content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.checksum;
  
  import com.scurrilous.circe.Hash;
  import com.scurrilous.circe.HashParameters;
  import com.scurrilous.circe.HashSupport;
  import com.scurrilous.circe.StatelessHash;
  import com.scurrilous.circe.crc.Sse42Crc32C;
  import com.scurrilous.circe.impl.AbstractHashProvider;
  import com.scurrilous.circe.params.CrcParameters;
  import java.util.EnumSet;
  
  public final class Crc32cSse42Provider extends AbstractHashProvider<HashParameters> {
  
      // Default chunks of 32 KB, then 4 KB, then 512 bytes
      private static final int[] DEFAULT_CHUNK = new int[] { 4096, 512, 64 };
  
      public Crc32cSse42Provider() {
          super(HashParameters.class);
      }
  
      @Override
      protected EnumSet<HashSupport> querySupportTyped(HashParameters params) {
          if (isCrc32C(params) && Sse42Crc32C.isSupported())
              return EnumSet.allOf(HashSupport.class);
          return EnumSet.noneOf(HashSupport.class);
      }
  
      @Override
      protected Hash get(HashParameters params, EnumSet<HashSupport> required) {
          if (isCrc32C(params) && Sse42Crc32C.isSupported())
              return getCacheable(params, required);
          throw new UnsupportedOperationException();
      }
  
      private static boolean isCrc32C(HashParameters params) {
          return params.equals(CrcParameters.CRC32C);
      }
  
      @Override
      protected StatelessHash createCacheable(HashParameters params, EnumSet<HashSupport> required) {
          return new Sse42Crc32C(DEFAULT_CHUNK);
      }
  }
  