Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2016 Open Networking Laboratory |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.onosproject.store.primitives.resources.impl; |
| 17 | |
| 18 | import static org.onosproject.store.service.MapEvent.Type.INSERT; |
| 19 | import static org.onosproject.store.service.MapEvent.Type.REMOVE; |
| 20 | import static org.onosproject.store.service.MapEvent.Type.UPDATE; |
| 21 | import io.atomix.copycat.client.session.Session; |
| 22 | import io.atomix.copycat.server.Commit; |
| 23 | import io.atomix.copycat.server.Snapshottable; |
| 24 | import io.atomix.copycat.server.StateMachineExecutor; |
| 25 | import io.atomix.copycat.server.session.SessionListener; |
| 26 | import io.atomix.copycat.server.storage.snapshot.SnapshotReader; |
| 27 | import io.atomix.copycat.server.storage.snapshot.SnapshotWriter; |
| 28 | import io.atomix.resource.ResourceStateMachine; |
| 29 | |
| 30 | import java.util.Collection; |
| 31 | import java.util.HashMap; |
| 32 | import java.util.Iterator; |
| 33 | import java.util.Map; |
| 34 | import java.util.Set; |
| 35 | import java.util.concurrent.atomic.AtomicLong; |
| 36 | import java.util.stream.Collectors; |
| 37 | |
| 38 | import org.onlab.util.CountDownCompleter; |
| 39 | import org.onlab.util.Match; |
| 40 | import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapCommands.TransactionPrepare; |
| 41 | import org.onosproject.store.service.MapEvent; |
| 42 | import org.onosproject.store.service.Versioned; |
| 43 | |
| 44 | import com.google.common.collect.Maps; |
| 45 | import com.google.common.collect.Sets; |
| 46 | |
| 47 | import static com.google.common.base.Preconditions.checkState; |
| 48 | |
| 49 | /** |
| 50 | * State Machine for {@link AtomixConsistentMap} resource. |
| 51 | */ |
| 52 | public class AtomixConsistentMapState extends ResourceStateMachine implements |
| 53 | SessionListener, Snapshottable { |
| 54 | private final Map<Long, Commit<? extends AtomixConsistentMapCommands.Listen>> listeners = new HashMap<>(); |
| 55 | private final Map<String, MapEntryValue> mapEntries = new HashMap<>(); |
| 56 | private final Set<String> preparedKeys = Sets.newHashSet(); |
| 57 | private final Map<TransactionId, Commit<? extends TransactionPrepare>> pendingTransactions = Maps |
| 58 | .newHashMap(); |
| 59 | private AtomicLong versionCounter = new AtomicLong(0); |
| 60 | |
| 61 | @Override |
| 62 | public void snapshot(SnapshotWriter writer) { |
| 63 | writer.writeLong(versionCounter.get()); |
| 64 | } |
| 65 | |
| 66 | @Override |
| 67 | public void install(SnapshotReader reader) { |
| 68 | versionCounter = new AtomicLong(reader.readLong()); |
| 69 | } |
| 70 | |
| 71 | @Override |
| 72 | protected void configure(StateMachineExecutor executor) { |
| 73 | // Listeners |
| 74 | executor.register(AtomixConsistentMapCommands.Listen.class, |
| 75 | this::listen); |
| 76 | executor.register(AtomixConsistentMapCommands.Unlisten.class, |
| 77 | this::unlisten); |
| 78 | // Queries |
| 79 | executor.register(AtomixConsistentMapCommands.ContainsKey.class, |
| 80 | this::containsKey); |
| 81 | executor.register(AtomixConsistentMapCommands.ContainsValue.class, |
| 82 | this::containsValue); |
| 83 | executor.register(AtomixConsistentMapCommands.EntrySet.class, |
| 84 | this::entrySet); |
| 85 | executor.register(AtomixConsistentMapCommands.Get.class, this::get); |
| 86 | executor.register(AtomixConsistentMapCommands.IsEmpty.class, |
| 87 | this::isEmpty); |
| 88 | executor.register(AtomixConsistentMapCommands.KeySet.class, |
| 89 | this::keySet); |
| 90 | executor.register(AtomixConsistentMapCommands.Size.class, this::size); |
