@Override
public BlockchainImpl getBlockchain() {
if (blockchain == null) {
blockchain = createBlockchain(genesis);
blockchain.setMinerCoinbase(coinbase);
}
return blockchain;
}
private BlockchainImpl createBlockchain(Genesis genesis) {
IndexedBlockStore blockStore = new IndexedBlockStore();
blockStore.init(new HashMapDB(), new HashMapDB());
Repository repository = new RepositoryImpl(new HashMapDB(), new HashMapDB());
ProgramInvokeFactoryImpl programInvokeFactory = new ProgramInvokeFactoryImpl();
EthereumListenerAdapter listener = new EthereumListenerAdapter();
BlockchainImpl blockchain = new BlockchainImpl(blockStore, repository);
blockchain.setParentHeaderValidator(new DependentBlockHeaderRuleAdapter());
blockchain.setProgramInvokeFactory(programInvokeFactory);
programInvokeFactory.setBlockchain(blockchain);
blockchain.byTest = true;
PendingStateImpl pendingState = new PendingStateImpl(listener, blockchain);
pendingState.init();
pendingState.setBlockchain(blockchain);
blockchain.setPendingState(pendingState);
Repository track = repository.startTracking();
for (ByteArrayWrapper key : genesis.getPremine().keySet()) {
track.createAccount(key.getData());
track.addBalance(key.getData(), genesis.getPremine().get(key).getBalance());
}
for (Pair<byte[], BigInteger> acc : initialBallances) {
track.createAccount(acc.getLeft());
track.addBalance(acc.getLeft(), acc.getRight());
}
track.commit();
blockStore.saveBlock(genesis, genesis.getCumulativeDifficulty(), true);
blockchain.setBestBlock(genesis);
blockchain.setTotalDifficulty(genesis.getCumulativeDifficulty());
return blockchain;
}
/**
* Economic Clustering concept (EC) solves the most critical flaw of "classical" Proof-of-Stake -
* the problem called "Nothing-at-Stake".
*
* <p>I ought to respect BCNext's wish and say that this concept is inspired by Economic Majority
* idea of Meni Rosenfeld (http://en.wikipedia.org/wiki/User:Meni_Rosenfeld).
*
* <p>EC is a vital part of Transparent Forging. Words "Mining in Nxt relies on cooperation of
* people and even forces it" (https://bitcointalk.org/index.php?topic=553205.0) were said about EC.
*
* <p>Keep in mind that this concept has not been peer reviewed. You are very welcome to do it...
*
* <p>Come-from-Beyond (21.05.2014)
*/
public final class EconomicClustering {
private static final Blockchain blockchain = BlockchainImpl.getInstance();
public static Block getECBlock(int timestamp) {
Block block = blockchain.getLastBlock();
if (timestamp < block.getTimestamp() - 15) {
throw new IllegalArgumentException(
"Timestamp cannot be more than 15 s earlier than last block timestamp: "
+ block.getTimestamp());
}
int distance = 0;
while (block.getTimestamp() > timestamp - Constants.EC_RULE_TERMINATOR
&& distance < Constants.EC_BLOCK_DISTANCE_LIMIT) {
block = blockchain.getBlock(block.getPreviousBlockId());
distance += 1;
}
return block;
}
public static boolean verifyFork(Transaction transaction) {
if (blockchain.getHeight() < Constants.DIGITAL_GOODS_STORE_BLOCK) {
return true;
}
if (transaction.getReferencedTransactionFullHash() != null) {
return true;
}
if (blockchain.getHeight() < Constants.EC_CHANGE_BLOCK_1) {
if (blockchain.getHeight() - transaction.getECBlockHeight()
> Constants.EC_BLOCK_DISTANCE_LIMIT) {
return false;
}
}
Block ecBlock = blockchain.getBlock(transaction.getECBlockId());
return ecBlock != null && ecBlock.getHeight() == transaction.getECBlockHeight();
}
}