gecko/dom/promise/Promise.h

288 lines
8.4 KiB
C++

/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_dom_Promise_h
#define mozilla_dom_Promise_h
#include "mozilla/Attributes.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/TypeTraits.h"
#include "mozilla/dom/BindingDeclarations.h"
#include "nsCycleCollectionParticipant.h"
#include "mozilla/dom/PromiseBinding.h"
#include "nsWrapperCache.h"
#include "nsAutoPtr.h"
#include "js/TypeDecls.h"
class nsIGlobalObject;
namespace mozilla {
namespace dom {
class AnyCallback;
class PromiseCallback;
class PromiseInit;
class PromiseNativeHandler;
class Promise MOZ_FINAL : public nsISupports,
public nsWrapperCache
{
friend class NativePromiseCallback;
friend class PromiseResolverMixin;
friend class PromiseResolverTask;
friend class PromiseTask;
friend class RejectPromiseCallback;
friend class ResolvePromiseCallback;
friend class WorkerPromiseResolverTask;
friend class WorkerPromiseTask;
friend class WrapperPromiseCallback;
~Promise();
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(Promise)
Promise(nsIGlobalObject* aGlobal);
typedef void (Promise::*MaybeFunc)(JSContext* aCx,
JS::Handle<JS::Value> aValue);
void MaybeResolve(JSContext* aCx,
JS::Handle<JS::Value> aValue);
void MaybeReject(JSContext* aCx,
JS::Handle<JS::Value> aValue);
// Helpers for using Promise from C++.
// Most DOM objects are handled already. To add a new type T, such as ints,
// or dictionaries, add an ArgumentToJSVal overload below.
template <typename T>
void MaybeResolve(T& aArg) {
MaybeSomething(aArg, &Promise::MaybeResolve);
}
template <typename T>
void MaybeReject(T& aArg) {
MaybeSomething(aArg, &Promise::MaybeReject);
}
// WebIDL
nsIGlobalObject* GetParentObject() const
{
return mGlobal;
}
virtual JSObject*
WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope) MOZ_OVERRIDE;
static already_AddRefed<Promise>
Constructor(const GlobalObject& aGlobal, PromiseInit& aInit,
ErrorResult& aRv);
static already_AddRefed<Promise>
Resolve(const GlobalObject& aGlobal, JSContext* aCx,
JS::Handle<JS::Value> aValue, ErrorResult& aRv);
static already_AddRefed<Promise>
Resolve(nsIGlobalObject* aGlobal, JSContext* aCx,
JS::Handle<JS::Value> aValue, ErrorResult& aRv);
static already_AddRefed<Promise>
Reject(const GlobalObject& aGlobal, JSContext* aCx,
JS::Handle<JS::Value> aValue, ErrorResult& aRv);
static already_AddRefed<Promise>
Reject(nsIGlobalObject* aGlobal, JSContext* aCx,
JS::Handle<JS::Value> aValue, ErrorResult& aRv);
already_AddRefed<Promise>
Then(AnyCallback* aResolveCallback, AnyCallback* aRejectCallback);
already_AddRefed<Promise>
Catch(AnyCallback* aRejectCallback);
// FIXME(nsm): Bug 956197
static already_AddRefed<Promise>
All(const GlobalObject& aGlobal, JSContext* aCx,
const Sequence<JS::Value>& aIterable, ErrorResult& aRv);
// FIXME(nsm): Bug 956197
static already_AddRefed<Promise>
Race(const GlobalObject& aGlobal, JSContext* aCx,
const Sequence<JS::Value>& aIterable, ErrorResult& aRv);
void AppendNativeHandler(PromiseNativeHandler* aRunnable);
private:
enum PromiseState {
Pending,
Resolved,
Rejected
};
enum PromiseTaskSync {
SyncTask,
AsyncTask
};
void SetState(PromiseState aState)
{
MOZ_ASSERT(mState == Pending);
MOZ_ASSERT(aState != Pending);
mState = aState;
}
void SetResult(JS::Handle<JS::Value> aValue)
{
mResult = aValue;
}
// This method processes promise's resolve/reject callbacks with promise's
// result. It's executed when the resolver.resolve() or resolver.reject() is
// called or when the promise already has a result and new callbacks are
// appended by then(), catch() or done().
void RunTask();
void RunResolveTask(JS::Handle<JS::Value> aValue,
Promise::PromiseState aState,
PromiseTaskSync aAsynchronous);
void AppendCallbacks(PromiseCallback* aResolveCallback,
PromiseCallback* aRejectCallback);
// If we have been rejected and our mResult is a JS exception,
// report it to the error console.
