[symbol table] use plain hash table to implement symbol table in isolate

The per-Isolate Symbol tables are implemented using NameDictionary
before, which has additional property details overhead
And NameDictionary is limited to 2^23, which limits the Symbol
tables to be a maximum of 2^23.

- replace NameDictionary with SymbolTable in isolate

Bug: v8:12575
Change-Id: Ica4f05aac3494f7dfa3a074c240d4ba25df814e9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3476897Reviewed-by: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79285}

BUILD.bazel

@@ -1751,6 +1751,7 @@ filegroup(
         "src/objects/string-set.h",
         "src/objects/string-table-inl.h",
         "src/objects/string-table.cc",
+        "src/objects/symbol-table.cc",
         "src/objects/string-table.h",
         "src/objects/string.cc",
         "src/objects/string.h",

BUILD.gn

@@ -4348,6 +4348,7 @@ v8_source_set("v8_base_without_compiler") {
     "src/objects/string-table.cc",
     "src/objects/string.cc",
     "src/objects/swiss-name-dictionary.cc",
+    "src/objects/symbol-table.cc",
     "src/objects/synthetic-module.cc",
     "src/objects/tagged-impl.cc",
     "src/objects/template-objects.cc",

src/builtins/base.tq

@@ -214,6 +214,7 @@ extern class OrderedHashMap extends HashTable;
 extern class OrderedHashSet extends HashTable;
 extern class OrderedNameDictionary extends HashTable;
 extern class NameToIndexHashTable extends HashTable;
+extern class RegisteredSymbolTable extends HashTable;
 extern class NameDictionary extends HashTable;
 extern class GlobalDictionary extends HashTable;
 extern class SimpleNumberDictionary extends HashTable;

src/diagnostics/objects-debug.cc

@@ -205,6 +205,7 @@ void HeapObject::HeapObjectVerify(Isolate* isolate) {
     case ORDERED_HASH_SET_TYPE:
     case ORDERED_NAME_DICTIONARY_TYPE:
     case NAME_TO_INDEX_HASH_TABLE_TYPE:
+    case REGISTERED_SYMBOL_TABLE_TYPE:
     case NAME_DICTIONARY_TYPE:
     case GLOBAL_DICTIONARY_TYPE:
     case NUMBER_DICTIONARY_TYPE:

src/diagnostics/objects-printer.cc

@@ -141,6 +141,9 @@ void HeapObject::HeapObjectPrint(std::ostream& os) {
     case NAME_TO_INDEX_HASH_TABLE_TYPE:
       NameToIndexHashTable::cast(*this).NameToIndexHashTablePrint(os);
       break;
+    case REGISTERED_SYMBOL_TABLE_TYPE:
+      RegisteredSymbolTable::cast(*this).RegisteredSymbolTablePrint(os);
+      break;
     case ORDERED_HASH_MAP_TYPE:
       OrderedHashMap::cast(*this).OrderedHashMapPrint(os);
       break;
@@ -969,6 +972,11 @@ void NameToIndexHashTable::NameToIndexHashTablePrint(std::ostream& os) {
   PrintHashMapContentsFull(os, *this);
 }
 
+void RegisteredSymbolTable::RegisteredSymbolTablePrint(std::ostream& os) {
+  PrintHashTableHeader(os, *this, "RegisteredSymbolTable");
+  PrintHashMapContentsFull(os, *this);
+}
+
 void NumberDictionary::NumberDictionaryPrint(std::ostream& os) {
   PrintHashTableHeader(os, *this, "NumberDictionary");
   PrintDictionaryContentsFull(os, *this);

src/execution/isolate.cc

@@ -4477,16 +4477,16 @@ ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
 Handle<Symbol> Isolate::SymbolFor(RootIndex dictionary_index,
                                   Handle<String> name, bool private_symbol) {
   Handle<String> key = factory()->InternalizeString(name);
-  Handle<NameDictionary> dictionary =
-      Handle<NameDictionary>::cast(root_handle(dictionary_index));
+  Handle<RegisteredSymbolTable> dictionary =
+      Handle<RegisteredSymbolTable>::cast(root_handle(dictionary_index));
   InternalIndex entry = dictionary->FindEntry(this, key);
   Handle<Symbol> symbol;
   if (entry.is_not_found()) {
     symbol =
         private_symbol ? factory()->NewPrivateSymbol() : factory()->NewSymbol();
     symbol->set_description(*key);
-    dictionary = NameDictionary::Add(this, dictionary, key, symbol,
-                                     PropertyDetails::Empty(), &entry);
+    dictionary = RegisteredSymbolTable::Add(this, dictionary, key, symbol);
+
     switch (dictionary_index) {
       case RootIndex::kPublicSymbolTable:
         symbol->set_is_in_public_symbol_table(true);

src/heap/setup-heap-internal.cc

@@ -477,6 +477,7 @@ bool Heap::CreateInitialMaps() {
                          simple_number_dictionary)
     ALLOCATE_VARSIZE_MAP(NAME_TO_INDEX_HASH_TABLE_TYPE,
                          name_to_index_hash_table)
+    ALLOCATE_VARSIZE_MAP(REGISTERED_SYMBOL_TABLE_TYPE, registered_symbol_table)
 
