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 mf.org.apache.xerces.xni;
  
  import java.util.Enumeration;
  
  /**
   * The Augmentations interface defines a table of additional data that may
   * be passed along the document pipeline. The information can contain extra
   * arguments or infoset augmentations, for example PSVI. This additional
   * information is identified by a String key.
   * <p/>
   * <strong>Note:</strong>
   * Methods that receive Augmentations are required to copy the information
   * if it is to be saved for use beyond the scope of the method.
   * The Augmentations content is volatile, and maybe modified by any method in
   * any component in the pipeline. Therefore, methods passed this structure
   * should not save any reference to the structure.
   *
   * @author Elena Litani, IBM
   * @version $Id: Augmentations.java 447247 2006-09-18 05:23:52Z mrglavas $
   */
  
  public interface Augmentations {
  
  
      /**
       * Add additional information identified by a key to the Augmentations structure.
       *
       * @param key  Identifier, can't be <code>null</code>
       * @param item Additional information
       * @return the previous value of the specified key in the Augmentations structure,
       * or <code>null</code> if it did not have one.
       */
      Object putItem(String key, Object item);
  
  
      /**
       * Get information identified by a key from the Augmentations structure
       *
       * @param key Identifier, can't be <code>null</code>
       * @return the value to which the key is mapped in the Augmentations structure;
       * <code>null</code> if the key is not mapped to any value.
       */
      Object getItem(String key);
  
  
      /**
       * Remove additional info from the Augmentations structure
       *
       * @param key Identifier, can't be <code>null</code>
       * @return the previous value of the specified key in the Augmentations structure,
       * or <code>null</code> if it did not have one.
       */
      Object removeItem(String key);
  
  
      /**
       * Returns an enumeration of the keys in the Augmentations structure
       */
      Enumeration keys();
  
  
      /**
       * Remove all objects from the Augmentations structure.
       */
      void removeAllItems();
  
  }
  