/*
    *  Copyright 2003-2004 The Apache Software Foundation
    *
    *  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 net.sf.collections15.collection;
  
  import java.io.Serializable;
  import java.util.Collection;
  import java.util.Iterator;
  
  /***
   * Decorates another <code>Collection</code> to synchronize its behaviour
   * for a multi-threaded environment.
   * <p>
   * Iterators must be manually synchronized:
   * <pre>
   * synchronized (coll) {
   *   Iterator<String> it = coll.iterator();
   *   // do stuff with iterator
   * }
   * </pre>
   * <p>
   * This class is Serializable from Commons Collections 3.1.
   *
   * @since Commons Collections 3.0
   * @version $Revision: 1.1 $ $Date: 2005/05/03 22:45:38 $
   * 
   * @author Stephen Colebourne
   */
  public class SynchronizedCollection<E> implements Collection<E>, Serializable {
  
      /*** Serialization version */
  	private static final long serialVersionUID = 3256438097226182708L;
  
  	/*** The collection to decorate */
      protected final Collection<E> collection;
  
  	/*** The object to lock on, needed for List/SortedSet views */
      protected final Object lock;
  
      /***
       * Factory method to create a synchronized collection.
       * 
       * @param coll  the collection to decorate, must not be null
       * @return a new synchronized collection
       * @throws IllegalArgumentException if collection is null
       */
      public static <T> Collection<T> decorate(Collection<T> coll) {
          return new SynchronizedCollection<T>(coll);
      }
      
      //-----------------------------------------------------------------------
      /***
       * Constructor that wraps (not copies).
       * 
       * @param collection  the collection to decorate, must not be null
       * @throws IllegalArgumentException if the collection is null
       */
      protected SynchronizedCollection(Collection<E> collection) {
          if (collection == null) {
              throw new IllegalArgumentException("Collection must not be null");
          }
          this.collection = collection;
          this.lock = this;
      }
  
      /***
       * Constructor that wraps (not copies).
       * 
       * @param collection  the collection to decorate, must not be null
       * @param lock  the lock object to use, must not be null
       * @throws IllegalArgumentException if the collection is null
       */
      protected SynchronizedCollection(Collection<E> collection, Object lock) {
          if (collection == null) {
              throw new IllegalArgumentException("Collection must not be null");
          }
          this.collection = collection;
          this.lock = lock;
      }
  
      //-----------------------------------------------------------------------
      public boolean add(E object) {
          synchronized (lock) {
              return collection.add(object);
          }
      }
  
     public boolean addAll(Collection<? extends E> coll) {
         synchronized (lock) {
             return collection.addAll(coll);
         }
     }
 
     public void clear() {
         synchronized (lock) {
             collection.clear();
         }
     }
 
     public boolean contains(Object object) {
         synchronized (lock) {
             return collection.contains(object);
         }
     }
 
     public boolean containsAll(Collection<?> coll) {
         synchronized (lock) {
             return collection.containsAll(coll);
         }
     }
 
     public boolean isEmpty() {
         synchronized (lock) {
             return collection.isEmpty();
         }
     }
 
     /***
      * Iterators must be manually synchronized.
      * <pre>
      * synchronized (coll) {
      *   Iterator it = coll.iterator();
      *   // do stuff with iterator
      * }
      * 
      * @return an iterator that must be manually synchronized on the collection
      */
     public Iterator<E> iterator() {
         return collection.iterator();
     }
 
     public Object[] toArray() {
         synchronized (lock) {
             return collection.toArray();
         }
     }
 
     public <T> T[] toArray(T[] object) {
         synchronized (lock) {
             return collection.toArray(object);
         }
     }
 
     public boolean remove(Object object) {
         synchronized (lock) {
             return collection.remove(object);
         }
     }
 
     public boolean removeAll(Collection<?> coll) {
         synchronized (lock) {
             return collection.removeAll(coll);
         }
     }
 
     public boolean retainAll(Collection<?> coll) {
         synchronized (lock) {
             return collection.retainAll(coll);
         }
     }
 
     public int size() {
         synchronized (lock) {
             return collection.size();
         }
     }
 
     public boolean equals(Object object) {
         synchronized (lock) {
             if (object == this) {
                 return true;
             }
             return collection.equals(object);
         }
     }
 
     public int hashCode() {
         synchronized (lock) {
             return collection.hashCode();
         }
     }
 
     public String toString() {
         synchronized (lock) {
             return collection.toString();
         }
     }
 
 }