third_party/WebKit/Source/bindings/core/v8/ScriptValue.h

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 * modification, are permitted provided that the following conditions are
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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#ifndef ScriptValue_h
#define ScriptValue_h

#include "bindings/core/v8/NativeValueTraits.h"
#include "bindings/core/v8/ScriptState.h"
#include "bindings/core/v8/SharedPersistent.h"
#include "core/CoreExport.h"
#include "wtf/Allocator.h"
#include "wtf/RefPtr.h"
#include "wtf/text/WTFString.h"
#include <v8.h>

namespace blink {

class CORE_EXPORT ScriptValue final {
  DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();

 public:
  // Defined in ToV8.h due to circular dependency
  template <typename T>
  static ScriptValue from(ScriptState*, T&& value);

  template <typename T, typename... Arguments>
  static inline T to(v8::Isolate* isolate,
                     v8::Local<v8::Value> value,
                     ExceptionState& exceptionState,
                     Arguments const&... arguments) {
    return NativeValueTraits<T>::nativeValue(isolate, value, exceptionState,
                                             arguments...);
  }

  template <typename T, typename... Arguments>
  static inline T to(v8::Isolate* isolate,
                     const ScriptValue& value,
                     ExceptionState& exceptionState,
                     Arguments const&... arguments) {
    return to<T>(isolate, value.v8Value(), exceptionState, arguments...);
  }

  ScriptValue() {}

  ScriptValue(ScriptState* scriptState, v8::Local<v8::Value> value)
      : m_scriptState(scriptState),
        m_value(value.IsEmpty() ? nullptr : SharedPersistent<v8::Value>::create(
                                                value,
                                                scriptState->isolate())) {
    ASSERT(isEmpty() || m_scriptState);
  }

  template <typename T>
  ScriptValue(ScriptState* scriptState, v8::MaybeLocal<T> value)
      : m_scriptState(scriptState),
        m_value(value.IsEmpty() ? nullptr : SharedPersistent<v8::Value>::create(
                                                value.ToLocalChecked(),
                                                scriptState->isolate())) {
    ASSERT(isEmpty() || m_scriptState);
  }

  ScriptValue(const ScriptValue& value)
      : m_scriptState(value.m_scriptState), m_value(value.m_value) {
    ASSERT(isEmpty() || m_scriptState);
  }

  ScriptState* getScriptState() const { return m_scriptState.get(); }

  v8::Isolate* isolate() const {
    return m_scriptState ? m_scriptState->isolate() : v8::Isolate::GetCurrent();
  }

  v8::Local<v8::Context> context() const {
    ASSERT(m_scriptState.get());
    return m_scriptState->context();
  }

  ScriptValue& operator=(const ScriptValue& value) {
    if (this != &value) {
      m_scriptState = value.m_scriptState;
      m_value = value.m_value;
    }
    return *this;
  }

  bool operator==(const ScriptValue& value) const {
    if (isEmpty())
      return value.isEmpty();
    if (value.isEmpty())
      return false;
    return *m_value == *value.m_value;
  }

  bool operator!=(const ScriptValue& value) const { return !operator==(value); }

  // This creates a new local Handle; Don't use this in performance-sensitive
  // places.
  bool isFunction() const {
    ASSERT(!isEmpty());
    v8::Local<v8::Value> value = v8Value();
    return !value.IsEmpty() && value->IsFunction();
  }

  // This creates a new local Handle; Don't use this in performance-sensitive
  // places.
  bool isNull() const {
    ASSERT(!isEmpty());
    v8::Local<v8::Value> value = v8Value();
    return !value.IsEmpty() && value->IsNull();
  }

  // This creates a new local Handle; Don't use this in performance-sensitive
  // places.
  bool isUndefined() const {
    ASSERT(!isEmpty());
    v8::Local<v8::Value> value = v8Value();
    return !value.IsEmpty() && value->IsUndefined();
  }

  // This creates a new local Handle; Don't use this in performance-sensitive
  // places.
  bool isObject() const {
    ASSERT(!isEmpty());
    v8::Local<v8::Value> value = v8Value();
    return !value.IsEmpty() && value->IsObject();
  }

  bool isEmpty() const { return !m_value.get() || m_value->isEmpty(); }

  void clear() { m_value = nullptr; }

  v8::Local<v8::Value> v8Value() const;
  // Returns v8Value() if a given ScriptState is the same as the
  // ScriptState which is associated with this ScriptValue. Otherwise
  // this "clones" the v8 value and returns it.
  v8::Local<v8::Value> v8ValueFor(ScriptState*) const;

  bool toString(String&) const;

  void setReference(const v8::Persistent<v8::Object>& parent,
                    v8::Isolate* isolate) {
    m_value->setReference(parent, isolate);
  }

  static ScriptValue createNull(ScriptState*);

 private:
  RefPtr<ScriptState> m_scriptState;
  RefPtr<SharedPersistent<v8::Value>> m_value;
};

}  // namespace blink

#endif  // ScriptValue_h