OLD | NEW |
| (Empty) |
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, KeyCollectionType type, | |
35 PropertyFilter filter) | |
36 : isolate_(isolate), type_(type), filter_(filter) {} | |
37 ~KeyAccumulator(); | |
38 | |
39 bool AddKey(uint32_t key); | |
40 bool AddKey(Object* key, AddKeyConversion convert); | |
41 bool AddKey(Handle<Object> key, AddKeyConversion convert); | |
42 void AddKeys(Handle<FixedArray> array, AddKeyConversion convert); | |
43 void AddKeys(Handle<JSObject> array, AddKeyConversion convert); | |
44 void AddKeysFromProxy(Handle<JSObject> array); | |
45 Maybe<bool> AddKeysFromProxy(Handle<JSProxy> proxy, Handle<FixedArray> keys); | |
46 void AddElementKeysFromInterceptor(Handle<JSObject> array); | |
47 // Jump to the next level, pushing the current |levelLength_| to | |
48 // |levelLengths_| and adding a new list to |elements_|. | |
49 void NextPrototype(); | |
50 // Sort the integer indices in the last list in |elements_| | |
51 void SortCurrentElementsList(); | |
52 Handle<FixedArray> GetKeys(GetKeysConversion convert = KEEP_NUMBERS); | |
53 int length() { return length_; } | |
54 Isolate* isolate() { return isolate_; } | |
55 | |
56 private: | |
57 bool AddIntegerKey(uint32_t key); | |
58 bool AddStringKey(Handle<Object> key, AddKeyConversion convert); | |
59 bool AddSymbolKey(Handle<Object> array); | |
60 void SortCurrentElementsListRemoveDuplicates(); | |
61 | |
62 Isolate* isolate_; | |
63 KeyCollectionType type_; | |
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 Handle<FixedArray> ownProxyKeys_; | |
77 // |length_| keeps track of the total number of all element and property keys. | |
78 int length_ = 0; | |
79 // |levelLength_| keeps track of the number of String keys in the current | |
80 // level. | |
81 int level_string_length_ = 0; | |
82 // |levelSymbolLength_| keeps track of the number of Symbol keys in the | |
83 // current level. | |
84 int level_symbol_length_ = 0; | |
85 | |
86 DISALLOW_COPY_AND_ASSIGN(KeyAccumulator); | |
87 }; | |
88 | |
89 // The FastKeyAccumulator handles the cases where there are no elements on the | |
90 // prototype chain and forwords the complex/slow cases to the normal | |
91 // KeyAccumulator. | |
92 class FastKeyAccumulator { | |
93 public: | |
94 FastKeyAccumulator(Isolate* isolate, Handle<JSReceiver> receiver, | |
95 KeyCollectionType type, PropertyFilter filter) | |
96 : isolate_(isolate), receiver_(receiver), type_(type), filter_(filter) { | |
97 Prepare(); | |
98 // TODO(cbruni): pass filter_ directly to the KeyAccumulator. | |
99 USE(filter_); | |
100 } | |
101 | |
102 bool is_receiver_simple_enum() { return is_receiver_simple_enum_; } | |
103 bool has_empty_prototype() { return has_empty_prototype_; } | |
104 | |
105 MaybeHandle<FixedArray> GetKeys(GetKeysConversion convert = KEEP_NUMBERS); | |
106 | |
107 private: | |
108 void Prepare(); | |
109 MaybeHandle<FixedArray> GetKeysFast(GetKeysConversion convert); | |
110 MaybeHandle<FixedArray> GetKeysSlow(GetKeysConversion convert); | |
111 | |
112 Isolate* isolate_; | |
113 Handle<JSReceiver> receiver_; | |
114 KeyCollectionType type_; | |
115 PropertyFilter filter_; | |
116 bool is_receiver_simple_enum_ = false; | |
117 bool has_empty_prototype_ = false; | |
118 | |
119 DISALLOW_COPY_AND_ASSIGN(FastKeyAccumulator); | |
120 }; | |
121 | |
122 } // namespace internal | |
123 } // namespace v8 | |
124 | |
125 #endif // V8_KEY_ACCUMULATOR_H_ | |
OLD | NEW |