fapifta commented on a change in pull request #1456: URL: https://github.com/apache/hadoop-ozone/pull/1456#discussion_r498861508
########## File path: hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/upgrade/OMUpgradeFinalizer.java ########## @@ -0,0 +1,303 @@ +/** + * 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.hadoop.ozone.om.upgrade; + +import org.apache.hadoop.ozone.om.OzoneManager; +import org.apache.hadoop.ozone.om.exceptions.OMException; +import org.apache.hadoop.ozone.om.exceptions.OMException.ResultCodes; +import org.apache.hadoop.ozone.upgrade.UpgradeFinalizer; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.List; +import java.util.Queue; +import java.util.concurrent.Callable; +import java.util.concurrent.ConcurrentLinkedQueue; + +import static org.apache.hadoop.ozone.om.exceptions.OMException.ResultCodes.INVALID_REQUEST; +import static org.apache.hadoop.ozone.om.exceptions.OMException.ResultCodes.PERSIST_UPGRADE_TO_LAYOUT_VERSION_FAILED; +import static org.apache.hadoop.ozone.om.exceptions.OMException.ResultCodes.REMOVE_UPGRADE_TO_LAYOUT_VERSION_FAILED; +import static org.apache.hadoop.ozone.om.exceptions.OMException.ResultCodes.UPDATE_LAYOUT_VERSION_FAILED; +import static org.apache.hadoop.ozone.upgrade.UpgradeFinalizer.Status.ALREADY_FINALIZED; +import static org.apache.hadoop.ozone.upgrade.UpgradeFinalizer.Status.FINALIZATION_DONE; +import static org.apache.hadoop.ozone.upgrade.UpgradeFinalizer.Status.FINALIZATION_IN_PROGRESS; +import static org.apache.hadoop.ozone.upgrade.UpgradeFinalizer.Status.FINALIZATION_REQUIRED; + +/** + * UpgradeFinalizer implementation for the Ozone Manager service. + */ +public class OMUpgradeFinalizer implements UpgradeFinalizer<OzoneManager> { + + private Status status = ALREADY_FINALIZED; + private OMLayoutVersionManagerImpl versionManager; + private String clientID; + + private Queue<String> msgs = new ConcurrentLinkedQueue<>(); + private boolean isDone = false; + + private static final OmUpgradeAction NOOP = a -> {}; Review comment: Ok, it turned out that if OMUpgradeAction has just one constants, that qualifies as a bad practice, as if an interface does contain just constants, that can have some disadvantages according to seemingly more clever ppl than me. :) I moved it back to OMUpgradeFinalizer, as due to the logic we need to preserve the OMUpgradeAction-ness of the NOOP to work well there, as we want to push OzoneManager instances to the executeAction, and the type system is against having a simple UpgradeAction as a NOOP. We can thin about adding this to OMLayoutFeature instead, but as we do not use it elsewhere at the moment, and because we use Optional and we provide just a null in case the finalize action is a noop, we do not need it elsewhere as it seems... An other approach can be an orElse(null), but with that we can even leave out the Optional in the OMLayoutFeature and LayoutFeature implementations/definitions, and instead checking if it is a NOOP, we can check for null. What do you think? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: ozone-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: ozone-issues-h...@hadoop.apache.org
