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Don't consider op_return outputs when distributing fees
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@marcos-iov
marcos-iov committed Jul 1, 2021
1 parent 59aa4d4 commit 50db665
Showing 1 changed file with 53 additions and 23 deletions.
76 changes: 53 additions & 23 deletions src/main/java/co/rsk/bitcoinj/wallet/Wallet.java
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@
package co.rsk.bitcoinj.wallet;

import com.google.common.collect.*;
import java.util.stream.Collectors;
import net.jcip.annotations.*;
import co.rsk.bitcoinj.core.BtcAbstractBlockChain;
import co.rsk.bitcoinj.core.Address;
Expand Down Expand Up @@ -575,31 +576,40 @@ public void completeTx(SendRequest req) throws InsufficientMoneyException {
value = value.add(output.getValue());
}

log.info("Completing send tx with {} outputs totalling {} and a fee of {}/kB", req.tx.getOutputs().size(),
value.toFriendlyString(), req.feePerKb.toFriendlyString());
log.info(
"Completing send tx with {} outputs totalling {} and a fee of {}/kB",
req.tx.getOutputs().size(),
value.toFriendlyString(),
req.feePerKb.toFriendlyString()
);

// If any inputs have already been added, we don't need to get their value from wallet
Coin totalInput = Coin.ZERO;
for (TransactionInput input : req.tx.getInputs())
if (input.getConnectedOutput() != null)
for (TransactionInput input : req.tx.getInputs()) {
if (input.getConnectedOutput() != null) {
totalInput = totalInput.add(input.getConnectedOutput().getValue());
else
} else {
log.warn("SendRequest transaction already has inputs but we don't know how much they are worth - they will be added to fee.");
}
}
value = value.subtract(totalInput);

List<TransactionInput> originalInputs = new ArrayList<TransactionInput>(req.tx.getInputs());
List<TransactionInput> originalInputs = new ArrayList<>(req.tx.getInputs());

// Check for dusty sends and the OP_RETURN limit.
if (req.ensureMinRequiredFee && !req.emptyWallet) { // Min fee checking is handled later for emptyWallet.
int opReturnCount = 0;
for (TransactionOutput output : req.tx.getOutputs()) {
if (output.isDust())
if (output.isDust()) {
throw new DustySendRequested();
if (output.getScriptPubKey().isOpReturn())
}
if (output.getScriptPubKey().isOpReturn()) {
++opReturnCount;
}
}
if (opReturnCount > 1) // Only 1 OP_RETURN per transaction allowed.
if (opReturnCount > 1) { // Only 1 OP_RETURN per transaction allowed.
throw new MultipleOpReturnRequested();
}
}

// Calculate a list of ALL potential candidates for spending and then ask a coin selector to provide us
Expand Down Expand Up @@ -628,13 +638,15 @@ public void completeTx(SendRequest req) throws InsufficientMoneyException {
log.info(" emptying {}", bestCoinSelection.valueGathered.toFriendlyString());
}

for (TransactionOutput output : bestCoinSelection.gathered)
for (TransactionOutput output : bestCoinSelection.gathered) {
req.tx.addInput(output);
}

if (req.emptyWallet) {
final Coin feePerKb = req.feePerKb == null ? Coin.ZERO : req.feePerKb;
if (!adjustOutputDownwardsForFee(req.tx, bestCoinSelection, feePerKb, req.ensureMinRequiredFee))
if (!adjustOutputDownwardsForFee(req.tx, bestCoinSelection, feePerKb, req.ensureMinRequiredFee)) {
throw new CouldNotAdjustDownwards();
}
}

if (updatedOutputValues != null) {
Expand All @@ -649,17 +661,20 @@ public void completeTx(SendRequest req) throws InsufficientMoneyException {
}

// Now shuffle the outputs to obfuscate which is the change.
if (req.shuffleOutputs)
if (req.shuffleOutputs) {
req.tx.shuffleOutputs();
}

