com.scurrilous.circe.HashProvider Maven / Gradle / Ivy
/*******************************************************************************
* Copyright 2014 Trevor Robinson
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
******************************************************************************/
package com.scurrilous.circe;
import java.util.EnumSet;
/**
* Interface used to obtain instances of various kinds of hash algorithms.
*/
public interface HashProvider {
/**
* Returns information about the available implementations corresponding to
* the given hash algorithm parameters.
*
* @param params the hash algorithm parameters
* @return a set of flags indicating the level of support
*/
EnumSet querySupport(HashParameters params);
/**
* Creates a stateful hash function using the given parameters.
*
* @param params the hash algorithm parameters
* @return a stateful hash function
* @throws UnsupportedOperationException if this provider cannot support the
* given parameters
*/
StatefulHash createStateful(HashParameters params);
/**
* Requests a stateless, int-width hash function with the given parameters.
* Because not all stateless hash functions are incremental, this method may
* be able to return implementations not supported by or more optimized than
* {@link #getIncrementalInt}.
*
* @param params the hash algorithm parameters
* @return a stateless int-width hash function
* @throws UnsupportedOperationException if this provider cannot support the
* given parameters
*/
StatelessIntHash getStatelessInt(HashParameters params);
/**
* Requests a stateless, long-width hash function with the given parameters.
* Because not all stateless hash functions are incremental, this method may
* be able to return implementations not supported by or more optimized than
* {@link #getIncrementalLong}.
*
* Note that this method may return a less efficient hash function than
* {@link #getStatelessInt} for hashes of 32 bits or less.
*
* @param params the hash algorithm parameters
* @return a stateless long-width hash function
* @throws UnsupportedOperationException if this provider cannot support the
* given parameters
*/
StatelessLongHash getStatelessLong(HashParameters params);
/**
* Requests an incremental, stateless, int-width hash function with the
* given parameters. Note that although an algorithm may be available in
* incremental form, some potentially more optimized implementations may not
* support that form, and therefore cannot be provided be this method.
*
* @param params the hash algorithm parameters
* @return a stateful int-width hash function
* @throws UnsupportedOperationException if this provider cannot support the
* given parameters
*/
IncrementalIntHash getIncrementalInt(HashParameters params);
/**
* Requests an incremental, stateless, long-width hash function with the
* given parameters. Note that although an algorithm may be available in
* incremental form, some potentially more optimized implementations may not
* support that form, and therefore cannot be provided be this method.
*
* Also note that this method may return a less efficient hash function than
* {@link #getIncrementalInt} for hashes of 32 bits or less.
*
* @param params the hash algorithm parameters
* @return a stateful long-width hash function
* @throws UnsupportedOperationException if this provider cannot support the
* given parameters
*/
IncrementalLongHash getIncrementalLong(HashParameters params);
}