neobytes/src/miner.cpp
Gregory Maxwell d6eb259953 [Fee logic] Don't count txins for priority to encourage sweeping.
This changes the priority calculation to not include the size of per-txin
 data including up to 110 bytes of scriptsig so that transactions which
 sweep up extra UTXO don't lose priority relative to ones that don't.

I'd toyed with some other variations, but it seems like any formulation
 which results in an incentive stronger than making them not count will
 sometimes create incentives to add extra outputs so that you have
 extra inputs to consume later.  The maximum credit is limited so that
 users don't lose the disincentive to stuff random data in their
 transactions, the limit of 110 is based on the size of a P2SH
 redemption with a compressed public key.

This shouldn't need a staged deployment because the priority is not
 used as a relay criteria, only a mining criteria.
2013-09-17 10:56:54 -07:00

682 lines
24 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2012 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 "core.h"
#include "wallet.h"
#include "miner.h"
#include "main.h"
//////////////////////////////////////////////////////////////////////////////
//
// BitcoinMiner
//
int static FormatHashBlocks(void* pbuffer, unsigned int len)
{
unsigned char* pdata = (unsigned char*)pbuffer;
unsigned int blocks = 1 + ((len + 8) / 64);
unsigned char* pend = pdata + 64 * blocks;
memset(pdata + len, 0, 64 * blocks - len);
pdata[len] = 0x80;
unsigned int bits = len * 8;
pend[-1] = (bits >> 0) & 0xff;
pend[-2] = (bits >> 8) & 0xff;
pend[-3] = (bits >> 16) & 0xff;
pend[-4] = (bits >> 24) & 0xff;
return blocks;
}
static const unsigned int pSHA256InitState[8] =
{0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};
void SHA256Transform(void* pstate, void* pinput, const void* pinit)
{
SHA256_CTX ctx;
unsigned char data[64];
SHA256_Init(&ctx);
for (int i = 0; i < 16; i++)
((uint32_t*)data)[i] = ByteReverse(((uint32_t*)pinput)[i]);
for (int i = 0; i < 8; i++)
ctx.h[i] = ((uint32_t*)pinit)[i];
SHA256_Update(&ctx, data, sizeof(data));
for (int i = 0; i < 8; i++)
((uint32_t*)pstate)[i] = ctx.h[i];
}
//
// ScanHash scans nonces looking for a hash with at least some zero bits.
// It operates on big endian data. Caller does the byte reversing.
// All input buffers are 16-byte aligned. nNonce is usually preserved
// between calls, but periodically or if nNonce is 0xffff0000 or above,
// the block is rebuilt and nNonce starts over at zero.
//
unsigned int static ScanHash_CryptoPP(char* pmidstate, char* pdata, char* phash1, char* phash, unsigned int& nHashesDone)
{
unsigned int& nNonce = *(unsigned int*)(pdata + 12);
for (;;)
{
// Crypto++ SHA256
// Hash pdata using pmidstate as the starting state into
// pre-formatted buffer phash1, then hash phash1 into phash
nNonce++;
SHA256Transform(phash1, pdata, pmidstate);
SHA256Transform(phash, phash1, pSHA256InitState);
// Return the nonce if the hash has at least some zero bits,
// caller will check if it has enough to reach the target
if (((unsigned short*)phash)[14] == 0)
return nNonce;
// If nothing found after trying for a while, return -1
if ((nNonce & 0xffff) == 0)
{
nHashesDone = 0xffff+1;
return (unsigned int) -1;
}
if ((nNonce & 0xfff) == 0)
boost::this_thread::interruption_point();
}
}
// Some explaining would be appreciated
class COrphan
{
public:
CTransaction* ptx;
