| 1 | package com.hammurapi.store; |
| 2 | |
| 3 | import java.io.Serializable; |
| 4 | import java.util.ArrayList; |
| 5 | import java.util.Collection; |
| 6 | import java.util.Collections; |
| 7 | import java.util.Comparator; |
| 8 | import java.util.Iterator; |
| 9 | import java.util.LinkedList; |
| 10 | import java.util.List; |
| 11 | import java.util.Map; |
| 12 | import java.util.concurrent.Callable; |
| 13 | import java.util.concurrent.ExecutorService; |
| 14 | import java.util.concurrent.Future; |
| 15 | import java.util.concurrent.locks.ReadWriteLock; |
| 16 | |
| 17 | import com.hammurapi.common.Util; |
| 18 | import com.hammurapi.extract.CommutativeOr; |
| 19 | import com.hammurapi.extract.ComparisonResult; |
| 20 | import com.hammurapi.extract.ComparisonResult.Type; |
| 21 | import com.hammurapi.extract.CompositePredicate; |
| 22 | import com.hammurapi.extract.Extractor; |
| 23 | import com.hammurapi.extract.IndexedExtractor; |
| 24 | import com.hammurapi.extract.Predicate; |
| 25 | import com.hammurapi.extract.True; |
| 26 | |
| 27 | /** |
| 28 | * Abstract base class for object stores. |
| 29 | * @author Pavel Vlasov |
| 30 | * |
| 31 | * @param <T> |
| 32 | * @param <S> Self-type - sub-type of store. Generic parameter for predicates, extractors, update tasks and views. |
| 33 | * S should be an interface for master store, deputy store and views to implement. |
| 34 | */ |
| 35 | public abstract class AbstractStore<T, PK, S extends Store<T,PK,S>> implements Store<T, PK, S> { |
| 36 | |
| 37 | /** |
| 38 | * @return Store for the mode with primary key. |
| 39 | */ |
| 40 | protected abstract Map<PK, Handle<T, PK, S>> getPkStore(); |
| 41 | |
| 42 | /** |
| 43 | * Store for the mode without primary key or pkStore values collection. |
| 44 | */ |
| 45 | protected abstract Collection<Handle<T, PK, S>> getNoPkStore(); |
| 46 | |
| 47 | /** |
| 48 | * @return Executor service to parallel processing. |
| 49 | */ |
| 50 | protected abstract ExecutorService getExecutorService(); |
| 51 | |
| 52 | /** |
| 53 | * Creates handle. |
| 54 | */ |
| 55 | protected abstract Handle<T, PK, S> createHandle(T obj, PK primaryKey, Map<S, Map<Extractor<T, ? super PK, S>, ? super PK>> cache, Predicate<T, S>[] validators); |
| 56 | |
| 57 | /** |
| 58 | * Creates collection for index entries |
| 59 | * @param unique Collection should be unique (set) |
| 60 | * @param ordered Collection should be ordered by the comparator or by natural order. |
| 61 | * @param comparator |
| 62 | * @return |
| 63 | */ |
| 64 | protected abstract Collection<Handle<T, PK, S>> createIndexCollection(boolean unique, boolean ordered, Comparator<T> comparator); |
| 65 | |
| 66 | protected Handle<T, PK, S> createHandle(T obj, Predicate<T, S>[] validators) { |
| 67 | return createHandle(obj, null, createCache(), validators); |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * @return Cache for extractors. |
| 72 | */ |
| 73 | protected abstract Map<S, Map<Extractor<T, ? super PK, S>, ? super PK>> createCache(); |
| 74 | |
| 75 | /** |
| 76 | * Creates a store which encapsulates current call state (e.g. locks currently held) and can be |
| 77 | * passed to executor for asynchronous execution. Delegates operate on behalf of the master |
| 78 | * store. They don't acquire locks if the master store already holds them. |
| 79 | * If the master store holds read lock then attempt of a deputy to acquire write lock will result in |
| 80 | * StoreException. |
| 81 | * @return |
| 82 | */ |
| 83 | protected abstract S createDeputy(); |
| 84 | protected abstract ReadWriteLock createMasterLock(); |
| 85 | |
| 86 | /** |
| 87 | * Invoked when some handles have been removed. |
| 88 | * This operation shall remove invalidated handles from store and index collections. |
| 89 | * This method is invoked outside of the write lock. |
| 90 | * @param removed Number of removed handles. |
| 91 | */ |
| 92 | protected abstract void onRemoved(int removed); |
| 93 | |
| 94 | /* |
| 95 | * Implementation note - removal of objects is done by marking Handle as removed. Handles may or may not be removed from store and index collections |
| 96 | * upon marking them as removed. Therefore there should be a "garbage collection" mechanism for removal of invalid handles. |
| 97 | */ |
| 98 | |
| 99 | @SuppressWarnings("unchecked") |
| 100 | @Override |
| 101 | public Handle<T, PK, S> put(T obj, Predicate<T, S>... validators) { |
| 102 | // Evaluate validators. |
| 103 | for (Predicate<T, S> v: validators) { |
| 104 | if (!v.extract((S) this, null, Util.wrap(obj))) { |
| 105 | return null; |
| 106 | } |
| 107 | } |
| 108 | writeLock().lock(); |
| 109 | try { |
| 110 | if (getPrimaryKeyExtractor()==null) { |
| 111 | Handle<T, PK, S> ret = createHandle(obj, validators); |
| 112 | if (getNoPkStore().add(ret)) { |
| 113 | updateIndices(ret, true); |
| 114 | } else { |
| 115 | // Not unique |
| 116 | for (Handle<T, PK, S> hi: getNoPkStore()) { |
| 117 | if (ret.equals(hi)) { |
| 118 | return hi; |
| 119 | } |
| 120 | } |
| 121 | } |
| 122 | return ret; |
| 123 | } else { |
