| /** |
| * 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.hbase.regionserver; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.List; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.hbase.classification.InterfaceAudience; |
| import org.apache.hadoop.hbase.regionserver.compactions.Compactor.CellSink; |
| |
| /** |
| * Base class for cell sink that separates the provided cells into multiple files. |
| */ |
| @InterfaceAudience.Private |
| public abstract class AbstractMultiFileWriter implements CellSink { |
| |
| private static final Log LOG = LogFactory.getLog(AbstractMultiFileWriter.class); |
| |
| /** Factory that is used to produce single StoreFile.Writer-s */ |
| protected WriterFactory writerFactory; |
| |
| /** Source scanner that is tracking KV count; may be null if source is not StoreScanner */ |
| protected StoreScanner sourceScanner; |
| |
| public interface WriterFactory { |
| public StoreFileWriter createWriter() throws IOException; |
| } |
| |
| /** |
| * Initializes multi-writer before usage. |
| * @param sourceScanner Optional store scanner to obtain the information about read progress. |
| * @param factory Factory used to produce individual file writers. |
| */ |
| public void init(StoreScanner sourceScanner, WriterFactory factory) { |
| this.writerFactory = factory; |
| this.sourceScanner = sourceScanner; |
| } |
| |
| /** |
| * Commit all writers. |
| * <p> |
| * Notice that here we use the same <code>maxSeqId</code> for all output files since we haven't |
| * find an easy to find enough sequence ids for different output files in some corner cases. See |
| * comments in HBASE-15400 for more details. |
| */ |
| public List<Path> commitWriters(long maxSeqId, boolean majorCompaction) throws IOException { |
| preCommitWriters(); |
| Collection<StoreFileWriter> writers = this.writers(); |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("Commit " + writers.size() + " writers, maxSeqId=" + maxSeqId |
| + ", majorCompaction=" + majorCompaction); |
| } |
| List<Path> paths = new ArrayList<Path>(); |
| for (StoreFileWriter writer : writers) { |
| if (writer == null) { |
| continue; |
| } |
| writer.appendMetadata(maxSeqId, majorCompaction); |
| preCloseWriter(writer); |
| paths.add(writer.getPath()); |
| writer.close(); |
| } |
| return paths; |
| } |
| |
| /** |
| * Close all writers without throwing any exceptions. This is used when compaction failed usually. |
| */ |
| public List<Path> abortWriters() { |
| List<Path> paths = new ArrayList<Path>(); |
| for (StoreFileWriter writer : writers()) { |
| try { |
| if (writer != null) { |
| paths.add(writer.getPath()); |
| writer.close(); |
| } |
| } catch (Exception ex) { |
| LOG.error("Failed to close the writer after an unfinished compaction.", ex); |
| } |
| } |
| return paths; |
| } |
| |
| protected abstract Collection<StoreFileWriter> writers(); |
| |
| /** |
| * Subclasses override this method to be called at the end of a successful sequence of append; all |
| * appends are processed before this method is called. |
| */ |
| protected void preCommitWriters() throws IOException { |
| } |
| |
| /** |
| * Subclasses override this method to be called before we close the give writer. Usually you can |
| * append extra metadata to the writer. |
| */ |
| protected void preCloseWriter(StoreFileWriter writer) throws IOException { |
| } |
| } |