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.filter;
019
020import java.io.IOException;
021import java.util.Objects;
022import org.apache.hadoop.hbase.Cell;
023import org.apache.hadoop.hbase.exceptions.DeserializationException;
024import org.apache.yetus.audience.InterfaceAudience;
025
026import org.apache.hbase.thirdparty.com.google.protobuf.InvalidProtocolBufferException;
027
028import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
029import org.apache.hadoop.hbase.shaded.protobuf.generated.FilterProtos;
030
031/**
032 * A wrapper filter that filters an entire row if any of the Cell checks do not pass.
033 * <p>
034 * For example, if all columns in a row represent weights of different things, with the values being
035 * the actual weights, and we want to filter out the entire row if any of its weights are zero. In
036 * this case, we want to prevent rows from being emitted if a single key is filtered. Combine this
037 * filter with a {@link ValueFilter}:
038 * </p>
039 * <p>
040 * <code>
041 * scan.setFilter(new SkipFilter(new ValueFilter(CompareOp.NOT_EQUAL,
042 *     new BinaryComparator(Bytes.toBytes(0))));
043 * </code> Any row which contained a column whose value was 0 will be filtered out (since
044 * ValueFilter will not pass that Cell). Without this filter, the other non-zero valued columns in
045 * the row would still be emitted.
046 * </p>
047 */
048@InterfaceAudience.Public
049public class SkipFilter extends FilterBase {
050  private boolean filterRow = false;
051  private Filter filter;
052
053  public SkipFilter(Filter filter) {
054    this.filter = filter;
055  }
056
057  public Filter getFilter() {
058    return filter;
059  }
060
061  @Override
062  public void reset() throws IOException {
063    filter.reset();
064    filterRow = false;
065  }
066
067  private void changeFR(boolean value) {
068    filterRow = filterRow || value;
069  }
070
071  @Override
072  public boolean filterRowKey(Cell cell) throws IOException {
073    // Impl in FilterBase might do unnecessary copy for Off heap backed Cells.
074    return false;
075  }
076
077  @Override
078  public ReturnCode filterCell(final Cell c) throws IOException {
079    ReturnCode rc = filter.filterCell(c);
080    changeFR(rc != ReturnCode.INCLUDE);
081    return rc;
082  }
083
084  @Override
085  public Cell transformCell(Cell v) throws IOException {
086    return filter.transformCell(v);
087  }
088
089  @Override
090  public boolean filterRow() {
091    return filterRow;
092  }
093
094  @Override
095  public boolean hasFilterRow() {
096    return true;
097  }
098
099  /**
100   * @return The filter serialized using pb
101   */
102  @Override
103  public byte[] toByteArray() throws IOException {
104    FilterProtos.SkipFilter.Builder builder = FilterProtos.SkipFilter.newBuilder();
105    builder.setFilter(ProtobufUtil.toFilter(this.filter));
106    return builder.build().toByteArray();
107  }
108
109  /**
110   * @param pbBytes A pb serialized {@link SkipFilter} instance
111   * @return An instance of {@link SkipFilter} made from <code>bytes</code> n * @see #toByteArray
112   */
113  public static SkipFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
114    FilterProtos.SkipFilter proto;
115    try {
116      proto = FilterProtos.SkipFilter.parseFrom(pbBytes);
117    } catch (InvalidProtocolBufferException e) {
118      throw new DeserializationException(e);
119    }
120    try {
121      return new SkipFilter(ProtobufUtil.toFilter(proto.getFilter()));
122    } catch (IOException ioe) {
123      throw new DeserializationException(ioe);
124    }
125  }
126
127  /**
128   * @param o the other filter to compare with
129   * @return true if and only if the fields of the filter that are serialized are equal to the
130   *         corresponding fields in other. Used for testing.
131   */
132  @Override
133  boolean areSerializedFieldsEqual(Filter o) {
134    if (o == this) return true;
135    if (!(o instanceof SkipFilter)) return false;
136
137    SkipFilter other = (SkipFilter) o;
138    return getFilter().areSerializedFieldsEqual(other.getFilter());
139  }
140
141  @Override
142  public boolean isFamilyEssential(byte[] name) throws IOException {
143    return filter.isFamilyEssential(name);
144  }
145
146  @Override
147  public String toString() {
148    return this.getClass().getSimpleName() + " " + this.filter.toString();
149  }
150
151  @Override
152  public boolean equals(Object obj) {
153    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
154  }
155
156  @Override
157  public int hashCode() {
158    return Objects.hash(this.filter);
159  }
160}