| /* |
| * 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.ignite.cache; |
| |
| import java.util.Set; |
| import javax.cache.Cache; |
| import javax.cache.processor.EntryProcessor; |
| import org.apache.ignite.IgniteCache; |
| |
| /** |
| * Cache entry that extends {@link javax.cache.Cache.Entry} by providing additional entry related information. |
| * <p> |
| * To get an instance of {@code CacheEntry} from {@link javax.cache.Cache.Entry} use |
| * {@link javax.cache.Cache.Entry#unwrap(Class)} method by passing {@code CacheEntry} class to it as the argument. |
| * <p> |
| * {@code CacheEntry} is supported only for {@link javax.cache.Cache.Entry} returned by one of the following methods: |
| * <ul> |
| * <li>{@link javax.cache.Cache#invoke(Object, EntryProcessor, Object...)}</li> |
| * <li>{@link javax.cache.Cache#invokeAll(Set, EntryProcessor, Object...)}</li> |
| * <li>invoke and invokeAll methods of {@link IgniteCache}</li> |
| * </ul> |
| * <p> |
| * To get an instance of {@code CacheEntry} directly use {@link IgniteCache#getEntry(Object)} or |
| * {@link IgniteCache#getEntries(Set)} methods. |
| * <p> |
| * {@code CacheEntry} is not supported for {@link javax.cache.Cache#iterator()} because of performance reasons. |
| * {@link javax.cache.Cache#iterator()} loads entries from all the cluster nodes and to speed up the load additional |
| * information, like entry's version, is ignored. |
| * |
| * <h2 class="header">Java Example</h2> |
| * <pre name="code" class="java"> |
| * IgniteCache<Integer, String> cache = grid(0).cache(null); |
| * |
| * CacheEntry<String, Integer> entry1 = cache.invoke(100, |
| * new EntryProcessor<Integer, String, CacheEntry<String, Integer>>() { |
| * public CacheEntry<String, Integer> process(MutableEntry<Integer, String> entry, |
| * Object... arguments) throws EntryProcessorException { |
| * return entry.unwrap(CacheEntry.class); |
| * } |
| * }); |
| * |
| * // Cache entry for the given key may be updated at some point later. |
| * |
| * CacheEntry<String, Integer> entry2 = cache.invoke(100, |
| * new EntryProcessor<Integer, String, CacheEntry<String, Integer>>() { |
| * public CacheEntry<String, Integer> process(MutableEntry<Integer, String> entry, |
| * Object... arguments) throws EntryProcessorException { |
| * return entry.unwrap(CacheEntry.class); |
| * } |
| * }); |
| * |
| * // Comparing entries' versions. |
| * if (entry1.version().compareTo(entry2.version()) < 0) { |
| * // the entry has been updated |
| * } |
| * </pre> |
| */ |
| public interface CacheEntry<K, V> extends Cache.Entry<K, V> { |
| /** |
| * Returns a comparable object representing the version of this cache entry. |
| * <p> |
| * It is valid to compare cache entries' versions for the same key. In this case the latter update will be |
| * represented by a higher version. The result of versions comparison of cache entries of different keys is |
| * undefined. |
| * |
| * @return Version of this cache entry. |
| */ |
| public Comparable version(); |
| } |