| 124 | Map<S, Map<Extractor<T, ? super PK, S>, ? super PK>> cache = createCache(); |
| 125 | PK primaryKey = getPrimaryKeyExtractor().extract((S) this, cache, Util.wrap(obj)); |
| 126 | Handle<T, PK, S> hi = getPkStore().get(primaryKey); |
| 127 | if (hi==null) { |
| 128 | hi = createHandle(obj, primaryKey, cache, validators); |
| 129 | updateIndices(hi, true); |
| 130 | getPkStore().put(primaryKey, hi); |
| 131 | } else { |
| 132 | hi.update(obj); |
| 133 | } |
| 134 | return hi; |
| 135 | } |
| 136 | } finally { |
| 137 | writeLock().unlock(); |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | @Override |
| 142 | public Iterable<T> getAll() { |
| 143 | readLock().lock(); |
| 144 | try { |
| 145 | Collection<T> ret = new ArrayList<T>(); |
| 146 | for (Handle<T, PK, S> hi: getNoPkStore()) { |
| 147 | if (hi.isValid()) { |
| 148 | ret.add(hi.get()); |
| 149 | } |
| 150 | } |
| 151 | return ret; |
| 152 | } finally { |
| 153 | readLock().unlock(); |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | @Override |
| 158 | public T getByPrimaryKey(PK primaryKey) { |
| 159 | readLock().lock(); |
| 160 | try { |
| 161 | if (getPrimaryKeyExtractor()==null) { |
| 162 | throw new IllegalStateException("Object store is configured without primary key"); |
| 163 | } |
| 164 | Handle<T, PK, S> hi = getPkStore().get(primaryKey); |
| 165 | if (hi==null || !hi.isValid()) { |
| 166 | // TODO - get from the backing store, update indices |
| 167 | return null; |
| 168 | } |
| 169 | return hi.get(); |
| 170 | } finally { |
| 171 | readLock().unlock(); |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | @Override |
| 176 | public Iterable<T> get(Predicate<T, S> selector) { |
| 177 | Collection<T> ret = new ArrayList<T>(); |
| 178 | for (Handle<T, PK, S> h: getHandles(selector)) { |
| 179 | ret.add(h.get()); |
| 180 | } |
| 181 | return ret; |
| 182 | } |
| 183 | |
| 184 | protected class SelectorTask implements Callable<Handle<T, PK, S>>, Serializable { |
| 185 | |
| 186 | private Predicate<T, S> selector; |
| 187 | private Handle<T, PK, S> handle; |
| 188 | |
| 189 | public SelectorTask(Handle<T, PK, S> handle, Predicate<T, S> selector) { |
| 190 | this.handle = handle; |
| 191 | this.selector = selector; |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * Returns object if predicate matches. |
| 196 | */ |
| 197 | @Override |
| 198 | public Handle<T, PK, S> call() throws Exception { |
| 199 | if (handle.isValid() && (selector==null || handle.extract(selector))) { |
| 200 | return handle; |
| 201 | } |
| 202 | return null; |
| 203 | } |
| 204 | |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * Result of applying index optimizations to data manipulation parameters. |
| 209 | * @author Pavel Vlasov |
| 210 | * |
| 211 | */ |
| 212 | private class IndexizationResult { |
| 213 | private Iterable<Handle<T, PK, S>> source; |
| 214 | private Predicate<T, S> selector; |
| 215 | private boolean ordered; |
| 216 | |
| 217 | public IndexizationResult( |
| 218 | Iterable<Handle<T, PK, S>> source, |
| 219 | Predicate<T, S> selector, |
| 220 | boolean ordered) { |
| 221 | super(); |
| 222 | this.source = source; |
| 223 | this.selector = selector; |
| 224 | this.ordered = ordered; |
| 225 | } |
| 226 | |
| 227 | /** |
| 228 | * @return Data to iterate over for further refinement. |
| 229 | */ |
| 230 | public Iterable<Handle<T, PK, S>> getSource() { |
| 231 | return source; |
| 232 | } |
| 233 | |
| 234 | /** |
| 235 | * @return Refined selector with parts addressed by indices already removed. |
| 236 | */ |
| 237 | public Predicate<T, S> getSelector() { |
| 238 | return selector; |
| 239 | } |
| 240 | |
| 241 | /** |
| 242 | * @return true if source is already ordered as required. |
| 243 | */ |
| 244 | public boolean isOrdered() { |
| 245 | return ordered; |
| 246 | } |
| 247 | |
| 248 | } |
| 249 | |
| 250 | private ComparisonResult.Type comparePredicates( |
| 251 | Predicate<T, S> selector, |
| 252 | AbstractIndex<T,PK,?,S> index |
| 253 | ) { |
| 254 | |
| 255 | if (selector==null) { |
| 256 | if (index.getPredicate()==null || True.getInstance().equals(index.getPredicate())) { |
| 257 | return Type.LESS_RESTRICTIVE; |
| 258 | } |
| 259 | return Type.NOT_EQUAL; |
| 260 | } |
| 261 | |
| 262 | if (index.getPredicate()==null || True.getInstance().equals(index.getPredicate())) { |
| 263 | return Type.LESS_RESTRICTIVE; |
| 264 | } |
| 265 | |
| 266 | ComparisonResult cr = index.getPredicate().compareTo(selector); |
| 267 | if (!cr.isOneToOneMapping()) { |
| 268 | return Type.NOT_EQUAL; |
| 269 | } |
| 270 | |
| 271 | switch (cr.getType()) { |
| 272 | case EQUAL: |
| 273 | case LESS_RESTRICTIVE: |
| 274 | return cr.getType(); |
| 275 | default: |
| 276 | return Type.NOT_EQUAL; |
| 277 | } |
| 278 | } |
| 279 | |
| 280 | /** |
| 281 | * @param <V> |
| 282 | * @param extractor |
| 283 | * @param comparator |
| 284 | * @return |
| 285 | */ |
| 286 | private <V> boolean compatibleOrder(Extractor<T, V, S> extractor, Comparator<V> comparator, AbstractIndex<T,PK,V,S> index) { |
| 287 | if (index.isOrdered()) { |
