Index: src/key-accumulator.h |
diff --git a/src/key-accumulator.h b/src/key-accumulator.h |
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+// 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: |
+ explicit KeyAccumulator(Isolate* isolate, |
+ KeyFilter filter = KeyFilter::SKIP_SYMBOLS) |
+ : 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); |
+ 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_; } |
+ |
+ private: |
+ bool AddIntegerKey(uint32_t key); |
+ bool AddStringKey(Handle<Object> key, AddKeyConversion convert); |
+ bool AddSymbolKey(Handle<Object> array); |
+ void SortCurrentElementsListRemoveDuplicates(); |
+ |
+ Isolate* isolate_; |
+ KeyFilter 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_ |