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

/*
 * Copyright (C) 2013 Google Inc. 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 with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef ScriptPromise_h
#define ScriptPromise_h

#include "bindings/core/v8/ScriptFunction.h"
#include "bindings/core/v8/ScriptValue.h"
#include "core/CoreExport.h"
#include "platform/heap/Handle.h"
#include "wtf/Allocator.h"
#include "wtf/PassRefPtr.h"
#include "wtf/Vector.h"
#include <v8.h>

namespace blink {

class DOMException;

// ScriptPromise is the class for representing Promise values in C++ world.
// ScriptPromise holds a Promise.
// So holding a ScriptPromise as a member variable in DOM object causes
// memory leaks since it has a reference from C++ to V8.
//
class CORE_EXPORT ScriptPromise final {
  DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();

 public:
  // Constructs an empty promise.
  ScriptPromise();

  // Constructs a ScriptPromise from |promise|.
  // If |promise| is not a Promise object, throws a v8 TypeError.
  ScriptPromise(ScriptState*, v8::Local<v8::Value> promise);

  ScriptPromise(const ScriptPromise&);

  ~ScriptPromise();

  ScriptPromise then(
      v8::Local<v8::Function> onFulfilled,
      v8::Local<v8::Function> onRejected = v8::Local<v8::Function>());

  bool isObject() const { return m_promise.isObject(); }

  bool isNull() const { return m_promise.isNull(); }

  bool isUndefinedOrNull() const {
    return m_promise.isUndefined() || m_promise.isNull();
  }

  ScriptValue getScriptValue() const { return m_promise; }

  v8::Local<v8::Value> v8Value() const { return m_promise.v8Value(); }

  v8::Isolate* isolate() const { return m_promise.isolate(); }

  bool isEmpty() const { return m_promise.isEmpty(); }

  void clear() { m_promise.clear(); }

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

  bool operator==(const ScriptPromise& value) const {
    return m_promise == value.m_promise;
  }

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

  // Constructs and returns a ScriptPromise from |value|.
  // if |value| is not a Promise object, returns a Promise object
  // resolved with |value|.
  // Returns |value| itself if it is a Promise.
  static ScriptPromise cast(ScriptState*, const ScriptValue& /*value*/);
  static ScriptPromise cast(ScriptState*, v8::Local<v8::Value> /*value*/);

  // Constructs and returns a ScriptPromise resolved with undefined.
  static ScriptPromise castUndefined(ScriptState*);

  static ScriptPromise reject(ScriptState*, const ScriptValue&);
  static ScriptPromise reject(ScriptState*, v8::Local<v8::Value>);

  static ScriptPromise rejectWithDOMException(ScriptState*, DOMException*);

  static v8::Local<v8::Promise> rejectRaw(ScriptState*, v8::Local<v8::Value>);

  // Constructs and returns a ScriptPromise to be resolved when all |promises|
  // are resolved. If one of |promises| is rejected, the returned
  // ScriptPromise is rejected.
  static ScriptPromise all(ScriptState*, const Vector<ScriptPromise>& promises);

  // This is a utility class intended to be used internally.
  // ScriptPromiseResolver is for general purpose.
  class CORE_EXPORT InternalResolver final {
    DISALLOW_NEW();

   public:
    explicit InternalResolver(ScriptState*);
    v8::Local<v8::Promise> v8Promise() const;
    ScriptPromise promise() const;
    void resolve(v8::Local<v8::Value>);
    void reject(v8::Local<v8::Value>);
    void clear() { m_resolver.clear(); }

   private:
    ScriptValue m_resolver;
  };

 private:
  static void increaseInstanceCount();
  static void decreaseInstanceCount();

  RefPtr<ScriptState> m_scriptState;
  ScriptValue m_promise;
};

}  // namespace blink

#endif  // ScriptPromise_h