content: /*******************************************************************************
   * 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;
  
  /**
   * Abstract hash function. Each actual hash function is provided using a
   * {@linkplain StatefulHash stateful} derived interface. Hash functions with an
   * output length that fits within an {@code int} or a {@code long} are also
   * generally provided using a {@linkplain StatelessHash stateless} derived
   * interface. Given a stateless hash object, a method is provided for obtaining
   * a new corresponding stateful object.
   */
  public interface Hash {
  
      /**
       * Returns the canonical name of this hash algorithm.
       * 
       * @return the name of this hash algorithm
       */
      String algorithm();
  
      /**
       * Returns the length in bytes of the output of this hash function.
       * 
       * @return the hash length in bytes
       */
      int length();
  
      /**
       * Returns whether this hash function supports unsafe access to arbitrary
       * memory addresses using methods such as
       * {@link StatefulHash#update(long, long)},
       * {@link StatelessIntHash#calculate(long, long)}, or
       * {@link IncrementalIntHash#resume(int, long, long)}. Such functions are
       * generally implemented in native code.
       * 
       * @return true if unsafe access is supported, false if not
       */
      boolean supportsUnsafe();
  }
  