Java Code Examples for org.bitcoinj.core.Block#getTimeSeconds()

/**
 * The flags indicating which script validation tests should be applied to
 * the given transaction. Enables support for alternative blockchains which enable
 * tests based on different criteria.
 *
 * @param block       block the transaction belongs to.
 * @param transaction to determine flags for.
 * @param height      height of the block, if known, null otherwise. Returned
 *                    tests should be a safe subset if block height is unknown.
 */
public EnumSet<Script.VerifyFlag> getTransactionVerificationFlags(final Block block,
                                                                  final Transaction transaction, final VersionTally tally, final Integer height) {
    final EnumSet<Script.VerifyFlag> verifyFlags = EnumSet.noneOf(Script.VerifyFlag.class);
    if (block.getTimeSeconds() >= NetworkParameters.BIP16_ENFORCE_TIME)
        verifyFlags.add(Script.VerifyFlag.P2SH);

    // Start enforcing CHECKLOCKTIMEVERIFY, (BIP65) for block.nVersion=4
    // blocks, when 75% of the network has upgraded:
    if (block.getVersion() >= Block.BLOCK_VERSION_BIP65 &&
            tally.getCountAtOrAbove(Block.BLOCK_VERSION_BIP65) > this.getMajorityEnforceBlockUpgrade()) {
        verifyFlags.add(Script.VerifyFlag.CHECKLOCKTIMEVERIFY);
    }

    return verifyFlags;
}
 

/**
 * Get a BlockInfo for the specified hash
 *
 * @param blockChain The blockchain object to pull the data from
 * @param blockHash The hash of the desired block
 * @param includeTx whether to include transactions (currently must be false)
 * @return block information (currently incomplete and untested)
 * @throws BlockStoreException Something went wrong
 */
private static BlockInfo getBlockInfoByHash(AbstractBlockChain blockChain, Sha256Hash blockHash, BlockInfo.IncludeTxFlag includeTx) throws BlockStoreException {
    if (includeTx == BlockInfo.IncludeTxFlag.YES) {
        throw new IllegalArgumentException("Including transactions not supported yet");
    }
    StoredBlock block = getStoredBlockByHash(blockChain, blockHash);
    Block header = block.getHeader();
    int blockHeight = block.getHeight();
    int confirmations = blockChain.getBestChainHeight() - blockHeight;
    log.trace("building BlockInfo for hash: {} height: {}", blockHash, blockHeight);
    return new BlockInfo(header.getHash(),
            confirmations,
            header.getMessageSize(),
            blockHeight,
            (int) header.getVersion(),
            header.getMerkleRoot(),
            -1,     // Unknown number of Transactions
            (includeTx == BlockInfo.IncludeTxFlag.IDONLY) ? hashListFromTxList(header.getTransactions()) : null,
            (int) header.getTimeSeconds(),
            header.getNonce(),
            null, // TODO: Return "bits" here
            new BigDecimal(header.getDifficultyTargetAsInteger()),  // TODO: Verify this is correct
            block.getChainWork().toString(),
            block.getPrev(blockChain.getBlockStore()).getHeader().getHash(),
            null);  // TODO: Extend BlockStore to make this information retrievable
}
 

@Override
public void checkDifficultyTransitions(final StoredBlock storedPrev, final Block nextBlock,
                                       final BlockStore blockStore) throws VerificationException, BlockStoreException {
    if (!isDifficultyTransitionPoint(storedPrev.getHeight()) && nextBlock.getTime().after(testnetDiffDate)) {
        Block prev = storedPrev.getHeader();

        // After 15th February 2012 the rules on the testnet change to avoid people running up the difficulty
        // and then leaving, making it too hard to mine a block. On non-difficulty transition points, easy
        // blocks are allowed if there has been a span of 20 minutes without one.
        final long timeDelta = nextBlock.getTimeSeconds() - prev.getTimeSeconds();
        // There is an integer underflow bug in bitcoin-qt that means mindiff blocks are accepted when time
        // goes backwards.
        if (timeDelta >= 0 && timeDelta <= NetworkParameters.TARGET_SPACING * 2) {
            // Walk backwards until we find a block that doesn't have the easiest proof of work, then check
            // that difficulty is equal to that one.
            StoredBlock cursor = storedPrev;
            while (!cursor.getHeader().equals(getGenesisBlock()) &&
                    cursor.getHeight() % getInterval() != 0 &&
                    cursor.getHeader().getDifficultyTargetAsInteger().equals(getMaxTarget()))
                cursor = cursor.getPrev(blockStore);
            BigInteger cursorTarget = cursor.getHeader().getDifficultyTargetAsInteger();
            BigInteger newTarget = nextBlock.getDifficultyTargetAsInteger();
            if (!cursorTarget.equals(newTarget))
                throw new VerificationException("Testnet block transition that is not allowed: " +
                        Long.toHexString(cursor.getHeader().getDifficultyTarget()) + " vs " +
                        Long.toHexString(nextBlock.getDifficultyTarget()));
        }
    } else {
        super.checkDifficultyTransitions(storedPrev, nextBlock, blockStore);
    }
}
 