| 288 | if ((extractor==null && index.getExtractor()==null) || extractor.equals(index.getExtractor())) { |
| 289 | if ((comparator==null && index.getComparator()==null) || comparator.equals(index.getComparator())) { |
| 290 | return true; |
| 291 | } |
| 292 | } |
| 293 | } |
| 294 | return false; |
| 295 | } |
| 296 | |
| 297 | /** |
| 298 | * Apply indexing optimizations. |
| 299 | * @return |
| 300 | */ |
| 301 | private <V> IndexizationResult indexize( |
| 302 | Predicate<T, S> selector, |
| 303 | final Extractor<T, V, S> extractor, |
| 304 | final boolean ordered, |
| 305 | Comparator<V> comparator) { |
| 306 | |
| 307 | class Candidate implements Comparable<Candidate> { |
| 308 | AbstractIndex<T,PK,?,S> index; |
| 309 | ComparisonResult.Type type; |
| 310 | private boolean offersOrdering; |
| 311 | |
| 312 | public Candidate(AbstractIndex<T, PK, ?, S> index, Type type, boolean offersOrdering) { |
| 313 | super(); |
| 314 | this.index = index; |
| 315 | this.type = type; |
| 316 | this.offersOrdering = offersOrdering; |
| 317 | } |
| 318 | |
| 319 | @Override |
| 320 | public int compareTo(Candidate o) { |
| 321 | |
| 322 | // If ordered, indices with compatible order come first, if not, unordered come first |
| 323 | if (ordered) { |
| 324 | if (offersOrdering) { |
| 325 | if (!o.offersOrdering) { |
| 326 | return -1; |
| 327 | } |
| 328 | } else { |
| 329 | if (o.offersOrdering) { |
| 330 | return 1; |
| 331 | } |
| 332 | } |
| 333 | } else { |
| 334 | if (index.isOrdered()) { |
| 335 | if (!o.index.isOrdered()) { |
| 336 | return 1; |
| 337 | } |
| 338 | } else { |
| 339 | if (o.index.isOrdered()) { |
| 340 | return -1; |
| 341 | } |
| 342 | } |
| 343 | } |
| 344 | |
| 345 | // Predicates equal to selector come first. |
| 346 | if (!o.type.equals(type)) { |
| 347 | return Type.EQUAL.equals(type) ? -1 : 1; |
| 348 | } |
| 349 | |
| 350 | // Less restrictive predicates come after more restrictive. |
| 351 | if (index.getPredicate()==null) { |
| 352 | if (o.index.getPredicate()!=null) { |
| 353 | return 1; |
| 354 | } |
| 355 | } else { |
| 356 | if (o.index.getPredicate()==null) { |
| 357 | return -1; |
| 358 | } |
| 359 | |
| 360 | ComparisonResult cr = index.getPredicate().compareTo(o.index.getPredicate()); |
| 361 | if (cr.isOneToOneMapping()) { |
| 362 | switch (cr.getType()) { |
| 363 | case LESS_RESTRICTIVE: |
| 364 | return 1; |
| 365 | case MORE_RESTRICTIVE: |
| 366 | return -1; |
| 367 | } |
| 368 | } |
| 369 | } |
| 370 | |
| 371 | if (index.isUnique()) { |
| 372 | if (!o.index.isUnique()) { |
| 373 | return -1; |
| 374 | } |
| 375 | } else { |
| 376 | if (o.index.isUnique()) { |
| 377 | return 1; |
| 378 | } |
| 379 | } |
| 380 | |
| 381 | // More costly index comes first |
| 382 | Extractor<T, ?, S> indexExtractor = index.getExtractor(); |
| 383 | Extractor<T, ?, S> otherExtractor = o.index.getExtractor(); |
| 384 | double indexCost = indexExtractor==null ? 0 : indexExtractor.getCost(); |
| 385 | double otherCost = otherExtractor==null ? 0 : otherExtractor.getCost(); |
| 386 | if (indexCost>0 && otherCost>0) { |
| 387 | if (indexCost*o.index.getGranularity()>otherCost*index.getGranularity()) { |
| 388 | return -1; |
| 389 | } |
| 390 | if (indexCost*o.index.getGranularity()<otherCost*index.getGranularity()) { |
| 391 | return -1; |
| 392 | } |
| 393 | } |
| 394 | |
| 395 | int gDelta = o.index.getGranularity() - index.getGranularity(); |
| 396 | if (gDelta!=0) { |
| 397 | return gDelta; |
| 398 | } |
| 399 | |
| 400 | // Apply synchronous first, lazy last |
| 401 | int typeCmp = type.compareTo(o.type); |
| 402 | if (typeCmp!=0) { |
| 403 | return typeCmp; |
| 404 | } |
| 405 | |
| 406 | return hashCode() - o.hashCode(); |
| 407 | } |
| 408 | |
| 409 | } |
| 410 | |
| 411 | List<Candidate> candidates = new ArrayList<Candidate>(); |
| 412 | for (AbstractIndex<T,PK,?,S> candidate: getIndices()) { |
| 413 | ComparisonResult.Type type = comparePredicates(selector, candidate); |
| 414 | if (!Type.NOT_EQUAL.equals(type)) { |
| 415 | // Add no-predicate indexes only if they offer ordering. |
| 416 | @SuppressWarnings("unchecked") |
| 417 | boolean offersOrdering = ordered && compatibleOrder(extractor, comparator, (AbstractIndex<T,PK,V,S>) candidate); |
| 418 | if (candidate.getPredicate()!=null || offersOrdering) { |
| 419 | candidates.add(new Candidate(candidate, type, offersOrdering)); |
| 420 | } |
| 421 | } |
| 422 | } |
| 423 | |
| 424 | if (!candidates.isEmpty()) { |
| 425 | Collections.sort(candidates); |
| 426 | Candidate indexToUse = candidates.get(0); |
| 427 | if (Type.EQUAL.equals(indexToUse.type)) { |
| 428 | return new IndexizationResult(indexToUse.index.getHandles(), null, indexToUse.offersOrdering); |
| 429 | } else if (selector instanceof CompositePredicate) { |
| 430 | @SuppressWarnings("unchecked") |
| 431 | Predicate<T, S> newSelector = ((CompositePredicate<T, ?, S, ?>) selector).remove(indexToUse.index.getPredicate()); |
| 432 | return new IndexizationResult(indexToUse.index.getHandles(), newSelector, indexToUse.offersOrdering); |
| 433 | } |
| 434 | // Less restrictive, not composite |
