OLD | NEW |
| (Empty) |
1 // Copyright 2013 the V8 project authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #include "src/keys.h" | |
6 | |
7 #include "src/elements.h" | |
8 #include "src/factory.h" | |
9 #include "src/isolate-inl.h" | |
10 #include "src/objects-inl.h" | |
11 #include "src/property-descriptor.h" | |
12 #include "src/prototype.h" | |
13 | |
14 namespace v8 { | |
15 namespace internal { | |
16 | |
17 KeyAccumulator::~KeyAccumulator() { | |
18 for (size_t i = 0; i < elements_.size(); i++) { | |
19 delete elements_[i]; | |
20 } | |
21 } | |
22 | |
23 Handle<FixedArray> KeyAccumulator::GetKeys(GetKeysConversion convert) { | |
24 if (length_ == 0) { | |
25 return isolate_->factory()->empty_fixed_array(); | |
26 } | |
27 // Make sure we have all the lengths collected. | |
28 NextPrototype(); | |
29 | |
30 if (type_ == OWN_ONLY && !ownProxyKeys_.is_null()) { | |
31 return ownProxyKeys_; | |
32 } | |
33 // Assemble the result array by first adding the element keys and then the | |
34 // property keys. We use the total number of String + Symbol keys per level in | |
35 // |level_lengths_| and the available element keys in the corresponding bucket | |
36 // in |elements_| to deduce the number of keys to take from the | |
37 // |string_properties_| and |symbol_properties_| set. | |
38 Handle<FixedArray> result = isolate_->factory()->NewFixedArray(length_); | |
39 int insertion_index = 0; | |
40 int string_properties_index = 0; | |
41 int symbol_properties_index = 0; | |
42 // String and Symbol lengths always come in pairs: | |
43 size_t max_level = level_lengths_.size() / 2; | |
44 for (size_t level = 0; level < max_level; level++) { | |
45 int num_string_properties = level_lengths_[level * 2]; | |
46 int num_symbol_properties = level_lengths_[level * 2 + 1]; | |
47 if (num_string_properties < 0) { | |
48 // If the |num_string_properties| is negative, the current level contains | |
49 // properties from a proxy, hence we skip the integer keys in |elements_| | |
50 // since proxies define the complete ordering. | |
51 num_string_properties = -num_string_properties; | |
52 } else if (level < elements_.size()) { | |
53 // Add the element indices for this prototype level. | |
54 std::vector<uint32_t>* elements = elements_[level]; | |
55 int num_elements = static_cast<int>(elements->size()); | |
56 for (int i = 0; i < num_elements; i++) { | |
57 Handle<Object> key; | |
58 if (convert == KEEP_NUMBERS) { | |
59 key = isolate_->factory()->NewNumberFromUint(elements->at(i)); | |
60 } else { | |
61 key = isolate_->factory()->Uint32ToString(elements->at(i)); | |
62 } | |
63 result->set(insertion_index, *key); | |
64 insertion_index++; | |
65 } | |
66 } | |
67 // Add the string property keys for this prototype level. | |
68 for (int i = 0; i < num_string_properties; i++) { | |
69 Object* key = string_properties_->KeyAt(string_properties_index); | |
70 result->set(insertion_index, key); | |
71 insertion_index++; | |
72 string_properties_index++; | |
73 } | |
74 // Add the symbol property keys for this prototype level. | |
75 for (int i = 0; i < num_symbol_properties; i++) { | |
76 Object* key = symbol_properties_->KeyAt(symbol_properties_index); | |
77 result->set(insertion_index, key); | |
78 insertion_index++; | |
79 symbol_properties_index++; | |
80 } | |
81 } | |
82 | |
83 DCHECK_EQ(insertion_index, length_); | |
84 return result; | |
85 } | |
86 | |
87 namespace { | |
88 | |
89 bool AccumulatorHasKey(std::vector<uint32_t>* sub_elements, uint32_t key) { | |
