public BackgroundCommiterCoinView(CoinView inner)
{
if (inner == null)
{
throw new ArgumentNullException("inner");
}
_Inner = inner;
_InnerCommitable = new CommitableCoinView(Inner);
_Commitable = new CommitableCoinView(_InnerCommitable);
FlushPeriod = TimeSpan.FromSeconds(5);
}
private void CheckIntputs(Transaction tx, CommitableCoinView inputs, int nSpendHeight)
{
if (!inputs.HaveInputs(tx))
{
ConsensusErrors.BadTransactionMissingInput.Throw();
}
Money nValueIn = Money.Zero;
Money nFees = Money.Zero;
for (int i = 0; i < tx.Inputs.Count; i++)
{
var prevout = tx.Inputs[i].PrevOut;
var coins = inputs.AccessCoins(prevout.Hash);
// If prev is coinbase, check that it's matured
if (coins.IsCoinbase)
{
if (nSpendHeight - coins.Height < COINBASE_MATURITY)
{
ConsensusErrors.BadTransactionPrematureCoinbaseSpending.Throw();
}
}
// Check for negative or overflow input values
nValueIn += coins.TryGetOutput(prevout.N).Value;
if (!MoneyRange(coins.TryGetOutput(prevout.N).Value) || !MoneyRange(nValueIn))
{
ConsensusErrors.BadTransactionInputValueOutOfRange.Throw();
}
}
if (nValueIn < tx.TotalOut)
{
ConsensusErrors.BadTransactionInBelowOut.Throw();
}
// Tally transaction fees
Money nTxFee = nValueIn - tx.TotalOut;
if (nTxFee < 0)
{
ConsensusErrors.BadTransactionNegativeFee.Throw();
}
nFees += nTxFee;
if (!MoneyRange(nFees))
{
ConsensusErrors.BadTransactionFeeOutOfRange.Throw();
}
}
private uint GetP2SHSigOpCount(Transaction tx, CommitableCoinView inputs)
{
if (tx.IsCoinBase)
{
return(0);
}
uint nSigOps = 0;
for (uint i = 0; i < tx.Inputs.Count; i++)
{
var prevout = inputs.GetOutputFor(tx.Inputs[i]);
if (prevout.ScriptPubKey.IsPayToScriptHash)
{
nSigOps += prevout.ScriptPubKey.GetSigOpCount(tx.Inputs[i].ScriptSig);
}
}
return(nSigOps);
}
private long GetTransactionSigOpCost(Transaction tx, CommitableCoinView inputs, ConsensusFlags flags)
{
long nSigOps = GetLegacySigOpCount(tx) * WITNESS_SCALE_FACTOR;
if (tx.IsCoinBase)
{
return(nSigOps);
}
if (flags.ScriptFlags.HasFlag(ScriptVerify.P2SH))
{
nSigOps += GetP2SHSigOpCount(tx, inputs) * WITNESS_SCALE_FACTOR;
}
for (var i = 0; i < tx.Inputs.Count; i++)
{
var prevout = inputs.GetOutputFor(tx.Inputs[i]);
nSigOps += CountWitnessSigOps(tx.Inputs[i].ScriptSig, prevout.ScriptPubKey, tx.Inputs[i].WitScript, flags);
}
return(nSigOps);
}
/// <summary>
/// Pull blocks, validate them and update the UTXO Set
/// </summary>
/// <param name="utxo">UTXO Set</param>
/// <param name="puller">Block source</param>
/// <returns>Stream of validated blocks</returns>
public IEnumerable <Block> Run(CoinViewStack utxoStack, BlockPuller puller)
{
var utxo = utxoStack.Top;
var cache = utxoStack.Find <CacheCoinView>();
var lookaheadPuller = puller as ILookaheadBlockPuller;
puller.SetLocation(utxo.Tip);
ThresholdConditionCache bip9 = new ThresholdConditionCache(_ConsensusParams);
StopWatch watch = new StopWatch();
bool rejected = false;
while (true)
{
Block block = null;
while (true)
{
rejected = false;
try
{
using (watch.Start(o => PerformanceCounter.AddBlockFetchingTime(o)))
{
block = puller.NextBlock();
}
ChainedBlock next;
ContextInformation context;
ConsensusFlags flags;
using (watch.Start(o => PerformanceCounter.AddBlockProcessingTime(o)))
{
CheckBlockHeader(block.Header);
next = new ChainedBlock(block.Header, block.Header.GetHash(), utxo.Tip);
context = new ContextInformation(next, this._ConsensusParams);
ContextualCheckBlockHeader(block.Header, context);
var states = bip9.GetStates(utxo.Tip);
flags = new ConsensusFlags(next, states, _ConsensusParams);
ContextualCheckBlock(block, flags, context);
CheckBlock(block);
}
