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.ArrayList; 022import java.util.Arrays; 023import java.util.Comparator; 024import java.util.List; 025import java.util.Objects; 026import java.util.PriorityQueue; 027import org.apache.hadoop.hbase.Cell; 028import org.apache.hadoop.hbase.CellComparator; 029import org.apache.hadoop.hbase.PrivateCellUtil; 030import org.apache.hadoop.hbase.exceptions.DeserializationException; 031import org.apache.hadoop.hbase.unsafe.HBasePlatformDependent; 032import org.apache.hadoop.hbase.util.Bytes; 033import org.apache.hadoop.hbase.util.Pair; 034import org.apache.yetus.audience.InterfaceAudience; 035 036import org.apache.hbase.thirdparty.com.google.protobuf.InvalidProtocolBufferException; 037import org.apache.hbase.thirdparty.com.google.protobuf.UnsafeByteOperations; 038 039import org.apache.hadoop.hbase.shaded.protobuf.generated.FilterProtos; 040import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos.BytesBytesPair; 041 042/** 043 * This is optimized version of a standard FuzzyRowFilter Filters data based on fuzzy row key. 044 * Performs fast-forwards during scanning. It takes pairs (row key, fuzzy info) to match row keys. 045 * Where fuzzy info is a byte array with 0 or 1 as its values: 046 * <ul> 047 * <li>0 - means that this byte in provided row key is fixed, i.e. row key's byte at same position 048 * must match</li> 049 * <li>1 - means that this byte in provided row key is NOT fixed, i.e. row key's byte at this 050 * position can be different from the one in provided row key</li> 051 * </ul> 052 * Example: 053 * <p/> 054 * Let's assume row key format is userId_actionId_year_month. Length of userId is fixed and is 4, 055 * length of actionId is 2 and year and month are 4 and 2 bytes long respectively. 056 * <p/> 057 * Let's assume that we need to fetch all users that performed certain action (encoded as "99") in 058 * Jan of any year. Then the pair (row key, fuzzy info) would be the following: 059 * 060 * <pre> 061 * row key = "????_99_????_01" (one can use any value instead of "?") 062 * fuzzy info = "\x01\x01\x01\x01\x00\x00\x00\x00\x01\x01\x01\x01\x00\x00\x00" 063 * </pre> 064 * 065 * I.e. fuzzy info tells the matching mask is "????_99_????_01", where at ? can be any value. 066 */ 067@InterfaceAudience.Public 068public class FuzzyRowFilter extends FilterBase { 069 private static final boolean UNSAFE_UNALIGNED = HBasePlatformDependent.unaligned(); 070 private List<Pair<byte[], byte[]>> fuzzyKeysData; 071 // Used to record whether we want to skip the current row. 072 // Usually we should use filterRowKey here but in the current scan implementation, if filterRowKey 073 // returns true, we will just skip to next row, instead of calling getNextCellHint to determine 074 // the actual next row, so we need to implement filterCell and return SEEK_NEXT_USING_HINT to let 075 // upper layer call getNextCellHint. 076 // And if we do not implement filterRow, sometimes we will get incorrect result when using 077 // FuzzyRowFilter together with other filters, please see the description for HBASE-26967 for more 078 // details. 079 private boolean filterRow; 080 private boolean done = false; 081 082 /** 083 * The index of a last successfully found matching fuzzy string (in fuzzyKeysData). We will start 084 * matching next KV with this one. If they do not match then we will return back to the one-by-one 085 * iteration over fuzzyKeysData. 