ExpireMap.java

/*
 * 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.lisp.ctl.impl.map;

import java.util.Collection;
import java.util.Set;

/**
 * A {@link java.util.concurrent.ConcurrentMap} that supports timed entry
 * eviction.
 */
public interface ExpireMap<K, V> {

    /**
     * Associates the specified value with the specified key in this map for the
     * specified duration (optional operation). If the map previously contained
     * a mapping for the key, the old value is replaced by the specified value.
     *
     * @param key      key with which the specified value is to be associated
     * @param value    value to be associated with the specified key
     * @param expireMs the maximum amount of time in ms during which the map
     *                 entry should remain in the map, this can also be
     *                 considered as (time-to-live: TTL) value. Note that when
     *                 we assign a value of 0, the map entry will be immediately
     *                 remove from the map.
     *
     * @throws UnsupportedOperationException if the <tt>put</tt> operation
     *         is not supported by this map
     * @throws ClassCastException if the class of the specified key or value
     *         prevents it from being stored in this map
     * @throws NullPointerException if the specified key or value is null
     *         and this map does not permit null keys or values
     * @throws IllegalArgumentException if some property of the specified key
     *         or value prevents it from being stored in this map
     */
    void put(K key, V value, long expireMs);

    /**
     * Associates the specified value with the specified key in this map for the
     * specified duration (optional operation). If the map previously contained
     * a mapping for the key, the old value is replaced by the specified value.
     * With this method, we can specify the expireMs with default value.
     *
     * @param key   key with which the specified value is to be associated
     * @param value value to be associated with the specified key
     *
     * @throws UnsupportedOperationException if the <tt>put</tt> operation
     *         is not supported by this map
     * @throws ClassCastException if the class of the specified key or value
     *         prevents it from being stored in this map
     * @throws NullPointerException if the specified key or value is null
     *         and this map does not permit null keys or values
     * @throws IllegalArgumentException if some property of the specified key
     *         or value prevents it from being stored in this map
     */
    void put(K key, V value);

    /**
     * Returns the value to which the specified key is mapped,
     * or {@code null} if this map contains no mapping for the key.
     *
     * @param key the key whose associated value is to be returned
     * @return the value to which the specified key is mapped, or
     *         {@code null} if this map contains no mapping for the key
     * @throws ClassCastException if the key is of an inappropriate type for
     *         this map
     * @throws NullPointerException if the specified key is null and this map
     *         does not permit null keys
     */
    V get(K key);

    /**
     * Removes all of the mappings from this map (optional operation).
     * The map will be empty after this call returns.
     *
     * @throws UnsupportedOperationException if the <tt>clear</tt> operation
     *         is not supported by this map
     */
    void clear();

    /**
     * Returns <tt>true</tt> if this map contains a mapping for the specified
     * key.  More formally, returns <tt>true</tt> if and only if
     * this map contains a mapping for a key <tt>k</tt> such that
     * <tt>(key==null ? k==null : key.equals(k))</tt>.  (There can be
     * at most one such mapping.)
     *
     * @param key key whose presence in this map is to be tested
     * @return <tt>true</tt> if this map contains a mapping for the specified
     *         key
     * @throws ClassCastException if the key is of an inappropriate type for
     *         this map
     * @throws NullPointerException if the specified key is null and this map
     *         does not permit null keys
     */
    boolean containsKey(K key);

    /**
     * Returns a {@link Set} view of the keys contained in this map.
     * The set is backed by the map, so changes to the map are
     * reflected in the set, and vice-versa.  If the map is modified
     * while an iteration over the set is in progress (except through
     * the iterator's own <tt>remove</tt> operation), the results of
     * the iteration are undefined.  The set supports element removal,
     * which removes the corresponding mapping from the map, via the
     * <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
     * <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
     * operations.  It does not support the <tt>add</tt> or <tt>addAll</tt>
     * operations.
     *
     * @return a set view of the keys contained in this map
     */
    Set<K> keySet();

    /**
     * Returns a {@link Collection} view of the values contained in this map.
     * The collection is backed by the map, so changes to the map are
     * reflected in the collection, and vice-versa.  If the map is
     * modified while an iteration over the collection is in progress
     * (except through the iterator's own <tt>remove</tt> operation),
     * the results of the iteration are undefined.  The collection
     * supports element removal, which removes the corresponding
     * mapping from the map, via the <tt>Iterator.remove</tt>,
     * <tt>Collection.remove</tt>, <tt>removeAll</tt>,
     * <tt>retainAll</tt> and <tt>clear</tt> operations.  It does not
     * support the <tt>add</tt> or <tt>addAll</tt> operations.
     *
     * @return a collection view of the values contained in this map
     */
    Collection<V> values();

    /**
     * Returns <tt>true</tt> if this map contains no key-value mappings.
     *
     * @return <tt>true</tt> if this map contains no key-value mappings
     */
    boolean isEmpty();

    /**
     * Removes the mapping for a key from this map if it is present
     * (optional operation).   More formally, if this map contains a mapping
     * from key <tt>k</tt> to value <tt>v</tt> such that
     * <code>(key==null ?  k==null : key.equals(k))</code>, that mapping
     * is removed.  (The map can contain at most one such mapping.)
     *
     * @param key key whose mapping is to be removed from the map
     * @return the previous value associated with <tt>key</tt>, or
     *         <tt>null</tt> if there was no mapping for <tt>key</tt>.
     * @throws UnsupportedOperationException if the <tt>remove</tt> operation
     *         is not supported by this map
     * @throws ClassCastException if the key is of an inappropriate type for
     *         this map
     * @throws NullPointerException if the specified key is null and this
     *         map does not permit null keys
     */
    V remove(K key);

    /**
     * Returns the number of key-value mappings in this map.  If the
     * map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
     * <tt>Integer.MAX_VALUE</tt>.
     *
     * @return the number of key-value mappings in this map
     */
    int size();
}