ContentStoreIF.java

/*
 * #!
 * Ontopia Content Store
 * #-
 * Copyright (C) 2001 - 2013 The Ontopia Project
 * #-
 * 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.ontopia.infoset.content;

import java.io.InputStream;

/**
 * INTERNAL: A simple content store interface that stores chunks of
 * data associated with an integer key. The underlying implementation
 * is responsible for creating the keys.
 */
public interface ContentStoreIF {

  /**
   * INTERNAL: Returns true if the content store contains an entry with
   * the specified key.
   */
  public boolean containsKey(int key) throws ContentStoreException;

  /**
   * INTERNAL: Gets the data value associated with the specified key.
   */
  public ContentInputStream get(int key) throws ContentStoreException;
  
  /**
   * INTERNAL: Creates an entry for the specified data value.
   */
  public int add(ContentInputStream data) throws ContentStoreException;
  
  /**
   * INTERNAL: Creates an entry for the specified data value.
   */
  public int add(InputStream data, int length) throws ContentStoreException;

  /**
   * INTERNAL: Removes the entry associated with the key. If the key
   * is not present the call has no effect.
   *
   * @return true if the key was present; false otherwise
   */
  public boolean remove(int key) throws ContentStoreException;

  /**
   * INTERNAL: Closes the content store. This allows all internal
   * resources to be released.
   */
  public void close() throws ContentStoreException;
  
}