| 91 | executor.register(AtomixConsistentMapCommands.Values.class, |
| 92 | this::values); |
| 93 | // Commands |
| 94 | executor.register(AtomixConsistentMapCommands.UpdateAndGet.class, |
| 95 | this::updateAndGet); |
| 96 | executor.register(AtomixConsistentMapCommands.Clear.class, this::clear); |
| 97 | executor.register(AtomixConsistentMapCommands.TransactionPrepare.class, |
| 98 | this::prepare); |
| 99 | executor.register(AtomixConsistentMapCommands.TransactionCommit.class, |
| 100 | this::commit); |
| 101 | executor.register( |
| 102 | AtomixConsistentMapCommands.TransactionRollback.class, |
| 103 | this::rollback); |
| 104 | } |
| 105 | |
| 106 | @Override |
| 107 | public void delete() { |
| 108 | // Delete Listeners |
| 109 | listeners.values().forEach(Commit::close); |
| 110 | listeners.clear(); |
| 111 | |
| 112 | // Delete Map entries |
| 113 | mapEntries.values().forEach(MapEntryValue::discard); |
| 114 | mapEntries.clear(); |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * Handles a contains key commit. |
| 119 | * |
| 120 | * @param commit |
| 121 | * containsKey commit |
| 122 | * @return {@code true} if map contains key |
| 123 | */ |
| 124 | protected boolean containsKey( |
| 125 | Commit<? extends AtomixConsistentMapCommands.ContainsKey> commit) { |
| 126 | try { |
| 127 | return toVersioned(mapEntries.get(commit.operation().key())) != null; |
| 128 | } finally { |
| 129 | commit.close(); |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | /** |
| 134 | * Handles a contains value commit. |
| 135 | * |
| 136 | * @param commit |
| 137 | * containsValue commit |
| 138 | * @return {@code true} if map contains value |
| 139 | */ |
| 140 | protected boolean containsValue( |
| 141 | Commit<? extends AtomixConsistentMapCommands.ContainsValue> commit) { |
| 142 | try { |
| 143 | Match<byte[]> valueMatch = Match |
| 144 | .ifValue(commit.operation().value()); |
| 145 | return mapEntries.values().stream() |
| 146 | .anyMatch(value -> valueMatch.matches(value.value())); |
| 147 | } finally { |
| 148 | commit.close(); |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | /** |
| 153 | * Handles a get commit. |
| 154 | * |
| 155 | * @param commit |
| 156 | * get commit |
| 157 | * @return value mapped to key |
| 158 | */ |
| 159 | protected Versioned<byte[]> get( |
| 160 | Commit<? extends AtomixConsistentMapCommands.Get> commit) { |
| 161 | try { |
| 162 | return toVersioned(mapEntries.get(commit.operation().key())); |
| 163 | } finally { |
| 164 | commit.close(); |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | /** |
| 169 | * Handles a count commit. |
| 170 | * |
| 171 | * @param commit |
| 172 | * size commit |
| 173 | * @return number of entries in map |
| 174 | */ |
| 175 | protected int size(Commit<? extends AtomixConsistentMapCommands.Size> commit) { |
| 176 | try { |
| 177 | return mapEntries.size(); |
| 178 | } finally { |
| 179 | commit.close(); |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | /** |
| 184 | * Handles an is empty commit. |
| 185 | * |
| 186 | * @param commit |
| 187 | * isEmpty commit |
| 188 | * @return {@code true} if map is empty |
| 189 | */ |
| 190 | protected boolean isEmpty( |
| 191 | Commit<? extends AtomixConsistentMapCommands.IsEmpty> commit) { |
| 192 | try { |
| 193 | return mapEntries.isEmpty(); |
| 194 | } finally { |
| 195 | commit.close(); |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | /** |
| 200 | * Handles a keySet commit. |
| 201 | * |
| 202 | * @param commit |
| 203 | * keySet commit |
| 204 | * @return set of keys in map |
| 205 | */ |
| 206 | protected Set<String> keySet( |
