001/*
002 * (C) Copyright 2012 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Anahide Tchertchian
018 */
019package org.nuxeo.runtime.service;
020
021/**
022 * Interface for services that need to track when the resources they hold have been last modified.
023 * <p>
024 * This is useful to invalidate high-level cache when deploying components in hot reload.
025 *
026 * @since 5.6
027 */
028public interface TimestampedService {
029
030    /**
031     * Returns the last modification timestamp or null if unknown.
032     * <p>
033     * This method is useful for third-party code implementing caching on resources held by the component/service.
034     *
035     * @since 5.6
036     * @see #setLastModified(Long)
037     */
038    Long getLastModified();
039
040    /**
041     * Sets the last modified date.
042     * <p>
043     * This method is supposed to be called whenever the component/service resources or state changes.
044     *
045     * @since 5.6
046     * @see #getLastModified()
047     */
048    void setLastModified(Long lastModified);
049
050}