Java tutorial
/* * This file is part of RskJ * Copyright (C) 2017 RSK Labs Ltd. * (derived from ethereumJ library, Copyright (c) 2016 <ether.camp>) * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.ethereum; import co.rsk.core.Coin; import co.rsk.core.RskAddress; import co.rsk.crypto.Keccak256; import org.apache.commons.lang3.StringUtils; import org.ethereum.core.Block; import org.ethereum.crypto.HashUtil; import org.ethereum.db.IndexedBlockStore; import org.ethereum.vm.DataWord; import org.mapdb.DB; import org.mapdb.DBMaker; import org.mapdb.Serializer; import java.io.File; import java.math.BigInteger; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Random; import static org.ethereum.crypto.HashUtil.EMPTY_TRIE_HASH; import static org.ethereum.db.IndexedBlockStore.BLOCK_INFO_SERIALIZER; public final class TestUtils { private TestUtils() { } public static byte[] randomBytes(int length) { byte[] result = new byte[length]; new Random().nextBytes(result); return result; } public static DataWord randomDataWord() { return new DataWord(randomBytes(32)); } public static RskAddress randomAddress() { return new RskAddress(randomBytes(20)); } public static Keccak256 randomHash() { return new Keccak256(randomBytes(32)); } public static Map<Long, List<IndexedBlockStore.BlockInfo>> createIndexMap(DB db) { Map<Long, List<IndexedBlockStore.BlockInfo>> index = db.hashMapCreate("index") .keySerializer(Serializer.LONG).valueSerializer(BLOCK_INFO_SERIALIZER).makeOrGet(); return index; } public static DB createMapDB(String testDBDir) { String blocksIndexFile = testDBDir + "/blocks/index"; File dbFile = new File(blocksIndexFile); if (!dbFile.getParentFile().exists()) dbFile.getParentFile().mkdirs(); DB db = DBMaker.fileDB(dbFile).transactionDisable().closeOnJvmShutdown().make(); return db; } public static List<Block> getRandomChain(byte[] startParentHash, long startNumber, long length) { List<Block> result = new ArrayList<>(); byte[] lastHash = startParentHash; long lastIndex = startNumber; for (int i = 0; i < length; ++i) { byte[] difficutly = new BigInteger(8, new Random()).toByteArray(); byte[] newHash = HashUtil.randomHash(); Block block = new Block(lastHash, newHash, RskAddress.nullAddress().getBytes(), null, difficutly, lastIndex, new byte[] { 0 }, 0, 0, null, null, null, null, EMPTY_TRIE_HASH, HashUtil.randomHash(), null, null, null, Coin.ZERO); ++lastIndex; lastHash = block.getHash().getBytes(); result.add(block); } return result; } public static String padRight(String s, int n) { return String.format("%1$-" + n + "s", s); } public static String padLeft(String s, int n) { return String.format("%1$" + n + "s", s); } public static String padZeroesLeft(String s, int n) { return StringUtils.leftPad(s, n, '0'); } }