| // Copyright 2012 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_KEY_ACCUMULATOR_H_ |
| #define V8_KEY_ACCUMULATOR_H_ |
| |
| #include "src/isolate.h" |
| #include "src/objects.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| enum AddKeyConversion { DO_NOT_CONVERT, CONVERT_TO_ARRAY_INDEX, PROXY_MAGIC }; |
| |
| // This is a helper class for JSReceiver::GetKeys which collects and sorts keys. |
| // GetKeys needs to sort keys per prototype level, first showing the integer |
| // indices from elements then the strings from the properties. However, this |
| // does not apply to proxies which are in full control of how the keys are |
| // sorted. |
| // |
| // For performance reasons the KeyAccumulator internally separates integer keys |
| // in |elements_| into sorted lists per prototype level. String keys are |
| // collected in |string_properties_|, a single OrderedHashSet (similar for |
| // Symbols in |symbol_properties_|. To separate the keys per level later when |
| // assembling the final list, |levelLengths_| keeps track of the number of |
| // String and Symbol keys per level. |
| // |
| // Only unique keys are kept by the KeyAccumulator, strings are stored in a |
| // HashSet for inexpensive lookups. Integer keys are kept in sorted lists which |
| // are more compact and allow for reasonably fast includes check. |
| class KeyAccumulator final BASE_EMBEDDED { |
| public: |
| KeyAccumulator(Isolate* isolate, PropertyFilter filter) |
| : isolate_(isolate), filter_(filter) {} |
| ~KeyAccumulator(); |
| |
| bool AddKey(uint32_t key); |
| bool AddKey(Object* key, AddKeyConversion convert = DO_NOT_CONVERT); |
| bool AddKey(Handle<Object> key, AddKeyConversion convert = DO_NOT_CONVERT); |
| void AddKeys(Handle<FixedArray> array, |
| AddKeyConversion convert = DO_NOT_CONVERT); |
| void AddKeys(Handle<JSObject> array, |
| AddKeyConversion convert = DO_NOT_CONVERT); |
| void AddKeysFromProxy(Handle<JSObject> array); |
| Maybe<bool> AddKeysFromProxy(Handle<JSProxy> proxy, Handle<FixedArray> keys); |
| void AddElementKeysFromInterceptor(Handle<JSObject> array); |
| // Jump to the next level, pushing the current |levelLength_| to |
| // |levelLengths_| and adding a new list to |elements_|. |
| void NextPrototype(); |
| // Sort the integer indices in the last list in |elements_| |
| void SortCurrentElementsList(); |
| Handle<FixedArray> GetKeys(GetKeysConversion convert = KEEP_NUMBERS); |
| int length() { return length_; } |
| Isolate* isolate() { return isolate_; } |
| |
| private: |
| bool AddIntegerKey(uint32_t key); |
| bool AddStringKey(Handle<Object> key, AddKeyConversion convert); |
| bool AddSymbolKey(Handle<Object> array); |
| void SortCurrentElementsListRemoveDuplicates(); |
| |
| Isolate* isolate_; |
| PropertyFilter filter_; |
| // |elements_| contains the sorted element keys (indices) per level. |
| std::vector<std::vector<uint32_t>*> elements_; |
| // |protoLengths_| contains the total number of keys (elements + properties) |
| // per level. Negative values mark counts for a level with keys from a proxy. |
| std::vector<int> level_lengths_; |
| // |string_properties_| contains the unique String property keys for all |
| // levels in insertion order per level. |
| Handle<OrderedHashSet> string_properties_; |
| // |symbol_properties_| contains the unique Symbol property keys for all |
| // levels in insertion order per level. |
| Handle<OrderedHashSet> symbol_properties_; |
| // |length_| keeps track of the total number of all element and property keys. |
| int length_ = 0; |
| // |levelLength_| keeps track of the number of String keys in the current |
| // level. |
| int level_string_length_ = 0; |
| // |levelSymbolLength_| keeps track of the number of Symbol keys in the |
| // current level. |
| int level_symbol_length_ = 0; |
| |
| DISALLOW_COPY_AND_ASSIGN(KeyAccumulator); |
| }; |
| |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| |
| #endif // V8_KEY_ACCUMULATOR_H_ |