BitcoinTransactionHelpers.java

/**
 * Copyright 2011 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.bitcoin.core;

import com.google.bitcoin.store.BlockStore;
import com.google.bitcoin.store.BlockStoreException;

import java.math.BigInteger;

public class BitcoinTransactionHelpers {
  public static Transaction createFakeTx(NetworkParameters params, BigInteger nanocoins, Address to) {
    Transaction t = new Transaction(params);
    TransactionOutput o1 = new TransactionOutput(params, t, nanocoins, to);
    t.addOutput(o1);
    // Make a previous tx simply to send us sufficient coins. This prev tx is not really valid but it doesn't
    // matter for our purposes.
    Transaction prevTx = new Transaction(params);
    TransactionOutput prevOut = new TransactionOutput(params, prevTx, nanocoins, to);
    prevTx.addOutput(prevOut);
    // Connect it.
    t.addInput(prevOut);
    return t;
  }

  public static class BlockPair {
    StoredBlock storedBlock;
    Block block;
  }

  // Emulates receiving a valid block that builds on top of the chain.
  public static BlockPair createFakeBlock(NetworkParameters params, BlockStore blockStore, long timeSeconds,
                                          Transaction... transactions) {
    try {
      Block b = blockStore.getChainHead().getHeader().createNextBlock(new ECKey().toAddress(params), timeSeconds);
      // Coinbase tx was already added.
      for (Transaction tx : transactions)
        b.addTransaction(tx);
      b.solve();
      BlockPair pair = new BlockPair();
      pair.block = b;
      pair.storedBlock = blockStore.getChainHead().build(b);
      blockStore.put(pair.storedBlock);
      blockStore.setChainHead(pair.storedBlock);
      return pair;
    } catch (VerificationException e) {
      throw new RuntimeException(e);  // Cannot happen.
    } catch (BlockStoreException e) {
      throw new RuntimeException(e);  // Cannot happen.
    }
  }

  public static BlockPair createFakeBlock(NetworkParameters params, BlockStore blockStore,
                                          Transaction... transactions) {
    return createFakeBlock(params, blockStore, Utils.now().getTime() / 1000, transactions);
  }

  public static Block makeSolvedTestBlock(NetworkParameters params,
                                          BlockStore blockStore) throws BlockStoreException {
    Block b = blockStore.getChainHead().getHeader().createNextBlock(new ECKey().toAddress(params));
    b.solve();
    return b;
  }

  public static Block makeSolvedTestBlock(NetworkParameters params,
                                          Block prev) throws BlockStoreException {
    Block b = prev.createNextBlock(new ECKey().toAddress(params));
    b.solve();
    return b;
  }
}