void MaybeReportRejected();
void MaybeResolveInternal(JSContext* aCx,
JS::Handle<JS::Value> aValue,
PromiseTaskSync aSync = AsyncTask);
void MaybeRejectInternal(JSContext* aCx,
JS::Handle<JS::Value> aValue,
PromiseTaskSync aSync = AsyncTask);
void ResolveInternal(JSContext* aCx,
JS::Handle<JS::Value> aValue,
PromiseTaskSync aSync = AsyncTask);
void RejectInternal(JSContext* aCx,
JS::Handle<JS::Value> aValue,
PromiseTaskSync aSync = AsyncTask);
// Helper methods for using Promises from C++
JSObject* GetOrCreateWrapper(JSContext* aCx);
// If ArgumentToJSValue returns false, it must set an exception on the
// JSContext.
// Accept strings.
bool
ArgumentToJSValue(const nsAString& aArgument,
JSContext* aCx,
JSObject* aScope,
JS::MutableHandle<JS::Value> aValue);
// Accept objects that inherit from nsWrapperCache and nsISupports (e.g. most
// DOM objects).
template <class T>
typename EnableIf<IsBaseOf<nsWrapperCache, T>::value &&
IsBaseOf<nsISupports, T>::value, bool>::Type
ArgumentToJSValue(T& aArgument,
JSContext* aCx,
JSObject* aScope,
JS::MutableHandle<JS::Value> aValue)
{
JS::Rooted<JSObject*> scope(aCx, aScope);
return WrapNewBindingObject(aCx, scope, aArgument, aValue);
}
// Accept objects that inherit from nsISupports but not nsWrapperCache (e.g.
// nsIDOMFile).
template <class T>
typename EnableIf<!IsBaseOf<nsWrapperCache, T>::value &&
IsBaseOf<nsISupports, T>::value, bool>::Type
ArgumentToJSValue(T& aArgument,
JSContext* aCx,
JSObject* aScope,
JS::MutableHandle<JS::Value> aValue)
{
JS::Rooted<JSObject*> scope(aCx, aScope);
nsresult rv = nsContentUtils::WrapNative(aCx, scope, &aArgument, aValue);
return NS_SUCCEEDED(rv);
}
template <template <typename> class SmartPtr, typename T>
bool
ArgumentToJSValue(const SmartPtr<T>& aArgument,
JSContext* aCx,
JSObject* aScope,
JS::MutableHandle<JS::Value> aValue)
{
return ArgumentToJSValue(*aArgument.get(), aCx, aScope, aValue);
}
template <typename T>
void MaybeSomething(T& aArgument, MaybeFunc aFunc) {
ThreadsafeAutoJSContext cx;
JSObject* wrapper = GetOrCreateWrapper(cx);
if (!wrapper) {
HandleException(cx);
return;
}
JSAutoCompartment ac(cx, wrapper);
JS::Rooted<JS::Value> val(cx);
if (!ArgumentToJSValue(aArgument, cx, wrapper, &val)) {
HandleException(cx);
return;
}
(this->*aFunc)(cx, val);
}
// Static methods for the PromiseInit functions.
static bool
JSCallback(JSContext *aCx, unsigned aArgc, JS::Value *aVp);
static bool
ThenableResolverCommon(JSContext* aCx, uint32_t /* PromiseCallback::Task */ aTask,
unsigned aArgc, JS::Value* aVp);
static bool
JSCallbackThenableResolver(JSContext *aCx, unsigned aArgc, JS::Value *aVp);
static bool
JSCallbackThenableRejecter(JSContext *aCx, unsigned aArgc, JS::Value *aVp);
static JSObject*
CreateFunction(JSContext* aCx, JSObject* aParent, Promise* aPromise,
int32_t aTask);
static JSObject*
CreateThenableFunction(JSContext* aCx, Promise* aPromise, uint32_t aTask);
void HandleException(JSContext* aCx);
nsRefPtr<nsIGlobalObject> mGlobal;
nsTArray<nsRefPtr<PromiseCallback> > mResolveCallbacks;
nsTArray<nsRefPtr<PromiseCallback> > mRejectCallbacks;
JS::Heap<JS::Value> mResult;
PromiseState mState;
bool mTaskPending;
bool mHadRejectCallback;
bool mResolvePending;
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_Promise_h