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, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018package org.apache.hadoop.hbase.regionserver.wal; 019 020import java.io.IOException; 021import org.apache.hadoop.hbase.wal.WALProvider.WriterBase; 022import org.apache.yetus.audience.InterfaceAudience; 023import org.slf4j.Logger; 024import org.slf4j.LoggerFactory; 025 026import org.apache.hbase.thirdparty.com.google.common.collect.ImmutableList; 027 028/** 029 * Base class for combined wal writer implementations. 030 */ 031@InterfaceAudience.Private 032public class CombinedWriterBase<T extends WriterBase> implements WriterBase { 033 034 private static final Logger LOG = LoggerFactory.getLogger(CombinedWriterBase.class); 035 036 // the order of this list is not critical now as we have already solved the case where writing to 037 // local succeed but remote fail, so implementation should implement concurrent sync to increase 038 // performance 039 protected final ImmutableList<T> writers; 040 041 protected CombinedWriterBase(ImmutableList<T> writers) { 042 this.writers = writers; 043 } 044 045 @Override 046 public void close() throws IOException { 047 Exception error = null; 048 for (T writer : writers) { 049 try { 050 writer.close(); 051 } catch (Exception e) { 052 LOG.warn("close writer failed", e); 053 if (error == null) { 054 error = e; 055 } 056 } 057 } 058 if (error != null) { 059 throw new IOException("Failed to close at least one writer, please see the warn log above. " 060 + "The cause is the first exception occurred", error); 061 } 062 } 063 064 @Override 065 public long getLength() { 066 return writers.get(0).getLength(); 067 } 068 069 @Override 070 public long getSyncedLength() { 071 return writers.get(0).getSyncedLength(); 072 } 073}