     ALLOCATE_VARSIZE_MAP(EMBEDDER_DATA_ARRAY_TYPE, embedder_data_array)
     ALLOCATE_VARSIZE_MAP(EPHEMERON_HASH_TABLE_TYPE, ephemeron_hash_table)
@@ -796,9 +797,12 @@ void Heap::CreateInitialObjects() {
 
   set_empty_property_dictionary(*empty_property_dictionary);
 
-  set_public_symbol_table(*empty_property_dictionary);
-  set_api_symbol_table(*empty_property_dictionary);
-  set_api_private_symbol_table(*empty_property_dictionary);
+  Handle<RegisteredSymbolTable> empty_symbol_table = RegisteredSymbolTable::New(
+      isolate(), 1, AllocationType::kReadOnly, USE_CUSTOM_MINIMUM_CAPACITY);
+  DCHECK(!empty_symbol_table->HasSufficientCapacityToAdd(1));
+  set_public_symbol_table(*empty_symbol_table);
+  set_api_symbol_table(*empty_symbol_table);
+  set_api_private_symbol_table(*empty_symbol_table);
 
   set_number_string_cache(*factory->NewFixedArray(
       kInitialNumberStringCacheSize * 2, AllocationType::kOld));

src/objects/hash-table-inl.h

@@ -35,6 +35,11 @@ ObjectHashTable::ObjectHashTable(Address ptr)
   SLOW_DCHECK(IsObjectHashTable());
 }
 
+RegisteredSymbolTable::RegisteredSymbolTable(Address ptr)
+    : HashTable<RegisteredSymbolTable, RegisteredSymbolTableShape>(ptr) {
+  SLOW_DCHECK(IsRegisteredSymbolTable());
+}
+
 EphemeronHashTable::EphemeronHashTable(Address ptr)
     : ObjectHashTableBase<EphemeronHashTable, ObjectHashTableShape>(ptr) {
   SLOW_DCHECK(IsEphemeronHashTable());
@@ -51,6 +56,7 @@ NameToIndexHashTable::NameToIndexHashTable(Address ptr)
 }
 
 CAST_ACCESSOR(ObjectHashTable)
+CAST_ACCESSOR(RegisteredSymbolTable)
 CAST_ACCESSOR(EphemeronHashTable)
 CAST_ACCESSOR(ObjectHashSet)
 CAST_ACCESSOR(NameToIndexHashTable)
@@ -135,6 +141,11 @@ Handle<Map> NameToIndexHashTable::GetMap(ReadOnlyRoots roots) {
   return roots.name_to_index_hash_table_map_handle();
 }
 
+// static
+Handle<Map> RegisteredSymbolTable::GetMap(ReadOnlyRoots roots) {
+  return roots.registered_symbol_table_map_handle();
+}
+
 // static
 Handle<Map> EphemeronHashTable::GetMap(ReadOnlyRoots roots) {
   return roots.ephemeron_hash_table_map_handle();
@@ -265,6 +276,21 @@ bool ObjectHashTableShape::IsMatch(Handle<Object> key, Object other) {
   return key->SameValue(other);
 }
 
+bool RegisteredSymbolTableShape::IsMatch(Handle<String> key, Object value) {
+  DCHECK(value.IsString());
+  return key->Equals(String::cast(value));
+}
+
+uint32_t RegisteredSymbolTableShape::Hash(ReadOnlyRoots roots,
+                                          Handle<String> key) {
+  return key->EnsureHash();
+}
+
+uint32_t RegisteredSymbolTableShape::HashForObject(ReadOnlyRoots roots,
+                                                   Object object) {
+  return String::cast(object).EnsureHash();
+}
+
 bool NameToIndexShape::IsMatch(Handle<Name> key, Object other) {
   return *key == other;
 }

src/objects/hash-table.h

@@ -479,6 +479,43 @@ class V8_EXPORT_PRIVATE NameToIndexHashTable
   }
 };
 
