electron/atom/common/promise_util.h

125 lines
3.9 KiB
C++

// Copyright (c) 2018 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#ifndef ATOM_COMMON_PROMISE_UTIL_H_
#define ATOM_COMMON_PROMISE_UTIL_H_
#include <string>
#include "atom/common/api/locker.h"
#include "atom/common/native_mate_converters/callback.h"
#include "content/public/browser/browser_thread.h"
#include "native_mate/converter.h"
namespace atom {
namespace util {
class Promise : public base::RefCounted<Promise> {
public:
explicit Promise(v8::Isolate* isolate);
v8::Isolate* isolate() const { return isolate_; }
v8::Local<v8::Context> GetContext() {
return v8::Local<v8::Context>::New(isolate_, context_);
}
virtual v8::Local<v8::Promise> GetHandle() const;
v8::Maybe<bool> Resolve() {
v8::HandleScope handle_scope(isolate());
v8::MicrotasksScope script_scope(isolate(),
v8::MicrotasksScope::kRunMicrotasks);
v8::Context::Scope context_scope(
v8::Local<v8::Context>::New(isolate(), GetContext()));
return GetInner()->Resolve(GetContext(), v8::Undefined(isolate()));
}
v8::Maybe<bool> Reject() {
v8::HandleScope handle_scope(isolate());
v8::MicrotasksScope script_scope(isolate(),
v8::MicrotasksScope::kRunMicrotasks);
v8::Context::Scope context_scope(
v8::Local<v8::Context>::New(isolate(), GetContext()));
return GetInner()->Reject(GetContext(), v8::Undefined(isolate()));
}
template <typename ReturnType, typename... ArgTypes>
v8::MaybeLocal<v8::Promise> Then(base::Callback<ReturnType(ArgTypes...)> cb) {
v8::HandleScope handle_scope(isolate());
v8::Context::Scope context_scope(
v8::Local<v8::Context>::New(isolate(), GetContext()));
v8::Local<v8::Value> value = mate::ConvertToV8(isolate(), cb);
v8::Local<v8::Function> handler = v8::Local<v8::Function>::Cast(value);
return GetHandle()->Then(GetContext(), handler);
}
// Promise resolution is a microtask
// We use the MicrotasksRunner to trigger the running of pending microtasks
template <typename T>
v8::Maybe<bool> Resolve(const T& value) {
v8::HandleScope handle_scope(isolate());
v8::MicrotasksScope script_scope(isolate(),
v8::MicrotasksScope::kRunMicrotasks);
v8::Context::Scope context_scope(
v8::Local<v8::Context>::New(isolate(), GetContext()));
return GetInner()->Resolve(GetContext(),
mate::ConvertToV8(isolate(), value));
}
template <typename T>
v8::Maybe<bool> Reject(const T& value) {
v8::HandleScope handle_scope(isolate());
v8::MicrotasksScope script_scope(isolate(),
v8::MicrotasksScope::kRunMicrotasks);
v8::Context::Scope context_scope(
v8::Local<v8::Context>::New(isolate(), GetContext()));
return GetInner()->Reject(GetContext(),
mate::ConvertToV8(isolate(), value));
}
v8::Maybe<bool> RejectWithErrorMessage(const std::string& error);
protected:
virtual ~Promise();
friend class base::RefCounted<Promise>;
v8::Isolate* isolate_;
v8::Global<v8::Context> context_;
private:
v8::Local<v8::Promise::Resolver> GetInner() const {
return resolver_.Get(isolate());
}
v8::Global<v8::Promise::Resolver> resolver_;
DISALLOW_COPY_AND_ASSIGN(Promise);
};
} // namespace util
} // namespace atom
namespace mate {
template <>
struct Converter<atom::util::Promise*> {
static v8::Local<v8::Value> ToV8(v8::Isolate* isolate,
atom::util::Promise* val);
// TODO(MarshallOfSound): Implement FromV8 to allow promise chaining
// in native land
// static bool FromV8(v8::Isolate* isolate,
// v8::Local<v8::Value> val,
// Promise* out);
};
} // namespace mate
#endif // ATOM_COMMON_PROMISE_UTIL_H_