ExprModel.java revision 716ba89e7f459f49ea85070d4710c1d79d715298
1/* 2 * Copyright (C) 2015 The Android Open Source Project 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 17package android.databinding.tool.expr; 18 19import com.google.common.base.Optional; 20import com.google.common.base.Preconditions; 21import com.google.common.base.Predicate; 22import com.google.common.collect.Iterables; 23import com.google.common.collect.Lists; 24 25import android.databinding.tool.reflection.ModelAnalyzer; 26import android.databinding.tool.reflection.ModelClass; 27import android.databinding.tool.util.L; 28import android.databinding.tool.writer.FlagSet; 29 30import java.util.ArrayList; 31import java.util.Arrays; 32import java.util.BitSet; 33import java.util.HashMap; 34import java.util.List; 35import java.util.Map; 36 37public class ExprModel { 38 39 Map<String, Expr> mExprMap = new HashMap<String, Expr>(); 40 41 List<Expr> mBindingExpressions = new ArrayList<Expr>(); 42 43 private int mInvalidateableFieldLimit = 0; 44 45 private int mRequirementIdCount = 0; 46 47 // each arg list receives a unique id even if it is the same arguments and method. 48 private int mArgListIdCounter = 0; 49 50 private static final String TRUE_KEY_SUFFIX = "== true"; 51 private static final String FALSE_KEY_SUFFIX = "== false"; 52 53 /** 54 * Any expression can be invalidated by invalidating this flag. 55 */ 56 private BitSet mInvalidateAnyFlags; 57 58 /** 59 * Used by code generation. Keeps the list of expressions that are waiting to be evaluated. 60 */ 61 private List<Expr> mPendingExpressions; 62 63 /** 64 * Used for converting flags into identifiers while debugging. 65 */ 66 private String[] mFlagMapping; 67 68 private BitSet mInvalidateableFlags; 69 private BitSet mConditionalFlags; 70 71 private int mFlagBucketCount;// how many buckets we use to identify flags 72 73 private List<Expr> mObservables; 74 75 private boolean mSealed = false; 76 77 private Map<String, String> mImports = new HashMap<String, String>(); 78 79 /** 80 * Adds the expression to the list of expressions and returns it. 81 * If it already exists, returns existing one. 82 * 83 * @param expr The new parsed expression 84 * @return The expression itself or another one if the same thing was parsed before 85 */ 86 public <T extends Expr> T register(T expr) { 87 Preconditions.checkState(!mSealed, "Cannot add expressions to a model after it is sealed"); 88 T existing = (T) mExprMap.get(expr.getUniqueKey()); 89 if (existing != null) { 90 Preconditions.checkState(expr.getParents().isEmpty(), 91 "If an expression already exists, it should've never been added to a parent," 92 + "if thats the case, somewhere we are creating an expression w/o" 93 + "calling expression model"); 94 // tell the expr that it is being swapped so that if it was added to some other expr 95 // as a parent, those can swap their references 96 expr.onSwappedWith(existing); 97 return existing; 98 } 99 mExprMap.put(expr.getUniqueKey(), expr); 100 expr.setModel(this); 101 return expr; 102 } 103 104 public void unregister(Expr expr) { 105 mExprMap.remove(expr.getUniqueKey()); 106 } 107 108 public Map<String, Expr> getExprMap() { 109 return mExprMap; 110 } 111 112 public int size() { 113 return mExprMap.size(); 114 } 115 116 public ComparisonExpr comparison(String op, Expr left, Expr right) { 117 return register(new ComparisonExpr(op, left, right)); 118 } 119 120 public InstanceOfExpr instanceOfOp(Expr expr, String type) { 121 return register(new InstanceOfExpr(expr, type)); 122 } 123 124 public FieldAccessExpr field(Expr parent, String name) { 125 return register(new FieldAccessExpr(parent, name)); 126 } 127 128 public