| /* |
| * 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.ambari.server.state; |
| |
| import java.util.List; |
| |
| /** |
| * The {@link RepositoryVersionState} represents the state of a repository on a |
| * particular host. Because hosts can contain a mixture of components from |
| * different repositories, there can be any combination of |
| * {@link RepositoryVersionState#CURRENT}} entries for a single host. A host may |
| * not have multiple entries for the same repository. |
| * <p/> |
| * |
| * |
| * <pre> |
| * Step 1: Initial Configuration |
| * Version 1 is CURRENT |
| * |
| * Step 2: Add another repository and trigger distributing repositories/installing packages |
| * Version 1: CURRENT |
| * Version 2: INSTALLING |
| * |
| * Step 3: distributing repositories/installing packages action finishes successfully or fails |
| * Version 1: CURRENT |
| * Version 2: INSTALLED |
| * |
| * or |
| * |
| * Version 1: CURRENT |
| * Version 2: INSTALL_FAILED (a retry can set this back to INSTALLING) |
| * |
| * Step 4: Perform an upgrade of every component on the host from version 1 to version 2 |
| * Version 1: INSTALLED |
| * Version 2: CURRENT |
| * |
| * Step 4a: Perform an upgrade of a single component, leaving other components on the prior version |
| * Version 1: CURRENT |
| * Version 2: CURRENT |
| * |
| * Step 4b: May revert to the original version via a downgrade, which is technically still an upgrade to a version |
| * and eventually becomes |
| * |
| * Version 1: CURRENT |
| * Version 2: INSTALLED |
| * |
| * ********************************************* |
| * Start states: NOT_REQUIRED, INSTALLING, CURRENT |
| * Allowed Transitions: |
| * INSTALLED -> CURRENT |
| * INSTALLING -> INSTALLED | INSTALL_FAILED | OUT_OF_SYNC |
| * INSTALLED -> INSTALLED | INSTALLING | OUT_OF_SYNC |
| * OUT_OF_SYNC -> INSTALLING |
| * INSTALL_FAILED -> INSTALLING |
| * CURRENT -> INSTALLED |
| * </pre> |
| */ |
| public enum RepositoryVersionState { |
| /** |
| * Repository version is not required |
| */ |
| NOT_REQUIRED(0), |
| |
| /** |
| * Repository version that is in the process of being installed. |
| */ |
| INSTALLING(3), |
| |
| /** |
| * Repository version that is installed and supported but not the active version. |
| */ |
| INSTALLED(2), |
| |
| /** |
| * Repository version that during the install process failed to install some components. |
| */ |
| INSTALL_FAILED(5), |
| |
| /** |
| * Repository version that is installed for some components but not for all. |
| */ |
| OUT_OF_SYNC(4), |
| |
| /** |
| * Repository version that is installed and supported and is the active version. |
| */ |
| CURRENT(1); |
| |
| private final int weight; |
| |
| /** |
| * Constructor. |
| * |
| * @param weight |
| * the weight of the state. |
| */ |
| private RepositoryVersionState(int weight) { |
| this.weight = weight; |
| } |
| |
| /** |
| * Gets a single representation of the repository state based on the supplied |
| * states. |
| * |
| * @param states |
| * the states to calculate the aggregate for. |
| * @return the "heaviest" state. |
| */ |
| public static RepositoryVersionState getAggregateState(List<RepositoryVersionState> states) { |
| if (null == states || states.isEmpty()) { |
| return NOT_REQUIRED; |
| } |
| |
| RepositoryVersionState heaviestState = states.get(0); |
| for (RepositoryVersionState state : states) { |
| if (state.weight > heaviestState.weight) { |
| heaviestState = state; |
| } |
| } |
| |
| return heaviestState; |
| } |
| |
| } |