LCOV - code coverage report
Current view: top level - src - keys.h (source / functions) Hit Total Coverage
Test: app.info Lines: 8 8 100.0 %
Date: 2017-04-26 Functions: 1 1 100.0 %

          Line data    Source code
       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:
      34        3702 :   KeyAccumulator(Isolate* isolate, KeyCollectionMode mode,
      35             :                  PropertyFilter filter)
      36    19316426 :       : 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 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             :   // Might return directly the object's enum_cache, copy the result before using
      57             :   // as an elements backing store for a JSObject.
      58             :   static Handle<FixedArray> GetOwnEnumPropertyKeys(Isolate* isolate,
      59             :                                                    Handle<JSObject> object);
      60             :   void AddKey(Object* key, AddKeyConversion convert = DO_NOT_CONVERT);
      61             :   void AddKey(Handle<Object> key, AddKeyConversion convert = DO_NOT_CONVERT);
      62             :   void AddKeys(Handle<FixedArray> array, AddKeyConversion convert);
      63             :   void AddKeys(Handle<JSObject> array_like, AddKeyConversion convert);
      64             : 
      65             :   // Jump to the next level, pushing the current |levelLength_| to
      66             :   // |levelLengths_| and adding a new list to |elements_|.
      67             :   Isolate* isolate() { return isolate_; }
      68             :   // Filter keys based on their property descriptors.
      69             :   PropertyFilter filter() { return filter_; }
      70             :   // The collection mode defines whether we collect the keys from the prototype
      71             :   // chain or only look at the receiver.
      72             :   KeyCollectionMode mode() { return mode_; }
      73             :   // In case of for-in loops we have to treat JSProxy keys differently and
      74             :   // deduplicate them. Additionally we convert JSProxy keys back to array
      75             :   // indices.
      76      628059 :   void set_is_for_in(bool value) { is_for_in_ = value; }
      77     9026129 :   void set_skip_indices(bool value) { skip_indices_ = value; }
      78             :   // The last_non_empty_prototype is used to limit the prototypes for which
      79             :   // we have to keep track of non-enumerable keys that can shadow keys
      80             :   // repeated on the prototype chain.
      81             :   void set_last_non_empty_prototype(Handle<JSReceiver> object) {
      82      628059 :     last_non_empty_prototype_ = object;
      83             :   }
      84             :   // Shadowing keys are used to filter keys. This happens when non-enumerable
      85             :   // keys appear again on the prototype chain.
      86             :   void AddShadowingKey(Object* key);
      87             :   void AddShadowingKey(Handle<Object> key);
      88             : 
      89             :  private:
      90             :   Maybe<bool> CollectOwnKeys(Handle<JSReceiver> receiver,
      91             :                              Handle<JSObject> object);
      92             :   Maybe<bool> CollectOwnJSProxyKeys(Handle<JSReceiver> receiver,
      93             :                                     Handle<JSProxy> proxy);
      94             :   Maybe<bool> CollectOwnJSProxyTargetKeys(Handle<JSProxy> proxy,
      95             :                                           Handle<JSReceiver> target);
      96             :   Maybe<bool> AddKeysFromJSProxy(Handle<JSProxy> proxy,
      97             :                                  Handle<FixedArray> keys);
      98             :   bool IsShadowed(Handle<Object> key);
      99             :   bool HasShadowingKeys();
     100             :   Handle<OrderedHashSet> keys() { return Handle<OrderedHashSet>::cast(keys_); }
     101             : 
     102             :   Isolate* isolate_;
     103             :   // keys_ is either an Handle<OrderedHashSet> or in the case of own JSProxy
     104             :   // keys a Handle<FixedArray>. The OrderedHashSet is in-place converted to the
     105             :   // result list, a FixedArray containing all collected keys.
     106             :   Handle<FixedArray> keys_;
     107             :   Handle<JSReceiver> last_non_empty_prototype_;
     108             :   Handle<ObjectHashSet> shadowing_keys_;
     109             :   KeyCollectionMode mode_;
     110             :   PropertyFilter filter_;
     111             :   bool is_for_in_ = false;
     112             :   bool skip_indices_ = false;
     113             :   // For all the keys on the first receiver adding a shadowing key we can skip
     114             :   // the shadow check.
     115             :   bool skip_shadow_check_ = true;
     116             : 
     117             :   DISALLOW_COPY_AND_ASSIGN(KeyAccumulator);
     118             : };
     119             : 
     120             : // The FastKeyAccumulator handles the cases where there are no elements on the
     121             : // prototype chain and forwords the complex/slow cases to the normal
     122             : // KeyAccumulator. This significantly speeds up the cases where the OWN_ONLY
     123             : // case where we do not have to walk the prototype chain.
     124             : class FastKeyAccumulator {
     125             :  public:
     126             :   FastKeyAccumulator(Isolate* isolate, Handle<JSReceiver> receiver,
     127             :                      KeyCollectionMode mode, PropertyFilter filter)
     128     4299764 :       : isolate_(isolate), receiver_(receiver), mode_(mode), filter_(filter) {
     129     2149882 :     Prepare();
     130             :   }
     131             : 
     132             :   bool is_receiver_simple_enum() { return is_receiver_simple_enum_; }
     133             :   bool has_empty_prototype() { return has_empty_prototype_; }
     134     2149882 :   void set_is_for_in(bool value) { is_for_in_ = value; }
     135             : 
     136             :   MaybeHandle<FixedArray> GetKeys(
     137             :       GetKeysConversion convert = GetKeysConversion::kKeepNumbers);
     138             : 
     139             :  private:
     140             :   void Prepare();
     141             :   MaybeHandle<FixedArray> GetKeysFast(GetKeysConversion convert);
     142             :   MaybeHandle<FixedArray> GetKeysSlow(GetKeysConversion convert);
     143             : 
     144             :   MaybeHandle<FixedArray> GetOwnKeysWithUninitializedEnumCache();
     145             : 
     146             :   Isolate* isolate_;
     147             :   Handle<JSReceiver> receiver_;
     148             :   Handle<JSReceiver> last_non_empty_prototype_;
     149             :   KeyCollectionMode mode_;
     150             :   PropertyFilter filter_;
     151             :   bool is_for_in_ = false;
     152             :   bool is_receiver_simple_enum_ = false;
     153             :   bool has_empty_prototype_ = false;
     154             : 
     155             :   DISALLOW_COPY_AND_ASSIGN(FastKeyAccumulator);
     156             : };
     157             : 
     158             : }  // namespace internal
     159             : }  // namespace v8
     160             : 
     161             : #endif  // V8_KEYS_H_

Generated by: LCOV version 1.10