package org.apache.lucene.facet.search;
/*
* 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.
*/
/**
* Declares an interface for heap (and heap alike) structures,
* handling a given type T
*
* @lucene.experimental
*/
public interface Heap<T> {
/**
* Get and remove the top of the Heap <BR>
* NOTE: Once {@link #pop()} is called no other {@link #add(Object)} or
* {@link #insertWithOverflow(Object)} should be called.
*/
public T pop();
/** Get (But not remove) the top of the Heap */
public T top();
/**
* Insert a new value, returning the overflowen object <br>
* NOTE: This method should not be called after invoking {@link #pop()}
*/
public T insertWithOverflow(T value);
/**
* Add a new value to the heap, return the new top(). <br>
* Some implementations may choose to not implement this functionality.
* In such a case <code>null</code> should be returned. <BR>
* NOTE: This method should not be called after invoking {@link #pop()}
*/
public T add(T frn);
/** Clear the heap */
public void clear();
/** Return the amount of objects currently in the heap */
public int size();
}