// Now sign the inputs, thus proving that we are entitled to redeem the connected outputs.
if (req.signInputs)
if (req.signInputs) {
signTransaction(req);
}

// Check size.
final int size = req.tx.unsafeBitcoinSerialize().length;
if (size > BtcTransaction.MAX_STANDARD_TX_SIZE)
if (size > BtcTransaction.MAX_STANDARD_TX_SIZE) {
throw new ExceededMaxTransactionSize();
}

// Label the transaction as being a user requested payment. This can be used to render GUI wallet
// transaction lists more appropriately, especially when the wallet starts to generate transactions itself
Expand Down Expand Up @@ -913,8 +928,13 @@ private static class FeeCalculation {

//region Fee calculation code

public FeeCalculation calculateFee(SendRequest req, Coin value, List<TransactionInput> originalInputs,
boolean needAtLeastReferenceFee, List<TransactionOutput> candidates) throws InsufficientMoneyException {
public FeeCalculation calculateFee(
SendRequest req,
Coin value,
List<TransactionInput> originalInputs,
boolean needAtLeastReferenceFee,
List<TransactionOutput> candidates
) throws InsufficientMoneyException {
FeeCalculation result;
Coin fee = Coin.ZERO;
while (true) {
Expand All @@ -929,16 +949,26 @@ public FeeCalculation calculateFee(SendRequest req, Coin value, List<Transaction
if (req.recipientsPayFees) {
result.updatedOutputValues = new ArrayList<Coin>();
}
for (int i = 0; i < req.tx.getOutputs().size(); i++) {
TransactionOutput output = new TransactionOutput(params, tx,
req.tx.getOutputs().get(i).bitcoinSerialize(), 0);
List<TransactionOutput> txOutputsExcludingOpReturn = req.tx.getOutputs()
.stream()
.filter(t -> !t.getScriptPubKey().isOpReturn())
.collect(Collectors.toList());
for (int i = 0; i < txOutputsExcludingOpReturn.size(); i++) {
TransactionOutput output = new TransactionOutput(
params,
tx,
txOutputsExcludingOpReturn.get(i).bitcoinSerialize(),
0
);
if (req.recipientsPayFees) {
// Subtract fee equally from each selected recipient
output.setValue(output.getValue().subtract(fee.divide(req.tx.getOutputs().size())));
output.setValue(output.getValue().subtract(fee.divide(txOutputsExcludingOpReturn.size())));
// first receiver pays the remainder not divisible by output count
if (i == 0) {
// Subtract fee equally from each selected recipient
output.setValue(
output.getValue().subtract(fee.divideAndRemainder(req.tx.getOutputs().size())[1])); // Subtract fee equally from each selected recipient
output.getValue().subtract(fee.divideAndRemainder(txOutputsExcludingOpReturn.size())[1])
);
}
result.updatedOutputValues.add(output.getValue());
if (output.getMinNonDustValue().isGreaterThan(output.getValue())) {
Expand All @@ -949,7 +979,7 @@ public FeeCalculation calculateFee(SendRequest req, Coin value, List<Transaction
}
CoinSelector selector = req.coinSelector == null ? coinSelector : req.coinSelector;
// selector is allowed to modify candidates list.
CoinSelection selection = selector.select(valueNeeded, new LinkedList<TransactionOutput>(candidates));
CoinSelection selection = selector.select(valueNeeded, new LinkedList<>(candidates));
result.bestCoinSelection = selection;
// Can we afford this?
if (selection.valueGathered.compareTo(valueNeeded) < 0) {
Expand Down Expand Up @@ -1013,8 +1043,8 @@ public FeeCalculation calculateFee(SendRequest req, Coin value, List<Transaction
// Include more fee and try again.
fee = feeNeeded;
}
return result;

return result;
}

private void addSuppliedInputs(BtcTransaction tx, List<TransactionInput> originalInputs) {
Expand Down

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