public StoredBlock get(Sha256Hash hash, boolean wasUndoableOnly) throws BlockStoreException {
// Optimize for chain head
if (chainHeadHash != null && chainHeadHash.equals(hash)) return chainHeadBlock;
if (verifiedChainHeadHash != null && verifiedChainHeadHash.equals(hash))
return verifiedChainHeadBlock;
maybeConnect();
PreparedStatement s = null;
try {
s =
conn.get()
.prepareStatement(
"SELECT chainWork, height, header, wasUndoable FROM headers WHERE hash = ?");
// We skip the first 4 bytes because (on prodnet) the minimum target has 4 0-bytes
byte[] hashBytes = new byte[28];
System.arraycopy(hash.getBytes(), 3, hashBytes, 0, 28);
s.setBytes(1, hashBytes);
ResultSet results = s.executeQuery();
if (!results.next()) {
return null;
}
// Parse it.
if (wasUndoableOnly && !results.getBoolean(4)) return null;
BigInteger chainWork = new BigInteger(results.getBytes(1));
int height = results.getInt(2);
Block b = new Block(params, results.getBytes(3));
b.verifyHeader();
StoredBlock stored = new StoredBlock(b, chainWork, height);
return stored;
} catch (SQLException ex) {
throw new BlockStoreException(ex);
} catch (ProtocolException e) {
// Corrupted database.
throw new BlockStoreException(e);
} catch (VerificationException e) {
// Should not be able to happen unless the database contains bad
// blocks.
throw new BlockStoreException(e);
} finally {
if (s != null)
try {
s.close();
} catch (SQLException e) {
throw new BlockStoreException("Failed to close PreparedStatement");
}
}
}
// filteredTxHashList contains all transactions, filteredTxn just a subset
private boolean add(
Block block,
boolean tryConnecting,
@Nullable List<Sha256Hash> filteredTxHashList,
@Nullable Map<Sha256Hash, Transaction> filteredTxn)
throws BlockStoreException, VerificationException, PrunedException {
// TODO: Use read/write locks to ensure that during chain download properties are still low
// latency.
lock.lock();
try {
// Quick check for duplicates to avoid an expensive check further down (in findSplit). This
// can happen a lot
// when connecting orphan transactions due to the dumb brute force algorithm we use.
if (block.equals(getChainHead().getHeader())) {
return true;
}
if (tryConnecting && orphanBlocks.containsKey(block.getHash())) {
return false;
}
// If we want to verify transactions (ie we are running with full blocks), verify that block
// has transactions
if (shouldVerifyTransactions() && block.transactions == null)
throw new VerificationException("Got a block header while running in full-block mode");
// Check for already-seen block, but only for full pruned mode, where the DB is
// more likely able to handle these queries quickly.
if (shouldVerifyTransactions() && blockStore.get(block.getHash()) != null) {
return true;
}
// Does this block contain any transactions we might care about? Check this up front before
// verifying the
// blocks validity so we can skip the merkle root verification if the contents aren't
// interesting. This saves
// a lot of time for big blocks.
boolean contentsImportant = shouldVerifyTransactions();
if (block.transactions != null) {
contentsImportant = contentsImportant || containsRelevantTransactions(block);
}
// Prove the block is internally valid: hash is lower than target, etc. This only checks the
// block contents
// if there is a tx sending or receiving coins using an address in one of our wallets. And
// those transactions
// are only lightly verified: presence in a valid connecting block is taken as proof of
// validity. See the
// article here for more details: http://code.google.com/p/bitcoinj/wiki/SecurityModel
try {
block.verifyHeader();
if (contentsImportant) block.verifyTransactions();
} catch (VerificationException e) {
log.error("Failed to verify block: ", e);
log.error(block.getHashAsString());
throw e;
}
// Try linking it to a place in the currently known blocks.
StoredBlock storedPrev = getStoredBlockInCurrentScope(block.getPrevBlockHash());
if (storedPrev == null) {
// We can't find the previous block. Probably we are still in the process of downloading the
// chain and a
// block was solved whilst we were doing it. We put it to one side and try to connect it
// later when we
// have more blocks.
checkState(tryConnecting, "bug in tryConnectingOrphans");
log.warn(
"Block does not connect: {} prev {}",
block.getHashAsString(),
block.getPrevBlockHash());
orphanBlocks.put(block.getHash(), new OrphanBlock(block, filteredTxHashList, filteredTxn));
return false;
} else {
checkState(lock.isHeldByCurrentThread());
// It connects to somewhere on the chain. Not necessarily the top of the best known chain.
params.checkDifficultyTransitions(storedPrev, block, blockStore);
connectBlock(
block, storedPrev, shouldVerifyTransactions(), filteredTxHashList, filteredTxn);
}
if (tryConnecting) tryConnectingOrphans();
return true;
} finally {
lock.unlock();
}
}