third_party/WebKit/Source/bindings/core/v8/V8PerContextData.cpp

/*
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#include "bindings/core/v8/V8PerContextData.h"

#include "bindings/core/v8/ConditionalFeatures.h"
#include "bindings/core/v8/ScriptState.h"
#include "bindings/core/v8/V8Binding.h"
#include "bindings/core/v8/V8ObjectConstructor.h"
#include "core/dom/Modulator.h"
#include "platform/InstanceCounters.h"
#include "wtf/PtrUtil.h"
#include "wtf/StringExtras.h"
#include <memory>
#include <stdlib.h>

namespace blink {

V8PerContextData::V8PerContextData(v8::Local<v8::Context> context)
    : m_isolate(context->GetIsolate()),
      m_wrapperBoilerplates(m_isolate),
      m_constructorMap(m_isolate),
      m_contextHolder(WTF::makeUnique<gin::ContextHolder>(m_isolate)),
      m_context(m_isolate, context),
      m_activityLogger(nullptr) {
  m_contextHolder->SetContext(context);

  v8::Context::Scope contextScope(context);
  ASSERT(m_errorPrototype.isEmpty());
  v8::Local<v8::Value> objectValue =
      context->Global()
          ->Get(context, v8AtomicString(m_isolate, "Error"))
          .ToLocalChecked();
  v8::Local<v8::Value> prototypeValue =
      objectValue.As<v8::Object>()
          ->Get(context, v8AtomicString(m_isolate, "prototype"))
          .ToLocalChecked();
  m_errorPrototype.set(m_isolate, prototypeValue);

  if (isMainThread())
    InstanceCounters::incrementCounter(
        InstanceCounters::V8PerContextDataCounter);
}

V8PerContextData::~V8PerContextData() {
  if (isMainThread())
    InstanceCounters::decrementCounter(
        InstanceCounters::V8PerContextDataCounter);
}

std::unique_ptr<V8PerContextData> V8PerContextData::create(
    v8::Local<v8::Context> context) {
  return WTF::wrapUnique(new V8PerContextData(context));
}

V8PerContextData* V8PerContextData::from(v8::Local<v8::Context> context) {
  return ScriptState::from(context)->perContextData();
}

v8::Local<v8::Object> V8PerContextData::createWrapperFromCacheSlowCase(
    const WrapperTypeInfo* type) {
  ASSERT(!m_errorPrototype.isEmpty());

  v8::Context::Scope scope(context());
  v8::Local<v8::Function> interfaceObject = constructorForType(type);
  if (interfaceObject.IsEmpty())
    return v8::Local<v8::Object>();
  v8::Local<v8::Object> instanceTemplate;
  if (!V8ObjectConstructor::newInstance(m_isolate, interfaceObject)
           .ToLocal(&instanceTemplate))
    return v8::Local<v8::Object>();
  m_wrapperBoilerplates.Set(type, instanceTemplate);
  return instanceTemplate->Clone();
}

v8::Local<v8::Function> V8PerContextData::constructorForTypeSlowCase(
    const WrapperTypeInfo* type) {
  ASSERT(!m_errorPrototype.isEmpty());

  v8::Local<v8::Context> currentContext = context();
  v8::Context::Scope scope(currentContext);
  const DOMWrapperWorld& world = DOMWrapperWorld::world(currentContext);
  // We shouldn't reach this point for the types that are implemented in v8 such
  // as typed arrays and hence don't have domTemplateFunction.
  ASSERT(type->domTemplateFunction);
  v8::Local<v8::FunctionTemplate> interfaceTemplate =
      type->domTemplate(m_isolate, world);
  // Getting the function might fail if we're running out of stack or memory.
  v8::Local<v8::Function> interfaceObject;
  if (!interfaceTemplate->GetFunction(currentContext).ToLocal(&interfaceObject))
    return v8::Local<v8::Function>();

  if (type->parentClass) {
    v8::Local<v8::Object> prototypeTemplate =
        constructorForType(type->parentClass);
    if (prototypeTemplate.IsEmpty())
      return v8::Local<v8::Function>();
    if (!v8CallBoolean(
            interfaceObject->SetPrototype(currentContext, prototypeTemplate)))
      return v8::Local<v8::Function>();
  }

  v8::Local<v8::Value> prototypeValue;
  if (!interfaceObject
           ->Get(currentContext, v8AtomicString(m_isolate, "prototype"))
           .ToLocal(&prototypeValue) ||
      !prototypeValue->IsObject())
    return v8::Local<v8::Function>();
  v8::Local<v8::Object> prototypeObject = prototypeValue.As<v8::Object>();
  if (prototypeObject->InternalFieldCount() == v8PrototypeInternalFieldcount &&
      type->wrapperTypePrototype == WrapperTypeInfo::WrapperTypeObjectPrototype)
    prototypeObject->SetAlignedPointerInInternalField(
        v8PrototypeTypeIndex, const_cast<WrapperTypeInfo*>(type));
  type->preparePrototypeAndInterfaceObject(currentContext, world,
                                           prototypeObject, interfaceObject,
                                           interfaceTemplate);
  if (type->wrapperTypePrototype ==
      WrapperTypeInfo::WrapperTypeExceptionPrototype) {
    if (!v8CallBoolean(prototypeObject->SetPrototype(
            currentContext, m_errorPrototype.newLocal(m_isolate))))
      return v8::Local<v8::Function>();
  }

  // Origin Trials
  installConditionalFeatures(type, ScriptState::from(currentContext),
                             prototypeObject, interfaceObject);

  m_constructorMap.Set(type, interfaceObject);

  return interfaceObject;
}

v8::Local<v8::Object> V8PerContextData::prototypeForType(
    const WrapperTypeInfo* type) {
  v8::Local<v8::Object> constructor = constructorForType(type);
  if (constructor.IsEmpty())
    return v8::Local<v8::Object>();
  v8::Local<v8::Value> prototypeValue;
  if (!constructor->Get(context(), v8String(m_isolate, "prototype"))
           .ToLocal(&prototypeValue) ||
      !prototypeValue->IsObject())
    return v8::Local<v8::Object>();
  return prototypeValue.As<v8::Object>();
}

void V8PerContextData::addCustomElementBinding(
    std::unique_ptr<V0CustomElementBinding> binding) {
  m_customElementBindings.push_back(std::move(binding));
}

void V8PerContextData::setModulator(Modulator* modulator) {
  DCHECK(!m_modulator);
  DCHECK(modulator);
  m_modulator = modulator;
}

void V8PerContextData::clearModulator() {
  m_modulator = nullptr;
}

}  // namespace blink