Java Code Examples for org.bitcoinj.store.BlockStore#get()

The following examples show how to use org.bitcoinj.store.BlockStore#get() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.

Example 1

Source File: BlockChainCache.java From jelectrum with MIT License

5 votes

public void undumbSelf(NetworkParameters params, BlockStore block_store)
  throws org.bitcoinj.store.BlockStoreException
{
  Sha256Hash genesis_hash = params.getGenesisBlock().getHash();
  StoredBlock cur = block_store.get(head);
  synchronized(update_lock)
  {
    while(true)
    {
      int height = cur.getHeight();

      if (!height_map.containsKey(height))
      {
        System.out.println("Height map missing: " + height);
        height_map.put(height, cur.getHeader().getHash());
      }
      if (main_chain.contains(cur.getHeader().getHash()))
      {
        System.out.println("Main chain missing: " + height);
        main_chain.add(cur.getHeader().getHash());
      }
      
      if (cur.getHeader().getHash().equals(genesis_hash)) return;
      
      cur = cur.getPrev(block_store);

    }


  }

}

Example 2

Source File: AbstractBitcoinNetParams.java From bcm-android with GNU General Public License v3.0

4 votes

@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));
}

Example 3

Source File: AbstractBitcoinNetParams.java From bisq-core with GNU Affero General Public License v3.0

4 votes

@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));
}

Example 4

Source File: AbstractBitcoinNetParams.java From green_android with GNU General Public License v3.0

4 votes

@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));
}

Example 5

Source File: AbstractBitcoinNetParams.java From GreenBits with GNU General Public License v3.0

4 votes

@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));
}

Example 6

Source File: StoredBlock.java From bcm-android with GNU General Public License v3.0

2 votes

/**
 * Given a block store, looks up the previous block in this chain. Convenience method for doing
 * <tt>store.get(this.getHeader().getPrevBlockHash())</tt>.
 *
 * @return the previous block in the chain or null if it was not found in the store.
 */
public StoredBlock getPrev(BlockStore store) throws BlockStoreException {
    return store.get(getHeader().getPrevBlockHash());
}

Example 7

Source File: StoredBlock.java From green_android with GNU General Public License v3.0

2 votes

/**
 * Given a block store, looks up the previous block in this chain. Convenience method for doing
 * <tt>store.get(this.getHeader().getPrevBlockHash())</tt>.
 *
 * @return the previous block in the chain or null if it was not found in the store.
 */
public StoredBlock getPrev(BlockStore store) throws BlockStoreException {
    return store.get(getHeader().getPrevBlockHash());
}

Example 8

Source File: StoredBlock.java From GreenBits with GNU General Public License v3.0

2 votes

/**
 * Given a block store, looks up the previous block in this chain. Convenience method for doing
 * <tt>store.get(this.getHeader().getPrevBlockHash())</tt>.
 *
 * @return the previous block in the chain or null if it was not found in the store.
 */
public StoredBlock getPrev(BlockStore store) throws BlockStoreException {
    return store.get(getHeader().getPrevBlockHash());
}