/// <summary>
/// Calculates pay-to-script-hash (BIP16) transaction signature operation cost.
/// </summary>
/// <param name="transaction">Transaction for which we are computing the cost.</param>
/// <param name="inputs">Map of previous transactions that have outputs we're spending.</param>
/// <returns>Signature operation cost for transaction.</returns>
private uint GetP2SHSignatureOperationsCount(Transaction transaction, UnspentOutputSet inputs)
{
if (transaction.IsCoinBase)
{
return(0);
}
uint sigOps = 0;
for (int i = 0; i < transaction.Inputs.Count; i++)
{
TxOut prevout = inputs.GetOutputFor(transaction.Inputs[i]);
if (prevout.ScriptPubKey.IsPayToScriptHash)
{
sigOps += prevout.ScriptPubKey.GetSigOpCount(transaction.Inputs[i].ScriptSig);
}
}
return(sigOps);
}
/// <inheritdoc />
public virtual void ExecuteBlock(RuleContext context, TaskScheduler taskScheduler = null)
{
this.logger.LogTrace("()");
Block block = context.BlockValidationContext.Block;
ChainedBlock index = context.BlockValidationContext.ChainedBlock;
DeploymentFlags flags = context.Flags;
UnspentOutputSet view = context.Set;
this.PerformanceCounter.AddProcessedBlocks(1);
taskScheduler = taskScheduler ?? TaskScheduler.Default;
//if (!context.SkipValidation)
//{
// if (flags.EnforceBIP30)
// {
// foreach (Transaction tx in block.Transactions)
// {
// UnspentOutputs coins = view.AccessCoins(tx.GetHash());
// if ((coins != null) && !coins.IsPrunable)
// {
// this.logger.LogTrace("(-)[BAD_TX_BIP_30]");
// ConsensusErrors.BadTransactionBIP30.Throw();
// }
// }
// }
//}
//else this.logger.LogTrace("BIP30 validation skipped for checkpointed block at height {0}.", index.Height);
long sigOpsCost = 0;
Money fees = Money.Satoshis(2290000);//Money.Zero;
var checkInputs = new List <Task <bool> >();
for (int txIndex = 0; txIndex < block.Transactions.Count; txIndex++)
{
this.PerformanceCounter.AddProcessedTransactions(1);
Transaction tx = block.Transactions[txIndex];
if (!context.SkipValidation)
{
if (!tx.IsCoinBase && (!context.IsPoS || (context.IsPoS && !tx.IsCoinStake)))
{
int[] prevheights;
if (!view.HaveInputs(tx))
{
this.logger.LogTrace("(-)[BAD_TX_NO_INPUT]");
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 (int 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))
{
this.logger.LogTrace("(-)[BAD_TX_NON_FINAL]");
ConsensusErrors.BadTransactionNonFinal.Throw();
}
}
// GetTransactionSignatureOperationCost 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).
sigOpsCost += this.GetTransactionSignatureOperationCost(tx, view, flags);
if (sigOpsCost > this.ConsensusOptions.MaxBlockSigopsCost)
{
ConsensusErrors.BadBlockSigOps.Throw();
}
// TODO: Simplify this condition.
if (!tx.IsCoinBase && (!context.IsPoS || (context.IsPoS && !tx.IsCoinStake)))
{
this.CheckInputs(tx, view, index.Height);
fees += view.GetValueIn(tx) - tx.TotalOut;
var txData = new PrecomputedTransactionData(tx);
for (int inputIndex = 0; inputIndex < tx.Inputs.Count; inputIndex++)
{
this.PerformanceCounter.AddProcessedInputs(1);
TxIn input = tx.Inputs[inputIndex];
int inputIndexCopy = inputIndex;
TxOut txout = view.GetOutputFor(input);
var checkInput = new Task <bool>(() =>
{
var checker = new TransactionChecker(tx, inputIndexCopy, 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);
}
}
}
this.UpdateCoinView(context, tx);
}
if (!context.SkipValidation)
{
this.CheckBlockReward(context, fees, index.Height, block);
bool passed = checkInputs.All(c => c.GetAwaiter().GetResult());
if (!passed)
{
this.logger.LogTrace("(-)[BAD_TX_SCRIPT]");
ConsensusErrors.BadTransactionScriptError.Throw();
}
}
else
{
this.logger.LogTrace("BIP68, SigOp cost, and block reward validation skipped for block at height {0}.", index.Height);
}
this.logger.LogTrace("(-)");
}