| 435 | return new IndexizationResult(indexToUse.index.getHandles(), selector, indexToUse.offersOrdering); |
| 436 | } |
| 437 | |
| 438 | /** |
| 439 | * Or selector - we can use multiple indices to select, the we have to sort anyway. |
| 440 | */ |
| 441 | if (selector instanceof CommutativeOr && ((CommutativeOr) selector).getParts().size()>1) { |
| 442 | Collection<Future<IndexizationResult>> indexizationResults = new LinkedList<Future<IndexizationResult>>(); |
| 443 | for (Predicate<T, S> part: ((CommutativeOr<T,S>) selector).getParts()) { |
| 444 | indexizationResults.add(getExecutorService().submit(new IndexizationTask<V>(part, extractor))); |
| 445 | } |
| 446 | |
| 447 | Collection<Handle<T, PK, S>> ret = new LinkedList<Handle<T, PK, S>>(); |
| 448 | Collection<Future<Handle<T, PK, S>>> fret = new LinkedList<Future<Handle<T, PK, S>>>(); |
| 449 | |
| 450 | for (Future<IndexizationResult> fir: indexizationResults) { |
| 451 | try { |
| 452 | IndexizationResult ir = fir.get(); |
| 453 | if (ir.getSelector()==null || True.getInstance().equals(ir.getSelector())) { |
| 454 | for (Handle<T, PK, S> h: ir.getSource()) { |
| 455 | ret.add(h); |
| 456 | } |
| 457 | } else { |
| 458 | for (Handle<T, PK, S> h: ir.getSource()) { |
| 459 | fret.add(getExecutorService().submit(new SelectorTask(h, ir.getSelector()))); |
| 460 | } |
| 461 | } |
| 462 | } catch (Exception e) { |
| 463 | throw new StoreException(e); |
| 464 | } |
| 465 | } |
| 466 | |
| 467 | for (Future<Handle<T, PK, S>> fh: fret) { |
| 468 | try { |
| 469 | Handle<T, PK, S> h = fh.get(); |
| 470 | if (h!=null) { |
| 471 | ret.add(h); |
| 472 | } |
| 473 | } catch (Exception e) { |
| 474 | throw new StoreException(e); |
| 475 | } |
| 476 | } |
| 477 | |
| 478 | return new IndexizationResult(ret, null, false); |
| 479 | } |
| 480 | |
| 481 | |
| 482 | return new IndexizationResult(getNoPkStore(), selector, false); |
| 483 | } |
| 484 | |
| 485 | protected class IndexizationTask<V> implements Callable<IndexizationResult> { |
| 486 | |
| 487 | private Predicate<T, S> selector; |
| 488 | private Extractor<T, V, S> extractor; |
| 489 | |
| 490 | public IndexizationTask(Predicate<T, S> selector, Extractor<T, V, S> extractor) { |
| 491 | this.selector = selector; |
| 492 | this.extractor = extractor; |
| 493 | } |
| 494 | |
| 495 | @Override |
| 496 | public IndexizationResult call() throws Exception { |
| 497 | return indexize(selector, extractor, false, null); |
| 498 | } |
| 499 | |
| 500 | } |
| 501 | |
| 502 | /** |
| 503 | * @param selector |
| 504 | * @return |
| 505 | */ |
| 506 | protected Iterable<Handle<T, PK, S>> getHandles(Predicate<T, S> selector) { |
| 507 | readLock().lock(); |
| 508 | try { |
| 509 | IndexizationResult ir = indexize(selector, null, false, null); |
| 510 | Collection<Future<Handle<T, PK, S>>> selectResults = new ArrayList<Future<Handle<T, PK, S>>>(); |
| 511 | for (Handle<T, PK, S> h: ir.getSource()) { |
| 512 | selectResults.add(getExecutorService().submit(new SelectorTask(h, ir.getSelector()))); |
| 513 | } |
| 514 | Collection<Handle<T, PK, S>> ret = new ArrayList<Handle<T, PK, S>>(); |
| 515 | for (Future<Handle<T, PK, S>> f: selectResults) { |
| 516 | try { |
| 517 | Handle<T, PK, S> result = f.get(); |
| 518 | if (result!=null) { |
| 519 | ret.add(result); |
| 520 | } |
| 521 | } catch (Exception e) { |
| 522 | throw new StoreException(e); |
| 523 | } |
| 524 | } |
| 525 | return ret; |
| 526 | } finally { |
| 527 | readLock().unlock(); |
| 528 | } |
| 529 | } |
| 530 | |
| 531 | protected class ExtractorTask<V> implements Callable<V>, Serializable { |
| 532 | |
| 533 | private Predicate<T, S> selector; |
| 534 | private Handle<T, PK, S> handle; |
| 535 | private Extractor<T, V, S> extractor; |
| 536 | |
| 537 | public ExtractorTask(Handle<T, PK, S> handle, Predicate<T, S> selector, Extractor<T, V, S> extractor) { |
| 538 | this.handle = handle; |
| 539 | this.selector = selector; |
| 540 | this.extractor = extractor; |
| 541 | } |
| 542 | |
| 543 | /** |
| 544 | * Returns object if predicate matches. |
| 545 | */ |
| 546 | @Override |
| 547 | public V call() throws Exception { |
| 548 | if (handle.isValid() && (selector==null || handle.extract(selector))) { |
| 549 | if (extractor==null) { |
| 550 | return ((V) handle.get()); |
| 551 | } |
| 552 | return handle.extract(extractor); |
| 553 | } |
| 554 | return null; |
| 555 | } |
| 556 | |
| 557 | } |
| 558 | |
| 559 | @Override |
| 560 | public <V> Iterable<V> get( |
| 561 | Predicate<T, S> selector, |
| 562 | Extractor<T, V, S> extractor, |
| 563 | boolean ordered, |
| 564 | Comparator<V> comparator) { |
| 565 | |
| 566 | readLock().lock(); |
| 567 | try { |
| 568 | IndexizationResult ir = indexize(selector, extractor, ordered, comparator); |
| 569 | Collection<Future<V>> extractResults = new ArrayList<Future<V>>(); |
| 570 | for (Handle<T, PK, S> h: ir.getSource()) { |
| 571 | extractResults.add(getExecutorService().submit(new ExtractorTask<V>(h, ir.getSelector(), extractor))); |
| 572 | } |
| 573 | List<V> ret = new ArrayList<V>(); |
| 574 | for (Future<V> f: extractResults) { |
| 575 | try { |
