Java Code Examples for org.ethereum.util.FastByteComparisons#compareTo()

@Override
public V prefixLookup(byte[] key, int prefixBytes) {

    for (Map.Entry<byte[], V> e : storage.entrySet()) {
        if (FastByteComparisons.compareTo(key, 0, prefixBytes, e.getKey(), 0, prefixBytes) == 0) {
            return e.getValue();
        }
    }

    return null;
}
 

@Test
public void testEqualsPerformance() {
	boolean testEnabled = false;
	
	if(testEnabled) {
		final int ITERATIONS = 10000000;
		long start1 = System.currentTimeMillis();
		for (int i = 0; i < ITERATIONS; i++) {
			Comparator<byte[]> comparator = UnsignedBytes
					.lexicographicalComparator();

			comparator.compare(wrapper1.getData(),
					wrapper2.getData());
		}
		System.out.println(System.currentTimeMillis() - start1 + "ms");
		
		long start2 = System.currentTimeMillis();
		for (int i = 0; i < ITERATIONS; i++) {
			Arrays.equals(wrapper1.getData(), wrapper2.getData());
		}
		System.out.println(System.currentTimeMillis() - start2 + "ms");
		
		long start3 = System.currentTimeMillis();
		for (int i = 0; i < ITERATIONS; i++) {
			FastByteComparisons.compareTo(wrapper1.getData(), 0, wrapper1.getData().length, wrapper2.getData(), 0, wrapper1.getData().length);
		}
		System.out.println(System.currentTimeMillis() - start3 + "ms");
	}
}
 

/**
 * Verify that block is valid for its difficulty
 * 
 * @return boolean
 */
public boolean validateNonce() {
	BigInteger max = BigInteger.valueOf(2).pow(256);
	byte[] target = BigIntegers.asUnsignedByteArray(32,
			max.divide(new BigInteger(1, this.getDifficulty())));
	byte[] hash = HashUtil.sha3(this.getEncodedWithoutNonce());
	byte[] concat = Arrays.concatenate(hash, this.getNonce());
	byte[] result = HashUtil.sha3(concat);
	return FastByteComparisons.compareTo(result, 0, 32, target, 0, 32) < 0;
}
 

private void processBlockHashes(BlockHashesMessage blockHashesMessage) {

        Blockchain blockchain = WorldManager.getInstance().getBlockchain();
        List<byte[]> receivedHashes = blockHashesMessage.getBlockHashes();
        BlockQueue chainQueue = blockchain.getQueue();

        // result is empty, peer has no more hashes
        // or peer doesn't have the best hash anymore
        if (receivedHashes.isEmpty()
                || !this.peerId.equals(hashRetrievalLock)) {
            startGetBlockTimer(); // start getting blocks from hash queue
            return;
        }

        Iterator<byte[]> hashIterator = receivedHashes.iterator();
        byte[] foundHash, latestHash = blockchain.getLatestBlockHash();
        while (hashIterator.hasNext()) {
            foundHash = hashIterator.next();
            if (FastByteComparisons.compareTo(foundHash, 0, 32, latestHash, 0, 32) != 0){
                chainQueue.addHash(foundHash);    // store unknown hashes in queue until known hash is found
            }
            else {

                logger.trace("Catch up with the hashes until: {[]}", foundHash);
                // if known hash is found, ignore the rest
                startGetBlockTimer(); // start getting blocks from hash queue
                return;
            }
        }
        // no known hash has been reached
        chainQueue.logHashQueueSize();
        sendGetBlockHashes(); // another getBlockHashes with last received hash.
    }
 

public boolean equals(Object other) {
	if (!(other instanceof ByteArrayWrapper))
		return false;
	byte[] otherData = ((ByteArrayWrapper) other).getData();
	return FastByteComparisons.compareTo(
			data, 0, data.length, 
			otherData, 0, otherData.length) == 0;
}
 

@Override
public int compareTo(DataWord o) {
    if (o == null || o.getData() == null) return -1;
    int result = FastByteComparisons.compareTo(
            data, 0, data.length,
            o.getData(), 0, o.getData().length);
    // Convert result into -1, 0 or 1 as is the convention
    return (int) Math.signum(result);
}
 

@Override
public boolean equals(Object other) {
    if (!(other instanceof ByteArrayWrapper)) {
        return false;
    }
    byte[] otherData = ((ByteArrayWrapper) other).getData();
    return FastByteComparisons.compareTo(
            data, 0, data.length,
            otherData, 0, otherData.length) == 0;
}
 

@Override
public int compareTo(DataWord o) {
    if (o == null) {
        return -1;
    }
    int result = FastByteComparisons.compareTo(
            data, 0, data.length,
            o.data, 0, o.data.length);
    // Convert result into -1, 0 or 1 as is the convention
    return (int) Math.signum(result);
}
 

