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.nio.ByteBuffer;
022import java.util.ArrayList;
023import java.util.Collections;
024import java.util.Iterator;
025import java.util.Objects;
026import java.util.Optional;
027import org.apache.hadoop.hbase.ByteBufferExtendedCell;
028import org.apache.hadoop.hbase.Cell;
029import org.apache.hadoop.hbase.HConstants;
030import org.apache.hadoop.hbase.KeyValue;
031import org.apache.hadoop.hbase.KeyValueUtil;
032import org.apache.hadoop.hbase.Tag;
033import org.apache.hadoop.hbase.exceptions.DeserializationException;
034import org.apache.hadoop.hbase.util.Bytes;
035import org.apache.hadoop.hbase.util.ClassSize;
036import org.apache.yetus.audience.InterfaceAudience;
037
038import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
039import org.apache.hbase.thirdparty.com.google.protobuf.InvalidProtocolBufferException;
040
041import org.apache.hadoop.hbase.shaded.protobuf.generated.FilterProtos;
042
043/**
044 * A filter that will only return the key component of each KV (the value will be rewritten as
045 * empty).
046 * <p>
047 * This filter can be used to grab all of the keys without having to also grab the values.
048 */
049@InterfaceAudience.Public
050public class KeyOnlyFilter extends FilterBase {
051
052  boolean lenAsVal;
053
054  public KeyOnlyFilter() {
055    this(false);
056  }
057
058  public KeyOnlyFilter(boolean lenAsVal) {
059    this.lenAsVal = lenAsVal;
060  }
061
062  @Override
063  public boolean filterRowKey(Cell cell) throws IOException {
064    // Impl in FilterBase might do unnecessary copy for Off heap backed Cells.
065    return false;
066  }
067
068  @Override
069  public Cell transformCell(Cell cell) {
070    return createKeyOnlyCell(cell);
071  }
072
073  private Cell createKeyOnlyCell(Cell c) {
074    if (c instanceof ByteBufferExtendedCell) {
075      return new KeyOnlyByteBufferExtendedCell((ByteBufferExtendedCell) c, lenAsVal);
076    } else {
077      return new KeyOnlyCell(c, lenAsVal);
078    }
079  }
080
081  @Override
082  public ReturnCode filterCell(final Cell ignored) throws IOException {
083    return ReturnCode.INCLUDE;
084  }
085
086  public static Filter createFilterFromArguments(ArrayList<byte[]> filterArguments) {
087    Preconditions.checkArgument((filterArguments.isEmpty() || filterArguments.size() == 1),
088      "Expected: 0 or 1 but got: %s", filterArguments.size());
089    KeyOnlyFilter filter = new KeyOnlyFilter();
090    if (filterArguments.size() == 1) {
091      filter.lenAsVal = ParseFilter.convertByteArrayToBoolean(filterArguments.get(0));
092    }
093    return filter;
094  }
095
096  /**
097   * @return The filter serialized using pb
098   */
099  @Override
100  public byte[] toByteArray() {
101    FilterProtos.KeyOnlyFilter.Builder builder = FilterProtos.KeyOnlyFilter.newBuilder();
102    builder.setLenAsVal(this.lenAsVal);
103    return builder.build().toByteArray();
104  }
105
106  /**
107   * @param pbBytes A pb serialized {@link KeyOnlyFilter} instance
108   * @return An instance of {@link KeyOnlyFilter} made from <code>bytes</code> n * @see #toByteArray
109   */
110  public static KeyOnlyFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
111    FilterProtos.KeyOnlyFilter proto;
112    try {
113      proto = FilterProtos.KeyOnlyFilter.parseFrom(pbBytes);
114    } catch (InvalidProtocolBufferException e) {
115      throw new DeserializationException(e);
116    }
117    return new KeyOnlyFilter(proto.getLenAsVal());
118  }
119
120  /**
121   * @param o the other filter to compare with
122   * @return true if and only if the fields of the filter that are serialized are equal to the
123   *         corresponding fields in other. Used for testing.
