[modules] Give Module an internal [hash] field

src/objects.cc

 // Copyright 2015 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.h"
 
 #include <cmath>
 #include <iomanip>
 #include <memory>
 #include <sstream>
@@ skipping 6151 matching lines @@
   }
 #endif
 
   DCHECK(object->HasDictionaryElements() ||
          object->HasSlowArgumentsElements() ||
          object->HasSlowStringWrapperElements());
   return dictionary;
 }
 
 
-static Smi* GenerateIdentityHash(Isolate* isolate) {
-  int hash_value;
-  int attempts = 0;
-  do {
-    // Generate a random 32-bit hash value but limit range to fit
-    // within a smi.
-    hash_value = isolate->random_number_generator()->NextInt() & Smi::kMaxValue;
-    attempts++;
-  } while (hash_value == 0 && attempts < 30);
-  hash_value = hash_value != 0 ? hash_value : 1;  // never return 0
-
-  return Smi::FromInt(hash_value);
-}
-
 template <typename ProxyType>
 static Smi* GetOrCreateIdentityHashHelper(Isolate* isolate,
                                           Handle<ProxyType> proxy) {
   Object* maybe_hash = proxy->hash();
   if (maybe_hash->IsSmi()) return Smi::cast(maybe_hash);
 
-  Smi* hash = GenerateIdentityHash(isolate);
+  Smi* hash = Smi::FromInt(isolate->GenerateIdentityHash(Smi::kMaxValue));
   proxy->set_hash(hash);
   return hash;
 }
 
 // static
 Object* JSObject::GetIdentityHash(Isolate* isolate, Handle<JSObject> object) {
   if (object->IsJSGlobalProxy()) {
     return JSGlobalProxy::cast(*object)->hash();
   }
   Handle<Name> hash_code_symbol = isolate->factory()->hash_code_symbol();
   return *JSReceiver::GetDataProperty(object, hash_code_symbol);
 }
 
 // static
 Smi* JSObject::GetOrCreateIdentityHash(Isolate* isolate,
                                        Handle<JSObject> object) {
   if (object->IsJSGlobalProxy()) {
     return GetOrCreateIdentityHashHelper(isolate,
                                          Handle<JSGlobalProxy>::cast(object));
   }
 
   Handle<Name> hash_code_symbol = isolate->factory()->hash_code_symbol();
   LookupIterator it(object, hash_code_symbol, object, LookupIterator::OWN);
   if (it.IsFound()) {
     DCHECK_EQ(LookupIterator::DATA, it.state());
     Object* maybe_hash = *it.GetDataValue();
     if (maybe_hash->IsSmi()) return Smi::cast(maybe_hash);
   }
 
-  Smi* hash = GenerateIdentityHash(isolate);
+  Smi* hash = Smi::FromInt(isolate->GenerateIdentityHash(Smi::kMaxValue));
   CHECK(AddDataProperty(&it, handle(hash, isolate), NONE, THROW_ON_ERROR,
                         CERTAINLY_NOT_STORE_FROM_KEYED)
             .IsJust());
   return hash;
 }
 
 // static
 Object* JSProxy::GetIdentityHash(Handle<JSProxy> proxy) {
   return proxy->hash();
 }
@@ skipping 13347 matching lines @@
   if (value->IsTheHole(isolate)) {
     THROW_NEW_ERROR(
         isolate, NewReferenceError(MessageTemplate::kNotDefined, name), Object);
   }
 
   return value;
 }
 
 namespace {
 
-template <typename T>
-struct HandleValueHash {
-  V8_INLINE size_t operator()(Handle<T> handle) const { return handle->Hash(); }
+struct ModuleHandleHash {
+  V8_INLINE size_t operator()(Handle<Module> module) const {
+    return module->hash();
+  }
 };
 
 struct ModuleHandleEqual {
   V8_INLINE bool operator()(Handle<Module> lhs, Handle<Module> rhs) const {
     return *lhs == *rhs;
   }
 };
 
