Simplify LambdaPromise implementation.

This commit is contained in:
levlam 2022-06-26 22:31:28 +03:00
parent f62632fcbc
commit 4b9990aff9

View File

@ -12,6 +12,7 @@
#include "td/utils/Closure.h"
#include "td/utils/common.h"
#include "td/utils/invoke.h"
#include "td/utils/logging.h"
#include "td/utils/MovableValue.h"
#include "td/utils/ScopeGuard.h"
#include "td/utils/Status.h"
@ -104,76 +105,48 @@ struct Ignore {
}
};
template <class ValueT, class FunctionOkT, class FunctionFailT = Ignore>
template <class ValueT, class FunctionT>
class LambdaPromise : public PromiseInterface<ValueT> {
enum class OnFail { None, Ok, Fail };
enum class State : int32 { Empty, Ready, Complete };
public:
void set_value(ValueT &&value) override {
CHECK(has_lambda_.get());
do_ok(ok_, std::move(value));
on_fail_ = OnFail::None;
CHECK(state_.get() == State::Ready);
func_(std::move(value));
state_ = State::Complete;
}
void set_error(Status &&error) override {
CHECK(has_lambda_.get());
if (state_.get() == State::Ready) {
do_error(std::move(error));
state_ = State::Complete;
}
}
LambdaPromise(const LambdaPromise &other) = delete;
LambdaPromise &operator=(const LambdaPromise &other) = delete;
LambdaPromise(LambdaPromise &&other) = default;
LambdaPromise &operator=(LambdaPromise &&other) = default;
~LambdaPromise() override {
if (has_lambda_.get()) {
if (state_.get() == State::Ready) {
do_error(Status::Error("Lost promise"));
}
}
template <class FromOkT, class FromFailT>
LambdaPromise(FromOkT &&ok, FromFailT &&fail, bool use_ok_as_fail)
: ok_(std::forward<FromOkT>(ok))
, fail_(std::forward<FromFailT>(fail))
, on_fail_(use_ok_as_fail ? OnFail::Ok : OnFail::Fail)
, has_lambda_(true) {
}
template <class FromOkT, std::enable_if_t<!std::is_same<std::decay_t<FromOkT>, LambdaPromise>::value, int> = 0>
LambdaPromise(FromOkT &&ok) : LambdaPromise(std::forward<FromOkT>(ok), Ignore(), true) {
template <class FromT>
explicit LambdaPromise(FromT &&func) : func_(std::forward<FromT>(func)), state_(State::Ready) {
}
private:
FunctionOkT ok_;
FunctionFailT fail_;
OnFail on_fail_ = OnFail::None;
MovableValue<bool> has_lambda_{false};
FunctionT func_;
MovableValue<State> state_{State::Empty};
void do_error(Status &&error) {
switch (on_fail_) {
case OnFail::None:
break;
case OnFail::Ok:
do_error(ok_, std::move(error));
break;
case OnFail::Fail:
do_error(fail_, std::move(error));
break;
template <class F = FunctionT>
std::enable_if_t<is_callable<F, Result<ValueT>>::value, void> do_error(Status &&status) {
func_(Result<ValueT>(std::move(status)));
}
on_fail_ = OnFail::None;
}
template <class F>
std::enable_if_t<is_callable<F, Result<ValueT>>::value, void> do_error(F &&f, Status &&status) {
f(Result<ValueT>(std::move(status)));
}
template <class Y, class F>
std::enable_if_t<!is_callable<F, Result<ValueT>>::value, void> do_error(F &&f, Y &&status) {
f(Auto());
}
template <class F>
std::enable_if_t<is_callable<F, Result<ValueT>>::value, void> do_ok(F &&f, ValueT &&result) {
f(Result<ValueT>(std::move(result)));
}
template <class F>
std::enable_if_t<!is_callable<F, Result<ValueT>>::value, void> do_ok(F &&f, ValueT &&result) {
f(std::move(result));
template <class Y, class F = FunctionT>
std::enable_if_t<!is_callable<F, Result<ValueT>>::value, void> do_error(Y &&status) {
func_(Auto());
}
};
} // namespace detail