set<uint256> setDependsOn;
double dPriority;
double dFeePerKb;
COrphan(CTransaction* ptxIn)
{
ptx = ptxIn;
dPriority = dFeePerKb = 0;
}
void print() const
{
printf("COrphan(hash=%s, dPriority=%.1f, dFeePerKb=%.1f)\n",
ptx->GetHash().ToString().c_str(), dPriority, dFeePerKb);
BOOST_FOREACH(uint256 hash, setDependsOn)
printf(" setDependsOn %s\n", hash.ToString().c_str());
}
};
uint64 nLastBlockTx = 0;
uint64 nLastBlockSize = 0;
// We want to sort transactions by priority and fee, so:
typedef boost::tuple<double, double, CTransaction*> TxPriority;
class TxPriorityCompare
{
bool byFee;
public:
TxPriorityCompare(bool _byFee) : byFee(_byFee) { }
bool operator()(const TxPriority& a, const TxPriority& b)
{
if (byFee)
{
if (a.get<1>() == b.get<1>())
return a.get<0>() < b.get<0>();
return a.get<1>() < b.get<1>();
}
else
{
if (a.get<0>() == b.get<0>())
return a.get<1>() < b.get<1>();
return a.get<0>() < b.get<0>();
}
}
};
CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
{
// Create new block
auto_ptr<CBlockTemplate> pblocktemplate(new CBlockTemplate());
if(!pblocktemplate.get())
return NULL;
CBlock *pblock = &pblocktemplate->block; // pointer for convenience
// Create coinbase tx
CTransaction txNew;
txNew.vin.resize(1);
txNew.vin[0].prevout.SetNull();
txNew.vout.resize(1);
txNew.vout[0].scriptPubKey = scriptPubKeyIn;
// Add our coinbase tx as first transaction
pblock->vtx.push_back(txNew);
pblocktemplate->vTxFees.push_back(-1); // updated at end
pblocktemplate->vTxSigOps.push_back(-1); // updated at end
// Largest block you're willing to create:
unsigned int nBlockMaxSize = GetArg("-blockmaxsize", MAX_BLOCK_SIZE_GEN/2);
// Limit to betweeen 1K and MAX_BLOCK_SIZE-1K for sanity:
nBlockMaxSize = std::max((unsigned int)1000, std::min((unsigned int)(MAX_BLOCK_SIZE-1000), nBlockMaxSize));
// How much of the block should be dedicated to high-priority transactions,
// included regardless of the fees they pay
unsigned int nBlockPrioritySize = GetArg("-blockprioritysize", DEFAULT_BLOCK_PRIORITY_SIZE);
nBlockPrioritySize = std::min(nBlockMaxSize, nBlockPrioritySize);
// Minimum block size you want to create; block will be filled with free transactions
// until there are no more or the block reaches this size:
unsigned int nBlockMinSize = GetArg("-blockminsize", 0);
nBlockMinSize = std::min(nBlockMaxSize, nBlockMinSize);
// Collect memory pool transactions into the block
int64 nFees = 0;
{
LOCK2(cs_main, mempool.cs);
CBlockIndex* pindexPrev = pindexBest;
CCoinsViewCache view(*pcoinsTip, true);
// Priority order to process transactions
list<COrphan> vOrphan; // list memory doesn't move
map<uint256, vector<COrphan*> > mapDependers;
bool fPrintPriority = GetBoolArg("-printpriority", false);
// This vector will be sorted into a priority queue:
vector<TxPriority> vecPriority;
vecPriority.reserve(mempool.mapTx.size());
for (map<uint256, CTransaction>::iterator mi = mempool.mapTx.begin(); mi != mempool.mapTx.end(); ++mi)
{
CTransaction& tx = (*mi).second;
if (tx.IsCoinBase() || !IsFinalTx(tx))
continue;
COrphan* porphan = NULL;
double dPriority = 0;
int64 nTotalIn = 0;
bool fMissingInputs = false;
BOOST_FOREACH(const CTxIn& txin, tx.vin)
{
// Read prev transaction
if (!view.HaveCoins(txin.prevout.hash))
{
// This should never happen; all transactions in the memory
// pool should connect to either transactions in the chain
// or other transactions in the memory pool.
