Home | History | Annotate | Download | only in src 
      1 // Copyright 2013 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 #include "src/key-accumulator.h"
      6 
      7 #include "src/elements.h"
      8 #include "src/factory.h"
      9 #include "src/isolate-inl.h"
     10 #include "src/objects-inl.h"
     11 #include "src/property-descriptor.h"
     12 
     13 
     14 namespace v8 {
     15 namespace internal {
     16 
     17 
     18 KeyAccumulator::~KeyAccumulator() {
     19   for (size_t i = 0; i < elements_.size(); i++) {
     20     delete elements_[i];
     21   }
     22 }
     23 
     24 
     25 Handle<FixedArray> KeyAccumulator::GetKeys(GetKeysConversion convert) {
     26   if (length_ == 0) {
     27     return isolate_->factory()->empty_fixed_array();
     28   }
     29   // Make sure we have all the lengths collected.
     30   NextPrototype();
     31 
     32   // Assemble the result array by first adding the element keys and then the
     33   // property keys. We use the total number of String + Symbol keys per level in
     34   // |level_lengths_| and the available element keys in the corresponding bucket
     35   // in |elements_| to deduce the number of keys to take from the
     36   // |string_properties_| and |symbol_properties_| set.
     37   Handle<FixedArray> result = isolate_->factory()->NewFixedArray(length_);
     38   int insertion_index = 0;
     39   int string_properties_index = 0;
     40   int symbol_properties_index = 0;
     41   // String and Symbol lengths always come in pairs:
     42   size_t max_level = level_lengths_.size() / 2;
     43   for (size_t level = 0; level < max_level; level++) {
     44     int num_string_properties = level_lengths_[level * 2];
     45     int num_symbol_properties = level_lengths_[level * 2 + 1];
     46     if (num_string_properties < 0) {
     47       // If the |num_string_properties| is negative, the current level contains
     48       // properties from a proxy, hence we skip the integer keys in |elements_|
     49       // since proxies define the complete ordering.
     50       num_string_properties = -num_string_properties;
     51     } else if (level < elements_.size()) {
     52       // Add the element indices for this prototype level.
     53       std::vector<uint32_t>* elements = elements_[level];
     54       int num_elements = static_cast<int>(elements->size());
     55       for (int i = 0; i < num_elements; i++) {
     56         Handle<Object> key;
     57         if (convert == KEEP_NUMBERS) {
     58           key = isolate_->factory()->NewNumberFromUint(elements->at(i));
     59         } else {
     60           key = isolate_->factory()->Uint32ToString(elements->at(i));
     61         }
     62         result->set(insertion_index, *key);
     63         insertion_index++;
     64       }
     65     }
     66     // Add the string property keys for this prototype level.
     67     for (int i = 0; i < num_string_properties; i++) {
     68       Object* key = string_properties_->KeyAt(string_properties_index);
     69       result->set(insertion_index, key);
     70       insertion_index++;
     71       string_properties_index++;
     72     }
     73     // Add the symbol property keys for this prototype level.
     74     for (int i = 0; i < num_symbol_properties; i++) {
     75       Object* key = symbol_properties_->KeyAt(symbol_properties_index);
     76       result->set(insertion_index, key);
     77       insertion_index++;
     78       symbol_properties_index++;
     79     }
     80   }
     81 
     82   DCHECK_EQ(insertion_index, length_);
     83   return result;
     84 }
     85 
     86 
     87 namespace {
     88 
     89 bool AccumulatorHasKey(std::vector<uint32_t>* sub_elements, uint32_t key) {
     90   return std::binary_search(sub_elements->begin(), sub_elements->end(), key);
     91 }
     92 
     93 }  // namespace
     94 
     95 bool KeyAccumulator::AddKey(Object* key, AddKeyConversion convert) {
     96   return AddKey(handle(key, isolate_), convert);
     97 }
     98 
     99 
    100 bool KeyAccumulator::AddKey(Handle<Object> key, AddKeyConversion convert) {
    101   if (key->IsSymbol()) {
    102     if (filter_ & SKIP_SYMBOLS) return false;
    103     if (Handle<Symbol>::cast(key)->is_private()) return false;
    104     return AddSymbolKey(key);
    105   }
    106   if (filter_ & SKIP_STRINGS) return false;
    107   // Make sure we do not add keys to a proxy-level (see AddKeysFromProxy).