90 return std::binary_search(sub_elements->begin(), sub_elements->end(), key); | |
91 } | |
92 | |
93 } // namespace | |
94 | |
95 bool KeyAccumulator::AddKey(Object* key, AddKeyConversion convert) { | |
96 return AddKey(handle(key, isolate_), convert); | |
97 } | |
98 | |
99 bool KeyAccumulator::AddKey(Handle<Object> key, AddKeyConversion convert) { | |
100 if (key->IsSymbol()) { | |
101 if (filter_ & SKIP_SYMBOLS) return false; | |
102 if (Handle<Symbol>::cast(key)->is_private()) return false; | |
103 return AddSymbolKey(key); | |
104 } | |
105 if (filter_ & SKIP_STRINGS) return false; | |
106 // Make sure we do not add keys to a proxy-level (see AddKeysFromProxy). | |
107 DCHECK_LE(0, level_string_length_); | |
108 // In some cases (e.g. proxies) we might get in String-converted ints which | |
109 // should be added to the elements list instead of the properties. For | |
110 // proxies we have to convert as well but also respect the original order. | |
111 // Therefore we add a converted key to both sides | |
112 if (convert == CONVERT_TO_ARRAY_INDEX || convert == PROXY_MAGIC) { | |
113 uint32_t index = 0; | |
114 int prev_length = length_; | |
115 int prev_proto = level_string_length_; | |
116 if ((key->IsString() && Handle<String>::cast(key)->AsArrayIndex(&index)) || | |
117 key->ToArrayIndex(&index)) { | |
118 bool key_was_added = AddIntegerKey(index); | |
119 if (convert == CONVERT_TO_ARRAY_INDEX) return key_was_added; | |
120 if (convert == PROXY_MAGIC) { | |
121 // If we had an array index (number) and it wasn't added, the key | |
122 // already existed before, hence we cannot add it to the properties | |
123 // keys as it would lead to duplicate entries. | |
124 if (!key_was_added) { | |
125 return false; | |
126 } | |
127 length_ = prev_length; | |
128 level_string_length_ = prev_proto; | |
129 } | |
130 } | |
131 } | |
132 return AddStringKey(key, convert); | |
133 } | |
134 | |
135 bool KeyAccumulator::AddKey(uint32_t key) { return AddIntegerKey(key); } | |
136 | |
137 bool KeyAccumulator::AddIntegerKey(uint32_t key) { | |
138 // Make sure we do not add keys to a proxy-level (see AddKeysFromProxy). | |
139 // We mark proxy-levels with a negative length | |
140 DCHECK_LE(0, level_string_length_); | |
141 // Binary search over all but the last level. The last one might not be | |
142 // sorted yet. | |
143 for (size_t i = 1; i < elements_.size(); i++) { | |
144 if (AccumulatorHasKey(elements_[i - 1], key)) return false; | |
145 } | |
146 elements_.back()->push_back(key); | |
147 length_++; | |
148 return true; | |
149 } | |
150 | |
151 bool KeyAccumulator::AddStringKey(Handle<Object> key, | |
152 AddKeyConversion convert) { | |
153 if (string_properties_.is_null()) { | |
154 string_properties_ = OrderedHashSet::Allocate(isolate_, 16); | |
155 } | |
156 // TODO(cbruni): remove this conversion once we throw the correct TypeError | |
157 // for non-string/symbol elements returned by proxies | |
158 if (convert == PROXY_MAGIC && key->IsNumber()) { | |
159 key = isolate_->factory()->NumberToString(key); | |
160 } | |
161 int prev_size = string_properties_->NumberOfElements(); | |
162 string_properties_ = OrderedHashSet::Add(string_properties_, key); | |
163 if (prev_size < string_properties_->NumberOfElements()) { | |
164 length_++; | |
165 level_string_length_++; | |
166 return true; | |
167 } else { | |
168 return false; | |
169 } | |
170 } | |
171 | |
172 bool KeyAccumulator::AddSymbolKey(Handle<Object> key) { | |
