Fold GetSelectionWaste() into ComputeAndSetWaste()

Both `GetSelectionWaste()` and `ComputeAndSetWaste()` now are part of
`SelectionResult`. Instead of `ComputeAndSetWaste()` being a wrapper for
`GetSelectionWaste()`, we combine them to a new function
`RecalculateWaste()`.

As I was combining the logic of the two functions, I noticed that
`GetSelectionWaste()` was making the odd assumption that the
`change_cost` being set to zero means that no change is created.
However, if we build transactions at a feerate of zero with the
`discard_feerate` also set to zero, we'd organically have a
`change_cost` of zero, even when we create change on a transaction.

This commit cleans up this duplicate meaning of `change_cost` and relies
on `GetChange()` to figure out whether there is change on basis of the
`min_viable_change` and whatever is left after deducting fees.

Since this broke a bunch of tests that relied on the double-meaning of
`change_cost` a bunch of tests had to be fixed.
This commit is contained in:
Murch
2023-08-21 15:27:23 -04:00
parent 5a5ab1d544
commit 7aa7e30441
6 changed files with 83 additions and 99 deletions

View File

@@ -711,7 +711,7 @@ util::Result<SelectionResult> ChooseSelectionResult(interfaces::Chain& chain, co
if (coin_selection_params.m_effective_feerate > CFeeRate{3 * coin_selection_params.m_long_term_feerate}) { // Minimize input set for feerates of at least 3×LTFRE (default: 30ṩ/vB+)
if (auto cg_result{CoinGrinder(groups.positive_group, nTargetValue, coin_selection_params.m_min_change_target, max_inputs_weight)}) {
cg_result->ComputeAndSetWaste(coin_selection_params.min_viable_change, coin_selection_params.m_cost_of_change, coin_selection_params.m_change_fee);
cg_result->RecalculateWaste(coin_selection_params.min_viable_change, coin_selection_params.m_cost_of_change, coin_selection_params.m_change_fee);
results.push_back(*cg_result);
} else {
append_error(cg_result);
@@ -746,7 +746,7 @@ util::Result<SelectionResult> ChooseSelectionResult(interfaces::Chain& chain, co
if (bump_fee_overestimate) {
result.SetBumpFeeDiscount(bump_fee_overestimate);
}
result.ComputeAndSetWaste(coin_selection_params.min_viable_change, coin_selection_params.m_cost_of_change, coin_selection_params.m_change_fee);
result.RecalculateWaste(coin_selection_params.min_viable_change, coin_selection_params.m_cost_of_change, coin_selection_params.m_change_fee);
}
// Choose the result with the least waste
@@ -771,7 +771,7 @@ util::Result<SelectionResult> SelectCoins(const CWallet& wallet, CoinsResult& av
if (selection_target <= 0) {
SelectionResult result(nTargetValue, SelectionAlgorithm::MANUAL);
result.AddInputs(pre_set_inputs.coins, coin_selection_params.m_subtract_fee_outputs);
result.ComputeAndSetWaste(coin_selection_params.min_viable_change, coin_selection_params.m_cost_of_change, coin_selection_params.m_change_fee);
result.RecalculateWaste(coin_selection_params.min_viable_change, coin_selection_params.m_cost_of_change, coin_selection_params.m_change_fee);
return result;
}
@@ -792,7 +792,7 @@ util::Result<SelectionResult> SelectCoins(const CWallet& wallet, CoinsResult& av
SelectionResult preselected(pre_set_inputs.total_amount, SelectionAlgorithm::MANUAL);
preselected.AddInputs(pre_set_inputs.coins, coin_selection_params.m_subtract_fee_outputs);
op_selection_result->Merge(preselected);
op_selection_result->ComputeAndSetWaste(coin_selection_params.min_viable_change,
op_selection_result->RecalculateWaste(coin_selection_params.min_viable_change,
coin_selection_params.m_cost_of_change,
coin_selection_params.m_change_fee);
}