    108   DCHECK_LE(0, level_string_length_);
    109   // In some cases (e.g. proxies) we might get in String-converted ints which
    110   // should be added to the elements list instead of the properties. For
    111   // proxies we have to convert as well but also respect the original order.
    112   // Therefore we add a converted key to both sides
    113   if (convert == CONVERT_TO_ARRAY_INDEX || convert == PROXY_MAGIC) {
    114     uint32_t index = 0;
    115     int prev_length = length_;
    116     int prev_proto = level_string_length_;
    117     if ((key->IsString() && Handle<String>::cast(key)->AsArrayIndex(&index)) ||
    118         key->ToArrayIndex(&index)) {
    119       bool key_was_added = AddIntegerKey(index);
    120       if (convert == CONVERT_TO_ARRAY_INDEX) return key_was_added;
    121       if (convert == PROXY_MAGIC) {
    122         // If we had an array index (number) and it wasn't added, the key
    123         // already existed before, hence we cannot add it to the properties
    124         // keys as it would lead to duplicate entries.
    125         if (!key_was_added) {
    126           return false;
    127         }
    128         length_ = prev_length;
    129         level_string_length_ = prev_proto;
    130       }
    131     }
    132   }
    133   return AddStringKey(key, convert);
    134 }
    135 
    136 
    137 bool KeyAccumulator::AddKey(uint32_t key) { return AddIntegerKey(key); }
    138 
    139 
    140 bool KeyAccumulator::AddIntegerKey(uint32_t key) {
    141   // Make sure we do not add keys to a proxy-level (see AddKeysFromProxy).
    142   // We mark proxy-levels with a negative length
    143   DCHECK_LE(0, level_string_length_);
    144   // Binary search over all but the last level. The last one might not be
    145   // sorted yet.
    146   for (size_t i = 1; i < elements_.size(); i++) {
    147     if (AccumulatorHasKey(elements_[i - 1], key)) return false;
    148   }
    149   elements_.back()->push_back(key);
    150   length_++;
    151   return true;
    152 }
    153 
    154 
    155 bool KeyAccumulator::AddStringKey(Handle<Object> key,
    156                                   AddKeyConversion convert) {
    157   if (string_properties_.is_null()) {
    158     string_properties_ = OrderedHashSet::Allocate(isolate_, 16);
    159   }
    160   // TODO(cbruni): remove this conversion once we throw the correct TypeError
    161   // for non-string/symbol elements returned by proxies
    162   if (convert == PROXY_MAGIC && key->IsNumber()) {
    163     key = isolate_->factory()->NumberToString(key);
    164   }
    165   int prev_size = string_properties_->NumberOfElements();
    166   string_properties_ = OrderedHashSet::Add(string_properties_, key);
    167   if (prev_size < string_properties_->NumberOfElements()) {
    168     length_++;
    169     level_string_length_++;
    170     return true;
    171   } else {
    172     return false;
    173   }
    174 }
    175 
    176 
    177 bool KeyAccumulator::AddSymbolKey(Handle<Object> key) {
    178   if (symbol_properties_.is_null()) {
    179     symbol_properties_ = OrderedHashSet::Allocate(isolate_, 16);
    180   }
    181   int prev_size = symbol_properties_->NumberOfElements();
    182   symbol_properties_ = OrderedHashSet::Add(symbol_properties_, key);
    183   if (prev_size < symbol_properties_->NumberOfElements()) {
    184     length_++;
    185     level_symbol_length_++;
    186     return true;
    187   } else {
    188     return false;
    189   }
    190 }
    191 
    192 
    193 void KeyAccumulator::AddKeys(Handle<FixedArray> array,
    194                              AddKeyConversion convert) {
    195   int add_length = array->length();
    196   if (add_length == 0) return;
    197   for (int i = 0; i < add_length; i++) {
    198     Handle<Object> current(array->get(i), isolate_);
    199     AddKey(current, convert);
    200   }
    201 }
    202 
    203 
    204 void KeyAccumulator::AddKeys(Handle<JSObject> array_like,
    205                              AddKeyConversion convert) {
    206   DCHECK(array_like->IsJSArray() || array_like->HasSloppyArgumentsElements());
    207   ElementsAccessor* accessor = array_like->GetElementsAccessor();
    208   accessor->AddElementsToKeyAccumulator(array_like, this, convert);
    209 }
    210 
    211 
    212 void KeyAccumulator::AddKeysFromProxy(Handle<JSObject> array_like) {
    213   // Proxies define a complete list of keys with no distinction of
    214   // elements and properties, which breaks the normal assumption for the
    215   // KeyAccumulator.
