/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited

  *

  * 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 org.acegisecurity.afterinvocation;

 import org.apache.commons.collections.iterators.ArrayIterator;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import java.lang.reflect.Array;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.Set;

 /**

  * A filter used to filter arrays.

  *

  * @author Ben Alex

  * @author Paulo Neves

  * @version $Id: ArrayFilterer.java 1784 2007-02-24 21:00:24Z luke_t $

  */

 class ArrayFilterer implements Filterer {

     //~ Static fields/initializers =====================================================================================

     protected static final Log logger =

             LogFactory.getLog(BasicAclEntryAfterInvocationCollectionFilteringProvider.class);

     //~ Instance fields ================================================================================================

     private Set removeList;

     private Object[] list;

     //~ Constructors ===================================================================================================

     ArrayFilterer(Object[] list) {

         this.list = list;

         // Collect the removed objects to a HashSet so that

         // it is fast to lookup them when a filtered array

         // is constructed.

         removeList = new HashSet();

     }

     //~ Methods ========================================================================================================

     /**

      *

      * @see org.acegisecurity.afterinvocation.Filterer#getFilteredObject()

      */

     public Object getFilteredObject() {

         // Recreate an array of same type and filter the removed objects.

         int originalSize = list.length;

         int sizeOfResultingList = originalSize - removeList.size();

         Object[] filtered = (Object[]) Array.newInstance(list.getClass().getComponentType(), sizeOfResultingList);

         for (int i = 0, j = 0; i < list.length; i++) {

             Object object = list[i];

             if (!removeList.contains(object)) {

                 filtered[j] = object;

                 j++;

             }

         }

         if (logger.isDebugEnabled()) {

             logger.debug("Original array contained " + originalSize + " elements; now contains " + sizeOfResultingList

                 + " elements");

         }

         return filtered;

     }

     /**

      *

      * @see org.acegisecurity.afterinvocation.Filterer#iterator()

      */

     public Iterator iterator() {

         return new ArrayIterator(list);

     }

     /**

      *

      * @see org.acegisecurity.afterinvocation.Filterer#remove(java.lang.Object)

      */

     public void remove(Object object) {

         removeList.add(object);

     }

 }