1 // Copyright 2012 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 #ifndef V8_KEY_ACCUMULATOR_H_ 6 #define V8_KEY_ACCUMULATOR_H_ 7 8 #include "src/isolate.h" 9 #include "src/objects.h" 10 11 namespace v8 { 12 namespace internal { 13 14 enum AddKeyConversion { DO_NOT_CONVERT, CONVERT_TO_ARRAY_INDEX, PROXY_MAGIC }; 15 16 // This is a helper class for JSReceiver::GetKeys which collects and sorts keys. 17 // GetKeys needs to sort keys per prototype level, first showing the integer 18 // indices from elements then the strings from the properties. However, this 19 // does not apply to proxies which are in full control of how the keys are 20 // sorted. 21 // 22 // For performance reasons the KeyAccumulator internally separates integer keys 23 // in |elements_| into sorted lists per prototype level. String keys are 24 // collected in |string_properties_|, a single OrderedHashSet (similar for 25 // Symbols in |symbol_properties_|. To separate the keys per level later when 26 // assembling the final list, |levelLengths_| keeps track of the number of 27 // String and Symbol keys per level. 28 // 29 // Only unique keys are kept by the KeyAccumulator, strings are stored in a 30 // HashSet for inexpensive lookups. Integer keys are kept in sorted lists which 31 // are more compact and allow for reasonably fast includes check. 32 class KeyAccumulator final BASE_EMBEDDED { 33 public: 34 KeyAccumulator(Isolate* isolate, PropertyFilter filter) 35 : isolate_(isolate), filter_(filter) {} 36 ~KeyAccumulator(); 37 38 bool AddKey(uint32_t key); 39 bool AddKey(Object* key, AddKeyConversion convert = DO_NOT_CONVERT); 40 bool AddKey(Handle<Object> key, AddKeyConversion convert = DO_NOT_CONVERT); 41 void AddKeys(Handle<FixedArray> array, 42 AddKeyConversion convert = DO_NOT_CONVERT); 43 void AddKeys(Handle<JSObject> array, 44 AddKeyConversion convert = DO_NOT_CONVERT); 45 void AddKeysFromProxy(Handle<JSObject> array); 46 Maybe<bool> AddKeysFromProxy(Handle<JSProxy> proxy, Handle<FixedArray> keys); 47 void AddElementKeysFromInterceptor(Handle<JSObject> array); 48 // Jump to the next level, pushing the current |levelLength_| to 49 // |levelLengths_| and adding a new list to |elements_|. 50 void NextPrototype(); 51 // Sort the integer indices in the last list in |elements_| 52 void SortCurrentElementsList(); 53 Handle<FixedArray> GetKeys(GetKeysConversion convert = KEEP_NUMBERS); 54 int length() { return length_; } 55 Isolate* isolate() { return isolate_; } 56 57 private: 58 bool AddIntegerKey(uint32_t key); 59 bool AddStringKey(Handle<Object> key, AddKeyConversion convert); 60 bool AddSymbolKey(Handle<Object> array); 61 void SortCurrentElementsListRemoveDuplicates(); 62 63 Isolate* isolate_; 64 PropertyFilter filter_; 65 // |elements_| contains the sorted element keys (indices) per level. 66 std::vector<std::vector<uint32_t>*> elements_; 67 // |protoLengths_| contains the total number of keys (elements + properties) 68 // per level. Negative values mark counts for a level with keys from a proxy. 69 std::vector<int> level_lengths_; 70 // |string_properties_| contains the unique String property keys for all 71 // levels in insertion order per level. 72 Handle<OrderedHashSet> string_properties_; 73 // |symbol_properties_| contains the unique Symbol property keys for all 74 // levels in insertion order per level. 75 Handle<OrderedHashSet> symbol_properties_; 76 // |length_| keeps track of the total number of all element and property keys. 77 int length_ = 0; 78 // |levelLength_| keeps track of the number of String keys in the current 79 // level. 80 int level_string_length_ = 0; 81 // |levelSymbolLength_| keeps track of the number of Symbol keys in the 82 // current level. 83 int level_symbol_length_ = 0; 84 85 DISALLOW_COPY_AND_ASSIGN(KeyAccumulator); 86 }; 87 88 89 } // namespace internal 90 } // namespace v8 91 92 93 #endif // V8_KEY_ACCUMULATOR_H_ 94