+class RegisteredSymbolTableShape : public BaseShape<Handle<String>> {
+ public:
+  static inline bool IsMatch(Handle<String> key, Object other);
+  static inline uint32_t Hash(ReadOnlyRoots roots, Handle<String> key);
+  static inline uint32_t HashForObject(ReadOnlyRoots roots, Object object);
+  static const int kPrefixSize = 0;
+  static const int kEntryValueIndex = 1;
+  static const int kEntrySize = 2;
+  static const bool kMatchNeedsHoleCheck = false;
+};
+
+class RegisteredSymbolTable
+    : public HashTable<RegisteredSymbolTable, RegisteredSymbolTableShape> {
+ public:
+  Object SlowReverseLookup(Object value);
+
+  // Returns the value at entry.
+  Object ValueAt(InternalIndex entry);
+
+  inline static Handle<Map> GetMap(ReadOnlyRoots roots);
+
+  static Handle<RegisteredSymbolTable> Add(Isolate* isolate,
+                                           Handle<RegisteredSymbolTable> table,
+                                           Handle<String> key, Handle<Symbol>);
+
+  DECL_CAST(RegisteredSymbolTable)
+  DECL_PRINTER(RegisteredSymbolTable)
+  OBJECT_CONSTRUCTORS(
+      RegisteredSymbolTable,
+      HashTable<RegisteredSymbolTable, RegisteredSymbolTableShape>);
+
+ private:
+  static inline int EntryToValueIndex(InternalIndex entry) {
+    return EntryToIndex(entry) + RegisteredSymbolTableShape::kEntryValueIndex;
+  }
+};
+
 }  // namespace internal
 }  // namespace v8
 

src/objects/map.cc

@@ -130,6 +130,7 @@ VisitorId Map::GetVisitorId(Map map) {
 
     case OBJECT_BOILERPLATE_DESCRIPTION_TYPE:
     case NAME_TO_INDEX_HASH_TABLE_TYPE:
+    case REGISTERED_SYMBOL_TABLE_TYPE:
     case CLOSURE_FEEDBACK_CELL_ARRAY_TYPE:
     case HASH_TABLE_TYPE:
     case ORDERED_HASH_MAP_TYPE:

src/objects/object-list-macros.h

@@ -220,6 +220,7 @@ class ZoneForwardList;
   V(StoreHandler)                              \
   V(String)                                    \
   V(StringSet)                                 \
+  V(RegisteredSymbolTable)                     \
   V(StringWrapper)                             \
   V(Struct)                                    \
   V(SwissNameDictionary)                       \

src/objects/objects-body-descriptors-inl.h

@@ -1070,6 +1070,7 @@ auto BodyDescriptorApply(InstanceType type, Args&&... args) {
     case NUMBER_DICTIONARY_TYPE:
     case SIMPLE_NUMBER_DICTIONARY_TYPE:
     case NAME_TO_INDEX_HASH_TABLE_TYPE:
+    case REGISTERED_SYMBOL_TABLE_TYPE:
     case SCRIPT_CONTEXT_TABLE_TYPE:
       return CALL_APPLY(FixedArray);
     case EPHEMERON_HASH_TABLE_TYPE:

src/objects/objects.cc

@@ -2330,6 +2330,7 @@ bool HeapObject::NeedsRehashing(InstanceType instance_type) const {
       return false;  // We'll rehash from the JSMap or JSSet referencing them.
     case NAME_DICTIONARY_TYPE:
     case NAME_TO_INDEX_HASH_TABLE_TYPE:
+    case REGISTERED_SYMBOL_TABLE_TYPE:
     case GLOBAL_DICTIONARY_TYPE:
     case NUMBER_DICTIONARY_TYPE:
     case SIMPLE_NUMBER_DICTIONARY_TYPE:
@@ -2359,6 +2360,7 @@ bool HeapObject::CanBeRehashed(PtrComprCageBase cage_base) const {
       return false;
     case NAME_DICTIONARY_TYPE:
     case NAME_TO_INDEX_HASH_TABLE_TYPE:
+    case REGISTERED_SYMBOL_TABLE_TYPE:
     case GLOBAL_DICTIONARY_TYPE:
     case NUMBER_DICTIONARY_TYPE:
     case SIMPLE_NUMBER_DICTIONARY_TYPE:
@@ -2391,6 +2393,9 @@ void HeapObject::RehashBasedOnMap(IsolateT* isolate) {
     case NAME_TO_INDEX_HASH_TABLE_TYPE:
       NameToIndexHashTable::cast(*this).Rehash(isolate);
       break;
+    case REGISTERED_SYMBOL_TABLE_TYPE:
+      RegisteredSymbolTable::cast(*this).Rehash(isolate);
+      break;
     case SWISS_NAME_DICTIONARY_TYPE:
       SwissNameDictionary::cast(*this).Rehash(isolate);
       break;
@@ -5993,6 +5998,21 @@ bool StringSet::Has(Isolate* isolate, Handle<String> name) {
   return FindEntry(isolate, *name).is_found();
 }
 
