/// <summary>
///
/// </summary>
/// <param name="transaction">The transaction that the script applies to.</param>
/// <param name="script"></param>
/// <param name="options"></param>
public ScriptEngine(MsgTx transaction, int txIndex, Script script, ScriptOptions options)
{
if (transaction == null)
{
throw new ArgumentNullException(nameof(transaction));
}
if (txIndex < 0 || txIndex >= transaction.TxIn.Length)
{
throw new ArgumentOutOfRangeException(nameof(txIndex));
}
if (script == null)
{
throw new ArgumentNullException(nameof(script));
}
if (options == null)
{
throw new ArgumentNullException(nameof(options));
}
_transaction = transaction;
_txIndex = txIndex;
_script = script;
_opCodeLookup = new Dictionary <OpCode, Action <ParsedOpCode> >();
Options = options;
MainStack = new ScriptStack(Options.AssertScriptIntegerMinimalEncoding);
AltStack = new ScriptStack(Options.AssertScriptIntegerMinimalEncoding);
BranchStack = new BranchStack();
InitializeOpCodeDictionary();
}
private bool CanExecuteNextOpCode(ParsedOpCode op)
{
// Ensure that disabled opcodes are always executed.
var branchOp = BranchStack.Peek();
return(branchOp == BranchOption.True ||
op.Code.IsConditional() ||
op.Code.IsDisabled());
}
private void OpNotIf()
{
switch (BranchStack.Peek())
{
case BranchOption.Skip:
case BranchOption.False:
BranchStack.Push(BranchOption.Skip);
break;
case BranchOption.True:
BranchStack.Push(!MainStack.PopBool() ? BranchOption.True : BranchOption.False);
break;
}
}
private void OpElse()
{
switch (BranchStack.Peek())
{
case BranchOption.Skip:
break;
case BranchOption.False:
BranchStack.Replace(BranchOption.True);
break;
case BranchOption.True:
BranchStack.Replace(BranchOption.False);
break;
}
}
private void OpEndIf()
{
BranchStack.Discard();
}