| 576 | V result = f.get(); |
| 577 | if (result!=null) { |
| 578 | ret.add(result); |
| 579 | } |
| 580 | } catch (Exception e) { |
| 581 | throw new StoreException(e); |
| 582 | } |
| 583 | } |
| 584 | if (ordered && !ir.isOrdered()) { |
| 585 | if (comparator==null) { |
| 586 | // Trick. |
| 587 | Collections.sort(ret, new NaturalComparator<V>()); |
| 588 | } else { |
| 589 | Collections.sort(ret, comparator); |
| 590 | } |
| 591 | } |
| 592 | return ret; |
| 593 | } finally { |
| 594 | readLock().unlock(); |
| 595 | } |
| 596 | } |
| 597 | |
| 598 | protected class ValueSelectorTask<V> implements Callable<V>, Serializable { |
| 599 | |
| 600 | private Predicate<V, S> selector; |
| 601 | private V value; |
| 602 | |
| 603 | public ValueSelectorTask(V value, Predicate<V, S> selector) { |
| 604 | this.value = value; |
| 605 | this.selector = selector; |
| 606 | } |
| 607 | |
| 608 | /** |
| 609 | * Returns object if predicate matches. |
| 610 | */ |
| 611 | @Override |
| 612 | public V call() throws Exception { |
| 613 | if (selector.extract(createDeputy(), null, Util.wrap(value))) { |
| 614 | return value; |
| 615 | } |
| 616 | return null; |
| 617 | } |
| 618 | |
| 619 | } |
| 620 | |
| 621 | @Override |
| 622 | public <V> Iterable<V> getMultiple( |
| 623 | Predicate<T, S> selector, |
| 624 | Extractor<T, Iterable<V>, S> extractor, |
| 625 | Predicate<V, S> valueSelector, |
| 626 | boolean ordered, |
| 627 | Comparator<V> comparator) { |
| 628 | readLock().lock(); |
| 629 | try { |
| 630 | // IndexizationResult ir = indexize(selector, extractor, ordered, comparator); |
| 631 | Collection<Future<Iterable<V>>> extractResults = new ArrayList<Future<Iterable<V>>>(); |
| 632 | for (Handle<T, PK, S> h: getNoPkStore()) { |
| 633 | extractResults.add(getExecutorService().submit(new ExtractorTask<Iterable<V>>(h, selector, extractor))); |
| 634 | } |
| 635 | List<V> ret = new ArrayList<V>(); |
| 636 | if (valueSelector==null) { |
| 637 | for (Future<Iterable<V>> f: extractResults) { |
| 638 | try { |
| 639 | Iterable<V> result = f.get(); |
| 640 | if (result!=null) { |
| 641 | for (V v: result) { |
| 642 | ret.add(v); |
| 643 | } |
| 644 | } |
| 645 | } catch (Exception e) { |
| 646 | throw new StoreException(e); |
| 647 | } |
| 648 | } |
| 649 | } else { |
| 650 | List<Future<V>> fRet = new LinkedList<Future<V>>(); |
| 651 | for (Future<Iterable<V>> f: extractResults) { |
| 652 | try { |
| 653 | Iterable<V> result = f.get(); |
| 654 | if (result!=null) { |
| 655 | for (V v: result) { |
| 656 | fRet.add(getExecutorService().submit(new ValueSelectorTask<V>(v, valueSelector))); |
| 657 | } |
| 658 | } |
| 659 | } catch (Exception e) { |
| 660 | throw new StoreException(e); |
| 661 | } |
| 662 | } |
| 663 | for (Future<V> f: fRet) { |
| 664 | try { |
| 665 | V result = f.get(); |
| 666 | if (result!=null) { |
| 667 | ret.add(result); |
| 668 | } |
| 669 | } catch (Exception e) { |
| 670 | throw new StoreException(e); |
| 671 | } |
| 672 | } |
| 673 | } |
| 674 | if (ordered) { |
| 675 | if (comparator==null) { |
| 676 | // Trick. |
| 677 | Collections.sort(ret, new NaturalComparator<V>()); |
| 678 | } else { |
| 679 | Collections.sort(ret, comparator); |
| 680 | } |
| 681 | } |
| 682 | return ret; |
| 683 | } finally { |
| 684 | readLock().unlock(); |
| 685 | } |
| 686 | } |
| 687 | |
| 688 | @Override |
| 689 | public void clear() { |
| 690 | writeLock().lock(); |
| 691 | try { |
| 692 | // Marking handles as removed. |
| 693 | for (Handle<T, PK, S> h: getNoPkStore()) { |
| 694 | h.remove(); |
| 695 | } |
| 696 | // TODO - clear indices, remove from the backing store. |
| 697 | if (getPrimaryKeyExtractor()==null) { |
| 698 | getNoPkStore().clear(); |
| 699 | } else { |
| 700 | getPkStore().clear(); |
| 701 | } |
| 702 | } finally { |
| 703 | writeLock().unlock(); |
| 704 | } |
| 705 | } |
| 706 | |
| 707 | @Override |
| 708 | public boolean remove(T obj) { |
| 709 | int cleanedUp = 0; |
| 710 | writeLock().lock(); |
| 711 | try { |
| 712 | Iterator<Handle<T, PK, S>> it = getNoPkStore().iterator(); |
| 713 | while (it.hasNext()) { |
| 714 | Handle<T, PK, S> next = it.next(); |
| 715 | if (obj.equals(next.get())) { |
| 716 | next.remove(); // Handles shall just invalidate self without modifying the containing collection. |
| 717 | it.remove(); |
| 718 | // TODO remove from indices, remove from the backing store. |
| 719 | return true; |
| 720 | } |
| 721 | // Clean up also directly removed (through handle.remove()) entries. |
| 722 | if (!next.isValid()) { |
| 723 | it.remove(); |
| 724 | ++cleanedUp; |
| 725 | } |
| 726 | } |
| 727 | return false; |
| 728 | } finally { |
| 729 | writeLock().unlock(); |
| 730 | onRemoved(-cleanedUp); |
| 731 | } |
| 732 | } |
| 733 | |
| 734 | public boolean removeByPrimaryKey(PK primaryKey) { |
| 735 | writeLock().lock(); |
| 736 | try { |
| 737 | if (getPrimaryKeyExtractor()==null) { |
| 738 | throw new IllegalStateException("Object store is configured without primary key"); |
| 739 | } |
| 740 | Handle<T, PK, S> hi = getPkStore().remove(primaryKey); |
| 741 | if (hi==null || !hi.isValid()) { |