| 207 | Commit<? extends AtomixConsistentMapCommands.KeySet> commit) { |
| 208 | try { |
| 209 | return mapEntries.keySet(); |
| 210 | } finally { |
| 211 | commit.close(); |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | /** |
| 216 | * Handles a values commit. |
| 217 | * |
| 218 | * @param commit |
| 219 | * values commit |
| 220 | * @return collection of values in map |
| 221 | */ |
| 222 | protected Collection<Versioned<byte[]>> values( |
| 223 | Commit<? extends AtomixConsistentMapCommands.Values> commit) { |
| 224 | try { |
| 225 | return mapEntries.values().stream().map(this::toVersioned) |
| 226 | .collect(Collectors.toList()); |
| 227 | } finally { |
| 228 | commit.close(); |
| 229 | } |
| 230 | } |
| 231 | |
| 232 | /** |
| 233 | * Handles a entry set commit. |
| 234 | * |
| 235 | * @param commit |
| 236 | * entrySet commit |
| 237 | * @return set of map entries |
| 238 | */ |
| 239 | protected Set<Map.Entry<String, Versioned<byte[]>>> entrySet( |
| 240 | Commit<? extends AtomixConsistentMapCommands.EntrySet> commit) { |
| 241 | try { |
| 242 | return mapEntries |
| 243 | .entrySet() |
| 244 | .stream() |
| 245 | .map(e -> Maps.immutableEntry(e.getKey(), |
| 246 | toVersioned(e.getValue()))) |
| 247 | .collect(Collectors.toSet()); |
| 248 | } finally { |
| 249 | commit.close(); |
| 250 | } |
| 251 | } |
| 252 | |
| 253 | /** |
| 254 | * Handles a update and get commit. |
| 255 | * |
| 256 | * @param commit |
| 257 | * updateAndGet commit |
| 258 | * @return update result |
| 259 | */ |
| 260 | protected MapEntryUpdateResult<String, byte[]> updateAndGet( |
| 261 | Commit<? extends AtomixConsistentMapCommands.UpdateAndGet> commit) { |
| 262 | MapEntryUpdateResult.Status updateStatus = validate(commit.operation()); |
| 263 | String key = commit.operation().key(); |
| 264 | MapEntryValue oldCommitValue = mapEntries.get(commit.operation().key()); |
| 265 | Versioned<byte[]> oldMapValue = toVersioned(oldCommitValue); |
| 266 | |
| 267 | if (updateStatus != MapEntryUpdateResult.Status.OK) { |
| 268 | commit.close(); |
| 269 | return new MapEntryUpdateResult<>(updateStatus, "", key, |
| 270 | oldMapValue, oldMapValue); |
| 271 | } |
| 272 | |
| 273 | byte[] newValue = commit.operation().value(); |
| 274 | long newVersion = versionCounter.incrementAndGet(); |
| 275 | Versioned<byte[]> newMapValue = newValue == null ? null |
| 276 | : new Versioned<>(newValue, newVersion); |
| 277 | |
| 278 | MapEvent.Type updateType = newValue == null ? REMOVE |
| 279 | : oldCommitValue == null ? INSERT : UPDATE; |
| 280 | if (updateType == REMOVE || updateType == UPDATE) { |
| 281 | mapEntries.remove(key); |
| 282 | oldCommitValue.discard(); |
| 283 | } |
| 284 | if (updateType == INSERT || updateType == UPDATE) { |
| 285 | mapEntries.put(key, new NonTransactionalCommit(newVersion, commit)); |
| 286 | } |
| 287 | notify(new MapEvent<>("", key, newMapValue, oldMapValue)); |
| 288 | return new MapEntryUpdateResult<>(updateStatus, "", key, oldMapValue, |
| 289 | newMapValue); |
| 290 | } |
| 291 | |
| 292 | /** |
| 293 | * Handles a clear commit. |
| 294 | * |
| 295 | * @param commit |
| 296 | * clear commit |
| 297 | * @return clear result |
| 298 | */ |
| 299 | protected MapEntryUpdateResult.Status clear( |
| 300 | Commit<? extends AtomixConsistentMapCommands.Clear> commit) { |
| 301 | try { |
| 302 | Iterator<Map.Entry<String, MapEntryValue>> iterator = mapEntries |
| 303 | .entrySet().iterator(); |
| 304 | while (iterator.hasNext()) { |
| 305 | Map.Entry<String, MapEntryValue> entry = iterator.next(); |
| 306 | String key = entry.getKey(); |
| 307 | MapEntryValue value = entry.getValue(); |