173 if (symbol_properties_.is_null()) { | |
174 symbol_properties_ = OrderedHashSet::Allocate(isolate_, 16); | |
175 } | |
176 int prev_size = symbol_properties_->NumberOfElements(); | |
177 symbol_properties_ = OrderedHashSet::Add(symbol_properties_, key); | |
178 if (prev_size < symbol_properties_->NumberOfElements()) { | |
179 length_++; | |
180 level_symbol_length_++; | |
181 return true; | |
182 } else { | |
183 return false; | |
184 } | |
185 } | |
186 | |
187 void KeyAccumulator::AddKeys(Handle<FixedArray> array, | |
188 AddKeyConversion convert) { | |
189 int add_length = array->length(); | |
190 if (add_length == 0) return; | |
191 for (int i = 0; i < add_length; i++) { | |
192 Handle<Object> current(array->get(i), isolate_); | |
193 AddKey(current, convert); | |
194 } | |
195 } | |
196 | |
197 void KeyAccumulator::AddKeys(Handle<JSObject> array_like, | |
198 AddKeyConversion convert) { | |
199 DCHECK(array_like->IsJSArray() || array_like->HasSloppyArgumentsElements()); | |
200 ElementsAccessor* accessor = array_like->GetElementsAccessor(); | |
201 accessor->AddElementsToKeyAccumulator(array_like, this, convert); | |
202 } | |
203 | |
204 void KeyAccumulator::AddKeysFromProxy(Handle<JSObject> array_like) { | |
205 // Proxies define a complete list of keys with no distinction of | |
206 // elements and properties, which breaks the normal assumption for the | |
207 // KeyAccumulator. | |
208 AddKeys(array_like, PROXY_MAGIC); | |
209 // Invert the current length to indicate a present proxy, so we can ignore | |
210 // element keys for this level. Otherwise we would not fully respect the order | |
211 // given by the proxy. | |
212 level_string_length_ = -level_string_length_; | |
213 } | |
214 | |
215 MaybeHandle<FixedArray> FilterProxyKeys(Isolate* isolate, Handle<JSProxy> owner, | |
216 Handle<FixedArray> keys, | |
217 PropertyFilter filter) { | |
218 if (filter == ALL_PROPERTIES) { | |
219 // Nothing to do. | |
220 return keys; | |
221 } | |
222 int store_position = 0; | |
223 for (int i = 0; i < keys->length(); ++i) { | |
224 Handle<Name> key(Name::cast(keys->get(i)), isolate); | |
225 if (key->FilterKey(filter)) continue; // Skip this key. | |
226 if (filter & ONLY_ENUMERABLE) { | |
227 PropertyDescriptor desc; | |
228 Maybe<bool> found = | |
229 JSProxy::GetOwnPropertyDescriptor(isolate, owner, key, &desc); | |
230 MAYBE_RETURN(found, MaybeHandle<FixedArray>()); | |
231 if (!found.FromJust() || !desc.enumerable()) continue; // Skip this key. | |
232 } | |
233 // Keep this key. | |
234 if (store_position != i) { | |
235 keys->set(store_position, *key); | |
236 } | |
237 store_position++; | |
238 } | |
239 if (store_position == 0) return isolate->factory()->empty_fixed_array(); | |
240 keys->Shrink(store_position); | |
241 return keys; | |
242 } | |
243 | |
244 // Returns "nothing" in case of exception, "true" on success. | |
245 Maybe<bool> KeyAccumulator::AddKeysFromProxy(Handle<JSProxy> proxy, | |
246 Handle<FixedArray> keys) { | |
247 ASSIGN_RETURN_ON_EXCEPTION_VALUE( | |
248 isolate_, keys, FilterProxyKeys(isolate_, proxy, keys, filter_), | |
249 Nothing<bool>()); | |
250 // Proxies define a complete list of keys with no distinction of | |
251 // elements and properties, which breaks the normal assumption for the | |
252 // KeyAccumulator. | |
253 if (type_ == OWN_ONLY) { | |
254 ownProxyKeys_ = keys; | |
255 level_string_length_ = keys->length(); | |
256 length_ = level_string_length_; | |
257 } else { | |
