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_KEYS_H_ 6 #define V8_KEYS_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 }; 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: KeyAccumulator(Isolate * isolate,KeyCollectionMode mode,PropertyFilter filter)34 KeyAccumulator(Isolate* isolate, KeyCollectionMode mode, 35 PropertyFilter filter) 36 : isolate_(isolate), mode_(mode), filter_(filter) {} 37 ~KeyAccumulator(); 38 39 static MaybeHandle<FixedArray> GetKeys( 40 Handle<JSReceiver> object, KeyCollectionMode mode, PropertyFilter filter, 41 GetKeysConversion keys_conversion = GetKeysConversion::kKeepNumbers, 42 bool filter_proxy_keys = true, bool is_for_in = false); 43 44 Handle<FixedArray> GetKeys( 45 GetKeysConversion convert = GetKeysConversion::kKeepNumbers); 46 Maybe<bool> CollectKeys(Handle<JSReceiver> receiver, 47 Handle<JSReceiver> object); 48 Maybe<bool> CollectOwnElementIndices(Handle<JSReceiver> receiver, 49 Handle<JSObject> object); 50 Maybe<bool> CollectOwnPropertyNames(Handle<JSReceiver> receiver, 51 Handle<JSObject> object); 52 Maybe<bool> CollectAccessCheckInterceptorKeys( 53 Handle<AccessCheckInfo> access_check_info, Handle<JSReceiver> receiver, 54 Handle<JSObject> object); 55 56 static Handle<FixedArray> GetEnumPropertyKeys(Isolate* isolate, 57 Handle<JSObject> object); 58 59 void AddKey(Object* key, AddKeyConversion convert = DO_NOT_CONVERT); 60 void AddKey(Handle<Object> key, AddKeyConversion convert = DO_NOT_CONVERT); 61 void AddKeys(Handle<FixedArray> array, AddKeyConversion convert); 62 void AddKeys(Handle<JSObject> array_like, AddKeyConversion convert); 63 64 // Jump to the next level, pushing the current |levelLength_| to 65 // |levelLengths_| and adding a new list to |elements_|. isolate()66 Isolate* isolate() { return isolate_; } filter()67 PropertyFilter filter() { return filter_; } set_filter_proxy_keys(bool filter)68 void set_filter_proxy_keys(bool filter) { filter_proxy_keys_ = filter; } set_is_for_in(bool value)69 void set_is_for_in(bool value) { is_for_in_ = value; } set_skip_indices(bool value)70 void set_skip_indices(bool value) { skip_indices_ = value; } set_last_non_empty_prototype(Handle<JSReceiver> object)71 void set_last_non_empty_prototype(Handle<JSReceiver> object) { 72 last_non_empty_prototype_ = object; 73 } 74 75 private: 76 Maybe<bool> CollectOwnKeys(Handle<JSReceiver> receiver, 77 Handle<JSObject> object); 78 Maybe<bool> CollectOwnJSProxyKeys(Handle<JSReceiver> receiver, 79 Handle<JSProxy> proxy); 80 Maybe<bool> CollectOwnJSProxyTargetKeys(Handle<JSProxy> proxy, 81 Handle<JSReceiver> target); 82 83 Maybe<bool> AddKeysFromJSProxy(Handle<JSProxy> proxy, 84 Handle<FixedArray> keys); 85 keys()86 Handle<OrderedHashSet> keys() { return Handle<OrderedHashSet>::cast(keys_); } 87 88 Isolate* isolate_; 89 // keys_ is either an Handle<OrderedHashSet> or in the case of own JSProxy 90 // keys a Handle<FixedArray>. 91 Handle<FixedArray> keys_; 92 Handle<JSReceiver> last_non_empty_prototype_; 93 KeyCollectionMode mode_; 94 PropertyFilter filter_; 95 bool filter_proxy_keys_ = true; 96 bool is_for_in_ = false; 97 bool skip_indices_ = false; 98 99 DISALLOW_COPY_AND_ASSIGN(KeyAccumulator); 100 }; 101 102 // The FastKeyAccumulator handles the cases where there are no elements on the 103 // prototype chain and forwords the complex/slow cases to the normal 104 // KeyAccumulator. 105 class FastKeyAccumulator { 106 public: FastKeyAccumulator(Isolate * isolate,Handle<JSReceiver> receiver,KeyCollectionMode mode,PropertyFilter filter)107 FastKeyAccumulator(Isolate* isolate, Handle<JSReceiver> receiver, 108 KeyCollectionMode mode, PropertyFilter filter) 109 : isolate_(isolate), receiver_(receiver), mode_(mode), filter_(filter) { 110 Prepare(); 111 } 112 is_receiver_simple_enum()113 bool is_receiver_simple_enum() { return is_receiver_simple_enum_; } has_empty_prototype()114 bool has_empty_prototype() { return has_empty_prototype_; } set_filter_proxy_keys(bool filter)115 void set_filter_proxy_keys(bool filter) { filter_proxy_keys_ = filter; } set_is_for_in(bool value)116 void set_is_for_in(bool value) { is_for_in_ = value; } 117 118 MaybeHandle<FixedArray> GetKeys( 119 GetKeysConversion convert = GetKeysConversion::kKeepNumbers); 120 121 private: 122 void Prepare(); 123 MaybeHandle<FixedArray> GetKeysFast(GetKeysConversion convert); 124 MaybeHandle<FixedArray> GetKeysSlow(GetKeysConversion convert); 125 126 Isolate* isolate_; 127 Handle<JSReceiver> receiver_; 128 Handle<JSReceiver> last_non_empty_prototype_; 129 KeyCollectionMode mode_; 130 PropertyFilter filter_; 131 bool filter_proxy_keys_ = true; 132 bool is_for_in_ = false; 133 bool is_receiver_simple_enum_ = false; 134 bool has_empty_prototype_ = false; 135 136 DISALLOW_COPY_AND_ASSIGN(FastKeyAccumulator); 137 }; 138 139 } // namespace internal 140 } // namespace v8 141 142 #endif // V8_KEYS_H_ 143