| /** |
| * 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.hdfs.server.namenode; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.concurrent.CountDownLatch; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory; |
| import org.apache.hadoop.hdfs.util.Canceler; |
| |
| import org.apache.hadoop.thirdparty.com.google.common.base.Preconditions; |
| |
| /** |
| * Context for an ongoing SaveNamespace operation. This class |
| * allows cancellation, and also is responsible for accumulating |
| * failed storage directories. |
| */ |
| @InterfaceAudience.Private |
| public class SaveNamespaceContext { |
| private final FSNamesystem sourceNamesystem; |
| private final long txid; |
| private final List<StorageDirectory> errorSDs = |
| Collections.synchronizedList(new ArrayList<StorageDirectory>()); |
| |
| private final Canceler canceller; |
| private final CountDownLatch completionLatch = new CountDownLatch(1); |
| |
| SaveNamespaceContext( |
| FSNamesystem sourceNamesystem, |
| long txid, |
| Canceler canceller) { |
| this.sourceNamesystem = sourceNamesystem; |
| this.txid = txid; |
| this.canceller = canceller; |
| } |
| |
| FSNamesystem getSourceNamesystem() { |
| return sourceNamesystem; |
| } |
| |
| long getTxId() { |
| return txid; |
| } |
| |
| void reportErrorOnStorageDirectory(StorageDirectory sd) { |
| errorSDs.add(sd); |
| } |
| |
| List<StorageDirectory> getErrorSDs() { |
| return errorSDs; |
| } |
| |
| void markComplete() { |
| Preconditions.checkState(completionLatch.getCount() == 1, |
| "Context already completed!"); |
| completionLatch.countDown(); |
| } |
| |
| public void checkCancelled() throws SaveNamespaceCancelledException { |
| if (canceller.isCancelled()) { |
| throw new SaveNamespaceCancelledException( |
| canceller.getCancellationReason()); |
| } |
| } |
| } |