@Override
public void checkDifficultyTransitions(final StoredBlock storedPrev, final Block nextBlock,
                                       final BlockStore blockStore) throws VerificationException, BlockStoreException {
    final Block prev = storedPrev.getHeader();

    // Is this supposed to be a difficulty transition point?
    if (!isDifficultyTransitionPoint(storedPrev.getHeight())) {

        // No ... so check the difficulty didn't actually change.
        if (nextBlock.getDifficultyTarget() != prev.getDifficultyTarget())
            throw new VerificationException("Unexpected change in difficulty at height " + storedPrev.getHeight() +
                    ": " + Long.toHexString(nextBlock.getDifficultyTarget()) + " vs " +
                    Long.toHexString(prev.getDifficultyTarget()));
        return;
    }

    // We need to find a block far back in the chain. It's OK that this is expensive because it only occurs every
    // two weeks after the initial block chain download.
    final Stopwatch watch = Stopwatch.createStarted();
    Sha256Hash hash = prev.getHash();
    StoredBlock cursor = null;
    final int interval = this.getInterval();
    for (int i = 0; i < interval; i++) {
        cursor = blockStore.get(hash);
        if (cursor == null) {
            // This should never happen. If it does, it means we are following an incorrect or busted chain.
            throw new VerificationException(
                    "Difficulty transition point but we did not find a way back to the last transition point. Not found: " + hash);
        }
        hash = cursor.getHeader().getPrevBlockHash();
    }
    checkState(cursor != null && isDifficultyTransitionPoint(cursor.getHeight() - 1),
            "Didn't arrive at a transition point.");
    watch.stop();
    if (watch.elapsed(TimeUnit.MILLISECONDS) > 50)
        log.info("Difficulty transition traversal took {}", watch);

    Block blockIntervalAgo = cursor.getHeader();
    int timespan = (int) (prev.getTimeSeconds() - blockIntervalAgo.getTimeSeconds());
    // Limit the adjustment step.
    final int targetTimespan = this.getTargetTimespan();
    if (timespan < targetTimespan / 4)
        timespan = targetTimespan / 4;
    if (timespan > targetTimespan * 4)
        timespan = targetTimespan * 4;

    BigInteger newTarget = Utils.decodeCompactBits(prev.getDifficultyTarget());
    newTarget = newTarget.multiply(BigInteger.valueOf(timespan));
    newTarget = newTarget.divide(BigInteger.valueOf(targetTimespan));

    if (newTarget.compareTo(this.getMaxTarget()) > 0) {
        log.info("Difficulty hit proof of work limit: {}", newTarget.toString(16));
        newTarget = this.getMaxTarget();
    }

    int accuracyBytes = (int) (nextBlock.getDifficultyTarget() >>> 24) - 3;
    long receivedTargetCompact = nextBlock.getDifficultyTarget();

    // The calculated difficulty is to a higher precision than received, so reduce here.
    BigInteger mask = BigInteger.valueOf(0xFFFFFFL).shiftLeft(accuracyBytes * 8);
    newTarget = newTarget.and(mask);
    long newTargetCompact = Utils.encodeCompactBits(newTarget);

    if (newTargetCompact != receivedTargetCompact)
        throw new VerificationException("Network provided difficulty bits do not match what was calculated: " +
                Long.toHexString(newTargetCompact) + " vs " + Long.toHexString(receivedTargetCompact));
}
 

@Override
public void checkDifficultyTransitions(final StoredBlock storedPrev, final Block nextBlock,
                                       final BlockStore blockStore) throws VerificationException, BlockStoreException {
    Block prev = storedPrev.getHeader();

    // Is this supposed to be a difficulty transition point?
    if (!isDifficultyTransitionPoint(storedPrev)) {

        // No ... so check the difficulty didn't actually change.
        if (nextBlock.getDifficultyTarget() != prev.getDifficultyTarget())
            throw new VerificationException("Unexpected change in difficulty at height " + storedPrev.getHeight() +
                    ": " + Long.toHexString(nextBlock.getDifficultyTarget()) + " vs " +
                    Long.toHexString(prev.getDifficultyTarget()));
        return;
    }

