. */
i->pcursor->Seek(DB_COINS);
// Cache key of first record
i->pcursor->GetKey(i->keyTmp);
return i;
}
bool CCoinsViewDBCursor::GetKey(uint256 &key) const
{
// Return cached key
if (keyTmp.first == DB_COINS) {
key = keyTmp.second;
return true;
}
return false;
}
bool CCoinsViewDBCursor::GetValue(CCoins &coins) const
{
return pcursor->GetValue(coins);
}
unsigned int CCoinsViewDBCursor::GetValueSize() const
{
return pcursor->GetValueSize();
}
bool CCoinsViewDBCursor::Valid() const
{
return keyTmp.first == DB_COINS;
}
void CCoinsViewDBCursor::Next()
{
pcursor->Next();
if (!pcursor->Valid() || !pcursor->GetKey(keyTmp))
keyTmp.first = 0; // Invalidate cached key after last record so that Valid() and GetKey() return false
}
bool CBlockTreeDB::WriteBatchSync(const std::vector<std::pair<int, const CBlockFileInfo*> >& fileInfo, int nLastFile, const std::vector<const CBlockIndex*>& blockinfo) {
CDBBatch batch(*this);
for (std::vector<std::pair<int, const CBlockFileInfo*> >::const_iterator it=fileInfo.begin(); it != fileInfo.end(); it++) {
batch.Write(make_pair(DB_BLOCK_FILES, it->first), *it->second);
}
batch.Write(DB_LAST_BLOCK, nLastFile);
for (std::vector<const CBlockIndex*>::const_iterator it=blockinfo.begin(); it != blockinfo.end(); it++) {
batch.Write(make_pair(DB_BLOCK_INDEX, (*it)->GetBlockHash()), CDiskBlockIndex(*it));
}
return WriteBatch(batch, true);
}
bool CBlockTreeDB::ReadTxIndex(const uint256 &txid, CDiskTxPos &pos) {
return Read(make_pair(DB_TXINDEX, txid), pos);
}
bool CBlockTreeDB::WriteTxIndex(const std::vector<std::pair<uint256, CDiskTxPos> >&vect) {
CDBBatch batch(*this);
for (std::vector<std::pair<uint256,CDiskTxPos> >::const_iterator it=vect.begin(); it!=vect.end(); it++)
batch.Write(make_pair(DB_TXINDEX, it->first), it->second);
return WriteBatch(batch);
}
bool CBlockTreeDB::WriteFlag(const std::string &name, bool fValue) {
return Write(std::make_pair(DB_FLAG, name), fValue ? '1' : '0');
}
bool CBlockTreeDB::ReadFlag(const std::string &name, bool &fValue) {
char ch;
if (!Read(std::make_pair(DB_FLAG, name), ch))
return false;
fValue = ch == '1';
return true;
}
bool CBlockTreeDB::LoadBlockIndexGuts(boost::function<CBlockIndex*(const uint256&)> insertBlockIndex)
{
boost::scoped_ptr<CDBIterator> pcursor(NewIterator());
pcursor->Seek(make_pair(DB_BLOCK_INDEX, uint256()));
// Load mapBlockIndex
while (pcursor->Valid()) {
boost::this_thread::interruption_point();
std::pair<char, uint256> key;
if (pcursor->GetKey(key) && key.first == DB_BLOCK_INDEX) {
CDiskBlockIndex diskindex;
if (pcursor->GetValue(diskindex)) {
// Construct block index object
CBlockIndex* pindexNew = insertBlockIndex(diskindex.GetBlockHash());
pindexNew->pprev = insertBlockIndex(diskindex.hashPrev);
pindexNew->nHeight = diskindex.nHeight;
pindexNew->nFile = diskindex.nFile;
pindexNew->nDataPos = diskindex.nDataPos;
pindexNew->nUndoPos = diskindex.nUndoPos;
pindexNew->nVersion = diskindex.nVersion;
pindexNew->hashMerkleRoot = diskindex.hashMerkleRoot;
pindexNew->nTime = diskindex.nTime;
pindexNew->nBits = diskindex.nBits;
pindexNew->nNonce = diskindex.nNonce;
pindexNew->nStatus = diskindex.nStatus;
pindexNew->nTx = diskindex.nTx;
// Litecoin: Disable PoW Sanity check while loading block index from disk.
// We use the sha256 hash for the block index for performance reasons, which is recorded for later use.
// CheckProofOfWork() uses the scrypt hash which is discarded after a block is accepted.
// While it is technically feasible to verify the PoW, doing so takes several minutes as it
// requires recomputing every PoW hash during every Litecoin startup.
// We opt instead to simply trust the data that is on your local disk.
//if (!CheckProofOfWork(pindexNew->GetBlockHash(), pindexNew->nBits, Params().GetConsensus()))
// return error("LoadBlockIndex(): CheckProofOfWork failed: %s", pindexNew->ToString());
pcursor->Next();
} else {
return error("LoadBlockIndex() : failed to read value");
}
} else {
break;
}
}
return true;
}