aboutsummaryrefslogtreecommitdiff
path: root/src/wallet/wallet.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/wallet/wallet.cpp')
-rw-r--r--src/wallet/wallet.cpp224
1 files changed, 94 insertions, 130 deletions
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index e848145a51..51ff683c2e 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2834,7 +2834,6 @@ bool CWallet::CreateTransactionInternal(
CMutableTransaction txNew;
FeeCalculation feeCalc;
- CAmount nFeeNeeded;
std::pair<int64_t, int64_t> tx_sizes;
int nBytes;
{
@@ -2919,7 +2918,6 @@ bool CWallet::CreateTransactionInternal(
coin_selection_params.m_cost_of_change = coin_selection_params.m_discard_feerate.GetFee(coin_selection_params.change_spend_size) + coin_selection_params.m_change_fee;
nFeeRet = 0;
- bool pick_new_inputs = true;
CAmount nValueIn = 0;
// BnB selector is the only selector used when this is true.
@@ -2932,7 +2930,6 @@ bool CWallet::CreateTransactionInternal(
nChangePosInOut = nChangePosRequest;
txNew.vin.clear();
txNew.vout.clear();
- bool fFirst = true;
CAmount nValueToSelect = nValue;
if (nSubtractFeeFromAmount == 0)
@@ -2946,33 +2943,14 @@ bool CWallet::CreateTransactionInternal(
{
CTxOut txout(recipient.nAmount, recipient.scriptPubKey);
- if (recipient.fSubtractFeeFromAmount)
- {
- assert(nSubtractFeeFromAmount != 0);
- txout.nValue -= nFeeRet / nSubtractFeeFromAmount; // Subtract fee equally from each selected recipient
-
- if (fFirst) // first receiver pays the remainder not divisible by output count
- {
- fFirst = false;
- txout.nValue -= nFeeRet % nSubtractFeeFromAmount;
- }
- }
- // Include the fee cost for outputs. Note this is only used for BnB right now
+ // Include the fee cost for outputs.
if (!coin_selection_params.m_subtract_fee_outputs) {
coin_selection_params.tx_noinputs_size += ::GetSerializeSize(txout, PROTOCOL_VERSION);
}
if (IsDust(txout, chain().relayDustFee()))
{
- if (recipient.fSubtractFeeFromAmount && nFeeRet > 0)
- {
- if (txout.nValue < 0)
- error = _("The transaction amount is too small to pay the fee");
- else
- error = _("The transaction amount is too small to send after the fee has been deducted");
- }
- else
- error = _("Transaction amount too small");
+ error = _("Transaction amount too small");
return false;
}
txNew.vout.push_back(txout);
@@ -2980,58 +2958,40 @@ bool CWallet::CreateTransactionInternal(
// Choose coins to use
bool bnb_used = false;
- if (pick_new_inputs) {
- nValueIn = 0;
- setCoins.clear();
- if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins, nValueIn, coin_control, coin_selection_params, bnb_used))
- {
- // If BnB was used, it was the first pass. No longer the first pass and continue loop with knapsack.
- if (bnb_used) {
- coin_selection_params.use_bnb = false;
- continue;
- }
- else {
- error = _("Insufficient funds");
- return false;
- }
+ nValueIn = 0;
+ setCoins.clear();
+ if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins, nValueIn, coin_control, coin_selection_params, bnb_used))
+ {
+ // If BnB was used, it was the first pass. No longer the first pass and continue loop with knapsack.
+ if (bnb_used) {
+ coin_selection_params.use_bnb = false;
+ continue;
+ }
+ else {
+ error = _("Insufficient funds");
+ return false;
}
- } else {
- bnb_used = false;
}
- const CAmount change_and_fee = nValueIn - nValueToSelect;
- if (change_and_fee > 0)
- {
- // Fill a vout to ourself
- CTxOut newTxOut(change_and_fee, scriptChange);
-
- // Never create dust outputs; if we would, just
- // add the dust to the fee.
- // The change_and_fee when BnB is used is always going to go to fees.
- if (IsDust(newTxOut, coin_selection_params.m_discard_feerate) || bnb_used)
- {
- nChangePosInOut = -1;
- nFeeRet += change_and_fee;
- }
- else
- {
- if (nChangePosInOut == -1)
- {
- // Insert change txn at random position:
- nChangePosInOut = GetRandInt(txNew.vout.size()+1);
- }
- else if ((unsigned int)nChangePosInOut > txNew.vout.size())
- {
- error = _("Change index out of range");
- return false;
- }
+ // Always make a change output
+ // We will reduce the fee from this change output later, and remove the output if it is too small.