    // We need to find a block far back in the chain. It's OK that this is expensive because it only occurs every
    // two weeks after the initial block chain download.
    final Stopwatch watch = Stopwatch.createStarted();
    StoredBlock cursor = blockStore.get(prev.getHash());
    for (int i = 0; i < this.getInterval() - 1; i++) {
        if (cursor == null) {
            // This should never happen. If it does, it means we are following an incorrect or busted chain.
            throw new VerificationException(
                    "Difficulty transition point but we did not find a way back to the genesis block.");
        }
        cursor = blockStore.get(cursor.getHeader().getPrevBlockHash());
    }
    watch.stop();
    if (watch.elapsed(TimeUnit.MILLISECONDS) > 50)
        log.info("Difficulty transition traversal took {}", watch);

    Block blockIntervalAgo = cursor.getHeader();
    int timespan = (int) (prev.getTimeSeconds() - blockIntervalAgo.getTimeSeconds());
    // Limit the adjustment step.
    final int targetTimespan = this.getTargetTimespan();
    if (timespan < targetTimespan / 4)
        timespan = targetTimespan / 4;
    if (timespan > targetTimespan * 4)
        timespan = targetTimespan * 4;

    BigInteger newTarget = Utils.decodeCompactBits(prev.getDifficultyTarget());
    newTarget = newTarget.multiply(BigInteger.valueOf(timespan));
    newTarget = newTarget.divide(BigInteger.valueOf(targetTimespan));

    if (newTarget.compareTo(this.getMaxTarget()) > 0) {
        log.info("Difficulty hit proof of work limit: {}", newTarget.toString(16));
        newTarget = this.getMaxTarget();
    }

    int accuracyBytes = (int) (nextBlock.getDifficultyTarget() >>> 24) - 3;
    long receivedTargetCompact = nextBlock.getDifficultyTarget();

    // The calculated difficulty is to a higher precision than received, so reduce here.
    BigInteger mask = BigInteger.valueOf(0xFFFFFFL).shiftLeft(accuracyBytes * 8);
    newTarget = newTarget.and(mask);
    long newTargetCompact = Utils.encodeCompactBits(newTarget);

    if (newTargetCompact != receivedTargetCompact)
        throw new VerificationException("Network provided difficulty bits do not match what was calculated: " +
                Long.toHexString(newTargetCompact) + " vs " + Long.toHexString(receivedTargetCompact));
}
 

@Override
public void checkDifficultyTransitions(final StoredBlock storedPrev, final Block nextBlock,
	final BlockStore blockStore) throws VerificationException, BlockStoreException {
    final Block prev = storedPrev.getHeader();

    // Is this supposed to be a difficulty transition point?
    if (!isDifficultyTransitionPoint(storedPrev.getHeight())) {

        // No ... so check the difficulty didn't actually change.
        if (nextBlock.getDifficultyTarget() != prev.getDifficultyTarget())
            throw new VerificationException("Unexpected change in difficulty at height " + storedPrev.getHeight() +
                    ": " + Long.toHexString(nextBlock.getDifficultyTarget()) + " vs " +
                    Long.toHexString(prev.getDifficultyTarget()));
        return;
    }

    // We need to find a block far back in the chain. It's OK that this is expensive because it only occurs every
    // two weeks after the initial block chain download.
    final Stopwatch watch = Stopwatch.createStarted();
    Sha256Hash hash = prev.getHash();
    StoredBlock cursor = null;
    final int interval = this.getInterval();
    for (int i = 0; i < interval; i++) {
        cursor = blockStore.get(hash);
        if (cursor == null) {
            // This should never happen. If it does, it means we are following an incorrect or busted chain.
            throw new VerificationException(
                    "Difficulty transition point but we did not find a way back to the last transition point. Not found: " + hash);
        }
        hash = cursor.getHeader().getPrevBlockHash();
    }
    checkState(cursor != null && isDifficultyTransitionPoint(cursor.getHeight() - 1),
            "Didn't arrive at a transition point.");
    watch.stop();
    if (watch.elapsed(TimeUnit.MILLISECONDS) > 50)
        log.info("Difficulty transition traversal took {}", watch);

    Block blockIntervalAgo = cursor.getHeader();
    int timespan = (int) (prev.getTimeSeconds() - blockIntervalAgo.getTimeSeconds());
    // Limit the adjustment step.
    final int targetTimespan = this.getTargetTimespan();
    if (timespan < targetTimespan / 4)
        timespan = targetTimespan / 4;
    if (timespan > targetTimespan * 4)
        timespan = targetTimespan * 4;

