galileo.dht.hash

Interface HashFunction<T>

All Known Implementing Classes:

ConstrainedGeohash, SHA1, SpatialHash, TinyHash

public interface HashFunction<T>

Interface for mapping arbitrary data to a specific location in a hash space.

Author:

malensek

Method Summary

Modifier and Type	Method and Description
java.math.BigInteger	hash(T data) Maps some given data to an integer location in the implemented hash space.
java.math.BigInteger	maxValue() Determines the maximum hash value that this hash function can produce.
java.math.BigInteger	randomHash() Returns a random location in the hash space.

Method Detail

hash

java.math.BigInteger hash(T data)
                   throws HashException

Maps some given data to an integer location in the implemented hash space.

Parameters:

data - Data to hash against.

Returns:

location in the hash space for the data.

Throws:

HashException

maxValue

java.math.BigInteger maxValue()

Determines the maximum hash value that this hash function can produce. For example, a 160-bit SHA1 max value would be 2^160.

Returns:

maximum possible value this hash function will produce.

randomHash

java.math.BigInteger randomHash()
                         throws HashException

Returns a random location in the hash space. This is used for seeding the first nodes in an overlay, or providing random positions to place nodes.

Returns:

random position in the hash space.

Throws:

HashException