geode/loader/include/Geode/utils/Promise.hpp

492 lines
22 KiB
C++

#pragma once
#include "Result.hpp"
#include "MiniFunction.hpp"
#include "../loader/Event.hpp"
namespace geode {
namespace impl {
struct DefaultProgress {
std::string message;
std::optional<uint8_t> percentage;
DefaultProgress() = default;
DefaultProgress(auto msg) : message(msg) {}
DefaultProgress(auto msg, uint8_t percentage) : message(msg), percentage(percentage) {}
};
}
struct CancelledState final {};
template <class T = impl::DefaultValue, class E = impl::DefaultError, class P = impl::DefaultProgress>
class PromiseEventFilter;
template <class T = impl::DefaultValue, class E = impl::DefaultError, class P = impl::DefaultProgress>
class Promise final {
public:
using Value = T;
using Error = E;
using Progress = P;
using OnResolved = utils::MiniFunction<void(Value)>;
using OnRejected = utils::MiniFunction<void(Error)>;
using OnProgress = utils::MiniFunction<void(Progress)>;
using OnFinished = utils::MiniFunction<void()>;
using OnCancelled = utils::MiniFunction<void()>;
using State = std::variant<Value, Error, Progress, CancelledState>;
using OnStateChange = utils::MiniFunction<void(State)>;
// These are needed if for example Value and Error are the same type
static constexpr size_t STATE_VALUE_INDEX = 0;
static constexpr size_t STATE_ERROR_INDEX = 1;
static constexpr size_t STATE_PROGRESS_INDEX = 2;
static constexpr size_t STATE_CANCELLED_INDEX = 3;
Promise() : m_data(std::make_shared<Data>()) {}
Promise(utils::MiniFunction<void(OnResolved, OnRejected)> source, bool threaded = true)
: Promise([source](auto resolve, auto reject, auto, auto) {
source(resolve, reject);
}) {}
Promise(utils::MiniFunction<void(OnResolved, OnRejected, OnProgress, OnCancelled)> source, bool threaded = true)
: Promise([source](auto onStateChanged) {
source(
[onStateChanged](auto&& value) {
onStateChanged(State(std::in_place_index<STATE_VALUE_INDEX>, value));
},
[onStateChanged](auto&& error) {
onStateChanged(State(std::in_place_index<STATE_ERROR_INDEX>, error));
},
[onStateChanged](auto&& progress) {
onStateChanged(State(std::in_place_index<STATE_PROGRESS_INDEX>, progress));
},
[onStateChanged]() {
onStateChanged(State(std::in_place_index<STATE_CANCELLED_INDEX>, CancelledState()));
}
);
}) {}
Promise(utils::MiniFunction<void(OnStateChange)> source, bool threaded = true) : m_data(std::make_shared<Data>()) {
if (threaded) {
std::thread([source = std::move(source), data = m_data]() mutable {
Promise::invoke_source(std::move(source), data);
}).detach();
}
else {
Promise::invoke_source(std::move(source), m_data);
}
}
Promise then(utils::MiniFunction<void(Value)>&& callback) {
return this->template then<Value>([callback](auto value) {
callback(value);
return std::move(value);
});
}
template <class T2>
requires (!std::is_void_v<T2>)
Promise<T2, E, P> then(utils::MiniFunction<T2(T)>&& callback) {
if (m_data->cancelled) return make_cancelled<T2, E, P>();
std::unique_lock<std::mutex> _(m_data->mutex);
// Check if this Promise has already been resolved, and if so
// immediately queue the callback with the value
if (m_data->result.has_value()) {
auto v = m_data->result.value();
if (v.index() == 0) {
Loader::get()->queueInMainThread([callback = std::move(callback), ok = std::move(std::get<0>(v))] {
callback(ok);
});
}