    BigInteger newTarget = Utils.decodeCompactBits(prev.getDifficultyTarget());
    newTarget = newTarget.multiply(BigInteger.valueOf(timespan));
    newTarget = newTarget.divide(BigInteger.valueOf(targetTimespan));

    if (newTarget.compareTo(this.getMaxTarget()) > 0) {
        log.info("Difficulty hit proof of work limit: {}", newTarget.toString(16));
        newTarget = this.getMaxTarget();
    }

    int accuracyBytes = (int) (nextBlock.getDifficultyTarget() >>> 24) - 3;
    long receivedTargetCompact = nextBlock.getDifficultyTarget();

    // The calculated difficulty is to a higher precision than received, so reduce here.
    BigInteger mask = BigInteger.valueOf(0xFFFFFFL).shiftLeft(accuracyBytes * 8);
    newTarget = newTarget.and(mask);
    long newTargetCompact = Utils.encodeCompactBits(newTarget);

    if (newTargetCompact != receivedTargetCompact)
        throw new VerificationException("Network provided difficulty bits do not match what was calculated: " +
                Long.toHexString(newTargetCompact) + " vs " + Long.toHexString(receivedTargetCompact));
}
 

@Override
public void checkDifficultyTransitions(final StoredBlock storedPrev, final Block nextBlock,
	final BlockStore blockStore) throws VerificationException, BlockStoreException {
    final Block prev = storedPrev.getHeader();

    // Is this supposed to be a difficulty transition point?
    if (!isDifficultyTransitionPoint(storedPrev.getHeight())) {

        // No ... so check the difficulty didn't actually change.
        if (nextBlock.getDifficultyTarget() != prev.getDifficultyTarget())
            throw new VerificationException("Unexpected change in difficulty at height " + storedPrev.getHeight() +
                    ": " + Long.toHexString(nextBlock.getDifficultyTarget()) + " vs " +
                    Long.toHexString(prev.getDifficultyTarget()));
        return;
    }

    // We need to find a block far back in the chain. It's OK that this is expensive because it only occurs every
    // two weeks after the initial block chain download.
    final Stopwatch watch = Stopwatch.createStarted();
    Sha256Hash hash = prev.getHash();
    StoredBlock cursor = null;
    final int interval = this.getInterval();
    for (int i = 0; i < interval; i++) {
        cursor = blockStore.get(hash);
        if (cursor == null) {
            // This should never happen. If it does, it means we are following an incorrect or busted chain.
            throw new VerificationException(
                    "Difficulty transition point but we did not find a way back to the last transition point. Not found: " + hash);
        }
        hash = cursor.getHeader().getPrevBlockHash();
    }
    checkState(cursor != null && isDifficultyTransitionPoint(cursor.getHeight() - 1),
            "Didn't arrive at a transition point.");
    watch.stop();
    if (watch.elapsed(TimeUnit.MILLISECONDS) > 50)
        log.info("Difficulty transition traversal took {}", watch);

    Block blockIntervalAgo = cursor.getHeader();
    int timespan = (int) (prev.getTimeSeconds() - blockIntervalAgo.getTimeSeconds());
    // Limit the adjustment step.
    final int targetTimespan = this.getTargetTimespan();
    if (timespan < targetTimespan / 4)
        timespan = targetTimespan / 4;
    if (timespan > targetTimespan * 4)
        timespan = targetTimespan * 4;

    BigInteger newTarget = Utils.decodeCompactBits(prev.getDifficultyTarget());
    newTarget = newTarget.multiply(BigInteger.valueOf(timespan));
    newTarget = newTarget.divide(BigInteger.valueOf(targetTimespan));

    if (newTarget.compareTo(this.getMaxTarget()) > 0) {
        log.info("Difficulty hit proof of work limit: {}", newTarget.toString(16));
        newTarget = this.getMaxTarget();
    }

    int accuracyBytes = (int) (nextBlock.getDifficultyTarget() >>> 24) - 3;
    long receivedTargetCompact = nextBlock.getDifficultyTarget();

    // The calculated difficulty is to a higher precision than received, so reduce here.
    BigInteger mask = BigInteger.valueOf(0xFFFFFFL).shiftLeft(accuracyBytes * 8);
    newTarget = newTarget.and(mask);
    long newTargetCompact = Utils.encodeCompactBits(newTarget);

    if (newTargetCompact != receivedTargetCompact)
        throw new VerificationException("Network provided difficulty bits do not match what was calculated: " +
                Long.toHexString(newTargetCompact) + " vs " + Long.toHexString(receivedTargetCompact));
}