FieldAccessExpr observableField(Expr parent, String name) { 129 return register(new FieldAccessExpr(parent, name, true)); 130 } 131 132 public SymbolExpr symbol(String text, Class type) { 133 return register(new SymbolExpr(text, type)); 134 } 135 136 public TernaryExpr ternary(Expr pred, Expr ifTrue, Expr ifFalse) { 137 return register(new TernaryExpr(pred, ifTrue, ifFalse)); 138 } 139 140 public IdentifierExpr identifier(String name) { 141 return register(new IdentifierExpr(name)); 142 } 143 144 public StaticIdentifierExpr staticIdentifier(String name) { 145 return register(new StaticIdentifierExpr(name)); 146 } 147 148 /** 149 * Creates a static identifier for the given class or returns the existing one. 150 */ 151 public StaticIdentifierExpr staticIdentifierFor(final ModelClass modelClass) { 152 final String type = modelClass.getCanonicalName(); 153 Optional<Expr> existing = Iterables.tryFind(mExprMap.values(), new Predicate<Expr>() { 154 @Override 155 public boolean apply(Expr input) { 156 if (!(input instanceof StaticIdentifierExpr)) { 157 return false; 158 } 159 StaticIdentifierExpr id = (StaticIdentifierExpr) input; 160 return id.getUserDefinedType().equals(type); 161 } 162 }); 163 if (existing.isPresent()) { 164 return (StaticIdentifierExpr) existing.get(); 165 } 166 167 // does not exist. Find a name for it. 168 int cnt = 0; 169 int dotIndex = type.lastIndexOf("."); 170 String baseName; 171 Preconditions.checkArgument(dotIndex < type.length() - 1, "Invalid type %s", type); 172 if (dotIndex == -1) { 173 baseName = type; 174 } else { 175 baseName = type.substring(dotIndex + 1); 176 } 177 while (true) { 178 String candidate = cnt == 0 ? baseName : baseName + cnt; 179 if (!mImports.containsKey(candidate)) { 180 return addImport(candidate, type); 181 } 182 cnt ++; 183 Preconditions.checkState(cnt < 100, "Failed to create an import for " + type); 184 } 185 } 186 187 public MethodCallExpr methodCall(Expr target, String name, List<Expr> args) { 188 return register(new MethodCallExpr(target, name, args)); 189 } 190 191 public MathExpr math(Expr left, String op, Expr right) { 192 return register(new MathExpr(left, op, right)); 193 } 194 195 public TernaryExpr logical(Expr left, String op, Expr right) { 196 if ("&&".equals(op)) { 197 // left && right 198 // left ? right : false 199 return register(new TernaryExpr(left, right, symbol("false", boolean.class))); 200 } else { 201 // left || right 202 // left ? true : right 203 return register(new TernaryExpr(left, symbol("true", boolean.class), right)); 204 } 205 } 206 207 public BitShiftExpr bitshift(Expr left, String op, Expr right) { 208 return register(new BitShiftExpr(left, op, right)); 209 } 210 211 public UnaryExpr unary(String op, Expr expr) { 212 return register(new UnaryExpr(op, expr)); 213 } 214 215 public Expr group(Expr grouped) { 216 return register(new GroupExpr(grouped)); 217 } 218 219 public Expr resourceExpr(String packageName, String resourceType, String resourceName, 220 List<Expr> args) { 221 return register(new ResourceExpr(packageName, resourceType, resourceName, args)); 222 } 223 224 public Expr bracketExpr(Expr variableExpr, Expr argExpr) { 225 return register(new BracketExpr(variableExpr, argExpr)); 226 } 227 228 public Expr castExpr(String type, Expr expr) { 229 return register(new CastExpr(type, expr)); 230 } 231 232 public List<Expr> getBindingExpressions() { 233 return mBindingExpressions; 234 } 235 236 public StaticIdentifierExpr addImport(String alias, String type) { 237 Preconditions.checkState(!mImports.containsKey(alias), 238 "%s has already been defined as %s", alias, type); 239 final StaticIdentifierExpr id = staticIdentifier(alias); 240 L.d("adding import %s as %s klass: %s", type, alias, id.getClass().getSimpleName()); 241 id.setUserDefinedType(type); 242 mImports.put(alias, type); 243 return id; 244 } 245 246 public Map<String, String> getImports() { 247 return mImports; 248 } 249 250 /** 251 * The actual thingy that is set on the binding target. 