Package org.infinispan.commons.hash

Class MurmurHash3

  • All Implemented Interfaces:
    Hash
    @ThreadSafe
@Immutable
public class MurmurHash3
extends Object
implements Hash
    MurmurHash3 implementation in Java, based on Austin Appleby's original in C Only implementing x64 version, because this should always be faster on 64 bit native processors, even 64 bit being ran with a 32 bit OS; this should also be as fast or faster than the x86 version on some modern 32 bit processors.
    Since:
    5.0
    Author:
    Patrick McFarland
    See Also:
    MurmurHash website, MurmurHash entry on Wikipedia

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static byte INVALID_CHAR  

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean equals​(Object other)  
      static MurmurHash3 getInstance()  
      int hash​(byte[] payload)
      Hashes a byte array efficiently.
      int hash​(int hashcode)
      An incremental version of the hash function, that spreads a pre-calculated hash code, such as one derived from Object.hashCode().
      static int hash​(long[] payload)
      Hashes a byte array efficiently.
      int hash​(Object o)
      A helper that calculates the hashcode of an object, choosing the optimal mechanism of hash calculation after considering the type of the object (byte array, String or Object).
      int hashCode()  
      static long[] MurmurHash3_x64_128​(byte[] key, int seed)
      Hash a value using the x64 128 bit variant of MurmurHash3
      static long[] MurmurHash3_x64_128​(long[] key, int seed)
      Hash a value using the x64 128 bit variant of MurmurHash3
      static int MurmurHash3_x64_32​(byte[] key, int seed)
      Hash a value using the x64 32 bit variant of MurmurHash3
      static int MurmurHash3_x64_32​(long[] key, int seed)
      Hash a value using the x64 32 bit variant of MurmurHash3
      static long MurmurHash3_x64_64​(byte[] key, int seed)
      Hash a value using the x64 64 bit variant of MurmurHash3
      static long MurmurHash3_x64_64​(long[] key, int seed)
      Hash a value using the x64 64 bit variant of MurmurHash3
      String toString()  

    • Method Detail

      • getInstance

        public static MurmurHash3 getInstance()

      • MurmurHash3_x64_128

        public static long[] MurmurHash3_x64_128​(byte[] key,
                                         int seed)
        Hash a value using the x64 128 bit variant of MurmurHash3
        Parameters:
        key - value to hash
        seed - random value
        Returns:
        128 bit hashed key, in an array containing two longs

      • MurmurHash3_x64_64

        public static long MurmurHash3_x64_64​(byte[] key,
                                      int seed)
        Hash a value using the x64 64 bit variant of MurmurHash3
        Parameters:
        key - value to hash
        seed - random value
        Returns:
        64 bit hashed key

      • MurmurHash3_x64_32

        public static int MurmurHash3_x64_32​(byte[] key,
                                     int seed)
        Hash a value using the x64 32 bit variant of MurmurHash3
        Parameters:
        key - value to hash
        seed - random value
        Returns:
        32 bit hashed key

      • MurmurHash3_x64_128

        public static long[] MurmurHash3_x64_128​(long[] key,
                                         int seed)
        Hash a value using the x64 128 bit variant of MurmurHash3
        Parameters:
        key - value to hash
        seed - random value
        Returns:
        128 bit hashed key, in an array containing two longs

      • MurmurHash3_x64_64

        public static long MurmurHash3_x64_64​(long[] key,
                                      int seed)
        Hash a value using the x64 64 bit variant of MurmurHash3
        Parameters:
        key - value to hash
        seed - random value
        Returns:
        64 bit hashed key

      • MurmurHash3_x64_32

        public static int MurmurHash3_x64_32​(long[] key,
                                     int seed)
        Hash a value using the x64 32 bit variant of MurmurHash3
        Parameters:
        key - value to hash
        seed - random value
        Returns:
        32 bit hashed key

      • hash

        public int hash​(byte[] payload)
        Description copied from interface: Hash
        Hashes a byte array efficiently.
        Specified by:
        hash in interface Hash
        Parameters:
        payload - a byte array to hash
        Returns:
        a hash code for the byte array

      • hash

        public static int hash​(long[] payload)
        Hashes a byte array efficiently.
        Parameters:
        payload - a byte array to hash
        Returns:
        a hash code for the byte array

      • hash

        public int hash​(int hashcode)
        Description copied from interface: Hash
        An incremental version of the hash function, that spreads a pre-calculated hash code, such as one derived from Object.hashCode().
        Specified by:
        hash in interface Hash
        Parameters:
        hashcode - an object's hashcode
        Returns:
        a spread and hashed version of the hashcode

      • hash

        public int hash​(Object o)
        Description copied from interface: Hash
        A helper that calculates the hashcode of an object, choosing the optimal mechanism of hash calculation after considering the type of the object (byte array, String or Object).
        Specified by:
        hash in interface Hash
        Parameters:
        o - object to hash
        Returns:
        a hashcode

      • equals

        public boolean equals​(Object other)

      • hashCode

        public int hashCode()

      • toString

        public String toString()