| 742 | // TODO - get from the backing store, update indices |
| 743 | return false; |
| 744 | } |
| 745 | hi.remove(); |
| 746 | return true; |
| 747 | } finally { |
| 748 | writeLock().unlock(); |
| 749 | } |
| 750 | |
| 751 | }; |
| 752 | |
| 753 | protected class RemoveTask implements Callable<Boolean>, Serializable { |
| 754 | |
| 755 | private Predicate<T, S> selector; |
| 756 | private Handle<T, PK, S> handle; |
| 757 | |
| 758 | public RemoveTask(Handle<T, PK, S> handle, Predicate<T, S> selector) { |
| 759 | this.handle = handle; |
| 760 | this.selector = selector; |
| 761 | } |
| 762 | |
| 763 | /** |
| 764 | * Removes object and returns true if predicate matches. |
| 765 | */ |
| 766 | @Override |
| 767 | public Boolean call() throws Exception { |
| 768 | if (handle.isValid() && handle.extract(selector)) { |
| 769 | handle.remove(); // TODO - remove from the backing store, shall be handled by handle.remove(). |
| 770 | return true; |
| 771 | } |
| 772 | return false; |
| 773 | } |
| 774 | |
| 775 | } |
| 776 | |
| 777 | @Override |
| 778 | public int remove(Predicate<T, S> selector) { |
| 779 | int ret = 0; |
| 780 | writeLock().lock(); |
| 781 | try { |
| 782 | IndexizationResult ir = indexize(selector, null, false, null); |
| 783 | Collection<Future<Boolean>> removeResults = new ArrayList<Future<Boolean>>(); |
| 784 | for (Handle<T, PK, S> h: ir.getSource()) { |
| 785 | removeResults.add(getExecutorService().submit(new RemoveTask(h, ir.getSelector()))); |
| 786 | } |
| 787 | for (Future<Boolean> f: removeResults) { |
| 788 | try { |
| 789 | if (f.get()) { |
| 790 | ++ret; |
| 791 | } |
| 792 | } catch (Exception e) { |
| 793 | throw new StoreException(e); |
| 794 | } |
| 795 | } |
| 796 | return ret; |
| 797 | } finally { |
| 798 | writeLock().unlock(); |
| 799 | onRemoved(ret); |
| 800 | } |
| 801 | } |
| 802 | |
| 803 | protected class UpdateCallable implements Callable<Boolean>, Serializable { |
| 804 | |
| 805 | private Predicate<T, S> selector; |
| 806 | private Handle<T, PK, S> handle; |
| 807 | private UpdateTask<T, PK, S> updater; |
| 808 | private S storeDeputy; |
| 809 | |
| 810 | public UpdateCallable(Handle<T, PK, S> handle, Predicate<T, S> selector, UpdateTask<T,PK,S> updater, S storeDeputy) { |
| 811 | this.handle = handle; |
| 812 | this.selector = selector; |
| 813 | this.updater = updater; |
| 814 | this.storeDeputy = storeDeputy; |
| 815 | } |
| 816 | |
| 817 | /** |
| 818 | * Updates object and returns true if predicate matches. |
| 819 | */ |
| 820 | @Override |
| 821 | public Boolean call() throws Exception { |
| 822 | if (handle.isValid() && handle.extract(selector)) { |
| 823 | updater.execute(storeDeputy, handle); // TODO - update backing store. |
| 824 | return true; |
| 825 | } |
| 826 | return false; |
| 827 | } |
| 828 | |
| 829 | } |
| 830 | |
| 831 | @Override |
| 832 | public int update(Predicate<T, S> selector, UpdateTask<T, PK, S> updater) { |
| 833 | writeLock().lock(); |
| 834 | try { |
| 835 | IndexizationResult ir = indexize(selector, null, false, null); |
| 836 | Collection<Future<Boolean>> updateResults = new ArrayList<Future<Boolean>>(); |
| 837 | for (Handle<T, PK, S> h: ir.getSource()) { |
| 838 | updateResults.add(getExecutorService().submit(new UpdateCallable(h, ir.getSelector(), updater, createDeputy()))); |
| 839 | } |
| 840 | int ret = 0; |
| 841 | for (Future<Boolean> f: updateResults) { |
| 842 | try { |
| 843 | if (f.get()) { |
| 844 | ++ret; |
| 845 | } |
| 846 | } catch (Exception e) { |
| 847 | throw new StoreException(e); |
| 848 | } |
| 849 | } |
| 850 | return ret; |
| 851 | } finally { |
| 852 | writeLock().unlock(); |
| 853 | } |
| 854 | } |
| 855 | |
| 856 | protected abstract Collection<AbstractIndex<T,PK, ?, S>> getIndices(); |
| 857 | |
| 858 | protected abstract <V> AbstractIndex<T,PK,V,S> createIndex( |
| 859 | Predicate<T, S> predicate, |
| 860 | Extractor<T, V, S> extractor, |
| 861 | Index.Type type, |
| 862 | boolean ordered, |
| 863 | Comparator<V> comparator); |
| 864 | |
| 865 | @SuppressWarnings("unchecked") |
| 866 | @Override |
| 867 | public <V> Index<T,PK,V,S> addIndex( |
| 868 | Predicate<T, S> predicate, |
| 869 | Extractor<T, V, S> extractor, |
| 870 | Index.Type type, |
| 871 | boolean ordered, |
| 872 | Comparator<V> comparator) { |
| 873 | |
| 874 | writeLock().lock(); |
| 875 | try { |
| 876 | for (AbstractIndex<T, PK, ?, S> index: getIndices()) { |
| 877 | if ((predicate==null && index.getPredicate()==null) || (predicate!=null && predicate.equals(index.getPredicate()))) { |
| 878 | if ((extractor == null && index.getExtractor()==null) || (extractor!=null && extractor.equals(index))) { |
| 879 | if (ordered) { |
| 880 | if (!index.isOrdered()) { |
| 881 | // Upgrade index to ordered |
| 882 | ((AbstractIndex<T,PK,V,S>) index).upgrade(type, ordered, comparator); |
| 883 | return (Index<T, PK, V, S>) index; |
| 884 | } else { |
| 885 | if ((index.getComparator()==null && comparator==null) || (comparator!=null && comparator.equals(index.getComparator()))) { |
| 886 | if (index.type.compareTo(type)>0) { |
