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.util;
019
020import java.io.IOException;
021import org.apache.hadoop.hbase.Cell;
022import org.apache.hadoop.hbase.CellBuilderType;
023import org.apache.hadoop.hbase.CellComparator;
024import org.apache.hadoop.hbase.CellUtil;
025import org.apache.hadoop.hbase.ExtendedCellBuilderFactory;
026import org.apache.yetus.audience.InterfaceAudience;
027
028/**
029 * Handles ROWPREFIX bloom related context. It works with both ByteBufferedCell and byte[] backed
030 * cells
031 */
032@InterfaceAudience.Private
033public class RowPrefixFixedLengthBloomContext extends RowBloomContext {
034  private final int prefixLength;
035
036  public RowPrefixFixedLengthBloomContext(BloomFilterWriter bloomFilterWriter,
037    CellComparator comparator, int prefixLength) {
038    super(bloomFilterWriter, comparator);
039    this.prefixLength = prefixLength;
040  }
041
042  public void writeBloom(Cell cell) throws IOException {
043    super.writeBloom(getRowPrefixCell(cell));
044  }
045
046  /**
047   * @param cell the cell
048   * @return the new cell created by row prefix
049   */
050  private Cell getRowPrefixCell(Cell cell) {
051    byte[] row = CellUtil.copyRow(cell);
052    return ExtendedCellBuilderFactory.create(CellBuilderType.DEEP_COPY)
053      .setRow(row, 0, Math.min(prefixLength, row.length)).setType(Cell.Type.Put).build();
054  }
055}