/**
    * 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.querymatcher;
  
  import java.io.IOException;
  
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.CellUtil;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.regionserver.DeleteTracker;
  import org.apache.hadoop.hbase.regionserver.ScanInfo;
  
  /**
   * Query matcher for stripe compaction if range drop deletes is used.
   */
  @InterfaceAudience.Private
  public class StripeCompactionScanQueryMatcher extends DropDeletesCompactionScanQueryMatcher {
  
    private final byte[] dropDeletesFromRow;
  
    private final byte[] dropDeletesToRow;
  
    private enum DropDeletesInOutput {
      BEFORE, IN, AFTER
    }
  
    private DropDeletesInOutput dropDeletesInOutput = DropDeletesInOutput.BEFORE;
  
    public StripeCompactionScanQueryMatcher(ScanInfo scanInfo, DeleteTracker deletes,
        long readPointToUse, long earliestPutTs, long oldestUnexpiredTS, long now,
        byte[] dropDeletesFromRow, byte[] dropDeletesToRow) {
      super(scanInfo, deletes, readPointToUse, earliestPutTs, oldestUnexpiredTS, now);
      this.dropDeletesFromRow = dropDeletesFromRow;
      this.dropDeletesToRow = dropDeletesToRow;
    }
  
    @Override
    public MatchCode match(Cell cell) throws IOException {
      MatchCode returnCode = preCheck(cell);
      if (returnCode != null) {
        return returnCode;
      }
      long mvccVersion = cell.getSequenceId();
      byte typeByte = cell.getTypeByte();
      if (CellUtil.isDelete(typeByte)) {
        if (mvccVersion > maxReadPointToTrackVersions) {
          return MatchCode.INCLUDE;
        }
        trackDelete(cell);
        if (dropDeletesInOutput == DropDeletesInOutput.IN) {
          // here we are running like major compaction
          trackDelete(cell);
          returnCode = tryDropDelete(cell);
          if (returnCode != null) {
            return returnCode;
          }
        } else {
          return MatchCode.INCLUDE;
        }
      } else {
        returnCode = checkDeleted(deletes, cell);
        if (returnCode != null) {
          return returnCode;
        }
      }
      // Skip checking column since we do not remove column during compaction.
      return columns.checkVersions(cell.getQualifierArray(), cell.getQualifierOffset(),
        cell.getQualifierLength(), cell.getTimestamp(), typeByte,
        mvccVersion > maxReadPointToTrackVersions);
    }
  
    private boolean entered() {
      return dropDeletesFromRow.length == 0 || rowComparator.compareRows(currentRow,
        dropDeletesFromRow, 0, dropDeletesFromRow.length) >= 0;
    }
  
    private boolean left() {
      return dropDeletesToRow.length > 0
          && rowComparator.compareRows(currentRow, dropDeletesToRow, 0, dropDeletesToRow.length) >= 0;
    }
  
    @Override
    protected void reset() {
      super.reset();
     // Check if we are about to enter or leave the drop deletes range.
     switch (dropDeletesInOutput) {
       case BEFORE:
         if (entered()) {
           if (left()) {
             // Already out of range, which means there are no rows within the range.
             dropDeletesInOutput = DropDeletesInOutput.AFTER;
           } else {
             dropDeletesInOutput = DropDeletesInOutput.IN;
           }
         }
         break;
       case IN:
         if (left()) {
           dropDeletesInOutput = DropDeletesInOutput.AFTER;
         }
         break;
       default:
         break;
     }
   }
 }