Package org.apache.hadoop.util.bloom

Class HashFunction

java.lang.Object
org.apache.hadoop.util.bloom.HashFunction
@Public @Stable public final class HashFunction extends Object
Implements a hash object that returns a certain number of hashed values.
See Also:
  • The general behavior of a key being stored in a filter
  • The general behavior of a filter

  • Constructor Summary

    Constructors
    Constructor
    Description
    HashFunction(int maxValue, int nbHash, int hashType)
    Constructor.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Clears this hash function.
    int[]
    hash(org.apache.hadoop.util.bloom.Key k)
    Hashes a specified key into several integers.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • HashFunction

      public HashFunction(int maxValue, int nbHash, int hashType)
      Constructor.

      Builds a hash function that must obey to a given maximum number of returned values and a highest value.

      Parameters:
      maxValue - The maximum highest returned value.
      nbHash - The number of resulting hashed values.
      hashType - type of the hashing function (see Hash).

  • Method Details

    • clear

      public void clear()
      Clears this hash function. A NOOP

    • hash

      public int[] hash(org.apache.hadoop.util.bloom.Key k)
      Hashes a specified key into several integers.
      Parameters:
      k - The specified key.
      Returns:
      The array of hashed values.