return make_cancelled<T2, E, P>();
}
return Promise<T2, E, P>([data = m_data, callback](auto fwdStateToNextPromise) {
data->callback = [fwdStateToNextPromise, callback](auto&& state) {
// Can't use std::visit if Value and Error are the same >:(
switch (state.index()) {
case STATE_VALUE_INDEX: {
auto mapped = callback(std::get<STATE_VALUE_INDEX>(state));
fwdStateToNextPromise(Promise<T2, E, P>::State(
std::in_place_index<STATE_VALUE_INDEX>,
std::move(mapped)
));
} break;
case STATE_ERROR_INDEX: {
fwdStateToNextPromise(Promise<T2, E, P>::State(
std::in_place_index<STATE_ERROR_INDEX>,
std::move(std::get<STATE_ERROR_INDEX>(state))
));
} break;
case STATE_PROGRESS_INDEX: {
fwdStateToNextPromise(Promise<T2, E, P>::State(
std::in_place_index<STATE_PROGRESS_INDEX>,
std::move(std::get<STATE_PROGRESS_INDEX>(state))
));
} break;
case STATE_CANCELLED_INDEX: {
fwdStateToNextPromise(Promise<T2, E, P>::State(
std::in_place_index<STATE_CANCELLED_INDEX>,
std::move(std::get<STATE_CANCELLED_INDEX>(state))
));
} break;
}
};
});
}
template <class T2, class E2>
requires (!std::is_void_v<T2>)
Promise<T2, E2, P> then(utils::MiniFunction<Result<T2, E2>(Result<T, E>)>&& callback) {
if (m_data->cancelled) return make_cancelled<T2, E2, P>();
std::unique_lock<std::mutex> _(m_data->mutex);
// Check if this Promise has already been resolved, and if so
// immediately queue the callback with the value
if (m_data->result.has_value()) {
auto v = m_data->result.value();
if (v.index() == 0) {
Loader::get()->queueInMainThread([callback = std::move(callback), ok = std::move(std::get<0>(v))] {
(void)callback(Ok(ok));
});
}
else {
Loader::get()->queueInMainThread([callback = std::move(callback), err = std::move(std::get<1>(v))] {
(void)callback(Err(err));
});
}
return make_cancelled<T2, E2, P>();
}
return Promise<T2, E2, P>([data = m_data, callback](auto fwdStateToNextPromise) {
data->callback = [fwdStateToNextPromise, callback](auto&& state) {
// Can't use std::visit if Value and Error are the same >:(
switch (state.index()) {
case STATE_VALUE_INDEX: {
auto mapped = callback(Ok(std::move(std::get<STATE_VALUE_INDEX>(state))));
if (mapped) {
fwdStateToNextPromise(Promise<T2, E2, P>::State(
std::in_place_index<STATE_VALUE_INDEX>,
std::move(mapped).unwrap()
));
}
else {
fwdStateToNextPromise(Promise<T2, E2, P>::State(
std::in_place_index<STATE_ERROR_INDEX>,
std::move(mapped).unwrapErr()
));
}
} break;
case STATE_ERROR_INDEX: {
auto mapped = callback(Err(std::move(std::get<STATE_ERROR_INDEX>(state))));
if (mapped) {
fwdStateToNextPromise(Promise<T2, E2, P>::State(
std::in_place_index<STATE_VALUE_INDEX>,
std::move(mapped).unwrap()
));
}
else {
fwdStateToNextPromise(Promise<T2, E2, P>::State(
std::in_place_index<STATE_ERROR_INDEX>,
std::move(mapped).unwrapErr()
));
}
} break;
case STATE_PROGRESS_INDEX: {
fwdStateToNextPromise(Promise<T2, E2, P>::State(
std::in_place_index<STATE_PROGRESS_INDEX>,
std::move(std::get<STATE_PROGRESS_INDEX>(state))
));
} break;
case STATE_CANCELLED_INDEX: {
fwdStateToNextPromise(Promise<T2, E2, P>::State(
std::in_place_index<STATE_CANCELLED_INDEX>,
std::move(std::get<STATE_CANCELLED_INDEX>(state))
));
} break;
}
};
});
}
Promise expect(utils::MiniFunction<void(Error)>&& callback) {
return this->template expect<Error>([callback](auto error) {
callback(error);
return std::move(error);
});
}