| 308 | Versioned<byte[]> removedValue = new Versioned<>(value.value(), |
| 309 | value.version()); |
| 310 | notify(new MapEvent<>("", key, null, removedValue)); |
| 311 | value.discard(); |
| 312 | iterator.remove(); |
| 313 | } |
| 314 | return MapEntryUpdateResult.Status.OK; |
| 315 | } finally { |
| 316 | commit.close(); |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | /** |
| 321 | * Handles a listen commit. |
| 322 | * |
| 323 | * @param commit |
| 324 | * listen commit |
| 325 | */ |
| 326 | protected void listen( |
| 327 | Commit<? extends AtomixConsistentMapCommands.Listen> commit) { |
| 328 | Long sessionId = commit.session().id(); |
| 329 | listeners.put(sessionId, commit); |
| 330 | commit.session() |
| 331 | .onStateChange( |
| 332 | state -> { |
| 333 | if (state == Session.State.CLOSED |
| 334 | || state == Session.State.EXPIRED) { |
| 335 | Commit<? extends AtomixConsistentMapCommands.Listen> listener = listeners |
| 336 | .remove(sessionId); |
| 337 | if (listener != null) { |
| 338 | listener.close(); |
| 339 | } |
| 340 | } |
| 341 | }); |
| 342 | } |
| 343 | |
| 344 | /** |
| 345 | * Handles an unlisten commit. |
| 346 | * |
| 347 | * @param commit |
| 348 | * unlisten commit |
| 349 | */ |
| 350 | protected void unlisten( |
| 351 | Commit<? extends AtomixConsistentMapCommands.Unlisten> commit) { |
| 352 | try { |
| 353 | Commit<? extends AtomixConsistentMapCommands.Listen> listener = listeners |
| 354 | .remove(commit.session()); |
| 355 | if (listener != null) { |
| 356 | listener.close(); |
| 357 | } |
| 358 | } finally { |
| 359 | commit.close(); |
| 360 | } |
| 361 | } |
| 362 | |
| 363 | /** |
| 364 | * Triggers a change event. |
| 365 | * |
| 366 | * @param value |
| 367 | * map event |
| 368 | */ |
| 369 | private void notify(MapEvent<String, byte[]> value) { |
| 370 | listeners.values().forEach( |
| 371 | commit -> commit.session().publish("change", value)); |
| 372 | } |
| 373 | |
| 374 | /** |
| 375 | * Handles an prepare commit. |
| 376 | * |
| 377 | * @param commit |
| 378 | * transaction prepare commit |
| 379 | * @return prepare result |
| 380 | */ |
| 381 | protected PrepareResult prepare( |
| 382 | Commit<? extends AtomixConsistentMapCommands.TransactionPrepare> commit) { |
| 383 | boolean ok = false; |
| 384 | try { |
| 385 | TransactionalMapUpdate<String, byte[]> transactionUpdate = commit |
| 386 | .operation().transactionUpdate(); |
| 387 | for (MapUpdate<String, byte[]> update : transactionUpdate.batch()) { |
| 388 | String key = update.key(); |
| 389 | if (preparedKeys.contains(key)) { |
| 390 | return PrepareResult.CONCURRENT_TRANSACTION; |
| 391 | } |
| 392 | MapEntryValue existingValue = mapEntries.get(key); |
| 393 | if (existingValue == null) { |
| 394 | if (update.currentValue() != null) { |
| 395 | return PrepareResult.OPTIMISTIC_LOCK_FAILURE; |
| 396 | } |
| 397 | } else { |
| 398 | if (existingValue.version() != update.currentVersion()) { |
| 399 | return PrepareResult.OPTIMISTIC_LOCK_FAILURE; |
| 400 | } |
| 401 | } |
| 402 | } |
| 403 | // No violations detected. Add to pendingTranctions and mark |
| 404 | // modified keys as |
| 405 | // currently locked to updates. |
| 406 | pendingTransactions.put(transactionUpdate.transactionId(), commit); |
| 407 | transactionUpdate.batch().forEach(u -> preparedKeys.add(u.key())); |
| 408 | ok = true; |
| 409 | return PrepareResult.OK; |
| 410 | } finally { |
| 411 | if (!ok) { |
| 412 | commit.close(); |
| 413 | } |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | /** |
| 418 | * Handles an commit commit (ha!). |
| 419 | * |
| 420 | * @param commit transaction commit commit |
