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.CellComparator;
023import org.apache.hadoop.hbase.ExtendedCell;
024import org.apache.hadoop.hbase.io.hfile.HFile;
025import org.apache.yetus.audience.InterfaceAudience;
026
027/**
028 * The bloom context that is used by the StorefileWriter to add the bloom details per cell
029 */
030@InterfaceAudience.Private
031public abstract class BloomContext {
032
033  protected BloomFilterWriter bloomFilterWriter;
034  protected CellComparator comparator;
035
036  public BloomContext(BloomFilterWriter bloomFilterWriter, CellComparator comparator) {
037    this.bloomFilterWriter = bloomFilterWriter;
038    this.comparator = comparator;
039  }
040
041  public Cell getLastCell() {
042    return this.bloomFilterWriter.getPrevCell();
043  }
044
045  /**
046   * Bloom information from the cell is retrieved
047   */
048  public void writeBloom(ExtendedCell cell) throws IOException {
049    // only add to the bloom filter on a new, unique key
050    if (isNewKey(cell)) {
051      sanityCheck(cell);
052      bloomFilterWriter.append(cell);
053    }
054  }
055
056  private void sanityCheck(ExtendedCell cell) throws IOException {
057    if (this.getLastCell() != null) {
058      if (comparator.compare(cell, this.getLastCell()) <= 0) {
059        throw new IOException("Added a key not lexically larger than" + " previous. Current cell = "
060          + cell + ", prevCell = " + this.getLastCell());
061      }
062    }
063  }
064
065  /**
066   * Adds the last bloom key to the HFile Writer as part of StorefileWriter close.
067   */
068  public abstract void addLastBloomKey(HFile.Writer writer) throws IOException;
069
070  /**
071   * Returns true if the cell is a new key as per the bloom type
072   * @param cell the cell to be verified
073   * @return true if a new key else false
074   */
075  protected abstract boolean isNewKey(ExtendedCell cell);
076}