if (!mempool.mapTx.count(txin.prevout.hash))
{
printf("ERROR: mempool transaction missing input\n");
if (fDebug) assert("mempool transaction missing input" == 0);
fMissingInputs = true;
if (porphan)
vOrphan.pop_back();
break;
}
// Has to wait for dependencies
if (!porphan)
{
// Use list for automatic deletion
vOrphan.push_back(COrphan(&tx));
porphan = &vOrphan.back();
}
mapDependers[txin.prevout.hash].push_back(porphan);
porphan->setDependsOn.insert(txin.prevout.hash);
nTotalIn += mempool.mapTx[txin.prevout.hash].vout[txin.prevout.n].nValue;
continue;
}
const CCoins &coins = view.GetCoins(txin.prevout.hash);
int64 nValueIn = coins.vout[txin.prevout.n].nValue;
nTotalIn += nValueIn;
int nConf = pindexPrev->nHeight - coins.nHeight + 1;
dPriority += (double)nValueIn * nConf;
}
if (fMissingInputs) continue;
// Priority is sum(valuein * age) / modified_txsize
unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
unsigned int nTxSizeMod = nTxSize;
// In order to avoid disincentivizing cleaning up the UTXO set we don't count
// the constant overhead for each txin and up to 110 bytes of scriptSig (which
// is enough to cover a compressed pubkey p2sh redemption) for priority.
// Providing any more cleanup incentive than making additional inputs free would
// risk encouraging people to create junk outputs to redeem later.
BOOST_FOREACH(const CTxIn& txin, tx.vin)
{
unsigned int offset = 41U + min(110U, (unsigned int)txin.scriptSig.size());
if (nTxSizeMod > offset)
nTxSizeMod -= offset;
}
dPriority /= nTxSizeMod;
// This is a more accurate fee-per-kilobyte than is used by the client code, because the
// client code rounds up the size to the nearest 1K. That's good, because it gives an
// incentive to create smaller transactions.
double dFeePerKb = double(nTotalIn-GetValueOut(tx)) / (double(nTxSize)/1000.0);
if (porphan)
{
porphan->dPriority = dPriority;
porphan->dFeePerKb = dFeePerKb;
}
else
vecPriority.push_back(TxPriority(dPriority, dFeePerKb, &(*mi).second));
}
// Collect transactions into block
uint64 nBlockSize = 1000;
uint64 nBlockTx = 0;
int nBlockSigOps = 100;
bool fSortedByFee = (nBlockPrioritySize <= 0);
TxPriorityCompare comparer(fSortedByFee);
std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
while (!vecPriority.empty())
{
// Take highest priority transaction off the priority queue:
double dPriority = vecPriority.front().get<0>();
double dFeePerKb = vecPriority.front().get<1>();
CTransaction& tx = *(vecPriority.front().get<2>());
std::pop_heap(vecPriority.begin(), vecPriority.end(), comparer);
vecPriority.pop_back();
// Size limits
unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
if (nBlockSize + nTxSize >= nBlockMaxSize)
continue;
// Legacy limits on sigOps:
unsigned int nTxSigOps = GetLegacySigOpCount(tx);
if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
continue;
// Skip free transactions if we're past the minimum block size:
