001/*
002 * Copyright The Apache Software Foundation
003 *
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *     http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020package org.apache.hadoop.hbase.filter;
021
022import java.io.IOException;
023import java.util.List;
024
025import org.apache.hadoop.hbase.Cell;
026import org.apache.yetus.audience.InterfaceAudience;
027import org.apache.hadoop.hbase.exceptions.DeserializationException;
028import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
029import org.apache.hadoop.hbase.shaded.protobuf.generated.FilterProtos;
030import org.apache.hbase.thirdparty.com.google.protobuf.InvalidProtocolBufferException;
031
032/**
033 * This is a Filter wrapper class which is used in the server side. Some filter
034 * related hooks can be defined in this wrapper. The only way to create a
035 * FilterWrapper instance is passing a client side Filter instance through
036 * {@link org.apache.hadoop.hbase.client.Scan#getFilter()}.
037 *
038 */
039@InterfaceAudience.Private
040final public class FilterWrapper extends Filter {
041  Filter filter = null;
042
043  public FilterWrapper( Filter filter ) {
044    if (null == filter) {
045      // ensure the filter instance is not null
046      throw new NullPointerException("Cannot create FilterWrapper with null Filter");
047    }
048    this.filter = filter;
049  }
050
051  /**
052   * @return The filter serialized using pb
053   */
054  @Override
055  public byte[] toByteArray() throws IOException {
056    FilterProtos.FilterWrapper.Builder builder =
057      FilterProtos.FilterWrapper.newBuilder();
058    builder.setFilter(ProtobufUtil.toFilter(this.filter));
059    return builder.build().toByteArray();
060  }
061
062  /**
063   * @param pbBytes A pb serialized {@link FilterWrapper} instance
064   * @return An instance of {@link FilterWrapper} made from <code>bytes</code>
065   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
066   * @see #toByteArray
067   */
068  public static FilterWrapper parseFrom(final byte [] pbBytes)
069  throws DeserializationException {
070    FilterProtos.FilterWrapper proto;
071    try {
072      proto = FilterProtos.FilterWrapper.parseFrom(pbBytes);
073    } catch (InvalidProtocolBufferException e) {
074      throw new DeserializationException(e);
075    }
076    try {
077      return new FilterWrapper(ProtobufUtil.toFilter(proto.getFilter()));
078    } catch (IOException ioe) {
079      throw new DeserializationException(ioe);
080    }
081  }
082
083  @Override
084  public void reset() throws IOException {
085    this.filter.reset();
086  }
087
088  @Override
089  public boolean filterAllRemaining() throws IOException {
090    return this.filter.filterAllRemaining();
091  }
092
093  @Override
094  public boolean filterRow() throws IOException {
095    return this.filter.filterRow();
096  }
097
098  @Override
099  public Cell getNextCellHint(Cell currentCell) throws IOException {
100    return this.filter.getNextCellHint(currentCell);
101  }
102
103  @Override
104  public boolean filterRowKey(byte[] buffer, int offset, int length) throws IOException {
105    // No call to this.
106    if (filterAllRemaining()) return true;
107    return this.filter.filterRowKey(buffer, offset, length);
108  }
109
110  @Override
111  public boolean filterRowKey(Cell cell) throws IOException {
112    if (filterAllRemaining()) return true;
113    return this.filter.filterRowKey(cell);
114  }
115
116  @Deprecated
117  @Override
118  public ReturnCode filterKeyValue(final Cell c) throws IOException {
119    return filterCell(c);
120  }
121
122  @Override
123  public ReturnCode filterCell(final Cell c) throws IOException {
124    return this.filter.filterCell(c);
125  }
126
127  @Override
128  public Cell transformCell(Cell v) throws IOException {
129    return this.filter.transformCell(v);
130  }
131
132  @Override
133  public boolean hasFilterRow() {
134    return this.filter.hasFilterRow();
135  }
136
137  @Override
138  public void filterRowCells(List<Cell> kvs) throws IOException {
139    filterRowCellsWithRet(kvs);
140  }
141
142  public enum FilterRowRetCode {
143    NOT_CALLED,
144    INCLUDE,     // corresponds to filter.filterRow() returning false
145    EXCLUDE,     // corresponds to filter.filterRow() returning true
146    INCLUDE_THIS_FAMILY  // exclude other families
147  }
148  public FilterRowRetCode filterRowCellsWithRet(List<Cell> kvs) throws IOException {
149    //To fix HBASE-6429,
150    //Filter with filterRow() returning true is incompatible with scan with limit
151    //1. hasFilterRow() returns true, if either filterRow() or filterRow(kvs) is implemented.
152    //2. filterRow() is merged with filterRow(kvs),
153    //so that to make all those row related filtering stuff in the same function.
154    this.filter.filterRowCells(kvs);
155    if (!kvs.isEmpty()) {
156      if (this.filter.filterRow()) {
157        kvs.clear();
158        return FilterRowRetCode.EXCLUDE;
159      }
160      return FilterRowRetCode.INCLUDE;
161    }
162    return FilterRowRetCode.NOT_CALLED;
163  }
164
165  @Override
166  public boolean isFamilyEssential(byte[] name) throws IOException {
167    return filter.isFamilyEssential(name);
168  }
169
170  /**
171   * @param o the other filter to compare with
172   * @return true if and only if the fields of the filter that are serialized
173   * are equal to the corresponding fields in other.  Used for testing.
174   */
175  @Override
176  boolean areSerializedFieldsEqual(Filter o) {
177    if (o == this) return true;
178    if (!(o instanceof FilterWrapper)) return false;
179
180    FilterWrapper other = (FilterWrapper)o;
181    return this.filter.areSerializedFieldsEqual(other.filter);
182  }
183}