124   */
125  @Override
126  boolean areSerializedFieldsEqual(Filter o) {
127    if (o == this) return true;
128    if (!(o instanceof KeyOnlyFilter)) return false;
129
130    KeyOnlyFilter other = (KeyOnlyFilter) o;
131    return this.lenAsVal == other.lenAsVal;
132  }
133
134  @Override
135  public boolean equals(Object obj) {
136    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
137  }
138
139  @Override
140  public int hashCode() {
141    return Objects.hash(this.lenAsVal);
142  }
143
144  static class KeyOnlyCell implements Cell {
145    private Cell cell;
146    private int keyLen;
147    private boolean lenAsVal;
148
149    public KeyOnlyCell(Cell c, boolean lenAsVal) {
150      this.cell = c;
151      this.lenAsVal = lenAsVal;
152      this.keyLen = KeyValueUtil.keyLength(c);
153    }
154
155    @Override
156    public byte[] getRowArray() {
157      return cell.getRowArray();
158    }
159
160    @Override
161    public int getRowOffset() {
162      return cell.getRowOffset();
163    }
164
165    @Override
166    public short getRowLength() {
167      return cell.getRowLength();
168    }
169
170    @Override
171    public byte[] getFamilyArray() {
172      return cell.getFamilyArray();
173    }
174
175    @Override
176    public int getFamilyOffset() {
177      return cell.getFamilyOffset();
178    }
179
180    @Override
181    public byte getFamilyLength() {
182      return cell.getFamilyLength();
183    }
184
185    @Override
186    public byte[] getQualifierArray() {
187      return cell.getQualifierArray();
188    }
189
190    @Override
191    public int getQualifierOffset() {
192      return cell.getQualifierOffset();
193    }
194
195    @Override
196    public int getQualifierLength() {
197      return cell.getQualifierLength();
198    }
199
200    @Override
201    public long getTimestamp() {
202      return cell.getTimestamp();
203    }
204
205    @Override
206    public byte getTypeByte() {
207      return cell.getTypeByte();
208    }
209
210    @Override
211    public Type getType() {
212      return cell.getType();
213    }
214
215    @Override
216    public long getSequenceId() {
217      return 0;
218    }
219
220    @Override
221    public byte[] getValueArray() {
222      if (lenAsVal) {
223        return Bytes.toBytes(cell.getValueLength());
224      } else {
225        return HConstants.EMPTY_BYTE_ARRAY;
226      }
227    }
228
229    @Override
230    public int getValueOffset() {
231      return 0;
232    }
233
234    @Override
235    public int getValueLength() {
236      if (lenAsVal) {
237        return Bytes.SIZEOF_INT;
238      } else {
239        return 0;
240      }
241    }
242
243    @Override
244    public int getSerializedSize() {
245      return KeyValue.KEYVALUE_INFRASTRUCTURE_SIZE + keyLen + getValueLength();
246    }
247
248    @Override
249    public byte[] getTagsArray() {
250      return HConstants.EMPTY_BYTE_ARRAY;
251    }
252
253    @Override
254    public int getTagsOffset() {
255      return 0;
256    }
257
258    @Override
259    public int getTagsLength() {
260      return 0;
261    }
262
263    @Override
264    public long heapSize() {
265      return cell.heapSize();
266    }
267  }
268
269  static class KeyOnlyByteBufferExtendedCell extends ByteBufferExtendedCell {
270    public static final int FIXED_OVERHEAD =
271      ClassSize.OBJECT + ClassSize.REFERENCE + Bytes.SIZEOF_BOOLEAN;
272    private ByteBufferExtendedCell cell;
273    private boolean lenAsVal;
274
275    public KeyOnlyByteBufferExtendedCell(ByteBufferExtendedCell c, boolean lenAsVal) {
276      this.cell = c;
277      this.lenAsVal = lenAsVal;
278    }
279
280    @Override
281    public byte[] getRowArray() {
282      return cell.getRowArray();
283    }
284
285    @Override
286    public int getRowOffset() {
287      return cell.getRowOffset();
288    }
289
290    @Override
291    public short getRowLength() {