var commitable = new CommitableCoinView(next, utxo);
using (watch.Start(o => PerformanceCounter.AddUTXOFetchingTime(o)))
{
commitable.FetchCoins(GetIdsToFetch(block, flags.EnforceBIP30));
}
commitable.SetInner(NullCoinView.Instance);
Task prefetching = GetPrefetchingTask(cache, lookaheadPuller, flags);
using (watch.Start(o => PerformanceCounter.AddBlockProcessingTime(o)))
{
ExecuteBlock(block, next, flags, commitable, null);
}
using (watch.Start(o => PerformanceCounter.AddUTXOFetchingTime(o)))
{
prefetching.Wait();
commitable.Commit(utxo);
}
}
catch (ConsensusErrorException ex)
{
rejected = true;
if (ex.ConsensusError == ConsensusErrors.TimeTooNew)
{
puller.Reject(block, RejectionMode.Temporary);
}
else
{
puller.Reject(block, RejectionMode.Permanent);
}
}
if (!rejected)
{
yield return(block);
}
}
}
}
public void ExecuteBlock(Block block, ChainedBlock index, ConsensusFlags flags, CommitableCoinView view, TaskScheduler taskScheduler)
{
PerformanceCounter.AddProcessedBlocks(1);
taskScheduler = taskScheduler ?? TaskScheduler.Default;
if (flags.EnforceBIP30)
{
foreach (var tx in block.Transactions)
{
var coins = view.AccessCoins(tx.GetHash());
if (coins != null && !coins.IsPrunable)
{
ConsensusErrors.BadTransactionBIP30.Throw();
}
}
}
long nSigOpsCost = 0;
Money nFees = Money.Zero;
List <Task <bool> > checkInputs = new List <Task <bool> >();
for (int i = 0; i < block.Transactions.Count; i++)
{
PerformanceCounter.AddProcessedTransactions(1);
var tx = block.Transactions[i];
if (!tx.IsCoinBase)
{
int[] prevheights;
if (!view.HaveInputs(tx))
{
ConsensusErrors.BadTransactionMissingInput.Throw();
}
prevheights = new int[tx.Inputs.Count];
// Check that transaction is BIP68 final
// BIP68 lock checks (as opposed to nLockTime checks) must
// be in ConnectBlock because they require the UTXO set
for (var j = 0; j < tx.Inputs.Count; j++)
{
prevheights[j] = (int)view.AccessCoins(tx.Inputs[j].PrevOut.Hash).Height;
}
if (!tx.CheckSequenceLocks(prevheights, index, flags.LockTimeFlags))
{
ConsensusErrors.BadTransactionNonFinal.Throw();
}
}
// GetTransactionSigOpCost counts 3 types of sigops:
// * legacy (always)
// * p2sh (when P2SH enabled in flags and excludes coinbase)
// * witness (when witness enabled in flags and excludes coinbase)
nSigOpsCost += GetTransactionSigOpCost(tx, view, flags);
if (nSigOpsCost > MAX_BLOCK_SIGOPS_COST)
{
ConsensusErrors.BadBlockSigOps.Throw();
}
if (!tx.IsCoinBase)
{
CheckIntputs(tx, view, index.Height);
nFees += view.GetValueIn(tx) - tx.TotalOut;
int ii = i;
var localTx = tx;
PrecomputedTransactionData txData = new PrecomputedTransactionData(tx);
for (int iInput = 0; iInput < tx.Inputs.Count; iInput++)
{
PerformanceCounter.AddProcessedInputs(1);
var input = tx.Inputs[iInput];
int iiIntput = iInput;
var txout = view.GetOutputFor(input);
var checkInput = new Task <bool>(() =>
{
if (UseConsensusLib)
{
Script.BitcoinConsensusError error;
return(Script.VerifyScriptConsensus(txout.ScriptPubKey, tx, (uint)iiIntput, flags.ScriptFlags, out error));
}
else
{
var checker = new TransactionChecker(tx, iiIntput, txout.Value, txData);
var ctx = new ScriptEvaluationContext();
ctx.ScriptVerify = flags.ScriptFlags;
return(ctx.VerifyScript(input.ScriptSig, txout.ScriptPubKey, checker));
}
});
checkInput.Start(taskScheduler);
checkInputs.Add(checkInput);
}
}
view.Update(tx, index.Height);
}
Money blockReward = nFees + GetBlockSubsidy(index.Height);
if (block.Transactions[0].TotalOut > blockReward)
{
ConsensusErrors.BadCoinbaseAmount.Throw();
}
var passed = checkInputs.All(c => c.GetAwaiter().GetResult());
if (!passed)
{
ConsensusErrors.BadTransactionScriptError.Throw();
}
}