if (fSortedByFee && (dFeePerKb < CTransaction::nMinTxFee) && (nBlockSize + nTxSize >= nBlockMinSize))
continue;
// Prioritize by fee once past the priority size or we run out of high-priority
// transactions:
if (!fSortedByFee &&
((nBlockSize + nTxSize >= nBlockPrioritySize) || !AllowFree(dPriority)))
{
fSortedByFee = true;
comparer = TxPriorityCompare(fSortedByFee);
std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
}
if (!view.HaveInputs(tx))
continue;
int64 nTxFees = view.GetValueIn(tx)-GetValueOut(tx);
nTxSigOps += GetP2SHSigOpCount(tx, view);
if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
continue;
CValidationState state;
if (!CheckInputs(tx, state, view, true, SCRIPT_VERIFY_P2SH))
continue;
CTxUndo txundo;
uint256 hash = tx.GetHash();
UpdateCoins(tx, state, view, txundo, pindexPrev->nHeight+1, hash);
// Added
pblock->vtx.push_back(tx);
pblocktemplate->vTxFees.push_back(nTxFees);
pblocktemplate->vTxSigOps.push_back(nTxSigOps);
nBlockSize += nTxSize;
++nBlockTx;
nBlockSigOps += nTxSigOps;
nFees += nTxFees;
if (fPrintPriority)
{
printf("priority %.1f feeperkb %.1f txid %s\n",
dPriority, dFeePerKb, tx.GetHash().ToString().c_str());
}
// Add transactions that depend on this one to the priority queue
if (mapDependers.count(hash))
{
BOOST_FOREACH(COrphan* porphan, mapDependers[hash])
{
if (!porphan->setDependsOn.empty())
{
porphan->setDependsOn.erase(hash);
if (porphan->setDependsOn.empty())
{
vecPriority.push_back(TxPriority(porphan->dPriority, porphan->dFeePerKb, porphan->ptx));
std::push_heap(vecPriority.begin(), vecPriority.end(), comparer);
}
}
}
}
}
nLastBlockTx = nBlockTx;
nLastBlockSize = nBlockSize;
printf("CreateNewBlock(): total size %"PRI64u"\n", nBlockSize);
pblock->vtx[0].vout[0].nValue = GetBlockValue(pindexPrev->nHeight+1, nFees);
pblocktemplate->vTxFees[0] = -nFees;
// Fill in header
pblock->hashPrevBlock = pindexPrev->GetBlockHash();
UpdateTime(*pblock, pindexPrev);
pblock->nBits = GetNextWorkRequired(pindexPrev, pblock);
pblock->nNonce = 0;
pblock->vtx[0].vin[0].scriptSig = CScript() << OP_0 << OP_0;
pblocktemplate->vTxSigOps[0] = GetLegacySigOpCount(pblock->vtx[0]);
CBlockIndex indexDummy(*pblock);
indexDummy.pprev = pindexPrev;
indexDummy.nHeight = pindexPrev->nHeight + 1;
CCoinsViewCache viewNew(*pcoinsTip, true);
CValidationState state;
if (!ConnectBlock(*pblock, state, &indexDummy, viewNew, true))
throw std::runtime_error("CreateNewBlock() : ConnectBlock failed");
}
return pblocktemplate.release();
}
CBlockTemplate* CreateNewBlockWithKey(CReserveKey& reservekey)
{
CPubKey pubkey;
if (!reservekey.GetReservedKey(pubkey))
return NULL;
CScript scriptPubKey = CScript() << pubkey << OP_CHECKSIG;
return CreateNewBlock(scriptPubKey);
}
void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int& nExtraNonce)
{
// Update nExtraNonce
static uint256 hashPrevBlock;
if (hashPrevBlock != pblock->hashPrevBlock)
{