252 * 253 * Input must be already registered 254 */ 255 public Expr bindingExpr(Expr bindingExpr) { 256 Preconditions.checkArgument(mExprMap.containsKey(bindingExpr.getUniqueKey()), 257 "Main expression should already be registered"); 258 if (!mBindingExpressions.contains(bindingExpr)) { 259 mBindingExpressions.add(bindingExpr); 260 } 261 return bindingExpr; 262 } 263 264 public List<Expr> getObservables() { 265 return mObservables; 266 } 267 268 /** 269 * Give id to each expression. Will be useful if we serialize. 270 */ 271 public void seal(ResolveListenersCallback resolveListeners) { 272 L.d("sealing model"); 273 List<Expr> notifiableExpressions = new ArrayList<Expr>(); 274 //ensure class analyzer. We need to know observables at this point 275 final ModelAnalyzer modelAnalyzer = ModelAnalyzer.getInstance(); 276 updateExpressions(modelAnalyzer); 277 278 if (resolveListeners != null) { 279 resolveListeners.resolveListeners(); 280 } 281 282 int counter = 0; 283 final Iterable<Expr> observables = filterObservables(modelAnalyzer); 284 List<String> flagMapping = Lists.newArrayList(); 285 mObservables = Lists.newArrayList(); 286 for (Expr expr : observables) { 287 // observables gets initial ids 288 flagMapping.add(expr.getUniqueKey()); 289 expr.setId(counter++); 290 mObservables.add(expr); 291 notifiableExpressions.add(expr); 292 L.d("observable %s", expr.getUniqueKey()); 293 } 294 295 // non-observable identifiers gets next ids 296 final Iterable<Expr> nonObservableIds = filterNonObservableIds(modelAnalyzer); 297 for (Expr expr : nonObservableIds) { 298 flagMapping.add(expr.getUniqueKey()); 299 expr.setId(counter++); 300 notifiableExpressions.add(expr); 301 L.d("non-observable %s", expr.getUniqueKey()); 302 } 303 304 // descendants of observables gets following ids 305 for (Expr expr : observables) { 306 for (Expr parent : expr.getParents()) { 307 if (parent.hasId()) { 308 continue;// already has some id, means observable 309 } 310 // only fields earn an id 311 if (parent instanceof FieldAccessExpr) { 312 FieldAccessExpr fae = (FieldAccessExpr) parent; 313 L.d("checking field access expr %s. getter: %s", fae,fae.getGetter()); 314 if (fae.isDynamic() && fae.getGetter().canBeInvalidated()) { 315 flagMapping.add(parent.getUniqueKey()); 316 parent.setId(counter++); 317 notifiableExpressions.add(parent); 318 L.d("notifiable field %s : %s for %s : %s", parent.getUniqueKey(), 319 Integer.toHexString(System.identityHashCode(parent)), 320 expr.getUniqueKey(), 321 Integer.toHexString(System.identityHashCode(expr))); 322 } 323 } 324 } 325 } 326 327 // non-dynamic binding expressions receive some ids so that they can be invalidated 328 L.d("list of binding expressions"); 329 for (int i = 0; i < mBindingExpressions.size(); i++) { 330 L.d("[%d] %s", i, mBindingExpressions.get(i)); 331 } 332 // we don't assign ids to constant binding expressions because now invalidateAll has its own 333 // flag. 334 335 for (Expr expr : notifiableExpressions) { 336 expr.enableDirectInvalidation(); 337 } 338 339 // make sure all dependencies are resolved to avoid future race conditions 340 for (Expr expr : mExprMap.values()) { 341 expr.getDependencies(); 342 } 343 final int invalidateAnyFlagIndex = counter ++; 344 flagMapping.add("INVALIDATE ANY"); 345 mInvalidateableFieldLimit = counter; 346 mInvalidateableFlags = new BitSet(); 347 for (int i = 0; i < mInvalidateableFieldLimit; i++) { 348 mInvalidateableFlags.set(i, true); 349 } 350 351 // make sure all dependencies are resolved to avoid future race conditions 352 for (Expr expr : mExprMap.values()) { 353 if (expr.isConditional()) { 354 L.d("requirement id for %s is %d", expr, counter); 355 expr.setRequirementId(counter); 356 flagMapping.add(expr.getUniqueKey() + FALSE_KEY_SUFFIX); 357 flagMapping.add(expr.getUniqueKey() + TRUE_KEY_SUFFIX); 358 counter += 2; 359 } 360 } 361 mConditionalFlags = new BitSet(); 362 for (int i = mInvalidateableFieldLimit; i < counter; i++) { 363 mConditionalFlags.set(i, true); 364 } 365 mRequirementIdCount = (counter - mInvalidateableFieldLimit) / 2; 366 367 // everybody gets an id 368 for (Map.Entry<String, Expr> entry : mExprMap.entrySet()) { 369 final Expr value = entry.getValue(); 370 if (!value.hasId()) { 371 value.setId(counter++); 372 } 373 } 374 375 mFlagMapping = new String[flagMapping.size()]; 376 flagMapping.toArray(mFlagMapping); 377 378 mFlagBucketCount = 1 + (getTotalFlagCount() / FlagSet.sBucketSize); 379 mInvalidateAnyFlags = new BitSet(); 380 mInvalidateAnyFlags.set(invalidateAnyFlagIndex, true); 381 382 for (Expr expr : mExprMap.values()) { 383 expr.getShouldReadFlagsWithConditionals(); 384 } 385 386 for (Expr expr : mExprMap.values()) { 387 // ensure all types are calculated 388 expr.getResolvedType(); 389 } 390 391 mSealed = true; 392 } 393 394 /** 395 * Run updateExpr on each binding expression until no new expressions are added. 396 * <p> 397 * Some expressions (e.g. field access) may replace themselves and add/remove new dependencies 398 * so we need to make sure each expression's update is called at least once. 399 */ 400 private void updateExpressions(ModelAnalyzer modelAnalyzer) { 401 int startSize = -1; 402 while (startSize != mExprMap.size()) { 403 startSize = mExprMap.size(); 404 ArrayList<Expr> exprs = new ArrayList<Expr>(mBindingExpressions); 405 for (Expr expr : exprs) { 406 expr.updateExpr(modelAnalyzer); 407 } 408 } 409 } 410 411 public int getFlagBucketCount() { 412 return mFlagBucketCount; 413 } 414 415 public int getTotalFlagCount() { 416 return mRequirementIdCount * 2 + mInvalidateableFieldLimit; 417 } 418 419 public int getInvalidateableFieldLimit() { 420 return mInvalidateableFieldLimit; 421 } 422 423 public String[] getFlagMapping() { 424 return mFlagMapping; 425 } 426 427 public String getFlag(int id) { 428 return mFlagMapping[id]; 429 } 430 431 private Iterable<Expr> filterNonObservableIds(final ModelAnalyzer modelAnalyzer) { 432 return Iterables.filter(mExprMap.values(), new Predicate<Expr>() { 433 @Override 434 public boolean apply(Expr input) { 435 return input instanceof IdentifierExpr 436 && !input.hasId() 437 && !input.isObservable() 438 && input.isDynamic(); 439 } 440 }); 441 } 442 443 private Iterable<Expr> filterObservables(final ModelAnalyzer modelAnalyzer) { 444 return Iterables.filter(mExprMap.values(), new Predicate<Expr>() { 445 @Override 446 public boolean apply(Expr input) { 447 return input.isObservable(); 448 } 449 }); 450 } 451 452 public List<Expr> getPendingExpressions() { 453 if (mPendingExpressions == null) { 454 mPendingExpressions = Lists.newArrayList(); 455 for (Expr expr : mExprMap.values()) { 456 if (!expr.isRead() && expr.isDynamic()) { 457 mPendingExpressions.add(expr); 458 } 459 } 460 } 461 return mPendingExpressions; 462 } 463 464 public boolean markBitsRead() { 465 // each has should read flags, we set them back on them 466 List<Expr> markedSomeFlagsRead = Lists.newArrayList(); 467 for (Expr expr : filterShouldRead(getPendingExpressions())) { 468 expr.markFlagsAsRead(expr.getShouldReadFlags()); 469 