com.tomgibara.crinch.hashing

Interface Hash<T>

Type Parameters:

T - the type of objects for which hashes may be generated

All Known Implementing Classes:

PerfectStringHash

public interface Hash<T>

Implementations of this interface can generate one hash value for a given object. Depending upon the implementation, null values may be supported.

Author:

tomgibara

Method Summary

Modifier and Type	Method and Description
HashRange	getRange()
BigInteger	hashAsBigInt(T value) The hash value as a BigInteger.
int	hashAsInt(T value) The hash value as an int.
long	hashAsLong(T value) The hash value as a long.

Method Detail

getRange

HashRange getRange()

hashAsBigInt

BigInteger hashAsBigInt(T value)
                 throws IllegalArgumentException

The hash value as a BigInteger. This method may be useful in circumstances where the generated hash is too large to be accomodated in a single primitive value, eg. if cryptographic hashes are being used.

Parameters:

value - the object to be hashed

Returns:

the object's hash code, never null

Throws:

IllegalArgumentException - if the value cannot be hashed

hashAsInt

int hashAsInt(T value)
       throws IllegalArgumentException

The hash value as an int. This method should provide better performance for integer-ranged hashes. This value is not guaranteed to lie within the indicated HashRange.

Parameters:

value - the object to be hashed

Returns:

the object's hash code

Throws:

IllegalArgumentException - if the value cannot be hashed

hashAsLong

long hashAsLong(T value)
         throws IllegalArgumentException

The hash value as a long. This method should provide better performance for long-ranged hashes. This value is not guaranteed to lie within the indicated HashRange.

Parameters:

value - the object to be hashed

Returns:

the object's hash code

Throws:

IllegalArgumentException - if the value cannot be hashed