| 887 | ((AbstractIndex<T,PK,V,S>) index).upgrade(type, ordered, comparator); |
| 888 | } |
| 889 | return (Index<T, PK, V, S>) index; |
| 890 | } |
| 891 | } |
| 892 | } else { |
| 893 | // Requested index not ordered, doesn't matter if existing index is ordered. |
| 894 | // Upgrade type if required. |
| 895 | if (index.type.compareTo(type)>0) { |
| 896 | ((AbstractIndex<T,PK,V,S>) index).upgrade(type, ordered, comparator); |
| 897 | } |
| 898 | return (Index<T, PK, V, S>) index; |
| 899 | } |
| 900 | } |
| 901 | } |
| 902 | } |
| 903 | AbstractIndex<T, PK, V, S> ret = createIndex(predicate, extractor, type, ordered, comparator); |
| 904 | for (Handle<T, PK, S> hi: getNoPkStore()) { |
| 905 | if (hi.isValid()) { |
| 906 | ret.update(hi, true); |
| 907 | } |
| 908 | } |
| 909 | getIndices().add(ret); |
| 910 | return ret.createProxy(); |
| 911 | } finally { |
| 912 | writeLock().unlock(); |
| 913 | } |
| 914 | |
| 915 | } |
| 916 | |
| 917 | private final Extractor<T,T, S> SELF_EXTRACTOR = new IndexedExtractor<T, S>(0); |
| 918 | |
| 919 | protected class QueryCallable<V> implements Callable<Boolean>, Serializable { |
| 920 | |
| 921 | private Predicate<T, S> selector; |
| 922 | private Handle<T, PK, S> handle; |
| 923 | private QueryTask<V, PK, S> query; |
| 924 | private S storeDeputy; |
| 925 | private Extractor<T, V, S> extractor; |
| 926 | |
| 927 | @SuppressWarnings("unchecked") |
| 928 | public QueryCallable( |
| 929 | Handle<T, PK, S> handle, |
| 930 | Predicate<T, S> selector, |
| 931 | Extractor<T, V, S> extractor, |
| 932 | QueryTask<V,PK, S> query, |
| 933 | S storeDeputy) { |
| 934 | this.handle = handle; |
| 935 | this.selector = selector; |
| 936 | this.query = query; |
| 937 | this.storeDeputy = storeDeputy.createUnmodifiableFacade(); |
| 938 | this.extractor = extractor; |
| 939 | if (this.extractor==null) { |
| 940 | this.extractor = (Extractor<T, V, S>) SELF_EXTRACTOR; |
| 941 | } |
| 942 | } |
| 943 | |
| 944 | /** |
| 945 | * Updates object and returns true if predicate matches. |
| 946 | */ |
| 947 | @Override |
| 948 | public Boolean call() throws Exception { |
| 949 | if (handle.isValid() && (selector==null || handle.extract(selector))) { |
| 950 | query.execute(storeDeputy, handle.extract(extractor), handle.getPrimaryKey()); |
| 951 | return true; |
| 952 | } |
| 953 | return false; |
| 954 | } |
| 955 | |
| 956 | } |
| 957 | |
| 958 | @Override |
| 959 | public int queryAll(final QueryTask<T, PK, S> query) { |
| 960 | readLock().lock(); |
| 961 | try { |
| 962 | Collection<Future<Boolean>> queryResults = new ArrayList<Future<Boolean>>(); |
| 963 | for (Handle<T, PK, S> h: getNoPkStore()) { |
| 964 | queryResults.add(getExecutorService().submit(new QueryCallable<T>(h, null, null, query, createDeputy()))); |
| 965 | } |
| 966 | int ret = 0; |
| 967 | for (Future<Boolean> f: queryResults) { |
| 968 | try { |
| 969 | if (f.get()) { |
| 970 | ++ret; |
| 971 | } |
| 972 | } catch (Exception e) { |
| 973 | throw new StoreException(e); |
| 974 | } |
| 975 | } |
| 976 | return ret; |
| 977 | } finally { |
| 978 | readLock().unlock(); |
| 979 | } |
| 980 | } |
| 981 | |
| 982 | @Override |
| 983 | public int query(Predicate<T, S> selector, QueryTask<T, PK, S> query) { |
| 984 | readLock().lock(); |
| 985 | try { |
| 986 | IndexizationResult ir = indexize(selector, null, false, null); |
| 987 | Collection<Future<Boolean>> queryResults = new ArrayList<Future<Boolean>>(); |
| 988 | for (Handle<T, PK, S> h: ir.getSource()) { |
| 989 | queryResults.add(getExecutorService().submit(new QueryCallable<T>(h, ir.getSelector(), null, query, createDeputy()))); |
| 990 | } |
| 991 | int ret = 0; |
| 992 | for (Future<Boolean> f: queryResults) { |
| 993 | try { |
| 994 | if (f.get()) { |
| 995 | ++ret; |
| 996 | } |
| 997 | } catch (Exception e) { |
| 998 | throw new StoreException(e); |
| 999 | } |
| 1000 | } |
| 1001 | |
| 1002 | return ret; |
| 1003 | } finally { |
| 1004 | readLock().unlock(); |
| 1005 | } |
| 1006 | } |
| 1007 | |
| 1008 | @Override |
| 1009 | public <V> int query( |
| 1010 | Predicate<T, S> selector, |
| 1011 | Extractor<T, V, S> extractor, |
| 1012 | QueryTask<V, PK, S> query) { |
| 1013 | |
| 1014 | readLock().lock(); |
| 1015 | try { |
| 1016 | IndexizationResult ir = indexize(selector, null, false, null); |
| 1017 | Collection<Future<Boolean>> queryResults = new ArrayList<Future<Boolean>>(); |
| 1018 | for (Handle<T, PK, S> h: ir.getSource()) { |
| 1019 | queryResults.add(getExecutorService().submit(new QueryCallable<V>(h, ir.getSelector(), extractor, query, createDeputy()))); |
| 1020 | } |
| 1021 | int ret = 0; |
| 1022 | for (Future<Boolean> f: queryResults) { |
| 1023 | try { |
| 1024 | if (f.get()) { |
| 1025 | ++ret; |
| 1026 | } |
| 1027 | } catch (Exception e) { |
| 1028 | throw new StoreException(e); |
| 1029 | } |
| 1030 | } |
| 1031 | |
| 1032 | return ret; |
| 1033 | } finally { |
| 1034 | readLock().unlock(); |
| 1035 | } |
| 1036 | } |
| 1037 | |
| 1038 | protected class QueryMultipleCallable<V> implements Callable<Collection<Future<Integer>>>, Serializable { |
| 1039 | |