@Override
public V prefixLookup(byte[] key, int prefixBytes) {
    try (ALock l = readLock.lock()) {
        for (Map.Entry<byte[], V> e : storage.entrySet()) {
            if (FastByteComparisons.compareTo(key, 0, prefixBytes, e.getKey(), 0, prefixBytes) == 0) {
                return e.getValue();
            }
        }

        return null;
    }
}
 

@Override
public int compareTo(DataWord o) {
    if (o == null) {
        return -1;
    }
    int result = FastByteComparisons.compareTo(
            data, 0, data.length,
            o.data, 0, o.data.length);
    // Convert result into -1, 0 or 1 as is the convention
    return (int) Math.signum(result);
}
 

public boolean equals(Object other) {
    if (!(other instanceof ByteArrayWrapper))
        return false;
    byte[] otherData = ((ByteArrayWrapper) other).getData();
    return FastByteComparisons.compareTo(
            data, 0, data.length,
            otherData, 0, otherData.length) == 0;
}
 

@Override
public boolean equals(Object other) {
    if (!(other instanceof ByteArrayWrapper)) {
        return false;
    }
    byte[] otherData = ((ByteArrayWrapper) other).getData();
    return FastByteComparisons.compareTo(
            data, 0, data.length,
            otherData, 0, otherData.length) == 0;
}
 

@Override
public V prefixLookup(byte[] key, int prefixBytes) {

    for (Map.Entry<byte[], V> e : storage.entrySet()) {
        if (FastByteComparisons.compareTo(key, 0, prefixBytes, e.getKey(), 0, prefixBytes) == 0) {
            return e.getValue();
        }
    }

    return null;
}
 

@Override
public V prefixLookup(byte[] key, int prefixBytes) {
    try (ALock l = readLock.lock()) {
        for (Map.Entry<byte[], V> e : storage.entrySet()) {
            if (FastByteComparisons.compareTo(key, 0, prefixBytes, e.getKey(), 0, prefixBytes) == 0) {
                return e.getValue();
            }
        }

        return null;
    }
}
 

@Override
public int compareTo(ByteArrayWrapper o) {
    return FastByteComparisons.compareTo(
            data, 0, data.length,
            o.getData(), 0, o.getData().length);
}
 

@Override
public int compareTo(ByteArrayWrapper o) {
    return FastByteComparisons.compareTo(
            data, 0, data.length,
            o.getData(), 0, o.getData().length);
}
 

@Override
public int compareTo(ByteArrayWrapper o) {
    return FastByteComparisons.compareTo(
            data, 0, data.length,
            o.getData(), 0, o.getData().length);
}
 

@Override
public int compareTo(ByteArrayWrapper o) {
	return FastByteComparisons.compareTo(
			data, 0, data.length, 
			o.getData(), 0, o.getData().length);
}
 

/**
	 * Adds a nonce to given block which complies with the given difficulty
	 * 
	 * For the PoC series, we use a simplified proof-of-work. 
	 * This is not ASIC resistant and is meant merely as a placeholder. 
	 * It utilizes the bare SHA3 hash function to secure the block chain by requiring 
	 * the SHA3 hash of the concatenation of the nonce and the header’s SHA3 hash to be 
	 * sufficiently low. It is formally defined as PoW:
	 * 
	 * 		PoW(H, n) ≡ BE(SHA3(SHA3(RLP(H!n)) ◦ n))
	 *
	 * 	where:
	 * 		RLP(H!n) is the RLP encoding of the block header H, not including the
	 *			final nonce component;
	 *		SHA3 is the SHA3 hash function accepting an arbitrary length series of
	 *			bytes and evaluating to a series of 32 bytes (i.e. 256-bit);
	 *		n is the nonce, a series of 32 bytes;
	 *		o is the series concatenation operator;
	 *		BE(X) evaluates to the value equal to X when interpreted as a
	 *			big-endian-encoded integer.
	 * 
	 * @param newBlock without a valid nonce
	 * @param difficulty - the mining difficulty
	 * @return true if valid nonce has been added to the block
	 */
	public boolean mine(Block newBlock, byte[] difficulty) {

		BigInteger max = BigInteger.valueOf(2).pow(256);
		byte[] target = BigIntegers.asUnsignedByteArray(32,
				max.divide(new BigInteger(1, difficulty)));

		byte[] hash = HashUtil.sha3(newBlock.getEncodedWithoutNonce());
		byte[] testNonce = new byte[32];
		byte[] concat;
		
		while(ByteUtil.increment(testNonce)) {
			concat = Arrays.concatenate(hash, testNonce);
			byte[] result = HashUtil.sha3(concat);
			if(FastByteComparisons.compareTo(result, 0, 32, target, 0, 32) < 0) {
				newBlock.setNonce(testNonce);
//				System.out.println(Hex.toHexString(newBlock.getEncoded()));
				return true;
			}
		}
		return false; // couldn't find a valid nonce
	}