markedSomeFlagsRead.add(expr); 470 } 471 return pruneDone(markedSomeFlagsRead); 472 } 473 474 private boolean pruneDone(List<Expr> markedSomeFlagsAsRead) { 475 boolean marked = true; 476 List<Expr> markedAsReadList = Lists.newArrayList(); 477 while (marked) { 478 marked = false; 479 for (Expr expr : mExprMap.values()) { 480 if (expr.isRead()) { 481 continue; 482 } 483 if (expr.markAsReadIfDone()) { 484 L.d("marked %s as read ", expr.getUniqueKey()); 485 marked = true; 486 markedAsReadList.add(expr); 487 markedSomeFlagsAsRead.remove(expr); 488 } 489 } 490 } 491 boolean elevated = false; 492 for (Expr markedAsRead : markedAsReadList) { 493 for (Dependency dependency : markedAsRead.getDependants()) { 494 if (dependency.getDependant().considerElevatingConditionals(markedAsRead)) { 495 elevated = true; 496 } 497 } 498 } 499 for (Expr partialRead : markedSomeFlagsAsRead) { 500 boolean allPathsAreSatisfied = partialRead.getAllCalculationPaths() 501 .areAllPathsSatisfied(partialRead.mReadSoFar); 502 if (!allPathsAreSatisfied) { 503 continue; 504 } 505 for (Dependency dependency : partialRead.getDependants()) { 506 if (dependency.getDependant().considerElevatingConditionals(partialRead)) { 507 elevated = true; 508 } 509 } 510 } 511 if (elevated) { 512 // some conditionals are elevated. We should re-calculate flags 513 for (Expr expr : getPendingExpressions()) { 514 if (!expr.isRead()) { 515 expr.invalidateReadFlags(); 516 } 517 } 518 mPendingExpressions = null; 519 } 520 return elevated; 521 } 522 523 public static Iterable<Expr> filterShouldRead(Iterable<Expr> exprs) { 524 return toCollection(Iterables.filter(exprs, sShouldReadPred)); 525 } 526 527 public static List<Expr> toCollection(Iterable<Expr> iterable) { 528 return Arrays.asList(Iterables.toArray(iterable, Expr.class)); 529 } 530 531 private static final Predicate<Expr> sShouldReadPred = new Predicate<Expr>() { 532 @Override 533 public boolean apply(final Expr expr) { 534 return !expr.getShouldReadFlags().isEmpty() && !Iterables.any( 535 expr.getDependencies(), new Predicate<Dependency>() { 536 @Override 537 public boolean apply(Dependency dependency) { 538 final boolean result = dependency.isConditional() || 539 dependency.getOther().hasNestedCannotRead(); 540 return result; 541 } 542 }); 543 } 544 }; 545 546 /** 547 * May return null if flag is equal to invalidate any flag. 548 */ 549 public Expr findFlagExpression(int flag) { 550 if (mInvalidateAnyFlags.get(flag)) { 551 return null; 552 } 553 final String key = mFlagMapping[flag]; 554 if (mExprMap.containsKey(key)) { 555 return mExprMap.get(key); 556 } 557 int falseIndex = key.indexOf(FALSE_KEY_SUFFIX); 558 if (falseIndex > -1) { 559 final String trimmed = key.substring(0, falseIndex); 560 return mExprMap.get(trimmed); 561 } 562 int trueIndex = key.indexOf(TRUE_KEY_SUFFIX); 563 if (trueIndex > -1) { 564 final String trimmed = key.substring(0, trueIndex); 565 return mExprMap.get(trimmed); 566 } 567 // log everything we call 568 StringBuilder error = new StringBuilder(); 569 error.append("cannot find flag:").append(flag).append("\n"); 570 error.append("invalidate any flag:").append(mInvalidateAnyFlags).append("\n"); 571 error.append("key:").append(key).append("\n"); 572 error.append("flag mapping:").append(Arrays.toString(mFlagMapping)); 573 Preconditions.checkArgument(false, error.toString()); 574 return null; 575 } 576 577 public BitSet getInvalidateAnyBitSet() { 578 return mInvalidateAnyFlags; 579 } 580 581 public Expr argListExpr(Iterable<Expr> expressions) { 582 return register(new ArgListExpr(mArgListIdCounter ++, expressions)); 583 } 584 585 public interface ResolveListenersCallback { 586 void resolveListeners(); 587 } 588} 589