001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020 package org.apache.directory.server.core.changelog; 021 022 023 024 /** 025 * A ChangeLogStore which allows tagging for tracking server state snapshots. 026 * At most one tag per revision can be created. There is no point to creating 027 * more than one tag on a revision in our case for snapshotting server state. 028 * 029 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 030 * @version $Rev$, $Date$ 031 */ 032 public interface TaggableChangeLogStore extends ChangeLogStore 033 { 034 /** 035 * Creates a tag for a snapshot of the server in a specific state at a revision. 036 * 037 * @param revision the revision to tag the snapshot 038 * @return the Tag associated with the revision 039 * @throws Exception if there is a problem taking a tag, or if 040 * the revision does not exist 041 */ 042 Tag tag( long revision ) throws Exception; 043 044 /** 045 * Creates a snapshot of the server at the current revision. 046 * 047 * @return the revision at which the tag is created 048 * @throws Exception if there is a problem taking a tag 049 */ 050 Tag tag() throws Exception; 051 052 /** 053 * Creates a snapshot of the server at the current revision with a description 054 * of the snapshot tag. 055 * 056 * @param description a description of the state associate with the tag 057 * @return the revision at which the tag is created 058 * @throws Exception if there is a problem taking a tag 059 */ 060 Tag tag( String description ) throws Exception; 061 062 063 /** 064 * Gets the latest tag if one was at all taken. 065 * 066 * @return the last tag to have been created (youngest), or null if no 067 * tags have been created 068 * @throws Exception on failures to access the tag store 069 */ 070 Tag getLatest() throws Exception; 071 072 073 /** 074 * Removes a Tag created for a given revision. 075 * 076 * @param revision the revision number that was tagged 077 * @return the removed tag, null if there is no Tag present with the given revision 078 * @throws Exception on failures to access the tag store 079 */ 080 Tag removeTag( long revision ) throws Exception; 081 082 /** 083 * Creates a tag with the given description for a snapshot of the server 084 * in a specific state at a revision. 085 * 086 * @param revision the revision number that was tagged 087 * @param descrition a description of the state associate with the tag 088 * @return the Tag associated with the revision 089 * @throws Exception on failures to access the tag store 090 */ 091 Tag tag( long revision, String descrition ) throws Exception; 092 }