258 AddKeys(keys, PROXY_MAGIC); | |
259 } | |
260 // Invert the current length to indicate a present proxy, so we can ignore | |
261 // element keys for this level. Otherwise we would not fully respect the order | |
262 // given by the proxy. | |
263 level_string_length_ = -level_string_length_; | |
264 return Just(true); | |
265 } | |
266 | |
267 void KeyAccumulator::AddElementKeysFromInterceptor( | |
268 Handle<JSObject> array_like) { | |
269 AddKeys(array_like, CONVERT_TO_ARRAY_INDEX); | |
270 // The interceptor might introduce duplicates for the current level, since | |
271 // these keys get added after the objects's normal element keys. | |
272 SortCurrentElementsListRemoveDuplicates(); | |
273 } | |
274 | |
275 void KeyAccumulator::SortCurrentElementsListRemoveDuplicates() { | |
276 // Sort and remove duplicates from the current elements level and adjust. | |
277 // the lengths accordingly. | |
278 auto last_level = elements_.back(); | |
279 size_t nof_removed_keys = last_level->size(); | |
280 std::sort(last_level->begin(), last_level->end()); | |
281 last_level->erase(std::unique(last_level->begin(), last_level->end()), | |
282 last_level->end()); | |
283 // Adjust total length by the number of removed duplicates. | |
284 nof_removed_keys -= last_level->size(); | |
285 length_ -= static_cast<int>(nof_removed_keys); | |
286 } | |
287 | |
288 void KeyAccumulator::SortCurrentElementsList() { | |
289 if (elements_.empty()) return; | |
290 auto element_keys = elements_.back(); | |
291 std::sort(element_keys->begin(), element_keys->end()); | |
292 } | |
293 | |
294 void KeyAccumulator::NextPrototype() { | |
295 // Store the protoLength on the first call of this method. | |
296 if (!elements_.empty()) { | |
297 level_lengths_.push_back(level_string_length_); | |
298 level_lengths_.push_back(level_symbol_length_); | |
299 } | |
300 elements_.push_back(new std::vector<uint32_t>()); | |
301 level_string_length_ = 0; | |
302 level_symbol_length_ = 0; | |
303 } | |
304 | |
305 namespace { | |
306 | |
307 void TrySettingEmptyEnumCache(JSReceiver* object) { | |
308 Map* map = object->map(); | |
309 DCHECK_EQ(kInvalidEnumCacheSentinel, map->EnumLength()); | |
310 if (!map->OnlyHasSimpleProperties()) return; | |
311 if (map->IsJSProxyMap()) return; | |
312 if (map->NumberOfOwnDescriptors() > 0) { | |
313 int number_of_enumerable_own_properties = | |
314 map->NumberOfDescribedProperties(OWN_DESCRIPTORS, ENUMERABLE_STRINGS); | |
315 if (number_of_enumerable_own_properties > 0) return; | |
316 } | |
317 DCHECK(object->IsJSObject()); | |
318 map->SetEnumLength(0); | |
319 } | |
320 | |
321 bool CheckAndInitalizeSimpleEnumCache(JSReceiver* object) { | |
322 if (object->map()->EnumLength() == kInvalidEnumCacheSentinel) { | |
323 TrySettingEmptyEnumCache(object); | |
324 } | |
325 if (object->map()->EnumLength() != 0) return false; | |
326 DCHECK(object->IsJSObject()); | |
327 return !JSObject::cast(object)->HasEnumerableElements(); | |
328 } | |
329 } // namespace | |
330 | |
331 void FastKeyAccumulator::Prepare() { | |
332 DisallowHeapAllocation no_gc; | |
333 // Directly go for the fast path for OWN_ONLY keys. | |
334 if (type_ == OWN_ONLY) return; | |
335 // Fully walk the prototype chain and find the last prototype with keys. | |
336 is_receiver_simple_enum_ = false; | |
337 has_empty_prototype_ = true; | |
338 JSReceiver* first_non_empty_prototype; | |
339 for (PrototypeIterator iter(isolate_, *receiver_); !iter.IsAtEnd(); | |
340 iter.Advance()) { | |
