src/bench/coin_selection.cpp

   1 // Copyright (c) 2012-2017 The Bitcoin Core developers
   2 // Distributed under the MIT software license, see the accompanying
   3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4
   5 #include <bench/bench.h>
   6 #include <wallet/wallet.h>
   7
   8 #include <set>
   9
  10 static void addCoin(const CAmount& nValue, const CWallet& wallet, std::vector<COutput>& vCoins)
  11 {
  12     int nInput = 0;
  13
  14     static int nextLockTime = 0;
  15     CMutableTransaction tx;
  16     tx.nLockTime = nextLockTime++; // so all transactions get different hashes
  17     tx.vout.resize(nInput + 1);
  18     tx.vout[nInput].nValue = nValue;
  19     CWalletTx* wtx = new CWalletTx(&wallet, MakeTransactionRef(std::move(tx)));
  20
  21     int nAge = 6 * 24;
  22     COutput output(wtx, nInput, nAge, true /* spendable */, true /* solvable */, true /* safe */);
  23     vCoins.push_back(output);
  24 }
  25
  26 // Simple benchmark for wallet coin selection. Note that it maybe be necessary
  27 // to build up more complicated scenarios in order to get meaningful
  28 // measurements of performance. From laanwj, "Wallet coin selection is probably
  29 // the hardest, as you need a wider selection of scenarios, just testing the
  30 // same one over and over isn't too useful. Generating random isn't useful
  31 // either for measurements."
  32 // (https://github.com/bitcoin/bitcoin/issues/7883#issuecomment-224807484)
  33 static void CoinSelection(benchmark::State& state)
  34 {
  35     const CWallet wallet;
  36     std::vector<COutput> vCoins;
  37     LOCK(wallet.cs_wallet);
  38
  39     while (state.KeepRunning()) {
  40         // Empty wallet.
  41         for (COutput output : vCoins)
  42             delete output.tx;
  43         vCoins.clear();
  44
  45         // Add coins.
  46         for (int i = 0; i < 1000; i++)
  47             addCoin(1000 * COIN, wallet, vCoins);
  48         addCoin(3 * COIN, wallet, vCoins);
  49
  50         std::set<CInputCoin> setCoinsRet;
  51         CAmount nValueRet;
  52         bool success = wallet.SelectCoinsMinConf(1003 * COIN, 1, 6, 0, vCoins, setCoinsRet, nValueRet);
  53         assert(success);
  54         assert(nValueRet == 1003 * COIN);
  55         assert(setCoinsRet.size() == 2);
  56     }
  57 }
  58
  59 BENCHMARK(CoinSelection, 650);