/*
* 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 org.apache.tools.ant.types.selectors.modifiedselector;
import java.util.Iterator;
/**
* A Cache let the user store key-value-pairs in a permanent manner and access
* them.
* It is possible that a client uses get() before load() therefore the
* implementation must ensure that no error occurred because of the wrong
* <i>order</i>.
* The implementing class should implement a useful toString() method.
*
* @version 2003-09-13
* @since Ant 1.6
*/
public interface Cache {
/**
* Checks its prerequisites.
* @return <i>true</i> if all is ok, otherwise <i>false</i>.
*/
boolean isValid();
/** Deletes the cache. If file based the file has to be deleted also. */
void delete();
/** Loads the cache, must handle not existing cache. */
void load();
/** Saves modification of the cache. */
void save();
/**
* Returns a value for a given key from the cache.
* @param key the key
* @return the stored value
*/
Object get(Object key);
/**
* Saves a key-value-pair in the cache.
* @param key the key
* @param value the value
*/
void put(Object key, Object value);
/**
* Returns an iterator over the keys in the cache.
* @return An iterator over the keys.
*/
Iterator<String> iterator();
}