package org.apache.archiva.checksum;
   
   /*
    * 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.
   */
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.List;
  import java.util.stream.Collectors;
  
  /**
   *
   * Class that handles checksums with streams.
   *
   * @author Martin Stockhammer <martin_s@apache.org>
   */
  public class StreamingChecksum
  {
      static final int BUFFER_SIZE=4096;
  
      public static void updateChecksums( InputStream input, List<ChecksumAlgorithm> algorithms, List<OutputStream> checksumOutput) {
          List<Checksum> checksums = algorithms.stream().map(a -> new Checksum( a )).collect( Collectors.toList());
          byte[] buffer = new byte[BUFFER_SIZE];
          int read;
          try
          {
              while ( ( read = input.read( buffer ) ) >= 0 )
              {
                  for (Checksum cs : checksums ) {
                      cs.update( buffer, 0, read );
                  }
              }
              int minIndex = Math.min(algorithms.size(), checksums.size());
              for (int csIndex = 0; csIndex<minIndex; csIndex++) {
                  Checksum cs = checksums.get(csIndex);
                  cs.finish();
                  OutputStream os =checksumOutput.get(csIndex);
                  if (os!=null)
                  {
                      os.write( cs.getChecksum( ).getBytes( ) );
                  }
              }
  
          } catch ( IOException e ) {
  
          }
      }
  }