086 */ 087 private int lastFoundIndex = -1; 088 089 /** 090 * Row tracker (keeps all next rows after SEEK_NEXT_USING_HINT was returned) 091 */ 092 private RowTracker tracker; 093 094 public FuzzyRowFilter(List<Pair<byte[], byte[]>> fuzzyKeysData) { 095 List<Pair<byte[], byte[]>> fuzzyKeyDataCopy = new ArrayList<>(fuzzyKeysData.size()); 096 097 for (Pair<byte[], byte[]> aFuzzyKeysData : fuzzyKeysData) { 098 if (aFuzzyKeysData.getFirst().length != aFuzzyKeysData.getSecond().length) { 099 Pair<String, String> readable = new Pair<>(Bytes.toStringBinary(aFuzzyKeysData.getFirst()), 100 Bytes.toStringBinary(aFuzzyKeysData.getSecond())); 101 throw new IllegalArgumentException("Fuzzy pair lengths do not match: " + readable); 102 } 103 104 Pair<byte[], byte[]> p = new Pair<>(); 105 // create a copy of pair bytes so that they are not modified by the filter. 106 p.setFirst(Arrays.copyOf(aFuzzyKeysData.getFirst(), aFuzzyKeysData.getFirst().length)); 107 p.setSecond(Arrays.copyOf(aFuzzyKeysData.getSecond(), aFuzzyKeysData.getSecond().length)); 108 109 // update mask ( 0 -> -1 (0xff), 1 -> 2) 110 p.setSecond(preprocessMask(p.getSecond())); 111 preprocessSearchKey(p); 112 113 fuzzyKeyDataCopy.add(p); 114 } 115 this.fuzzyKeysData = fuzzyKeyDataCopy; 116 this.tracker = new RowTracker(); 117 } 118 119 private void preprocessSearchKey(Pair<byte[], byte[]> p) { 120 if (!UNSAFE_UNALIGNED) { 121 // do nothing 122 return; 123 } 124 byte[] key = p.getFirst(); 125 byte[] mask = p.getSecond(); 126 for (int i = 0; i < mask.length; i++) { 127 // set non-fixed part of a search key to 0. 128 if (mask[i] == 2) { 129 key[i] = 0; 130 } 131 } 132 } 133 134 /** 135 * We need to preprocess mask array, as since we treat 2's as unfixed positions and -1 (0xff) as 136 * fixed positions 137 * @return mask array 138 */ 139 private byte[] preprocessMask(byte[] mask) { 140 if (!UNSAFE_UNALIGNED) { 141 // do nothing 142 return mask; 143 } 144 if (isPreprocessedMask(mask)) return mask; 145 for (int i = 0; i < mask.length; i++) { 146 if (mask[i] == 0) { 147 mask[i] = -1; // 0 -> -1 148 } else if (mask[i] == 1) { 149 mask[i] = 2;// 1 -> 2 150 } 151 } 152 return mask; 153 } 154 155 private boolean isPreprocessedMask(byte[] mask) { 156 for (int i = 0; i < mask.length; i++) { 157 if (mask[i] != -1 && mask[i] != 2) { 158 return false; 159 } 160 } 161 return true; 162 } 163 164 @Override 165 public void reset() throws IOException { 166 filterRow = false; 167 } 168 169 @Override 170 public boolean filterRow() throws IOException { 171 return filterRow; 172 } 173 174 @Override 175 public ReturnCode filterCell(final Cell c) { 176 final int startIndex = lastFoundIndex >= 0 ? lastFoundIndex : 0; 177 final int size = fuzzyKeysData.size(); 178 for (int i = startIndex; i < size + startIndex; i++) { 179 final int index = i % size; 180 Pair<byte[], byte[]> fuzzyData = fuzzyKeysData.get(index); 181 // This shift is idempotent - always end up with 0 and -1 as mask values. 