Java Code Examples for com.google.common.hash.HashCode#asInt()

public final static int[] computeSequenceHashes(final String seq, final int nGramSize, boolean doReverseCompliment)
{
	HashFunction hf = Hashing.murmur3_32(0);

	int[] hashes = new int[seq.length() - nGramSize + 1];
	for (int iter = 0; iter < hashes.length; iter++)
	{
		String str = seq.substring(iter, iter + nGramSize);
		
		String strReverse = null;
		if (doReverseCompliment)
		{
			strReverse  = Utils.rc(str);
			if (strReverse.compareTo(str)<0)
				str = strReverse;
		}

		HashCode hc = hf.newHasher().putUnencodedChars(str).hash();
		hashes[iter] = hc.asInt();
	}

	return hashes;
}
 

/**
 * Build a stringified MAC address using the ClusterMetadata hash for uniqueness.
 * Form of MAC is "02:eb" followed by four bytes of clusterMetadata hash.
 *
 * @param cm cluster metadata
 * @return stringified mac address
 */
static String fingerprintMac(ClusterMetadata cm) {
    if (cm == null) {
        return DEFAULT_MAC;
    }

    HashFunction hf = Hashing.murmur3_32();
    HashCode hc = hf.newHasher().putObject(cm, ClusterMetadata.HASH_FUNNEL).hash();
    int unqf = hc.asInt();

    StringBuilder sb = new StringBuilder();
    sb.append("02:eb");
    for (int i = 0; i < 4; i++) {
        byte b = (byte) (unqf >> i * 8);
        sb.append(String.format(":%02X", b));
    }
    return sb.toString();
}
 

private int hash() {
    // Guava documentation recommends using putUnencodedChars to hash raw character bytes within any encoding
    // unless cross-language compatibility is needed. See the Hasher.putString documentation for more info.
    Funnel<TrafficSelector> selectorFunnel = (from, into) -> from.criteria()
            .forEach(c -> into.putUnencodedChars(c.toString()));

    HashFunction hashFunction = Hashing.murmur3_32();
    HashCode hashCode = hashFunction.newHasher()
            .putUnencodedChars(deviceId.toString())
            .putObject(selector, selectorFunnel)
            .putInt(priority)
            .putUnencodedChars(tableId.toString())
            .hash();

    return hashCode.asInt();
}
 

public int getNodeIndex(int numNodes, String key)
{
  HashFunction hf = Hashing.md5();
  HashCode hc = hf.hashString(key, Charsets.UTF_8);
  int initialNodeIndex = Hashing.consistentHash(hc, numNodes);
  int finalNodeIndex = initialNodeIndex;
  if (hc.asInt() % 2 == 0) {
    finalNodeIndex = getNextRunningNodeIndex(initialNodeIndex);
  }
  else {
    finalNodeIndex = getPreviousRunningNodeIndex(initialNodeIndex);
  }

  return finalNodeIndex;
}
 

public final static int[] computeHashesIntDouble(double obj, int numWords, int seed)
{
	int[] hashes = new int[numWords];

	HashFunction hf = Hashing.murmur3_32(seed);

	for (int iter = 0; iter < numWords; iter++)
	{
		HashCode hc = hf.newHasher().putDouble(obj).putInt(iter).hash();

		hashes[iter] = hc.asInt();
	}

	return hashes;
}
 

public final static int[] computeHashesIntFloat(float obj, int numWords, int seed)
{
	int[] hashes = new int[numWords];

	HashFunction hf = Hashing.murmur3_32(seed);

	for (int iter = 0; iter < numWords; iter++)
	{
		HashCode hc = hf.newHasher().putFloat(obj).putInt(iter).hash();

		hashes[iter] = hc.asInt();
	}

	return hashes;
}
 

public final static int[] computeHashesIntInt(int obj, int numWords, int seed)
{
	int[] hashes = new int[numWords];

	HashFunction hf = Hashing.murmur3_32(seed);

	for (int iter = 0; iter < numWords; iter++)
	{
		HashCode hc = hf.newHasher().putInt(obj).putInt(iter).hash();

		hashes[iter] = hc.asInt();
	}

	return hashes;
}
 

public final static int[] computeHashesIntLong(long obj, int numWords, int seed)
{
	int[] hashes = new int[numWords];

	HashFunction hf = Hashing.murmur3_32(seed);

	for (int iter = 0; iter < numWords; iter++)
	{
		HashCode hc = hf.newHasher().putLong(obj).putInt(iter).hash();

		hashes[iter] = hc.asInt();
	}

	return hashes;
}
 

public final static int[] computeHashesIntString(String obj, int numWords, int seed)
{
	int[] hashes = new int[numWords];

	HashFunction hf = Hashing.murmur3_32(seed);

	for (int iter = 0; iter < numWords; iter++)
	{
		HashCode hc = hf.newHasher().putUnencodedChars(obj).putInt(iter).hash();

		hashes[iter] = hc.asInt();
	}

	return hashes;
}
 

public static double[] randomStringGuassianVector(String str, int n, int seed)
{
	int[] seeds = new int[4];
	for (int iter=0; iter<4; iter++)
	{
		HashFunction hf = Hashing.murmur3_32(seed*4+iter);
		HashCode hc = hf.newHasher().putUnencodedChars(str).hash();
		
		seeds[iter] = hc.asInt();
	}
	
	//now generate the guassian
	MersenneTwisterFast rand = new MersenneTwisterFast(seeds);
	
	double[] vec = new double[n];
	for (int iter=0; iter<n; iter++)
	{
		vec[iter] = rand.nextGaussian();
	}
	
	//normalize
	double norm = BasicMath.norm(vec);		
	if (norm<1.0e-10)
		return vec;
	
	return BasicMath.mult(vec, 1.0/norm);
}