/**
    * 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.compactions;
  
  import java.io.IOException;
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.regionserver.InternalScanner;
  import org.apache.hadoop.hbase.regionserver.ScanType;
  import org.apache.hadoop.hbase.regionserver.Store;
  import org.apache.hadoop.hbase.regionserver.StoreFileScanner;
  import org.apache.hadoop.hbase.regionserver.StripeMultiFileWriter;
  import org.apache.hadoop.hbase.regionserver.throttle.ThroughputController;
  import org.apache.hadoop.hbase.security.User;
  import org.apache.hadoop.hbase.util.Bytes;
  
  /**
   * This is the placeholder for stripe compactor. The implementation, as well as the proper javadoc,
   * will be added in HBASE-7967.
   */
  @InterfaceAudience.Private
  public class StripeCompactor extends AbstractMultiOutputCompactor<StripeMultiFileWriter> {
    private static final Log LOG = LogFactory.getLog(StripeCompactor.class);
  
    public StripeCompactor(Configuration conf, Store store) {
      super(conf, store);
    }
  
    private final class StripeInternalScannerFactory implements InternalScannerFactory {
  
      private final byte[] majorRangeFromRow;
  
      private final byte[] majorRangeToRow;
  
      public StripeInternalScannerFactory(byte[] majorRangeFromRow, byte[] majorRangeToRow) {
        this.majorRangeFromRow = majorRangeFromRow;
        this.majorRangeToRow = majorRangeToRow;
      }
  
      @Override
      public ScanType getScanType(CompactionRequest request) {
        // If majorRangeFromRow and majorRangeToRow are not null, then we will not use the return
        // value to create InternalScanner. See the createScanner method below. The return value is
        // also used when calling coprocessor hooks.
        return ScanType.COMPACT_RETAIN_DELETES;
      }
  
      @Override
      public InternalScanner createScanner(List<StoreFileScanner> scanners, ScanType scanType,
          FileDetails fd, long smallestReadPoint) throws IOException {
        return (majorRangeFromRow == null)
            ? StripeCompactor.this.createScanner(store, scanners, scanType, smallestReadPoint,
              fd.earliestPutTs)
            : StripeCompactor.this.createScanner(store, scanners, smallestReadPoint, fd.earliestPutTs,
              majorRangeFromRow, majorRangeToRow);
      }
    }
  
    public List<Path> compact(CompactionRequest request, final List<byte[]> targetBoundaries,
        final byte[] majorRangeFromRow, final byte[] majorRangeToRow,
        ThroughputController throughputController, User user) throws IOException {
      if (LOG.isDebugEnabled()) {
        StringBuilder sb = new StringBuilder();
        sb.append("Executing compaction with " + targetBoundaries.size() + " boundaries:");
        for (byte[] tb : targetBoundaries) {
          sb.append(" [").append(Bytes.toString(tb)).append("]");
        }
        LOG.debug(sb.toString());
      }
      return compact(request, new StripeInternalScannerFactory(majorRangeFromRow, majorRangeToRow),
        new CellSinkFactory<StripeMultiFileWriter>() {
  
          @Override
          public StripeMultiFileWriter createWriter(InternalScanner scanner, FileDetails fd,
              boolean shouldDropBehind) throws IOException {
            StripeMultiFileWriter writer = new StripeMultiFileWriter.BoundaryMultiWriter(
                store.getComparator(), targetBoundaries, majorRangeFromRow, majorRangeToRow);
            initMultiWriter(writer, scanner, fd, shouldDropBehind);
            return writer;
         }
       }, throughputController, user);
   }
 
   public List<Path> compact(CompactionRequest request, final int targetCount, final long targetSize,
       final byte[] left, final byte[] right, byte[] majorRangeFromRow, byte[] majorRangeToRow,
       ThroughputController throughputController, User user) throws IOException {
     if (LOG.isDebugEnabled()) {
       LOG.debug(
         "Executing compaction with " + targetSize + " target file size, no more than " + targetCount
             + " files, in [" + Bytes.toString(left) + "] [" + Bytes.toString(right) + "] range");
     }
     return compact(request, new StripeInternalScannerFactory(majorRangeFromRow, majorRangeToRow),
       new CellSinkFactory<StripeMultiFileWriter>() {
 
         @Override
         public StripeMultiFileWriter createWriter(InternalScanner scanner, FileDetails fd,
             boolean shouldDropBehind) throws IOException {
           StripeMultiFileWriter writer = new StripeMultiFileWriter.SizeMultiWriter(
               store.getComparator(), targetCount, targetSize, left, right);
           initMultiWriter(writer, scanner, fd, shouldDropBehind);
           return writer;
         }
       }, throughputController, user);
   }
 
   @Override
   protected List<Path> commitWriter(StripeMultiFileWriter writer, FileDetails fd,
       CompactionRequest request) throws IOException {
     List<Path> newFiles = writer.commitWriters(fd.maxSeqId, request.isMajor(), request.getFiles());
     assert !newFiles.isEmpty() : "Should have produced an empty file to preserve metadata.";
     return newFiles;
   }
 }