External string table.

src/api.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3064 matching lines @@
 
 
 i::Handle<i::String> NewExternalAsciiStringHandle(
       v8::String::ExternalAsciiStringResource* resource) {
   i::Handle<i::String> result =
       i::Factory::NewExternalStringFromAscii(resource);
   return result;
 }
 
 
-static void DisposeExternalString(v8::Persistent<v8::Value> obj,
-                                  void* parameter) {
-  ENTER_V8;
-  i::ExternalTwoByteString* str =
-      i::ExternalTwoByteString::cast(*Utils::OpenHandle(*obj));
-
-  // External symbols are deleted when they are pruned out of the symbol
-  // table. Generally external symbols are not registered with the weak handle
-  // callbacks unless they are upgraded to a symbol after being externalized.
-  if (!str->IsSymbol()) {
-    v8::String::ExternalStringResource* resource =
-        reinterpret_cast<v8::String::ExternalStringResource*>(parameter);
-    if (resource != NULL) {
-      const int total_size =
-          static_cast<int>(resource->length() * sizeof(*resource->data()));
-      i::Counters::total_external_string_memory.Decrement(total_size);
-
-      // The object will continue to live in the JavaScript heap until the
-      // handle is entirely cleaned out by the next GC. For example the
-      // destructor for the resource below could bring it back to life again.
-      // Which is why we make sure to not have a dangling pointer here.
-      str->set_resource(NULL);
-      delete resource;
-    }
-  }
-
-  // In any case we do not need this handle any longer.
-  obj.Dispose();
-}
-
-
-static void DisposeExternalAsciiString(v8::Persistent<v8::Value> obj,
-                                       void* parameter) {
-  ENTER_V8;
-  i::ExternalAsciiString* str =
-      i::ExternalAsciiString::cast(*Utils::OpenHandle(*obj));
-
-  // External symbols are deleted when they are pruned out of the symbol
-  // table. Generally external symbols are not registered with the weak handle
-  // callbacks unless they are upgraded to a symbol after being externalized.
-  if (!str->IsSymbol()) {
-    v8::String::ExternalAsciiStringResource* resource =
-        reinterpret_cast<v8::String::ExternalAsciiStringResource*>(parameter);
-    if (resource != NULL) {
-      const int total_size =
-          static_cast<int>(resource->length() * sizeof(*resource->data()));
-      i::Counters::total_external_string_memory.Decrement(total_size);
-
-      // The object will continue to live in the JavaScript heap until the
-      // handle is entirely cleaned out by the next GC. For example the
-      // destructor for the resource below could bring it back to life again.
-      // Which is why we make sure to not have a dangling pointer here.
-      str->set_resource(NULL);
-      delete resource;
-    }
-  }
-
-  // In any case we do not need this handle any longer.
-  obj.Dispose();
-}
-
-
 Local<String> v8::String::NewExternal(
       v8::String::ExternalStringResource* resource) {
   EnsureInitialized("v8::String::NewExternal()");
   LOG_API("String::NewExternal");
   ENTER_V8;
-  const int total_size =
-      static_cast<int>(resource->length() * sizeof(*resource->data()));
-  i::Counters::total_external_string_memory.Increment(total_size);
   i::Handle<i::String> result = NewExternalStringHandle(resource);
-  i::Handle<i::Object> handle = i::GlobalHandles::Create(*result);
-  i::GlobalHandles::MakeWeak(handle.location(),
-                             resource,
-                             &DisposeExternalString);
+  i::ExternalStringTable::AddString(*result);
   return Utils::ToLocal(result);
 }
 
 
 bool v8::String::MakeExternal(v8::String::ExternalStringResource* resource) {
   if (IsDeadCheck("v8::String::MakeExternal()")) return false;
   if (this->IsExternal()) return false;  // Already an external string.
   ENTER_V8;
   i::Handle<i::String> obj = Utils::OpenHandle(this);
   bool result = obj->MakeExternal(resource);
   if (result && !obj->IsSymbol()) {
-    // Operation was successful and the string is not a symbol. In this case
-    // we need to make sure that the we call the destructor for the external
-    // resource when no strong references to the string remain.
-    i::Handle<i::Object> handle = i::GlobalHandles::Create(*obj);
-    i::GlobalHandles::MakeWeak(handle.location(),
-                               resource,
-                               &DisposeExternalString);
+    i::ExternalStringTable::AddString(*obj);
   }
   return result;
 }
 
 
 Local<String> v8::String::NewExternal(
       v8::String::ExternalAsciiStringResource* resource) {
   EnsureInitialized("v8::String::NewExternal()");
   LOG_API("String::NewExternal");
   ENTER_V8;
-  const int total_size =
-      static_cast<int>(resource->length() * sizeof(*resource->data()));
-  i::Counters::total_external_string_memory.Increment(total_size);
   i::Handle<i::String> result = NewExternalAsciiStringHandle(resource);
-  i::Handle<i::Object> handle = i::GlobalHandles::Create(*result);
-  i::GlobalHandles::MakeWeak(handle.location(),
-                             resource,
-                             &DisposeExternalAsciiString);
+  i::ExternalStringTable::AddString(*result);
   return Utils::ToLocal(result);
 }
 
 
 bool v8::String::MakeExternal(
     v8::String::ExternalAsciiStringResource* resource) {
   if (IsDeadCheck("v8::String::MakeExternal()")) return false;
   if (this->IsExternal()) return false;  // Already an external string.
   ENTER_V8;
   i::Handle<i::String> obj = Utils::OpenHandle(this);
   bool result = obj->MakeExternal(resource);
   if (result && !obj->IsSymbol()) {
-    // Operation was successful and the string is not a symbol. In this case
-    // we need to make sure that the we call the destructor for the external
-    // resource when no strong references to the string remain.
-    i::Handle<i::Object> handle = i::GlobalHandles::Create(*obj);
-    i::GlobalHandles::MakeWeak(handle.location(),
-                               resource,
-                               &DisposeExternalAsciiString);
+    i::ExternalStringTable::AddString(*obj);
   }
   return result;
 }
 
 
 bool v8::String::CanMakeExternal() {
   if (IsDeadCheck("v8::String::CanMakeExternal()")) return false;
   i::Handle<i::String> obj = Utils::OpenHandle(this);
   int size = obj->Size();  // Byte size of the original string.
   if (size < i::ExternalString::kSize)
@@ skipping 683 matching lines @@
 
 
 char* HandleScopeImplementer::Iterate(ObjectVisitor* v, char* storage) {
   HandleScopeImplementer* thread_local =
       reinterpret_cast<HandleScopeImplementer*>(storage);
   thread_local->IterateThis(v);
   return storage + ArchiveSpacePerThread();
 }
 
 } }  // namespace v8::internal