package org.apache.archiva.transaction;
   
   /*
    * 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.File;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.codehaus.plexus.digest.Digester;
  
  /**
   * Implement commit/rollback semantics for a set of files.
   *
   */
  public class FileTransaction
  {
      private List<AbstractTransactionEvent> events = new ArrayList<>();
  
      public void commit()
          throws TransactionException
      {
          List<TransactionEvent> toRollback = new ArrayList<TransactionEvent>( events.size() );
  
          for ( TransactionEvent event : events )
          {
              try
              {
                  event.commit();
  
                  toRollback.add( event );
              }
              catch ( IOException e )
              {
                  try
                  {
                      rollback( toRollback );
  
                      throw new TransactionException( "Unable to commit file transaction", e );
                  }
                  catch ( IOException ioe )
                  {
                      throw new TransactionException(
                          "Unable to commit file transaction, and rollback failed with error: '" + ioe.getMessage() + "'",
                          e );
                  }
              }
          }
      }
  
      private void rollback( List<TransactionEvent> toRollback )
          throws IOException
      {
          for ( TransactionEvent event : toRollback )
          {
              event.rollback();
          }
      }
  
      /**
       * @param source
       * @param destination
       * @param digesters   {@link List}&lt;{@link org.codehaus.plexus.digest.Digester}&gt; digesters to use for checksumming
       */
      public void copyFile( File source, File destination, List<? extends Digester> digesters )
      {
          events.add( new CopyFileEvent( source, destination, digesters ) );
      }
  
      /**
       * @param content
       * @param destination
       * @param digesters   {@link List}&lt;{@link org.codehaus.plexus.digest.Digester}&gt; digesters to use for checksumming
       */
      public void createFile( String content, File destination, List<? extends Digester> digesters )
      {
          events.add( new CreateFileEvent( content, destination, digesters ) );
      }
  }