Coverage Summary for Class: GasPriceTracker (org.ethereum.listener)

Class Class, % Method, % Line, %
GasPriceTracker 100% (1/1) 50% (3/6) 29.4% (10/34)


1 /* 2  * This file is part of RskJ 3  * Copyright (C) 2017 RSK Labs Ltd. 4  * (derived from ethereumJ library, Copyright (c) 2016 <ether.camp>) 5  * 6  * This program is free software: you can redistribute it and/or modify 7  * it under the terms of the GNU Lesser General Public License as published by 8  * the Free Software Foundation, either version 3 of the License, or 9  * (at your option) any later version. 10  * 11  * This program is distributed in the hope that it will be useful, 12  * but WITHOUT ANY WARRANTY; without even the implied warranty of 13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14  * GNU Lesser General Public License for more details. 15  * 16  * You should have received a copy of the GNU Lesser General Public License 17  * along with this program. If not, see <http://www.gnu.org/licenses/>. 18  */ 19  20 package org.ethereum.listener; 21  22 import co.rsk.core.Coin; 23 import co.rsk.remasc.RemascTransaction; 24 import org.ethereum.core.Block; 25 import org.ethereum.core.Transaction; 26 import org.ethereum.core.TransactionReceipt; 27 import org.slf4j.Logger; 28 import org.slf4j.LoggerFactory; 29  30 import java.math.BigInteger; 31 import java.util.Arrays; 32 import java.util.List; 33 import java.util.concurrent.atomic.AtomicReference; 34  35 /** 36  * Calculates a 'reasonable' Gas price based on statistics of the latest transaction's Gas prices 37  * 38  * Normally the price returned should be sufficient to execute a transaction since ~25% of the latest 39  * transactions were executed at this or lower price. 40  * 41  * Created by Anton Nashatyrev on 22.09.2015. 42  */ 43 public class GasPriceTracker extends EthereumListenerAdapter { 44  45  private static final Logger logger = LoggerFactory.getLogger("gaspricetracker"); 46  47  private static final int WINDOW_SIZE = 512; 48  49  private static final BigInteger BI_10 = BigInteger.valueOf(10); 50  private static final BigInteger BI_11 = BigInteger.valueOf(11); 51  52  private final Coin[] window = new Coin[WINDOW_SIZE]; 53  private final AtomicReference<Coin> bestBlockPriceRef = new AtomicReference<>(); 54  55  private Coin defaultPrice = Coin.valueOf(20_000_000_000L); 56  private int idx = WINDOW_SIZE - 1; 57  58  private Coin lastVal; 59  60  @Override 61  public void onBestBlock(Block block, List<TransactionReceipt> receipts) { 62  bestBlockPriceRef.set(block.getMinimumGasPrice()); 63  } 64  65  @Override 66  public synchronized void onBlock(Block block, List<TransactionReceipt> receipts) { 67  logger.trace("Start onBlock"); 68  69  defaultPrice = block.getMinimumGasPrice(); 70  71  for (Transaction tx : block.getTransactionsList()) { 72  onTransaction(tx); 73  } 74  75  logger.trace("End onBlock"); 76  } 77  78  private void onTransaction(Transaction tx) { 79  if (tx instanceof RemascTransaction) { 80  return; 81  } 82  83  if (idx == -1) { 84  idx = WINDOW_SIZE - 1; 85  lastVal = null; // recalculate only 'sometimes' 86  } 87  88  window[idx--] = tx.getGasPrice(); 89  } 90  91  public synchronized Coin getGasPrice() { 92  if (window[0] == null) { // not filled yet 93  return defaultPrice; 94  } else { 95  if (lastVal == null) { 96  Coin[] values = Arrays.copyOf(window, WINDOW_SIZE); 97  Arrays.sort(values); 98  lastVal = values[values.length / 4]; // 25% percentile 99  } 100  101  Coin bestBlockPrice = bestBlockPriceRef.get(); 102  if (bestBlockPrice == null) { 103  return lastVal; 104  } else { 105  return Coin.max(lastVal, bestBlockPrice.multiply(BI_11).divide(BI_10)); 106  } 107  } 108  } 109 }