electron/shell/common/gin_helper/constructor.h
trop[bot] 0ea8decb0a
refactor: make a variadic gin_helper::internal::InvokeFactory() (#46027)
refactor: make a variadic gin_helper::internal::InvokeFactory()

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Charles Kerr <charles@charleskerr.com>
2025-03-13 23:41:22 -05:00

103 lines
3.1 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 ELECTRON_SHELL_COMMON_GIN_HELPER_CONSTRUCTOR_H_
#define ELECTRON_SHELL_COMMON_GIN_HELPER_CONSTRUCTOR_H_
#include <tuple>
#include "shell/common/gin_helper/function_template.h"
#include "shell/common/gin_helper/wrappable_base.h"
namespace gin_helper {
namespace internal {
// Convert a `gin::Argument`'s arguments into a tuple of native types
// by iteratively calling gin_helper::GetNextArgument().
template <typename... Types>
class GinArgumentsToTuple {
public:
[[nodiscard]] static std::pair<bool /*ok*/, std::tuple<Types...>> GetArgs(
gin::Arguments* args) {
bool ok = true;
InvokerOptions opts{.holder_is_first_argument = true};
auto tup = std::make_tuple(GetNextArg<Types>(args, opts, ok)...);
return {ok, std::move(tup)};
}
private:
template <typename T>
static T GetNextArg(gin::Arguments* args, InvokerOptions& opts, bool& ok) {
auto val = T{};
ok = ok && gin_helper::GetNextArgument(args, opts, 0, &val);
opts.holder_is_first_argument = false;
return val;
}
};
// Invoke a callback with arguments extracted from `args`.
template <typename... Types>
WrappableBase* InvokeFactory(
gin::Arguments* args,
const base::RepeatingCallback<WrappableBase*(Types...)>& callback) {
auto [ok, tup] = GinArgumentsToTuple<Types...>::GetArgs(args);
if (!ok)
return {};
return std::apply(
[&callback](Types... args) { return callback.Run(std::move(args)...); },
std::move(tup));
}
template <typename Sig>
void InvokeNew(const base::RepeatingCallback<Sig>& factory,
v8::Isolate* isolate,
gin_helper::Arguments* args) {
if (!args->IsConstructCall()) {
args->ThrowError("Requires constructor call");
return;
}
WrappableBase* object;
{
// Don't continue if the constructor throws an exception.
v8::TryCatch try_catch{isolate};
object = internal::InvokeFactory(args, factory);
if (try_catch.HasCaught()) {
try_catch.ReThrow();
return;
}
}
if (!object)
args->ThrowError();
return;
}
} // namespace internal
// Create a FunctionTemplate that can be "new"ed in JavaScript.
// It is user's responsibility to ensure this function is called for one type
// only ONCE in the program's whole lifetime, otherwise we would have memory
// leak.
template <typename T, typename Sig>
v8::Local<v8::Function> CreateConstructor(
v8::Isolate* isolate,
const base::RepeatingCallback<Sig>& func) {
#ifndef NDEBUG
static bool called = false;
CHECK(!called) << "CreateConstructor can only be called for one type once";
called = true;
#endif
v8::Local<v8::FunctionTemplate> templ = gin_helper::CreateFunctionTemplate(
isolate, base::BindRepeating(&internal::InvokeNew<Sig>, func));
templ->InstanceTemplate()->SetInternalFieldCount(1);
T::BuildPrototype(isolate, templ);
return templ->GetFunction(isolate->GetCurrentContext()).ToLocalChecked();
}
} // namespace gin_helper
#endif // ELECTRON_SHELL_COMMON_GIN_HELPER_CONSTRUCTOR_H_