+ const CAmount change_and_fee = nValueIn - nValue;
+ assert(change_and_fee >= 0);
+ CTxOut newTxOut(change_and_fee, scriptChange);
- std::vector<CTxOut>::iterator position = txNew.vout.begin()+nChangePosInOut;
- txNew.vout.insert(position, newTxOut);
- }
- } else {
- nChangePosInOut = -1;
+ if (nChangePosInOut == -1)
+ {
+ // Insert change txn at random position:
+ nChangePosInOut = GetRandInt(txNew.vout.size()+1);
}
+ else if ((unsigned int)nChangePosInOut > txNew.vout.size())
+ {
+ error = _("Change index out of range");
+ return false;
+ }
+
+ assert(nChangePosInOut != -1);
+ auto change_position = txNew.vout.insert(txNew.vout.begin() + nChangePosInOut, newTxOut);
// Dummy fill vin for maximum size estimation
//
@@ -3039,76 +2999,80 @@ bool CWallet::CreateTransactionInternal(
txNew.vin.push_back(CTxIn(coin.outpoint,CScript()));
}
+ // Calculate the transaction fee
tx_sizes = CalculateMaximumSignedTxSize(CTransaction(txNew), this, coin_control.fAllowWatchOnly);
nBytes = tx_sizes.first;
if (nBytes < 0) {
error = _("Signing transaction failed");
return false;
}
+ nFeeRet = coin_selection_params.m_effective_feerate.GetFee(nBytes);
- nFeeNeeded = coin_selection_params.m_effective_feerate.GetFee(nBytes);
- if (nFeeRet >= nFeeNeeded) {
- // Reduce fee to only the needed amount if possible. This
- // prevents potential overpayment in fees if the coins
- // selected to meet nFeeNeeded result in a transaction that
- // requires less fee than the prior iteration.
-
- // If we have no change and a big enough excess fee, then
- // try to construct transaction again only without picking
- // new inputs. We now know we only need the smaller fee
- // (because of reduced tx size) and so we should add a
- // change output. Only try this once.
- if (nChangePosInOut == -1 && nSubtractFeeFromAmount == 0 && pick_new_inputs) {
- unsigned int tx_size_with_change = nBytes + coin_selection_params.change_output_size + 2; // Add 2 as a buffer in case increasing # of outputs changes compact size
- CAmount fee_needed_with_change = coin_selection_params.m_effective_feerate.GetFee(tx_size_with_change);
- CAmount minimum_value_for_change = GetDustThreshold(change_prototype_txout, coin_selection_params.m_discard_feerate);
- if (nFeeRet >= fee_needed_with_change + minimum_value_for_change) {
- pick_new_inputs = false;
- nFeeRet = fee_needed_with_change;
- continue;
- }
- }
-
- // If we have change output already, just increase it
- if (nFeeRet > nFeeNeeded && nChangePosInOut != -1 && nSubtractFeeFromAmount == 0) {
- CAmount extraFeePaid = nFeeRet - nFeeNeeded;
- std::vector<CTxOut>::iterator change_position = txNew.vout.begin()+nChangePosInOut;
- change_position->nValue += extraFeePaid;
- nFeeRet -= extraFeePaid;
- }
- break; // Done, enough fee included.
- }
- else if (!pick_new_inputs) {
- // This shouldn't happen, we should have had enough excess
- // fee to pay for the new output and still meet nFeeNeeded
- // Or we should have just subtracted fee from recipients and
- // nFeeNeeded should not have changed
- error = _("Transaction fee and change calculation failed");
- return false;
+ // Subtract fee from the change output if not subtrating it from recipient outputs
+ CAmount fee_needed = nFeeRet;
+ if (nSubtractFeeFromAmount == 0) {
+ change_position->nValue -= fee_needed;
}
- // Try to reduce change to include necessary fee
- if (nChangePosInOut != -1 && nSubtractFeeFromAmount == 0) {
- CAmount additionalFeeNeeded = nFeeNeeded - nFeeRet;
- std::vector<CTxOut>::iterator change_position = txNew.vout.begin()+nChangePosInOut;
- // Only reduce change if remaining amount is still a large enough output.