182 for (int j = 0; j < fuzzyData.getSecond().length; j++) { 183 fuzzyData.getSecond()[j] >>= 2; 184 } 185 SatisfiesCode satisfiesCode = satisfies(isReversed(), c.getRowArray(), c.getRowOffset(), 186 c.getRowLength(), fuzzyData.getFirst(), fuzzyData.getSecond()); 187 if (satisfiesCode == SatisfiesCode.YES) { 188 lastFoundIndex = index; 189 return ReturnCode.INCLUDE; 190 } 191 } 192 // NOT FOUND -> seek next using hint 193 lastFoundIndex = -1; 194 filterRow = true; 195 return ReturnCode.SEEK_NEXT_USING_HINT; 196 197 } 198 199 @Override 200 public Cell getNextCellHint(Cell currentCell) { 201 boolean result = tracker.updateTracker(currentCell); 202 if (result == false) { 203 done = true; 204 return null; 205 } 206 byte[] nextRowKey = tracker.nextRow(); 207 return PrivateCellUtil.createFirstOnRow(nextRowKey, 0, (short) nextRowKey.length); 208 } 209 210 /** 211 * If we have multiple fuzzy keys, row tracker should improve overall performance. It calculates 212 * all next rows (one per every fuzzy key) and put them (the fuzzy key is bundled) into a priority 213 * queue so that the smallest row key always appears at queue head, which helps to decide the 214 * "Next Cell Hint". As scanning going on, the number of candidate rows in the RowTracker will 215 * remain the size of fuzzy keys until some of the fuzzy keys won't possibly have matches any 216 * more. 217 */ 218 private class RowTracker { 219 private final PriorityQueue<Pair<byte[], Pair<byte[], byte[]>>> nextRows; 220 private boolean initialized = false; 221 222 RowTracker() { 223 nextRows = new PriorityQueue<>(fuzzyKeysData.size(), 224 new Comparator<Pair<byte[], Pair<byte[], byte[]>>>() { 225 @Override 226 public int compare(Pair<byte[], Pair<byte[], byte[]>> o1, 227 Pair<byte[], Pair<byte[], byte[]>> o2) { 228 return isReversed() 229 ? Bytes.compareTo(o2.getFirst(), o1.getFirst()) 230 : Bytes.compareTo(o1.getFirst(), o2.getFirst()); 231 } 232 }); 233 } 234 235 byte[] nextRow() { 236 if (nextRows.isEmpty()) { 237 throw new IllegalStateException("NextRows should not be empty, " 238 + "make sure to call nextRow() after updateTracker() return true"); 239 } else { 240 return nextRows.peek().getFirst(); 241 } 242 } 243 244 boolean updateTracker(Cell currentCell) { 245 if (!initialized) { 246 for (Pair<byte[], byte[]> fuzzyData : fuzzyKeysData) { 247 updateWith(currentCell, fuzzyData); 248 } 249 initialized = true; 250 } else { 251 while (!nextRows.isEmpty() && !lessThan(currentCell, nextRows.peek().getFirst())) { 252 Pair<byte[], Pair<byte[], byte[]>> head = nextRows.poll(); 253 Pair<byte[], byte[]> fuzzyData = head.getSecond(); 254 updateWith(currentCell, fuzzyData); 255 } 256 } 257 return !nextRows.isEmpty(); 258 } 259 260 boolean lessThan(Cell currentCell, byte[] nextRowKey) { 261 int compareResult = 262 CellComparator.getInstance().compareRows(currentCell, nextRowKey, 0, nextRowKey.length); 263 return (!isReversed() && compareResult < 0) || (isReversed() && compareResult > 0); 264 } 265 266 void updateWith(Cell currentCell, Pair<byte[], byte[]> fuzzyData) { 267 byte[] nextRowKeyCandidate = 268 getNextForFuzzyRule(isReversed(), currentCell.getRowArray(), currentCell.getRowOffset(), 269 currentCell.getRowLength(), fuzzyData.getFirst(), fuzzyData.getSecond()); 270 if (nextRowKeyCandidate != null) { 271 nextRows.add(new Pair<>(nextRowKeyCandidate, fuzzyData)); 272 } 273 } 274 275 } 276 277 @Override 278 public boolean filterAllRemaining() { 279 return done; 280 } 281 282 /** Returns The filter serialized using pb */ 283 @Override 284 public byte[] toByteArray() { 285 FilterProtos.FuzzyRowFilter.Builder builder = FilterProtos.FuzzyRowFilter.newBuilder(); 286 for (Pair<byte[], byte[]> fuzzyData : fuzzyKeysData) { 287 BytesBytesPair.Builder bbpBuilder = BytesBytesPair.newBuilder(); 288 bbpBuilder.setFirst(UnsafeByteOperations.unsafeWrap(fuzzyData.getFirst())); 289 bbpBuilder.setSecond(UnsafeByteOperations.unsafeWrap(fuzzyData.getSecond())); 290 builder.addFuzzyKeysData(bbpBuilder); 291 } 292 return builder.build().toByteArray(); 293 } 294 295 /** 296 * Parse a serialized representation of {@link FuzzyRowFilter} 297 * @param pbBytes A pb serialized {@link FuzzyRowFilter} instance 298 * @return An instance of {@link FuzzyRowFilter} made from <code>bytes</code> 299 * @throws DeserializationException if an error occurred 300 * @see #toByteArray 301 */ 302 public static FuzzyRowFilter parseFrom(final byte[] pbBytes) throws DeserializationException { 303 FilterProtos.FuzzyRowFilter proto; 304 try { 305 proto = FilterProtos.FuzzyRowFilter.parseFrom(pbBytes); 306 } catch (InvalidProtocolBufferException e) { 307 throw new DeserializationException(e); 308 } 309 int count = proto.getFuzzyKeysDataCount(); 310 ArrayList<Pair<byte[], byte[]>> fuzzyKeysData = new ArrayList<>(count); 311 for (int i = 0; i < count; ++i) { 312 BytesBytesPair current = proto.getFuzzyKeysData(i); 313 byte[] keyBytes = current.getFirst().toByteArray(); 314 byte[] keyMeta = current.getSecond().toByteArray(); 315 fuzzyKeysData.add(new Pair<>(keyBytes, keyMeta)); 316 } 317 return new FuzzyRowFilter(fuzzyKeysData); 318 } 319 320 @Override 321 public String toString() { 322 final StringBuilder sb = new StringBuilder(); 323 sb.append("FuzzyRowFilter"); 324 sb.append("{fuzzyKeysData="); 325 for (Pair<byte[], byte[]> fuzzyData : fuzzyKeysData) { 326 sb.append('{').append(Bytes.toStringBinary(fuzzyData.getFirst())).append(":"); 327 sb.append(Bytes.toStringBinary(fuzzyData.getSecond())).append('}'); 328 } 329 sb.append("}, "); 330 return sb.toString(); 331 } 332 333 // Utility methods 334 335 static enum SatisfiesCode { 336 /** row satisfies fuzzy rule */ 337 YES, 338 /** row doesn't satisfy fuzzy rule, but there's possible greater row that does */ 339 NEXT_EXISTS, 340 /** row doesn't satisfy fuzzy rule and there's no greater row that does */ 341 NO_NEXT 342 } 343 344 static SatisfiesCode satisfies(byte[] row, byte[] fuzzyKeyBytes, byte[] fuzzyKeyMeta) { 345 return satisfies(false, row, 0, row.length, fuzzyKeyBytes, fuzzyKeyMeta); 346 } 347 348 static SatisfiesCode satisfies(boolean reverse, byte[] row, byte[] fuzzyKeyBytes, 349 byte[] fuzzyKeyMeta) { 350 return satisfies(reverse, row, 0, row.length, fuzzyKeyBytes, fuzzyKeyMeta); 351 } 352 353 static SatisfiesCode satisfies(boolean reverse, byte[] row, int offset, int length, 354 byte[] fuzzyKeyBytes, byte[] fuzzyKeyMeta) { 355 356 if (!UNSAFE_UNALIGNED) { 357 return satisfiesNoUnsafe(reverse, row, offset, length, fuzzyKeyBytes, fuzzyKeyMeta); 358 } 359 360 if (row == null) { 361 // do nothing, let scan to proceed 362 return SatisfiesCode.YES; 363 } 364 length = Math.min(length, fuzzyKeyBytes.length); 365 int numWords = length / Bytes.SIZEOF_LONG; 366 367 int j = numWords << 3; // numWords * SIZEOF_LONG; 368 369 for (int i = 0; i < j; i += Bytes.SIZEOF_LONG) { 370 long fuzzyBytes = Bytes.toLong(fuzzyKeyBytes, i); 371 long fuzzyMeta = Bytes.toLong(fuzzyKeyMeta, i); 372 long rowValue = Bytes.toLong(row, offset + i); 373 if ((rowValue & fuzzyMeta) != fuzzyBytes) { 374 // We always return NEXT_EXISTS 375 return SatisfiesCode.NEXT_EXISTS; 376 } 377 } 378 379 int off = j; 380 381 if (length - off >= Bytes.SIZEOF_INT) { 382 int fuzzyBytes = Bytes.toInt(fuzzyKeyBytes, off); 383 int fuzzyMeta = Bytes.toInt(fuzzyKeyMeta, off); 384 int rowValue = Bytes.toInt(row, offset + off); 385 if ((rowValue & fuzzyMeta) != fuzzyBytes) { 386 // We always return NEXT_EXISTS 387 return SatisfiesCode.NEXT_EXISTS; 388 } 389 off += Bytes.SIZEOF_INT; 390 } 391 392 if (length - off >= Bytes.SIZEOF_SHORT) { 393 short fuzzyBytes = Bytes.toShort(fuzzyKeyBytes, off); 394 short fuzzyMeta = Bytes.toShort(fuzzyKeyMeta, off); 395 short rowValue = Bytes.toShort(row, offset + off); 396 if ((rowValue & fuzzyMeta) != fuzzyBytes) { 397 // We always return NEXT_EXISTS 398 // even if it does not (in this case getNextForFuzzyRule 399 // will return null) 400 return SatisfiesCode.NEXT_EXISTS; 401 } 402 off += Bytes.SIZEOF_SHORT; 403 } 404 405 if (length - off >= Bytes.SIZEOF_BYTE) { 406 int fuzzyBytes = fuzzyKeyBytes[off] & 0xff; 407 int fuzzyMeta = fuzzyKeyMeta[off] & 0xff; 408 int rowValue = row[offset + off] & 0xff; 409 if ((rowValue & fuzzyMeta) != fuzzyBytes) { 410 // We always return NEXT_EXISTS 411 return SatisfiesCode.NEXT_EXISTS; 412 } 413 } 414 return SatisfiesCode.YES; 415 } 416 417 static SatisfiesCode satisfiesNoUnsafe(boolean reverse, byte[] row, int offset, int length, 418 byte[] fuzzyKeyBytes, byte[] fuzzyKeyMeta) { 419 if (row == null) { 420 // do nothing, let scan to proceed 421 return SatisfiesCode.YES; 422 } 423 424 Order order = Order.orderFor(reverse); 425 boolean nextRowKeyCandidateExists = false; 426 427 for (int i = 0; i < fuzzyKeyMeta.length && i < length; i++) { 428 // First, checking if this position is fixed and not equals the given one 429 boolean byteAtPositionFixed = fuzzyKeyMeta[i] == 0; 430 boolean fixedByteIncorrect = byteAtPositionFixed && fuzzyKeyBytes[i] != row[i + offset]; 431 if (fixedByteIncorrect) { 432 // in this case there's another row that satisfies fuzzy rule and bigger than this row 433 if (nextRowKeyCandidateExists) { 434 return SatisfiesCode.NEXT_EXISTS; 435 } 436 437 // If this row byte is less than fixed then there's a byte array bigger than 438 // this row and which satisfies the fuzzy rule. Otherwise there's no such byte array: 439 // this row is simply bigger than any byte array that satisfies the fuzzy rule 440 boolean rowByteLessThanFixed = (row[i + offset] & 0xFF) < (fuzzyKeyBytes[i] & 0xFF); 441 if (rowByteLessThanFixed && !reverse) { 442 return SatisfiesCode.NEXT_EXISTS; 443 } else if (!rowByteLessThanFixed && reverse) { 444 return SatisfiesCode.NEXT_EXISTS; 445 } else { 446 return SatisfiesCode.NO_NEXT; 447 } 448 } 449 450 // Second, checking if this position is not fixed and byte value is not the biggest. In this 451 // case there's a byte array bigger than this row and which satisfies the fuzzy rule. To get 452 // bigger byte array that satisfies the rule we need to just increase this byte 453 // (see the code of getNextForFuzzyRule below) by one. 454 // Note: if non-fixed byte is already at biggest value, this doesn't allow us to say there's 455 // bigger one that satisfies the rule as it can't be increased. 