/**
* Checks if a transaction is considered "standard" by the reference client's IsStandardTx and
* AreInputsStandard functions.
*
* <p>Note that this method currently only implements a minimum of checks. More to be added later.
*/
public static RuleViolation isStandard(Transaction tx) {
// TODO: Finish this function off.
if (tx.getVersion() > 1 || tx.getVersion() < 1) {
log.warn("TX considered non-standard due to unknown version number {}", tx.getVersion());
return RuleViolation.VERSION;
}
final List<TransactionOutput> outputs = tx.getOutputs();
for (int i = 0; i < outputs.size(); i++) {
TransactionOutput output = outputs.get(i);
RuleViolation violation = isOutputStandard(output);
if (violation != RuleViolation.NONE) {
log.warn("TX considered non-standard due to output {} violating rule {}", i, violation);
return violation;
}
}
final List<TransactionInput> inputs = tx.getInputs();
for (int i = 0; i < inputs.size(); i++) {
TransactionInput input = inputs.get(i);
RuleViolation violation = isInputStandard(input);
if (violation != RuleViolation.NONE) {
log.warn("TX considered non-standard due to input {} violating rule {}", i, violation);
return violation;
}
}
return RuleViolation.NONE;
}
@Override
public String toString() {
if (!analyzed) return "Pending risk analysis for " + tx.getHashAsString();
else if (nonFinal != null) return "Risky due to non-finality of " + nonFinal.getHashAsString();
else if (nonStandard != null)
return "Risky due to non-standard tx " + nonStandard.getHashAsString();
else return "Non-risky";
}
private Result analyzeIsFinal() {
// Transactions we create ourselves are, by definition, not at risk of double spending against
// us.
if (tx.getConfidence().getSource() == TransactionConfidence.Source.SELF) return Result.OK;
final int height = wallet.getLastBlockSeenHeight();
final long time = wallet.getLastBlockSeenTimeSecs();
// If the transaction has a lock time specified in blocks, we consider that if the tx would
// become final in the
// next block it is not risky (as it would confirm normally).
final int adjustedHeight = height + 1;
if (!tx.isFinal(adjustedHeight, time)) {
nonFinal = tx;
return Result.NON_FINAL;
}
for (Transaction dep : dependencies) {
if (!dep.isFinal(adjustedHeight, time)) {
nonFinal = dep;
return Result.NON_FINAL;
}
}
return Result.OK;
}