- if (change_position->nValue >= MIN_FINAL_CHANGE + additionalFeeNeeded) {
- change_position->nValue -= additionalFeeNeeded;
- nFeeRet += additionalFeeNeeded;
- break; // Done, able to increase fee from change
- }
+ // We want to drop the change to fees if:
+ // 1. The change output would be dust
+ // 2. The change is within the (almost) exact match window, i.e. it is less than or equal to the cost of the change output (cost_of_change)
+ CAmount change_amount = change_position->nValue;
+ if (IsDust(*change_position, coin_selection_params.m_discard_feerate) || change_amount <= coin_selection_params.m_cost_of_change)
+ {
+ nChangePosInOut = -1;
+ change_amount = 0;
+ txNew.vout.erase(change_position);
+
+ // Because we have dropped this change, the tx size and required fee will be different, so let's recalculate those
+ tx_sizes = CalculateMaximumSignedTxSize(CTransaction(txNew), this, coin_control.fAllowWatchOnly);
+ nBytes = tx_sizes.first;
+ fee_needed = coin_selection_params.m_effective_feerate.GetFee(nBytes);
}
- // If subtracting fee from recipients, we now know what fee we
- // need to subtract, we have no reason to reselect inputs
- if (nSubtractFeeFromAmount > 0) {
- pick_new_inputs = false;
+ // If the fee is covered, there's no need to loop or subtract from recipients
+ if (fee_needed <= change_and_fee - change_amount) {
+ nFeeRet = change_and_fee - change_amount;
+ break;
}
- // Include more fee and try again.
- nFeeRet = nFeeNeeded;
- coin_selection_params.use_bnb = false;
- continue;
+ // Reduce output values for subtractFeeFromAmount
+ if (nSubtractFeeFromAmount != 0) {
+ CAmount to_reduce = fee_needed + change_amount - change_and_fee;
+ int i = 0;
+ bool fFirst = true;
+ for (const auto& recipient : vecSend)
+ {
+ if (i == nChangePosInOut) {
+ ++i;
+ }
+ CTxOut& txout = txNew.vout[i];
+
+ if (recipient.fSubtractFeeFromAmount)
+ {
+ txout.nValue -= to_reduce / nSubtractFeeFromAmount; // Subtract fee equally from each selected recipient
+
+ if (fFirst) // first receiver pays the remainder not divisible by output count
+ {
+ fFirst = false;
+ txout.nValue -= to_reduce % nSubtractFeeFromAmount;
+ }
+
+ // Error if this output is reduced to be below dust
+ if (IsDust(txout, chain().relayDustFee())) {
+ if (txout.nValue < 0) {
+ error = _("The transaction amount is too small to pay the fee");
+ } else {
+ error = _("The transaction amount is too small to send after the fee has been deducted");
+ }
+ return false;
+ }
+ }
+ ++i;
+ }
+ nFeeRet = fee_needed;
+ break; // The fee has been deducted from the recipients, nothing left to do here
+ }
}
// Give up if change keypool ran out and change is required
@@ -3170,8 +3134,8 @@ bool CWallet::CreateTransactionInternal(
reservedest.KeepDestination();
fee_calc_out = feeCalc;
- WalletLogPrintf("Fee Calculation: Fee:%d Bytes:%u Needed:%d Tgt:%d (requested %d) Reason:\"%s\" Decay %.5f: Estimation: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out) Fail: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out)\n",
- nFeeRet, nBytes, nFeeNeeded, feeCalc.returnedTarget, feeCalc.desiredTarget, StringForFeeReason(feeCalc.reason), feeCalc.est.decay,
+ WalletLogPrintf("Fee Calculation: Fee:%d Bytes:%u Tgt:%d (requested %d) Reason:\"%s\" Decay %.5f: Estimation: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out) Fail: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out)\n",
+ nFeeRet, nBytes, feeCalc.returnedTarget, feeCalc.desiredTarget, StringForFeeReason(feeCalc.reason), feeCalc.est.decay,
feeCalc.est.pass.start, feeCalc.est.pass.end,
(feeCalc.est.pass.totalConfirmed + feeCalc.est.pass.inMempool + feeCalc.est.pass.leftMempool) > 0.0 ? 100 * feeCalc.est.pass.withinTarget / (feeCalc.est.pass.totalConfirmed + feeCalc.est.pass.inMempool + feeCalc.est.pass.leftMempool) : 0.0,
feeCalc.est.pass.withinTarget, feeCalc.est.pass.totalConfirmed, feeCalc.est.pass.inMempool, feeCalc.est.pass.leftMempool,
generated by cgit v1.2.3 (git 2.26.2) at 2024-11-06 13:26:54 +0000