wallet: Move discard feerate fetching to CreateTransaction

Instead of fetching the discard feerate for each SelectCoinsMinConf
iteration, fetch and cache it once during CreateTransaction so that it
is shared for each SelectCoinsMinConf through
coin_selection_params.m_discard_feerate.

Does not change behavior.
This commit is contained in:
Andrew Chow
2021-02-04 19:11:24 -05:00
parent 448d04b931
commit bdd0c2934b
4 changed files with 13 additions and 10 deletions

View File

@@ -2374,7 +2374,7 @@ bool CWallet::SelectCoinsMinConf(const CAmount& nTargetValue, const CoinEligibil
std::vector<OutputGroup> groups = GroupOutputs(coins, !coin_selection_params.m_avoid_partial_spends, effective_feerate, coin_selection_params.m_long_term_feerate, eligibility_filter, true /* positive_only */);
// Calculate cost of change
CAmount cost_of_change = GetDiscardRate(*this).GetFee(coin_selection_params.change_spend_size) + coin_selection_params.effective_fee.GetFee(coin_selection_params.change_output_size);
CAmount cost_of_change = coin_selection_params.m_discard_feerate.GetFee(coin_selection_params.change_spend_size) + coin_selection_params.effective_fee.GetFee(coin_selection_params.change_output_size);
// Calculate the fees for things that aren't inputs
CAmount not_input_fees = coin_selection_params.effective_fee.GetFee(coin_selection_params.tx_noinputs_size);
@@ -2798,7 +2798,8 @@ bool CWallet::CreateTransactionInternal(
CTxOut change_prototype_txout(0, scriptChange);
coin_selection_params.change_output_size = GetSerializeSize(change_prototype_txout);
CFeeRate discard_rate = GetDiscardRate(*this);
// Set discard feerate
coin_selection_params.m_discard_feerate = GetDiscardRate(*this);
// Get the fee rate to use effective values in coin selection
coin_selection_params.effective_fee = GetMinimumFeeRate(*this, coin_control, &feeCalc);
@@ -2917,7 +2918,7 @@ bool CWallet::CreateTransactionInternal(
// Never create dust outputs; if we would, just
// add the dust to the fee.
// The nChange when BnB is used is always going to go to fees.
if (IsDust(newTxOut, discard_rate) || bnb_used)
if (IsDust(newTxOut, coin_selection_params.m_discard_feerate) || bnb_used)
{
nChangePosInOut = -1;
nFeeRet += nChange;
@@ -2969,7 +2970,7 @@ bool CWallet::CreateTransactionInternal(
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.effective_fee.GetFee(tx_size_with_change);
CAmount minimum_value_for_change = GetDustThreshold(change_prototype_txout, discard_rate);
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;