+Handle<RegisteredSymbolTable> RegisteredSymbolTable::Add(
+    Isolate* isolate, Handle<RegisteredSymbolTable> table, Handle<String> key,
+    Handle<Symbol> symbol) {
+  // Validate that the key is absent.
+  SLOW_DCHECK(table->FindEntry(isolate, key).is_not_found());
+
+  table = EnsureCapacity(isolate, table);
+  uint32_t hash = ShapeT::Hash(ReadOnlyRoots(isolate), key);
+  InternalIndex entry = table->FindInsertionEntry(isolate, hash);
+  table->set(EntryToIndex(entry), *key);
+  table->set(EntryToValueIndex(entry), *symbol);
+  table->ElementAdded();
+  return table;
+}
+
 Handle<ObjectHashSet> ObjectHashSet::Add(Isolate* isolate,
                                          Handle<ObjectHashSet> set,
                                          Handle<Object> key) {
@@ -6322,6 +6342,10 @@ Object ObjectHashTableBase<Derived, Shape>::ValueAt(InternalIndex entry) {
   return this->get(EntryToValueIndex(entry));
 }
 
+Object RegisteredSymbolTable::ValueAt(InternalIndex entry) {
+  return this->get(EntryToValueIndex(entry));
+}
+
 Object NameToIndexHashTable::ValueAt(InternalIndex entry) {
   return this->get(EntryToValueIndex(entry));
 }
@@ -6911,6 +6935,7 @@ EXTERN_DEFINE_HASH_TABLE(StringSet, StringSetShape)
 EXTERN_DEFINE_HASH_TABLE(CompilationCacheTable, CompilationCacheShape)
 EXTERN_DEFINE_HASH_TABLE(ObjectHashSet, ObjectHashSetShape)
 EXTERN_DEFINE_HASH_TABLE(NameToIndexHashTable, NameToIndexShape)
+EXTERN_DEFINE_HASH_TABLE(RegisteredSymbolTable, RegisteredSymbolTableShape)
 
 EXTERN_DEFINE_OBJECT_BASE_HASH_TABLE(ObjectHashTable, ObjectHashTableShape)
 EXTERN_DEFINE_OBJECT_BASE_HASH_TABLE(EphemeronHashTable, ObjectHashTableShape)

src/objects/symbol-table.cc

+// Copyright 2022 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.
+
+#include "src/objects/hash-table-inl.h"
+
+namespace v8 {
+namespace internal {
+
+Object RegisteredSymbolTable::SlowReverseLookup(Object value) {
+  ReadOnlyRoots roots = this->GetReadOnlyRoots();
+  for (InternalIndex i : this->IterateEntries()) {
+    Object k;
+    if (!this->ToKey(roots, i, &k)) continue;
+    Object e = this->ValueAt(i);
+    if (e == value) return k;
+  }
+  return roots.undefined_value();
+}
+
+}  // namespace internal
+}  // namespace v8

src/roots/roots.h

@@ -97,6 +97,7 @@ class Symbol;
   V(Map, ordered_hash_map_map, OrderedHashMapMap)                              \
   V(Map, ordered_hash_set_map, OrderedHashSetMap)                              \
   V(Map, name_to_index_hash_table_map, NameToIndexHashTableMap)                \
+  V(Map, registered_symbol_table_map, RegisteredSymbolTableMap)                \
   V(Map, ordered_name_dictionary_map, OrderedNameDictionaryMap)                \
   V(Map, preparse_data_map, PreparseDataMap)                                   \
   V(Map, property_array_map, PropertyArrayMap)                                 \
@@ -298,9 +299,9 @@ class Symbol;
   /* Caches */                                                              \
   V(FixedArray, number_string_cache, NumberStringCache)                     \
   /* Lists and dictionaries */                                              \
-  V(NameDictionary, public_symbol_table, PublicSymbolTable)                \
-  V(NameDictionary, api_symbol_table, ApiSymbolTable)                      \
-  V(NameDictionary, api_private_symbol_table, ApiPrivateSymbolTable)       \
+  V(RegisteredSymbolTable, public_symbol_table, PublicSymbolTable)          \
+  V(RegisteredSymbolTable, api_symbol_table, ApiSymbolTable)                \
+  V(RegisteredSymbolTable, api_private_symbol_table, ApiPrivateSymbolTable) \
   V(WeakArrayList, script_list, ScriptList)                                 \
   V(FixedArray, materialized_objects, MaterializedObjects)                  \
   V(WeakArrayList, detached_contexts, DetachedContexts)                     \