/*
 * Copyright 2016-present Open Networking Laboratory
 *
 * 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 org.onosproject.store.service;

import java.util.Map;
import java.util.NavigableSet;

/**
 * Tree map interface counterpart to {@link AsyncConsistentTreeMap}.
 */
 public interface ConsistentTreeMap<K, V> extends ConsistentMap<K, V> {

    /**
     * Returns the lowest key in the map.
     *
     * @return the key or null if none exist
     */
     K firstKey();

    /**
     * Returns the highest key in the map.
     *
     * @return the key or null if none exist
     */
     K lastKey();

    /**
     * Returns the entry associated with the least key greater than or equal to the key.
     *
     * @param key the key
     * @return the entry or null
     */
     Map.Entry<K, Versioned<V>> ceilingEntry(K key);

    /**
     * Returns the entry associated with the greatest key less than or equal to key.
     *
     * @param key the key
     * @return the entry or null
     */
     Map.Entry<K, Versioned<V>> floorEntry(K key);

    /**
     * Returns the entry associated with the lest key greater than key.
     *
     * @param key the key
     * @return the entry or null
     */
     Map.Entry<K, Versioned<V>> higherEntry(K key);

    /**
     * Returns the entry associated with the largest key less than key.
     *
     * @param key the key
     * @return the entry or null
     */
     Map.Entry<K, Versioned<V>> lowerEntry(K key);

    /**
     * Returns the entry associated with the lowest key in the map.
     *
     * @return the entry or null
     */
     Map.Entry<K, Versioned<V>> firstEntry();

    /**
     * Returns the entry associated with the highest key in the map.
     *
     * @return the entry or null
     */
     Map.Entry<K, Versioned<V>> lastEntry();

    /**
     * Returns and removes the entry associated with the lowest key.
     *
     * @return the entry or null
     */
     Map.Entry<K, Versioned<V>> pollFirstEntry();

    /**
     * Returns and removes the entry associated with the highest key.
     *
     * @return the entry or null
     */
     Map.Entry<K, Versioned<V>> pollLastEntry();

    /**
     * Returns the entry associated with the greatest key less than key.
     *
     * @param key the key
     * @return the entry or null
     */
     K lowerKey(K key);

    /**
     * Returns the entry associated with the highest key less than or equal to key.
     *
     * @param key the key
     * @return the entry or null
     */
     K floorKey(K key);

    /**
     * Returns the lowest key greater than or equal to key.
     *
     * @param key the key
     * @return the key or null
     */
     K ceilingKey(K key);

    /**
     * Returns the lowest key greater than key.
     *
     * @param key the key
     * @return the key or null
     */
     K higherKey(K key);

    /**
     * Returns a navigable set of the keys in this map.
     *
     * @return a navigable key set
     */
     NavigableSet<K> navigableKeySet();

}