+struct StringHandleHash {
+  V8_INLINE size_t operator()(Handle<String> string) const {
+    return string->Hash();
+  }
+};
+
 struct StringHandleEqual {
   V8_INLINE bool operator()(Handle<String> lhs, Handle<String> rhs) const {
     return lhs->Equals(*rhs);
   }
 };
 
 class UnorderedStringSet
-    : public std::unordered_set<Handle<String>, HandleValueHash<String>,
+    : public std::unordered_set<Handle<String>, StringHandleHash,
                                 StringHandleEqual,
                                 zone_allocator<Handle<String>>> {
  public:
   explicit UnorderedStringSet(Zone* zone)
-      : std::unordered_set<Handle<String>, HandleValueHash<String>,
-                           StringHandleEqual, zone_allocator<Handle<String>>>(
-            2 /* bucket count */, HandleValueHash<String>(),
-            StringHandleEqual(), zone_allocator<Handle<String>>(zone)) {}
+      : std::unordered_set<Handle<String>, StringHandleHash, StringHandleEqual,
+                           zone_allocator<Handle<String>>>(
+            2 /* bucket count */, StringHandleHash(), StringHandleEqual(),
+            zone_allocator<Handle<String>>(zone)) {}
 };
 
 class UnorderedModuleSet
-    : public std::unordered_set<Handle<Module>, HandleValueHash<Module>,
+    : public std::unordered_set<Handle<Module>, ModuleHandleHash,
                                 ModuleHandleEqual,
                                 zone_allocator<Handle<Module>>> {
  public:
   explicit UnorderedModuleSet(Zone* zone)
-      : std::unordered_set<Handle<Module>, HandleValueHash<Module>,
-                           ModuleHandleEqual, zone_allocator<Handle<Module>>>(
-            2 /* bucket count */, HandleValueHash<Module>(),
-            ModuleHandleEqual(), zone_allocator<Handle<Module>>(zone)) {}
+      : std::unordered_set<Handle<Module>, ModuleHandleHash, ModuleHandleEqual,
+                           zone_allocator<Handle<Module>>>(
+            2 /* bucket count */, ModuleHandleHash(), ModuleHandleEqual(),
+            zone_allocator<Handle<Module>>(zone)) {}
 };
 
 class UnorderedStringMap
     : public std::unordered_map<
-          Handle<String>, Handle<Object>, HandleValueHash<String>,
-          StringHandleEqual,
+          Handle<String>, Handle<Object>, StringHandleHash, StringHandleEqual,
           zone_allocator<std::pair<const Handle<String>, Handle<Object>>>> {
  public:
   explicit UnorderedStringMap(Zone* zone)
       : std::unordered_map<
-            Handle<String>, Handle<Object>, HandleValueHash<String>,
-            StringHandleEqual,
+            Handle<String>, Handle<Object>, StringHandleHash, StringHandleEqual,
             zone_allocator<std::pair<const Handle<String>, Handle<Object>>>>(
-            2 /* bucket count */, HandleValueHash<String>(),
-            StringHandleEqual(),
+            2 /* bucket count */, StringHandleHash(), StringHandleEqual(),
             zone_allocator<std::pair<const Handle<String>, Handle<Object>>>(
                 zone)) {}
 };
 
 }  // anonymous namespace
 
 class Module::ResolveSet
     : public std::unordered_map<
-          Handle<Module>, UnorderedStringSet*, HandleValueHash<Module>,
+          Handle<Module>, UnorderedStringSet*, ModuleHandleHash,
           ModuleHandleEqual, zone_allocator<std::pair<const Handle<Module>,
                                                       UnorderedStringSet*>>> {
  public:
   explicit ResolveSet(Zone* zone)
       : std::unordered_map<Handle<Module>, UnorderedStringSet*,
-                           HandleValueHash<Module>, ModuleHandleEqual,
+                           ModuleHandleHash, ModuleHandleEqual,
                            zone_allocator<std::pair<const Handle<Module>,
                                                     UnorderedStringSet*>>>(
-            2 /* bucket count */, HandleValueHash<Module>(),
-            ModuleHandleEqual(),
+            2 /* bucket count */, ModuleHandleHash(), ModuleHandleEqual(),
             zone_allocator<
                 std::pair<const Handle<Module>, UnorderedStringSet*>>(zone)),
         zone_(zone) {}
 
   Zone* zone() const { return zone_; }
 
  private:
   Zone* zone_;
 };
 
@@ skipping 423 matching lines @@
         ns, Accessors::ModuleNamespaceEntryInfo(isolate, name, attr))
         .Check();
   }
   JSObject::PreventExtensions(ns, THROW_ON_ERROR).ToChecked();
 
   return ns;
 }
 
 }  // namespace internal
 }  // namespace v8