| /* |
| * 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 CallbackPromiseAdapter_h |
| #define CallbackPromiseAdapter_h |
| |
| #include "bindings/core/v8/ScriptPromiseResolver.h" |
| #include "public/platform/WebCallbacks.h" |
| #include "wtf/PtrUtil.h" |
| #include "wtf/TypeTraits.h" |
| #include <memory> |
| #include <utility> |
| |
| namespace blink { |
| |
| // CallbackPromiseAdapter is a WebCallbacks subclass and resolves / rejects the |
| // stored resolver when onSuccess / onError is called, respectively. |
| // |
| // Basically CallbackPromiseAdapter<S, T> is a subclass of |
| // WebCallbacks<S::WebType, T::WebType>. There are some exceptions: |
| // - If S or T don't have WebType (e.g. S = bool), a default WebType holder |
| // called trivial WebType holder is used. For example, |
| // CallbackPromiseAdapter<bool, void> is a subclass of |
| // WebCallbacks<bool, void>. |
| // - If a WebType is std::unique_ptr<T>, its corresponding type parameter on |
| // WebCallbacks is std::unique_ptr<T>, because WebCallbacks must be exposed to |
| // Chromium. |
| // |
| // When onSuccess is called with a S::WebType value, the value is passed to |
| // S::take and the resolver is resolved with its return value. Ditto for |
| // onError. |
| // |
| // ScriptPromiseResolver::resolve / reject will not be called when the execution |
| // context is stopped. |
| // |
| // Example: |
| // class MyClass { |
| // public: |
| // using WebType = std::unique_ptr<WebMyClass>; |
| // static PassRefPtr<MyClass> take(ScriptPromiseResolver* resolver, |
| // std::unique_ptr<WebMyClass> webInstance) |
| // { |
| // return MyClass::create(webInstance); |
| // } |
| // ... |
| // }; |
| // class MyErrorClass { |
| // public: |
| // using WebType = const WebMyErrorClass&; |
| // static MyErrorClass take(ScriptPromiseResolver* resolver, |
| // const WebErrorClass& webError) |
| // { |
| // return MyErrorClass(webError); |
| // } |
| // ... |
| // }; |
| // std::unique_ptr<WebCallbacks<std::unique_ptr<WebMyClass>, const WebMyErrorClass&>> |
| // callbacks = wrapUnique(new CallbackPromiseAdapter<MyClass, MyErrorClass>( |
| // resolver)); |
| // ... |
| // |
| // std::unique_ptr<WebCallbacks<bool, const WebMyErrorClass&>> callbacks2 = |
| // wrapUnique(new CallbackPromiseAdapter<bool, MyErrorClass>(resolver)); |
| // ... |
| // |
| // |
| // In order to implement the above exceptions, we have template classes below. |
| // OnSuccess and OnError provide onSuccess and onError implementation, and there |
| // are utility templates that provide the trivial WebType holder. |
| |
| namespace internal { |
| |
| // This template is placed outside of CallbackPromiseAdapterInternal because |
| // explicit specialization is forbidden in a class scope. |
| template <typename T> |
| struct CallbackPromiseAdapterTrivialWebTypeHolder { |
| using WebType = T; |
| static T take(ScriptPromiseResolver*, const T& x) { return x; } |
| }; |
| template <> |
| struct CallbackPromiseAdapterTrivialWebTypeHolder<void> { |
| using WebType = void; |
| }; |
| |
| class CallbackPromiseAdapterInternal { |
| private: |
| template <typename T> |
| static T webTypeHolderMatcher( |
| typename std::remove_reference<typename T::WebType>::type*); |
| template <typename T> |
| static CallbackPromiseAdapterTrivialWebTypeHolder<T> webTypeHolderMatcher( |
| ...); |
| template <typename T> |
| using WebTypeHolder = decltype(webTypeHolderMatcher<T>(nullptr)); |
| |
| template <typename S, typename T> |
| class Base : public WebCallbacks<typename S::WebType, typename T::WebType> { |
| public: |
| explicit Base(ScriptPromiseResolver* resolver) : m_resolver(resolver) {} |
| ScriptPromiseResolver* resolver() { return m_resolver; } |
| |
| private: |
| Persistent<ScriptPromiseResolver> m_resolver; |
| }; |
| |
| template <typename S, typename T> |
| class OnSuccess : public Base<S, T> { |
| public: |
| explicit OnSuccess(ScriptPromiseResolver* resolver) |
| : Base<S, T>(resolver) {} |
| void onSuccess(typename S::WebType result) override { |
| ScriptPromiseResolver* resolver = this->resolver(); |
| if (!resolver->getExecutionContext() || |
| resolver->getExecutionContext()->activeDOMObjectsAreStopped()) |
| return; |
| resolver->resolve(S::take(resolver, std::move(result))); |
| } |
| }; |
| template <typename T> |
| class OnSuccess<CallbackPromiseAdapterTrivialWebTypeHolder<void>, T> |
| : public Base<CallbackPromiseAdapterTrivialWebTypeHolder<void>, T> { |
| public: |
| explicit OnSuccess(ScriptPromiseResolver* resolver) |
| : Base<CallbackPromiseAdapterTrivialWebTypeHolder<void>, T>(resolver) {} |
| void onSuccess() override { |
| ScriptPromiseResolver* resolver = this->resolver(); |
| if (!resolver->getExecutionContext() || |
| resolver->getExecutionContext()->activeDOMObjectsAreStopped()) |
| return; |
| resolver->resolve(); |
| } |
| }; |
| template <typename S, typename T> |
| class OnError : public OnSuccess<S, T> { |
| public: |
| explicit OnError(ScriptPromiseResolver* resolver) |
| : OnSuccess<S, T>(resolver) {} |
| void onError(typename T::WebType e) override { |
| ScriptPromiseResolver* resolver = this->resolver(); |
| if (!resolver->getExecutionContext() || |
| resolver->getExecutionContext()->activeDOMObjectsAreStopped()) |
| return; |
| ScriptState::Scope scope(resolver->getScriptState()); |
| resolver->reject(T::take(resolver, std::move(e))); |
| } |
| }; |
| template <typename S> |
| class OnError<S, CallbackPromiseAdapterTrivialWebTypeHolder<void>> |
| : public OnSuccess<S, CallbackPromiseAdapterTrivialWebTypeHolder<void>> { |
| public: |
| explicit OnError(ScriptPromiseResolver* resolver) |
| : OnSuccess<S, CallbackPromiseAdapterTrivialWebTypeHolder<void>>( |
| resolver) {} |
| void onError() override { |
| ScriptPromiseResolver* resolver = this->resolver(); |
| if (!resolver->getExecutionContext() || |
| resolver->getExecutionContext()->activeDOMObjectsAreStopped()) |
| return; |
| resolver->reject(); |
| } |
| }; |
| |
| public: |
| template <typename S, typename T> |
| class CallbackPromiseAdapter final |
| : public OnError<WebTypeHolder<S>, WebTypeHolder<T>> { |
| WTF_MAKE_NONCOPYABLE(CallbackPromiseAdapter); |
| |
| public: |
| explicit CallbackPromiseAdapter(ScriptPromiseResolver* resolver) |
| : OnError<WebTypeHolder<S>, WebTypeHolder<T>>(resolver) {} |
| }; |
| }; |
| |
| } // namespace internal |
| |
| template <typename S, typename T> |
| using CallbackPromiseAdapter = |
| internal::CallbackPromiseAdapterInternal::CallbackPromiseAdapter<S, T>; |
| |
| } // namespace blink |
| |
| #endif |