From 9b5950db8683f9b4be03f79ee0aae8a780b01a4b Mon Sep 17 00:00:00 2001 From: Andrew Chow Date: Wed, 4 Mar 2020 16:35:15 -0500 Subject: [PATCH] bnb: exit selection when best_waste is 0 If we find a solution which has no waste, just use that. This solution is what we would consider to be optimal, and other solutions we find would have to also have 0 waste, so they are equivalent to the first one with 0 waste. Thus we can optimize by just choosing the first one with 0 waste. --- src/wallet/coinselection.cpp | 3 +++ src/wallet/test/coinselector_tests.cpp | 7 +++---- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/src/wallet/coinselection.cpp b/src/wallet/coinselection.cpp index 5bbb2c0ad0..079a5d3d53 100644 --- a/src/wallet/coinselection.cpp +++ b/src/wallet/coinselection.cpp @@ -106,6 +106,9 @@ bool SelectCoinsBnB(std::vector& utxo_pool, const CAmount& target_v best_selection = curr_selection; best_selection.resize(utxo_pool.size()); best_waste = curr_waste; + if (best_waste == 0) { + break; + } } curr_waste -= (curr_value - actual_target); // Remove the excess value as we will be selecting different coins now backtrack = true; diff --git a/src/wallet/test/coinselector_tests.cpp b/src/wallet/test/coinselector_tests.cpp index 21d57cb898..2081518909 100644 --- a/src/wallet/test/coinselector_tests.cpp +++ b/src/wallet/test/coinselector_tests.cpp @@ -176,8 +176,8 @@ BOOST_AUTO_TEST_CASE(bnb_search_test) selection.clear(); // Select 5 Cent - add_coin(3 * CENT, 3, actual_selection); - add_coin(2 * CENT, 2, actual_selection); + add_coin(4 * CENT, 4, actual_selection); + add_coin(1 * CENT, 1, actual_selection); BOOST_CHECK(SelectCoinsBnB(GroupCoins(utxo_pool), 5 * CENT, 0.5 * CENT, selection, value_ret, not_input_fees)); BOOST_CHECK(equal_sets(selection, actual_selection)); BOOST_CHECK_EQUAL(value_ret, 5 * CENT); @@ -204,9 +204,8 @@ BOOST_AUTO_TEST_CASE(bnb_search_test) // Select 10 Cent add_coin(5 * CENT, 5, utxo_pool); + add_coin(5 * CENT, 5, actual_selection); add_coin(4 * CENT, 4, actual_selection); - add_coin(3 * CENT, 3, actual_selection); - add_coin(2 * CENT, 2, actual_selection); add_coin(1 * CENT, 1, actual_selection); BOOST_CHECK(SelectCoinsBnB(GroupCoins(utxo_pool), 10 * CENT, 0.5 * CENT, selection, value_ret, not_input_fees)); BOOST_CHECK(equal_sets(selection, actual_selection));