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;
019
020import java.io.IOException;
021import java.util.ArrayList;
022import java.util.Collection;
023import java.util.Collections;
024import java.util.List;
025import org.apache.hadoop.fs.Path;
026import org.apache.yetus.audience.InterfaceAudience;
027import org.slf4j.Logger;
028import org.slf4j.LoggerFactory;
029
030/**
031 * Base class for cell sink that separates the provided cells into multiple files.
032 */
033@InterfaceAudience.Private
034public abstract class AbstractMultiFileWriter implements CellSink, ShipperListener {
035
036  private static final Logger LOG = LoggerFactory.getLogger(AbstractMultiFileWriter.class);
037
038  /** Factory that is used to produce single StoreFile.Writer-s */
039  protected WriterFactory writerFactory;
040
041  /** Source scanner that is tracking KV count; may be null if source is not StoreScanner */
042  protected StoreScanner sourceScanner;
043
044  public interface WriterFactory {
045    public StoreFileWriter createWriter() throws IOException;
046
047    default StoreFileWriter createWriterWithStoragePolicy(String fileStoragePolicy)
048      throws IOException {
049      return createWriter();
050    };
051  }
052
053  /**
054   * Initializes multi-writer before usage.
055   * @param sourceScanner Optional store scanner to obtain the information about read progress.
056   * @param factory       Factory used to produce individual file writers.
057   */
058  public void init(StoreScanner sourceScanner, WriterFactory factory) {
059    this.writerFactory = factory;
060    this.sourceScanner = sourceScanner;
061  }
062
063  /**
064   * Commit all writers.
065   * <p>
066   * Notice that here we use the same <code>maxSeqId</code> for all output files since we haven't
067   * find an easy to find enough sequence ids for different output files in some corner cases. See
068   * comments in HBASE-15400 for more details.
069   */
070  public List<Path> commitWriters(long maxSeqId, boolean majorCompaction) throws IOException {
071    return commitWriters(maxSeqId, majorCompaction, Collections.emptyList());
072  }
073
074  public List<Path> commitWriters(long maxSeqId, boolean majorCompaction,
075    Collection<HStoreFile> storeFiles) throws IOException {
076    preCommitWriters();
077    Collection<StoreFileWriter> writers = this.writers();
078    if (LOG.isDebugEnabled()) {
079      LOG.debug("Commit " + writers.size() + " writers, maxSeqId=" + maxSeqId + ", majorCompaction="
080        + majorCompaction);
081    }
082    List<Path> paths = new ArrayList<>();
083    for (StoreFileWriter writer : writers) {
084      if (writer == null) {
085        continue;
086      }
087      writer.appendMetadata(maxSeqId, majorCompaction, storeFiles);
088      preCloseWriter(writer);
089      paths.add(writer.getPath());
090      writer.close();
091    }
092    return paths;
093  }
094
095  /**
096   * Close all writers without throwing any exceptions. This is used when compaction failed usually.
097   */
098  public List<Path> abortWriters() {
099    List<Path> paths = new ArrayList<>();
100    for (StoreFileWriter writer : writers()) {
101      try {
102        if (writer != null) {
103          paths.add(writer.getPath());
104          writer.close();
105        }
106      } catch (Exception ex) {
107        LOG.error("Failed to close the writer after an unfinished compaction.", ex);
108      }
109    }
110    return paths;
111  }
112
113  protected abstract Collection<StoreFileWriter> writers();
114
115  /**
116   * Subclasses override this method to be called at the end of a successful sequence of append; all
117   * appends are processed before this method is called.
118   */
119  protected void preCommitWriters() throws IOException {
120  }
121
122  /**
123   * Subclasses override this method to be called before we close the give writer. Usually you can
124   * append extra metadata to the writer.
125   */
126  protected void preCloseWriter(StoreFileWriter writer) throws IOException {
127  }
128
129  @Override
130  public void beforeShipped() throws IOException {
131    Collection<StoreFileWriter> writers = writers();
132    if (writers != null) {
133      for (StoreFileWriter writer : writers) {
134        if (writer != null) {
135          writer.beforeShipped();
136        }
137      }
138    }
139  }
140}