456 if (fuzzyKeyMeta[i] == 1 && !order.isMax(fuzzyKeyBytes[i])) { 457 nextRowKeyCandidateExists = true; 458 } 459 } 460 return SatisfiesCode.YES; 461 } 462 463 static byte[] getNextForFuzzyRule(byte[] row, byte[] fuzzyKeyBytes, byte[] fuzzyKeyMeta) { 464 return getNextForFuzzyRule(false, row, 0, row.length, fuzzyKeyBytes, fuzzyKeyMeta); 465 } 466 467 static byte[] getNextForFuzzyRule(boolean reverse, byte[] row, byte[] fuzzyKeyBytes, 468 byte[] fuzzyKeyMeta) { 469 return getNextForFuzzyRule(reverse, row, 0, row.length, fuzzyKeyBytes, fuzzyKeyMeta); 470 } 471 472 /** Abstracts directional comparisons based on scan direction. */ 473 private enum Order { 474 ASC { 475 @Override 476 public boolean lt(int lhs, int rhs) { 477 return lhs < rhs; 478 } 479 480 @Override 481 public boolean gt(int lhs, int rhs) { 482 return lhs > rhs; 483 } 484 485 @Override 486 public byte inc(byte val) { 487 // TODO: what about over/underflow? 488 return (byte) (val + 1); 489 } 490 491 @Override 492 public boolean isMax(byte val) { 493 return val == (byte) 0xff; 494 } 495 496 @Override 497 public byte min() { 498 return 0; 499 } 500 }, 501 DESC { 502 @Override 503 public boolean lt(int lhs, int rhs) { 504 return lhs > rhs; 505 } 506 507 @Override 508 public boolean gt(int lhs, int rhs) { 509 return lhs < rhs; 510 } 511 512 @Override 513 public byte inc(byte val) { 514 // TODO: what about over/underflow? 515 return (byte) (val - 1); 516 } 517 518 @Override 519 public boolean isMax(byte val) { 520 return val == 0; 521 } 522 523 @Override 524 public byte min() { 525 return (byte) 0xFF; 526 } 527 }; 528 529 public static Order orderFor(boolean reverse) { 530 return reverse ? DESC : ASC; 531 } 532 533 /** Returns true when {@code lhs < rhs}. */ 534 public abstract boolean lt(int lhs, int rhs); 535 536 /** Returns true when {@code lhs > rhs}. */ 537 public abstract boolean gt(int lhs, int rhs); 538 539 /** Returns {@code val} incremented by 1. */ 540 public abstract byte inc(byte val); 541 542 /** Return true when {@code val} is the maximum value */ 543 public abstract boolean isMax(byte val); 544 545 /** Return the minimum value according to this ordering scheme. */ 546 public abstract byte min(); 547 } 548 549 /** 550 * @return greater byte array than given (row) which satisfies the fuzzy rule if it exists, null 551 * otherwise 552 */ 553 static byte[] getNextForFuzzyRule(boolean reverse, byte[] row, int offset, int length, 554 byte[] fuzzyKeyBytes, byte[] fuzzyKeyMeta) { 555 // To find out the next "smallest" byte array that satisfies fuzzy rule and "greater" than 556 // the given one we do the following: 557 // 1. setting values on all "fixed" positions to the values from fuzzyKeyBytes 558 // 2. if during the first step given row did not increase, then we increase the value at 559 // the first "non-fixed" position (where it is not maximum already) 560 561 // It is easier to perform this by using fuzzyKeyBytes copy and setting "non-fixed" position 562 // values than otherwise. 