| /* |
| * 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.tephra.persist; |
| |
| import org.apache.hadoop.io.LongWritable; |
| import org.apache.hadoop.io.SequenceFile; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.io.EOFException; |
| import java.io.IOException; |
| |
| /** |
| * {@link TransactionLogReader} that can read v1 (default) version of Transaction logs. The logs are expected to |
| * have a sequence of {@link TransactionEdit}s. |
| */ |
| public class HDFSTransactionLogReaderV1 implements TransactionLogReader { |
| private static final Logger LOG = LoggerFactory.getLogger(HDFSTransactionLogReaderV1.class); |
| private final SequenceFile.Reader reader; |
| private final LongWritable key; |
| private boolean closed; |
| |
| public HDFSTransactionLogReaderV1(SequenceFile.Reader reader) { |
| this.reader = reader; |
| this.key = new LongWritable(); |
| } |
| |
| @Override |
| public TransactionEdit next() throws IOException { |
| return next(new TransactionEdit()); |
| } |
| |
| @Override |
| public TransactionEdit next(TransactionEdit reuse) throws IOException { |
| if (closed) { |
| return null; |
| } |
| |
| try { |
| co.cask.tephra.persist.TransactionEdit oldTxEdit = new co.cask.tephra.persist.TransactionEdit(); |
| boolean successful = reader.next(key, oldTxEdit); |
| return successful ? TransactionEdit.convertCaskTxEdit(oldTxEdit) : null; |
| } catch (EOFException e) { |
| LOG.warn("Hit an unexpected EOF while trying to read the Transaction Edit. Skipping the entry.", e); |
| return null; |
| } |
| } |
| |
| @Override |
| public void close() throws IOException { |
| if (closed) { |
| return; |
| } |
| reader.close(); |
| closed = true; |
| } |
| } |