Revert of [key-accumulator] Starting to reimplement the key-accumulator

src/keys.h

-// 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, KeyCollectionType type,
-                 PropertyFilter filter)
-      : isolate_(isolate), type_(type), filter_(filter) {}
-  ~KeyAccumulator();
-
-  bool AddKey(uint32_t key);
-  bool AddKey(Object* key, AddKeyConversion convert);
-  bool AddKey(Handle<Object> key, AddKeyConversion convert);
-  void AddKeys(Handle<FixedArray> array, AddKeyConversion convert);
-  void AddKeys(Handle<JSObject> array, AddKeyConversion 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_;
-  KeyCollectionType type_;
-  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_;
-  Handle<FixedArray> ownProxyKeys_;
-  // |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);
-};
-
-// The FastKeyAccumulator handles the cases where there are no elements on the
-// prototype chain and forwords the complex/slow cases to the normal
-// KeyAccumulator.
-class FastKeyAccumulator {
- public:
-  FastKeyAccumulator(Isolate* isolate, Handle<JSReceiver> receiver,
-                     KeyCollectionType type, PropertyFilter filter)
-      : isolate_(isolate), receiver_(receiver), type_(type), filter_(filter) {
-    Prepare();
-    // TODO(cbruni): pass filter_ directly to the KeyAccumulator.
-    USE(filter_);
-  }
-
-  bool is_receiver_simple_enum() { return is_receiver_simple_enum_; }
-  bool has_empty_prototype() { return has_empty_prototype_; }
-
-  MaybeHandle<FixedArray> GetKeys(GetKeysConversion convert = KEEP_NUMBERS);
-
- private:
-  void Prepare();
-  MaybeHandle<FixedArray> GetKeysFast(GetKeysConversion convert);
-  MaybeHandle<FixedArray> GetKeysSlow(GetKeysConversion convert);
-
-  Isolate* isolate_;
-  Handle<JSReceiver> receiver_;
-  KeyCollectionType type_;
-  PropertyFilter filter_;
-  bool is_receiver_simple_enum_ = false;
-  bool has_empty_prototype_ = false;
-
-  DISALLOW_COPY_AND_ASSIGN(FastKeyAccumulator);
-};
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_KEY_ACCUMULATOR_H_