292      return cell.getRowLength();
293    }
294
295    @Override
296    public byte[] getFamilyArray() {
297      return cell.getFamilyArray();
298    }
299
300    @Override
301    public int getFamilyOffset() {
302      return cell.getFamilyOffset();
303    }
304
305    @Override
306    public byte getFamilyLength() {
307      return cell.getFamilyLength();
308    }
309
310    @Override
311    public byte[] getQualifierArray() {
312      return cell.getQualifierArray();
313    }
314
315    @Override
316    public int getQualifierOffset() {
317      return cell.getQualifierOffset();
318    }
319
320    @Override
321    public int getQualifierLength() {
322      return cell.getQualifierLength();
323    }
324
325    @Override
326    public long getTimestamp() {
327      return cell.getTimestamp();
328    }
329
330    @Override
331    public byte getTypeByte() {
332      return cell.getTypeByte();
333    }
334
335    @Override
336    public void setSequenceId(long seqId) throws IOException {
337      cell.setSequenceId(seqId);
338    }
339
340    @Override
341    public void setTimestamp(long ts) throws IOException {
342      cell.setTimestamp(ts);
343    }
344
345    @Override
346    public void setTimestamp(byte[] ts) throws IOException {
347      cell.setTimestamp(ts);
348    }
349
350    @Override
351    public long getSequenceId() {
352      return 0;
353    }
354
355    @Override
356    public Type getType() {
357      return cell.getType();
358    }
359
360    @Override
361    public byte[] getValueArray() {
362      if (lenAsVal) {
363        return Bytes.toBytes(cell.getValueLength());
364      } else {
365        return HConstants.EMPTY_BYTE_ARRAY;
366      }
367    }
368
369    @Override
370    public int getValueOffset() {
371      return 0;
372    }
373
374    @Override
375    public int getValueLength() {
376      if (lenAsVal) {
377        return Bytes.SIZEOF_INT;
378      } else {
379        return 0;
380      }
381    }
382
383    @Override
384    public byte[] getTagsArray() {
385      return HConstants.EMPTY_BYTE_ARRAY;
386    }
387
388    @Override
389    public int getTagsOffset() {
390      return 0;
391    }
392
393    @Override
394    public int getTagsLength() {
395      return 0;
396    }
397
398    @Override
399    public ByteBuffer getRowByteBuffer() {
400      return cell.getRowByteBuffer();
401    }
402
403    @Override
404    public int getRowPosition() {
405      return cell.getRowPosition();
406    }
407
408    @Override
409    public ByteBuffer getFamilyByteBuffer() {
410      return cell.getFamilyByteBuffer();
411    }
412
413    @Override
414    public int getFamilyPosition() {
415      return cell.getFamilyPosition();
416    }
417
418    @Override
419    public ByteBuffer getQualifierByteBuffer() {
420      return cell.getQualifierByteBuffer();
421    }
422
423    @Override
424    public int getQualifierPosition() {
425      return cell.getQualifierPosition();
426    }
427
428    @Override
429    public ByteBuffer getValueByteBuffer() {
430      if (lenAsVal) {
431        return ByteBuffer.wrap(Bytes.toBytes(cell.getValueLength()));
432      } else {
433        return HConstants.EMPTY_BYTE_BUFFER;
434      }
435    }
436
437    @Override
438    public int getValuePosition() {
439      return 0;
440    }
441
442    @Override
443    public ByteBuffer getTagsByteBuffer() {
444      return HConstants.EMPTY_BYTE_BUFFER;
445    }
446
447    @Override
448    public int getTagsPosition() {
449      return 0;
450    }
451
452    @Override
453    public Iterator<Tag> getTags() {
454      return Collections.emptyIterator();
455    }
456
457    @Override
458    public Optional<Tag> getTag(byte type) {
459      return Optional.empty();
460    }
461
462    @Override
463    public long heapSize() {
464      return ClassSize.align(FIXED_OVERHEAD + cell.heapSize());
465    }
466  }
467
468}