    216   AddKeys(array_like, PROXY_MAGIC);
    217   // Invert the current length to indicate a present proxy, so we can ignore
    218   // element keys for this level. Otherwise we would not fully respect the order
    219   // given by the proxy.
    220   level_string_length_ = -level_string_length_;
    221 }
    222 
    223 
    224 MaybeHandle<FixedArray> FilterProxyKeys(Isolate* isolate, Handle<JSProxy> owner,
    225                                         Handle<FixedArray> keys,
    226                                         PropertyFilter filter) {
    227   if (filter == ALL_PROPERTIES) {
    228     // Nothing to do.
    229     return keys;
    230   }
    231   int store_position = 0;
    232   for (int i = 0; i < keys->length(); ++i) {
    233     Handle<Name> key(Name::cast(keys->get(i)), isolate);
    234     if (key->FilterKey(filter)) continue;  // Skip this key.
    235     if (filter & ONLY_ENUMERABLE) {
    236       PropertyDescriptor desc;
    237       Maybe<bool> found =
    238           JSProxy::GetOwnPropertyDescriptor(isolate, owner, key, &desc);
    239       MAYBE_RETURN(found, MaybeHandle<FixedArray>());
    240       if (!found.FromJust() || !desc.enumerable()) continue;  // Skip this key.
    241     }
    242     // Keep this key.
    243     if (store_position != i) {
    244       keys->set(store_position, *key);
    245     }
    246     store_position++;
    247   }
    248   if (store_position == 0) return isolate->factory()->empty_fixed_array();
    249   keys->Shrink(store_position);
    250   return keys;
    251 }
    252 
    253 
    254 // Returns "nothing" in case of exception, "true" on success.
    255 Maybe<bool> KeyAccumulator::AddKeysFromProxy(Handle<JSProxy> proxy,
    256                                              Handle<FixedArray> keys) {
    257   ASSIGN_RETURN_ON_EXCEPTION_VALUE(
    258       isolate_, keys, FilterProxyKeys(isolate_, proxy, keys, filter_),
    259       Nothing<bool>());
    260   // Proxies define a complete list of keys with no distinction of
    261   // elements and properties, which breaks the normal assumption for the
    262   // KeyAccumulator.
    263   AddKeys(keys, PROXY_MAGIC);
    264   // Invert the current length to indicate a present proxy, so we can ignore
    265   // element keys for this level. Otherwise we would not fully respect the order
    266   // given by the proxy.
    267   level_string_length_ = -level_string_length_;
    268   return Just(true);
    269 }
    270 
    271 
    272 void KeyAccumulator::AddElementKeysFromInterceptor(
    273     Handle<JSObject> array_like) {
    274   AddKeys(array_like, CONVERT_TO_ARRAY_INDEX);
    275   // The interceptor might introduce duplicates for the current level, since
    276   // these keys get added after the objects's normal element keys.
    277   SortCurrentElementsListRemoveDuplicates();
    278 }
    279 
    280 
    281 void KeyAccumulator::SortCurrentElementsListRemoveDuplicates() {
    282   // Sort and remove duplicates from the current elements level and adjust.
    283   // the lengths accordingly.
    284   auto last_level = elements_.back();
    285   size_t nof_removed_keys = last_level->size();
    286   std::sort(last_level->begin(), last_level->end());
    287   last_level->erase(std::unique(last_level->begin(), last_level->end()),
    288                     last_level->end());
    289   // Adjust total length by the number of removed duplicates.
    290   nof_removed_keys -= last_level->size();
    291   length_ -= static_cast<int>(nof_removed_keys);
    292 }
    293 
    294 
    295 void KeyAccumulator::SortCurrentElementsList() {
    296   if (elements_.empty()) return;
    297   auto element_keys = elements_.back();
    298   std::sort(element_keys->begin(), element_keys->end());
    299 }
    300 
    301 
    302 void KeyAccumulator::NextPrototype() {
    303   // Store the protoLength on the first call of this method.
    304   if (!elements_.empty()) {
    305     level_lengths_.push_back(level_string_length_);
    306     level_lengths_.push_back(level_symbol_length_);
    307   }
    308   elements_.push_back(new std::vector<uint32_t>());
    309   level_string_length_ = 0;
    310   level_symbol_length_ = 0;
    311 }
    312 
    313 
    314 }  // namespace internal
    315 }  // namespace v8
    316