com.ebay.jetstream.messaging.transport.netty.schedulingalgorithm.consistenthashing.MurmurHashFunction.java Source code

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Here is the source code for com.ebay.jetstream.messaging.transport.netty.schedulingalgorithm.consistenthashing.MurmurHashFunction.java

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/*******************************************************************************
 *  Copyright  2012-2015 eBay Software Foundation
 *  This program is dual licensed under the MIT and Apache 2.0 licenses.
 *  Please see LICENSE for more information.
 *******************************************************************************/
package com.ebay.jetstream.messaging.transport.netty.schedulingalgorithm.consistenthashing;

import com.google.common.hash.HashCode;
import com.google.common.hash.HashFunction;
import com.google.common.hash.Hashing;

public class MurmurHashFunction
        implements com.ebay.jetstream.messaging.transport.netty.schedulingalgorithm.consistenthashing.HashFunction {

    HashFunction m_hf;
    int m_seed = 2147368987;

    public int getSeed() {
        return m_seed;
    }

    public void setSeed(int seed) {
        this.m_seed = seed;
        m_hf = Hashing.murmur3_128(m_seed);
    }

    public MurmurHashFunction() {
        m_hf = Hashing.murmur3_128(m_seed);
    }

    public Long hash(Object val) {

        long hash;
        HashCode hc;

        if (val instanceof String)
            hc = m_hf.newHasher().putString((String) val).hash();
        else if (val instanceof Long)
            hc = m_hf.newHasher().putLong((Long) val).hash();
        else if (val instanceof Integer)
            hc = m_hf.newHasher().putInt((Integer) val).hash();
        else if (val instanceof Boolean)
            hc = m_hf.newHasher().putBoolean((Boolean) val).hash();
        else if (val instanceof byte[])
            hc = m_hf.newHasher().putBytes((byte[]) val).hash();
        else
            hc = m_hf.newHasher().putInt(val.hashCode()).hash();
        return hc.asLong();

    }

}