| 1040 | private Predicate<T, S> selector; |
| 1041 | private Handle<T, PK, S> handle; |
| 1042 | private QueryTask<V, PK, S> query; |
| 1043 | private S storeDeputy; |
| 1044 | private Extractor<T, Iterable<V>, S> extractor; |
| 1045 | private Predicate<V, S> valueSelector; |
| 1046 | |
| 1047 | public QueryMultipleCallable( |
| 1048 | Handle<T, PK, S> handle, |
| 1049 | Predicate<T, S> selector, |
| 1050 | Extractor<T, Iterable<V>, S> extractor, |
| 1051 | Predicate<V, S> valueSelector, |
| 1052 | QueryTask<V,PK,S> query, |
| 1053 | S storeDeputy) { |
| 1054 | this.handle = handle; |
| 1055 | this.selector = selector; |
| 1056 | this.query = query; |
| 1057 | this.storeDeputy = storeDeputy; |
| 1058 | this.extractor = extractor; |
| 1059 | this.valueSelector = valueSelector; |
| 1060 | } |
| 1061 | |
| 1062 | /** |
| 1063 | * Updates object and returns true if predicate matches. |
| 1064 | */ |
| 1065 | @Override |
| 1066 | public Collection<Future<Integer>> call() throws Exception { |
| 1067 | if (handle.isValid() && (selector==null || handle.extract(selector))) { |
| 1068 | Collection<Future<Integer>> queryItemTasks = new LinkedList<Future<Integer>>(); |
| 1069 | for (V v: handle.extract(extractor)) { |
| 1070 | queryItemTasks.add(getExecutorService().submit(new QueryItemCallable<V>(v, valueSelector, handle.getPrimaryKey(), query, storeDeputy))); |
| 1071 | } |
| 1072 | return queryItemTasks; |
| 1073 | } |
| 1074 | return Collections.emptyList(); |
| 1075 | } |
| 1076 | |
| 1077 | } |
| 1078 | |
| 1079 | protected class QueryItemCallable<V> implements Callable<Integer> { |
| 1080 | |
| 1081 | private V v; |
| 1082 | private PK primaryKey; |
| 1083 | private QueryTask<V, PK, S> query; |
| 1084 | private S storeDeputy; |
| 1085 | private Predicate<V, S> valueSelector; |
| 1086 | |
| 1087 | public QueryItemCallable( |
| 1088 | V v, |
| 1089 | Predicate<V, S> valueSelector, |
| 1090 | PK primaryKey, QueryTask<V, PK, S> query, |
| 1091 | S storeDeputy) { |
| 1092 | this.v = v; |
| 1093 | this.valueSelector = valueSelector; |
| 1094 | this.primaryKey = primaryKey; |
| 1095 | this.query = query; |
| 1096 | this.storeDeputy = storeDeputy.createUnmodifiableFacade(); |
| 1097 | } |
| 1098 | |
| 1099 | @Override |
| 1100 | public Integer call() throws Exception { |
| 1101 | if (valueSelector==null || valueSelector.extract(storeDeputy, null, Util.wrap(v))) { |
| 1102 | query.execute(storeDeputy, v, primaryKey); |
| 1103 | } |
| 1104 | return 1; |
| 1105 | } |
| 1106 | |
| 1107 | } |
| 1108 | |
| 1109 | @Override |
| 1110 | public <V> int queryMultiple( |
| 1111 | Predicate<T, S> selector, |
| 1112 | Extractor<T, Iterable<V>, S> extractor, |
| 1113 | Predicate<V, S> valueSelector, |
| 1114 | QueryTask<V, PK, S> query) { |
| 1115 | readLock().lock(); |
| 1116 | try { |
| 1117 | IndexizationResult ir = indexize(selector, null, false, null); |
| 1118 | Collection<Future<Collection<Future<Integer>>>> queryResults = new ArrayList<Future<Collection<Future<Integer>>>>(); |
| 1119 | for (Handle<T, PK, S> h: ir.getSource()) { |
| 1120 | queryResults.add(getExecutorService().submit(new QueryMultipleCallable<V>(h, ir.getSelector(), extractor, valueSelector, query, createDeputy()))); |
| 1121 | } |
| 1122 | Collection<Future<Integer>> itemResults = new LinkedList<Future<Integer>>(); |
| 1123 | for (Future<Collection<Future<Integer>>> f: queryResults) { |
| 1124 | try { |
| 1125 | itemResults.addAll(f.get()); |
| 1126 | } catch (Exception e) { |
| 1127 | throw new StoreException(e); |
| 1128 | } |
| 1129 | } |
| 1130 | |
| 1131 | int ret=0; |
| 1132 | for (Future<Integer> f: itemResults) { |
| 1133 | try { |
| 1134 | ret+=f.get(); |
| 1135 | } catch (Exception e) { |
| 1136 | throw new StoreException(e); |
| 1137 | } |
| 1138 | } |
| 1139 | return ret; |
| 1140 | } finally { |
| 1141 | readLock().unlock(); |
| 1142 | } |
| 1143 | } |
| 1144 | |
| 1145 | /** |
| 1146 | * This method is invoked by handle implementations. |
| 1147 | * It shall not be invoked by client code. |
| 1148 | * @param handle |
| 1149 | * @param isNew |
| 1150 | */ |
| 1151 | protected void updateIndices(Handle<T, PK, S> handle, boolean isNew) { |
| 1152 | Iterator<AbstractIndex<T, PK, ?, S>> it = getIndices().iterator(); |
| 1153 | while (it.hasNext()) { |
| 1154 | ((AbstractIndex<T, PK, ?, S>) it.next()).update(handle, isNew); |
| 1155 | } |
| 1156 | } |
| 1157 | |
| 1158 | @Override |
| 1159 | public Iterator<T> iterator() { |
| 1160 | return getAll().iterator(); |
| 1161 | } |
| 1162 | |
| 1163 | @Override |
| 1164 | public S createView( |
| 1165 | Predicate<T, S> selector, |
| 1166 | ViewType viewType) { |
| 1167 | |
| 1168 | switch (viewType) { |
| 1169 | case LIVE: |
| 1170 | return createLiveView(selector); |
| 1171 | case SYNCHRONOUS: |
| 1172 | case ASYNCHRONOUS: |
| 1173 | case LAZY: |
| 1174 | default: |
| 1175 | throw new UnsupportedOperationException("View type is not supported: "+viewType); |
| 1176 | } |
| 1177 | } |
| 1178 | |
| 1179 | protected abstract S createLiveView(Predicate<T, S> selector); |
| 1180 | |
| 1181 | // protected |
| 1182 | |
| 1183 | } |