563 byte[] result = 564 Arrays.copyOf(fuzzyKeyBytes, length > fuzzyKeyBytes.length ? length : fuzzyKeyBytes.length); 565 if (reverse && length > fuzzyKeyBytes.length) { 566 // we need trailing 0xff's instead of trailing 0x00's 567 for (int i = fuzzyKeyBytes.length; i < result.length; i++) { 568 result[i] = (byte) 0xFF; 569 } 570 } 571 int toInc = -1; 572 final Order order = Order.orderFor(reverse); 573 574 boolean increased = false; 575 for (int i = 0; i < result.length; i++) { 576 if (i >= fuzzyKeyMeta.length || fuzzyKeyMeta[i] == 0 /* non-fixed */) { 577 result[i] = row[offset + i]; 578 if (!order.isMax(row[offset + i])) { 579 // this is "non-fixed" position and is not at max value, hence we can increase it 580 toInc = i; 581 } 582 } else if (i < fuzzyKeyMeta.length && fuzzyKeyMeta[i] == -1 /* fixed */) { 583 if (order.lt((row[i + offset] & 0xFF), (fuzzyKeyBytes[i] & 0xFF))) { 584 // if setting value for any fixed position increased the original array, 585 // we are OK 586 increased = true; 587 break; 588 } 589 590 if (order.gt((row[i + offset] & 0xFF), (fuzzyKeyBytes[i] & 0xFF))) { 591 // if setting value for any fixed position makes array "smaller", then just stop: 592 // in case we found some non-fixed position to increase we will do it, otherwise 593 // there's no "next" row key that satisfies fuzzy rule and "greater" than given row 594 break; 595 } 596 } 597 } 598 599 if (!increased) { 600 if (toInc < 0) { 601 return null; 602 } 603 result[toInc] = order.inc(result[toInc]); 604 605 // Setting all "non-fixed" positions to zeroes to the right of the one we increased so 606 // that found "next" row key is the smallest possible 607 for (int i = toInc + 1; i < result.length; i++) { 608 if (i >= fuzzyKeyMeta.length || fuzzyKeyMeta[i] == 0 /* non-fixed */) { 609 result[i] = order.min(); 610 } 611 } 612 } 613 614 return reverse ? result : trimTrailingZeroes(result, fuzzyKeyMeta, toInc); 615 } 616 617 /** 618 * For forward scanner, next cell hint should not contain any trailing zeroes unless they are part 619 * of fuzzyKeyMeta hint = '\x01\x01\x01\x00\x00' will skip valid row '\x01\x01\x01' 620 * @param toInc - position of incremented byte 621 * @return trimmed version of result 622 */ 623 624 private static byte[] trimTrailingZeroes(byte[] result, byte[] fuzzyKeyMeta, int toInc) { 625 int off = fuzzyKeyMeta.length >= result.length ? result.length - 1 : fuzzyKeyMeta.length - 1; 626 for (; off >= 0; off--) { 627 if (fuzzyKeyMeta[off] != 0) break; 628 } 629 if (off < toInc) off = toInc; 630 byte[] retValue = new byte[off + 1]; 631 System.arraycopy(result, 0, retValue, 0, retValue.length); 632 return retValue; 633 } 634 635 /** 636 * Returns true if and only if the fields of the filter that are serialized are equal to the 637 * corresponding fields in other. Used for testing. 638 */ 639 @Override 640 boolean areSerializedFieldsEqual(Filter o) { 641 if (o == this) { 642 return true; 643 } 644 if (!(o instanceof FuzzyRowFilter)) { 645 return false; 646 } 647 FuzzyRowFilter other = (FuzzyRowFilter) o; 648 if (this.fuzzyKeysData.size() != other.fuzzyKeysData.size()) return false; 649 for (int i = 0; i < fuzzyKeysData.size(); ++i) { 650 Pair<byte[], byte[]> thisData = this.fuzzyKeysData.get(i); 651 Pair<byte[], byte[]> otherData = other.fuzzyKeysData.get(i); 652 if ( 653 !(Bytes.equals(thisData.getFirst(), otherData.getFirst()) 654 && Bytes.equals(thisData.getSecond(), otherData.getSecond())) 655 ) { 656 return false; 657 } 658 } 659 return true; 660 } 661 662 @Override 663 public boolean equals(Object obj) { 664 return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj); 665 } 666 667 @Override 668 public int hashCode() { 669 return Objects.hash(this.fuzzyKeysData); 670 } 671}