nExtraNonce = 0;
hashPrevBlock = pblock->hashPrevBlock;
}
++nExtraNonce;
unsigned int nHeight = pindexPrev->nHeight+1; // Height first in coinbase required for block.version=2
pblock->vtx[0].vin[0].scriptSig = (CScript() << nHeight << CBigNum(nExtraNonce)) + COINBASE_FLAGS;
assert(pblock->vtx[0].vin[0].scriptSig.size() <= 100);
pblock->hashMerkleRoot = pblock->BuildMerkleTree();
}
void FormatHashBuffers(CBlock* pblock, char* pmidstate, char* pdata, char* phash1)
{
//
// Pre-build hash buffers
//
struct
{
struct unnamed2
{
int nVersion;
uint256 hashPrevBlock;
uint256 hashMerkleRoot;
unsigned int nTime;
unsigned int nBits;
unsigned int nNonce;
}
block;
unsigned char pchPadding0[64];
uint256 hash1;
unsigned char pchPadding1[64];
}
tmp;
memset(&tmp, 0, sizeof(tmp));
tmp.block.nVersion = pblock->nVersion;
tmp.block.hashPrevBlock = pblock->hashPrevBlock;
tmp.block.hashMerkleRoot = pblock->hashMerkleRoot;
tmp.block.nTime = pblock->nTime;
tmp.block.nBits = pblock->nBits;
tmp.block.nNonce = pblock->nNonce;
FormatHashBlocks(&tmp.block, sizeof(tmp.block));
FormatHashBlocks(&tmp.hash1, sizeof(tmp.hash1));
// Byte swap all the input buffer
for (unsigned int i = 0; i < sizeof(tmp)/4; i++)
((unsigned int*)&tmp)[i] = ByteReverse(((unsigned int*)&tmp)[i]);
// Precalc the first half of the first hash, which stays constant
SHA256Transform(pmidstate, &tmp.block, pSHA256InitState);
memcpy(pdata, &tmp.block, 128);
memcpy(phash1, &tmp.hash1, 64);
}
bool CheckWork(CBlock* pblock, CWallet& wallet, CReserveKey& reservekey)
{
uint256 hash = pblock->GetHash();
uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
if (hash > hashTarget)
return false;
//// debug print
printf("BitcoinMiner:\n");
printf("proof-of-work found \n hash: %s \ntarget: %s\n", hash.GetHex().c_str(), hashTarget.GetHex().c_str());
pblock->print();
printf("generated %s\n", FormatMoney(pblock->vtx[0].vout[0].nValue).c_str());
// Found a solution
{
LOCK(cs_main);
if (pblock->hashPrevBlock != hashBestChain)
return error("BitcoinMiner : generated block is stale");
// Remove key from key pool
reservekey.KeepKey();
// Track how many getdata requests this block gets
{
LOCK(wallet.cs_wallet);
wallet.mapRequestCount[pblock->GetHash()] = 0;
}
// Process this block the same as if we had received it from another node
CValidationState state;
if (!ProcessBlock(state, NULL, pblock))
return error("BitcoinMiner : ProcessBlock, block not accepted");
}
return true;
}
void static BitcoinMiner(CWallet *pwallet)
{
printf("BitcoinMiner started\n");
SetThreadPriority(THREAD_PRIORITY_LOWEST);
RenameThread("bitcoin-miner");
// Each thread has its own key and counter
CReserveKey reservekey(pwallet);
unsigned int nExtraNonce = 0;
try { while (true) {
if (Params().NetworkID() != CChainParams::REGTEST) {
// Busy-wait for the network to come online so we don't waste time mining
// on an obsolete chain. In regtest mode we expect to fly solo.