341 JSReceiver* current = iter.GetCurrent<JSReceiver>(); | |
342 if (CheckAndInitalizeSimpleEnumCache(current)) continue; | |
343 has_empty_prototype_ = false; | |
344 first_non_empty_prototype = current; | |
345 // TODO(cbruni): use the first non-empty prototype. | |
346 USE(first_non_empty_prototype); | |
347 return; | |
348 } | |
349 DCHECK(has_empty_prototype_); | |
350 is_receiver_simple_enum_ = | |
351 receiver_->map()->EnumLength() != kInvalidEnumCacheSentinel && | |
352 !JSObject::cast(*receiver_)->HasEnumerableElements(); | |
353 } | |
354 | |
355 namespace { | |
356 Handle<FixedArray> GetOwnKeysWithElements(Isolate* isolate, | |
357 Handle<JSObject> object, | |
358 GetKeysConversion convert) { | |
359 Handle<FixedArray> keys = JSObject::GetFastEnumPropertyKeys(isolate, object); | |
360 ElementsAccessor* accessor = object->GetElementsAccessor(); | |
361 return accessor->PrependElementIndices(object, keys, convert, | |
362 ONLY_ENUMERABLE); | |
363 } | |
364 | |
365 MaybeHandle<FixedArray> GetOwnKeysWithUninitializedEnumCache( | |
366 Isolate* isolate, Handle<JSObject> object) { | |
367 // Uninitalized enum cache | |
368 Map* map = object->map(); | |
369 if (object->elements() != isolate->heap()->empty_fixed_array() || | |
370 object->elements() != isolate->heap()->empty_slow_element_dictionary()) { | |
371 // Assume that there are elements. | |
372 return MaybeHandle<FixedArray>(); | |
373 } | |
374 int number_of_own_descriptors = map->NumberOfOwnDescriptors(); | |
375 if (number_of_own_descriptors == 0) { | |
376 map->SetEnumLength(0); | |
377 return isolate->factory()->empty_fixed_array(); | |
378 } | |
379 // We have no elements but possibly enumerable property keys, hence we can | |
380 // directly initialize the enum cache. | |
381 return JSObject::GetFastEnumPropertyKeys(isolate, object); | |
382 } | |
383 | |
384 } // namespace | |
385 | |
386 MaybeHandle<FixedArray> FastKeyAccumulator::GetKeys(GetKeysConversion convert) { | |
387 Handle<FixedArray> keys; | |
388 if (GetKeysFast(convert).ToHandle(&keys)) { | |
389 return keys; | |
390 } | |
391 return GetKeysSlow(convert); | |
392 } | |
393 | |
394 MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysFast( | |
395 GetKeysConversion convert) { | |
396 bool own_only = has_empty_prototype_ || type_ == OWN_ONLY; | |
397 if (!own_only || !receiver_->map()->OnlyHasSimpleProperties()) { | |
398 return MaybeHandle<FixedArray>(); | |
399 } | |
400 | |
401 Handle<FixedArray> keys; | |
402 DCHECK(receiver_->IsJSObject()); | |
403 Handle<JSObject> object = Handle<JSObject>::cast(receiver_); | |
404 | |
405 int enum_length = receiver_->map()->EnumLength(); | |
406 if (enum_length == kInvalidEnumCacheSentinel) { | |
407 // Try initializing the enum cache and return own properties. | |
408 if (GetOwnKeysWithUninitializedEnumCache(isolate_, object) | |
409 .ToHandle(&keys)) { | |
410 is_receiver_simple_enum_ = | |
411 object->map()->EnumLength() != kInvalidEnumCacheSentinel; | |
412 return keys; | |
413 } | |
414 } | |
415 // The properties-only case failed because there were probably elements on the | |
416 // receiver. | |
417 return GetOwnKeysWithElements(isolate_, object, convert); | |
418 } | |
419 | |
420 MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysSlow( | |
421 GetKeysConversion convert) { | |
422 return JSReceiver::GetKeys(receiver_, type_, ENUMERABLE_STRINGS); | |
423 } | |
424 | |
425 } // namespace internal | |
426 } // namespace v8 | |
OLD | NEW |