| 421 | * @return commit result |
| 422 | */ |
| 423 | protected CommitResult commit( |
| 424 | Commit<? extends AtomixConsistentMapCommands.TransactionCommit> commit) { |
| 425 | TransactionId transactionId = commit.operation().transactionId(); |
| 426 | try { |
| 427 | Commit<? extends AtomixConsistentMapCommands.TransactionPrepare> prepareCommit = pendingTransactions |
| 428 | .remove(transactionId); |
| 429 | if (prepareCommit == null) { |
| 430 | return CommitResult.UNKNOWN_TRANSACTION_ID; |
| 431 | } |
| 432 | TransactionalMapUpdate<String, byte[]> transactionalUpdate = prepareCommit |
| 433 | .operation().transactionUpdate(); |
| 434 | long totalReferencesToCommit = transactionalUpdate |
| 435 | .batch() |
| 436 | .stream() |
| 437 | .filter(update -> update.type() != MapUpdate.Type.REMOVE_IF_VERSION_MATCH) |
| 438 | .count(); |
| 439 | CountDownCompleter<Commit<? extends AtomixConsistentMapCommands.TransactionPrepare>> completer = |
| 440 | new CountDownCompleter<>(prepareCommit, totalReferencesToCommit, Commit::close); |
| 441 | for (MapUpdate<String, byte[]> update : transactionalUpdate.batch()) { |
| 442 | String key = update.key(); |
| 443 | MapEntryValue previousValue = mapEntries.remove(key); |
| 444 | MapEntryValue newValue = null; |
| 445 | checkState(preparedKeys.remove(key), "key is not prepared"); |
| 446 | if (update.type() != MapUpdate.Type.REMOVE_IF_VERSION_MATCH) { |
| 447 | newValue = new TransactionalCommit(key, |
| 448 | versionCounter.incrementAndGet(), completer); |
| 449 | } |
| 450 | mapEntries.put(key, newValue); |
| 451 | // Notify map listeners |
| 452 | notify(new MapEvent<>("", key, toVersioned(newValue), |
| 453 | toVersioned(previousValue))); |
| 454 | } |
| 455 | return CommitResult.OK; |
| 456 | } finally { |
| 457 | commit.close(); |
| 458 | } |
| 459 | } |
| 460 | |
| 461 | /** |
| 462 | * Handles an rollback commit (ha!). |
| 463 | * |
| 464 | * @param commit transaction rollback commit |
| 465 | * @return rollback result |
| 466 | */ |
| 467 | protected RollbackResult rollback( |
| 468 | Commit<? extends AtomixConsistentMapCommands.TransactionRollback> commit) { |
| 469 | TransactionId transactionId = commit.operation().transactionId(); |
| 470 | try { |
| 471 | Commit<? extends AtomixConsistentMapCommands.TransactionPrepare> prepareCommit = pendingTransactions |
| 472 | .remove(transactionId); |
| 473 | if (prepareCommit == null) { |
| 474 | return RollbackResult.UNKNOWN_TRANSACTION_ID; |
| 475 | } else { |
| 476 | prepareCommit.operation().transactionUpdate().batch() |
| 477 | .forEach(u -> preparedKeys.remove(u.key())); |
| 478 | prepareCommit.close(); |
| 479 | return RollbackResult.OK; |
| 480 | } |
| 481 | } finally { |
| 482 | commit.close(); |
| 483 | } |
| 484 | } |
| 485 | |
| 486 | private MapEntryUpdateResult.Status validate( |
| 487 | AtomixConsistentMapCommands.UpdateAndGet update) { |
| 488 | MapEntryValue existingValue = mapEntries.get(update.key()); |
| 489 | if (existingValue == null && update.value() == null) { |
| 490 | return MapEntryUpdateResult.Status.NOOP; |
| 491 | } |
| 492 | if (preparedKeys.contains(update.key())) { |
| 493 | return MapEntryUpdateResult.Status.WRITE_LOCK; |
| 494 | } |
| 495 | byte[] existingRawValue = existingValue == null ? null : existingValue |
| 496 | .value(); |
| 497 | Long existingVersion = existingValue == null ? null : existingValue |
| 498 | .version(); |
| 499 | return update.valueMatch().matches(existingRawValue) |
| 500 | && update.versionMatch().matches(existingVersion) ? MapEntryUpdateResult.Status.OK |
| 501 | : MapEntryUpdateResult.Status.PRECONDITION_FAILED; |