while (vNodes.empty())
MilliSleep(1000);
}
//
// Create new block
//
unsigned int nTransactionsUpdatedLast = nTransactionsUpdated;
CBlockIndex* pindexPrev = pindexBest;
auto_ptr<CBlockTemplate> pblocktemplate(CreateNewBlockWithKey(reservekey));
if (!pblocktemplate.get())
return;
CBlock *pblock = &pblocktemplate->block;
IncrementExtraNonce(pblock, pindexPrev, nExtraNonce);
printf("Running BitcoinMiner with %"PRIszu" transactions in block (%u bytes)\n", pblock->vtx.size(),
::GetSerializeSize(*pblock, SER_NETWORK, PROTOCOL_VERSION));
//
// Pre-build hash buffers
//
char pmidstatebuf[32+16]; char* pmidstate = alignup<16>(pmidstatebuf);
char pdatabuf[128+16]; char* pdata = alignup<16>(pdatabuf);
char phash1buf[64+16]; char* phash1 = alignup<16>(phash1buf);
FormatHashBuffers(pblock, pmidstate, pdata, phash1);
unsigned int& nBlockTime = *(unsigned int*)(pdata + 64 + 4);
unsigned int& nBlockBits = *(unsigned int*)(pdata + 64 + 8);
unsigned int& nBlockNonce = *(unsigned int*)(pdata + 64 + 12);
//
// Search
//
int64 nStart = GetTime();
uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
uint256 hashbuf[2];
uint256& hash = *alignup<16>(hashbuf);
while (true)
{
unsigned int nHashesDone = 0;
unsigned int nNonceFound;
// Crypto++ SHA256
nNonceFound = ScanHash_CryptoPP(pmidstate, pdata + 64, phash1,
(char*)&hash, nHashesDone);
// Check if something found
if (nNonceFound != (unsigned int) -1)
{
for (unsigned int i = 0; i < sizeof(hash)/4; i++)
((unsigned int*)&hash)[i] = ByteReverse(((unsigned int*)&hash)[i]);
if (hash <= hashTarget)
{
// Found a solution
pblock->nNonce = ByteReverse(nNonceFound);
assert(hash == pblock->GetHash());
SetThreadPriority(THREAD_PRIORITY_NORMAL);
CheckWork(pblock, *pwallet, reservekey);
SetThreadPriority(THREAD_PRIORITY_LOWEST);
// In regression test mode, stop mining after a block is found. This
// allows developers to controllably generate a block on demand.
if (Params().NetworkID() == CChainParams::REGTEST)
throw boost::thread_interrupted();
break;
}
}
// Meter hashes/sec
static int64 nHashCounter;
if (nHPSTimerStart == 0)
{
nHPSTimerStart = GetTimeMillis();
nHashCounter = 0;
}
else
nHashCounter += nHashesDone;
if (GetTimeMillis() - nHPSTimerStart > 4000)
{
static CCriticalSection cs;
{
LOCK(cs);
if (GetTimeMillis() - nHPSTimerStart > 4000)
{
dHashesPerSec = 1000.0 * nHashCounter / (GetTimeMillis() - nHPSTimerStart);
nHPSTimerStart = GetTimeMillis();
nHashCounter = 0;
static int64 nLogTime;
if (GetTime() - nLogTime > 30 * 60)
{
nLogTime = GetTime();
printf("hashmeter %6.0f khash/s\n", dHashesPerSec/1000.0);
}
}
}
}
// Check for stop or if block needs to be rebuilt
boost::this_thread::interruption_point();
if (vNodes.empty() && Params().NetworkID() != CChainParams::REGTEST)
break;
if (nBlockNonce >= 0xffff0000)
break;
if (nTransactionsUpdated != nTransactionsUpdatedLast && GetTime() - nStart > 60)
break;
if (pindexPrev != pindexBest)
break;
// Update nTime every few seconds
UpdateTime(*pblock, pindexPrev);
nBlockTime = ByteReverse(pblock->nTime);
if (TestNet())
{
// Changing pblock->nTime can change work required on testnet:
nBlockBits = ByteReverse(pblock->nBits);
hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
}
}
} }
catch (boost::thread_interrupted)
{
printf("BitcoinMiner terminated\n");
throw;
}
}
void GenerateBitcoins(bool fGenerate, CWallet* pwallet)
{
static boost::thread_group* minerThreads = NULL;
int nThreads = GetArg("-genproclimit", -1);
if (nThreads < 0) {
if (Params().NetworkID() == CChainParams::REGTEST)
nThreads = 1;
else
nThreads = boost::thread::hardware_concurrency();
}
if (minerThreads != NULL)
{
minerThreads->interrupt_all();
delete minerThreads;
minerThreads = NULL;
}
if (nThreads == 0 || !fGenerate)
return;
minerThreads = new boost::thread_group();
for (int i = 0; i < nThreads; i++)
minerThreads->create_thread(boost::bind(&BitcoinMiner, pwallet));
}