content: package edu.berkeley.nlp.lm.util;
  
  /**
   * Taken/modified from
   * http://d3s.mff.cuni.cz/~holub/sw/javamurmurhash/MurmurHash.java
   * 
   */
  public final class MurmurHash
  {
  
  	/**
  	 * Generates 32 bit hash from byte array of the given length and seed.
  	 * 
  	 * @param data
  	 *            int array to hash
  	 * @param length
  	 *            length of the array to hash
  	 * @param seed
  	 *            initial seed value
  	 * @return 32 bit hash of the given array
  	 */
  	public static int hash32(final int[] data, int startPos, int endPos, int seed) {
  		// 'm' and 'r' are mixing constants generated offline.
  		// They're not really 'magic', they just happen to work well.
  		final int m = 0x5bd1e995;
  		final int r = 24;
  		final int length = endPos - startPos;
  		// Initialize the hash to a random value
  		int h = seed ^ length;
  
  		for (int i = startPos; i < endPos; i++) {
  			int k = data[i];
  			k *= m;
  			k ^= k >>> r;
  			k *= m;
  			h *= m;
  			h ^= k;
  		}
  
  		h ^= h >>> 13;
  		h *= m;
  		h ^= h >>> 15;
  
  		return h;
  	}
  
  	public static int hash32(final int[] data, int startPos, int endPos) {
  		return hash32(data, startPos, endPos, 0x9747b28c);
  	}
  
  	public static long hashOneLong(final long k_, final int seed) {
  		long k = k_;
  		final long m = 0xc6a4a7935bd1e995L;
  		final int r = 47;
  
  		long h = (seed & 0xffffffffl) ^ (1 * m);
  
  		k *= m;
  		k ^= k >>> r;
  		k *= m;
  
  		h ^= k;
  		h *= m;
  
  		h ^= h >>> r;
  		h *= m;
  		h ^= h >>> r;
  
  		return h;
  	}
  
  	public static long hashThreeLongs(final long k1, final long k2, final long k3) {
  
  		final int seed = 0x9747b28c;
  		final long m = 0xc6a4a7935bd1e995L;
  		final int r = 47;
  
  		long h = (seed & 0xffffffffl) ^ (1 * m);
  		for (int i = 0; i <= 2; ++i) {
  			long k = -1;
  			switch (i) {
  				case 0:
  					k = k1;
  					break;
  				case 1:
  					k = k2;
  					break;
  				case 2:
  					k = k3;
  					break;
  				default:
  					assert false;
  			}
  			k *= m;
  			k ^= k >>> r;
  			k *= m;
  
  			h ^= k;
  			h *= m;
  		}
  
  		h ^= h >>> r;
  		h *= m;
  		h ^= h >>> r;
  
  		return h;
  	}
  
  }