| 502 | } |
| 503 | |
| 504 | private Versioned<byte[]> toVersioned(MapEntryValue value) { |
| 505 | return value == null ? null : new Versioned<>(value.value(), |
| 506 | value.version()); |
| 507 | } |
| 508 | |
| 509 | @Override |
| 510 | public void register(Session session) { |
| 511 | } |
| 512 | |
| 513 | @Override |
| 514 | public void unregister(Session session) { |
| 515 | closeListener(session.id()); |
| 516 | } |
| 517 | |
| 518 | @Override |
| 519 | public void expire(Session session) { |
| 520 | closeListener(session.id()); |
| 521 | } |
| 522 | |
| 523 | @Override |
| 524 | public void close(Session session) { |
| 525 | closeListener(session.id()); |
| 526 | } |
| 527 | |
| 528 | private void closeListener(Long sessionId) { |
| 529 | Commit<? extends AtomixConsistentMapCommands.Listen> commit = listeners |
| 530 | .remove(sessionId); |
| 531 | if (commit != null) { |
| 532 | commit.close(); |
| 533 | } |
| 534 | } |
| 535 | |
| 536 | /** |
| 537 | * Interface implemented by map values. |
| 538 | */ |
| 539 | private interface MapEntryValue { |
| 540 | /** |
| 541 | * Returns the raw {@code byte[]}. |
| 542 | * |
| 543 | * @return raw value |
| 544 | */ |
| 545 | byte[] value(); |
| 546 | |
| 547 | /** |
| 548 | * Returns the version of the value. |
| 549 | * |
| 550 | * @return version |
| 551 | */ |
| 552 | long version(); |
| 553 | |
| 554 | /** |
| 555 | * Discards the value by invoke appropriate clean up actions. |
| 556 | */ |
| 557 | void discard(); |
| 558 | } |
| 559 | |
| 560 | /** |
| 561 | * A {@code MapEntryValue} that is derived from a non-transactional update |
| 562 | * i.e. via any standard map update operation. |
| 563 | */ |
| 564 | private class NonTransactionalCommit implements MapEntryValue { |
| 565 | private final long version; |
| 566 | private final Commit<? extends AtomixConsistentMapCommands.UpdateAndGet> commit; |
| 567 | |
| 568 | public NonTransactionalCommit( |
| 569 | long version, |
| 570 | Commit<? extends AtomixConsistentMapCommands.UpdateAndGet> commit) { |
| 571 | this.version = version; |
| 572 | this.commit = commit; |
| 573 | } |
| 574 | |
| 575 | @Override |
| 576 | public byte[] value() { |
| 577 | return commit.operation().value(); |
| 578 | } |
| 579 | |
| 580 | @Override |
| 581 | public long version() { |
| 582 | return version; |
| 583 | } |
| 584 | |
| 585 | @Override |
| 586 | public void discard() { |
| 587 | commit.close(); |
| 588 | } |
| 589 | } |
| 590 | |
| 591 | /** |
| 592 | * A {@code MapEntryValue} that is derived from updates submitted via a |
| 593 | * transaction. |
| 594 | */ |
| 595 | private class TransactionalCommit implements MapEntryValue { |
| 596 | private final String key; |
| 597 | private final long version; |
| 598 | private final CountDownCompleter<Commit<? extends AtomixConsistentMapCommands.TransactionPrepare>> completer; |
| 599 | |
| 600 | public TransactionalCommit( |
| 601 | String key, |
| 602 | long version, |
| 603 | CountDownCompleter<Commit<? extends AtomixConsistentMapCommands.TransactionPrepare>> commit) { |
| 604 | this.key = key; |
| 605 | this.version = version; |
| 606 | this.completer = commit; |
| 607 | } |
| 608 | |
| 609 | @Override |
| 610 | public byte[] value() { |
| 611 | TransactionalMapUpdate<String, byte[]> update = completer.object() |
| 612 | .operation().transactionUpdate(); |
| 613 | return update.valueForKey(key); |
| 614 | } |
| 615 | |
| 616 | @Override |
| 617 | public long version() { |
| 618 | return version; |
| 619 | } |
| 620 | |
| 621 | @Override |
| 622 | public void discard() { |
| 623 | completer.countDown(); |
| 624 | } |
| 625 | } |
| 626 | } |