template <class E2>
requires (!std::is_void_v<E2>)
Promise<T, E2, P> expect(utils::MiniFunction<E2(E)>&& callback) {
if (m_data->cancelled) return make_cancelled<T, E2, P>();
std::unique_lock<std::mutex> _(m_data->mutex);
// Check if this Promise has already been resolved, and if so
// immediately queue the callback with the value
if (m_data->result.has_value()) {
auto v = m_data->result.value();
if (v.index() == 1) {
Loader::get()->queueInMainThread([callback = std::move(callback), err = std::move(std::get<1>(v))] {
callback(err);
});
}
return make_cancelled<T, E2, P>();
}
return Promise<T, E2, P>([data = m_data, callback](auto fwdStateToNextPromise) {
data->callback = [fwdStateToNextPromise, callback](auto&& state) {
// Can't use std::visit if Value and Error are the same >:(
switch (state.index()) {
case STATE_VALUE_INDEX: {
fwdStateToNextPromise(Promise<T, E2, P>::State(
std::in_place_index<STATE_VALUE_INDEX>,
std::move(std::get<STATE_VALUE_INDEX>(state))
));
} break;
case STATE_ERROR_INDEX: {
auto mapped = callback(std::get<STATE_ERROR_INDEX>(state));
fwdStateToNextPromise(Promise<T, E2, P>::State(
std::in_place_index<STATE_ERROR_INDEX>,
std::move(mapped)
));
} break;
case STATE_PROGRESS_INDEX: {
fwdStateToNextPromise(Promise<T, E2, P>::State(
std::in_place_index<STATE_PROGRESS_INDEX>,
std::move(std::get<STATE_PROGRESS_INDEX>(state))
));
} break;
case STATE_CANCELLED_INDEX: {
fwdStateToNextPromise(Promise<T, E2, P>::State(
std::in_place_index<STATE_CANCELLED_INDEX>,
std::move(std::get<STATE_CANCELLED_INDEX>(state))
));
} break;
}
};
});
}
Promise progress(utils::MiniFunction<void(Progress)>&& callback) {
return this->template progress<Progress>([callback](auto prog) {
callback(prog);
return std::move(prog);
});
}
template <class P2>
requires (!std::is_void_v<P2>)
Promise<T, E, P2> progress(utils::MiniFunction<P2(P)>&& callback) {
if (m_data->cancelled) return make_cancelled<T, E, P2>();
std::unique_lock<std::mutex> _(m_data->mutex);
// Check if this Promise has already been resolved
if (m_data->result.has_value()) {
return make_cancelled<T, E, P2>();
}
return Promise<T, E, P2>([data = m_data, callback](auto fwdStateToNextPromise) {
data->callback = [fwdStateToNextPromise, callback](auto&& state) {
if (state.index() == STATE_PROGRESS_INDEX) {
auto mapped = callback(std::get<STATE_PROGRESS_INDEX>(state));
fwdStateToNextPromise(Promise<T, E, P2>::State(std::in_place_index<STATE_PROGRESS_INDEX>, mapped));
}
else {
fwdStateToNextPromise(state);
}
};
});
}
Promise finally(utils::MiniFunction<void()>&& callback) {
if (m_data->cancelled) return make_cancelled();
std::unique_lock<std::mutex> _(m_data->mutex);
// Check if this Promise has already been resolved, and if so
// immediately queue the callback with the value
if (m_data->result.has_value()) {
Loader::get()->queueInMainThread([callback = std::move(callback)] {
callback();
});
return make_cancelled();
}
return Promise([data = m_data, callback](auto fwdStateToNextPromise) {
data->callback = [fwdStateToNextPromise, callback](auto&& state) {
if (state.index() == STATE_VALUE_INDEX || state.index() == STATE_ERROR_INDEX) {
callback();
}
fwdStateToNextPromise(state);
};
});
}
Promise cancelled(utils::MiniFunction<void()>&& callback) {
if (m_data->cancelled) {
Loader::get()->queueInMainThread([callback = std::move(callback)] {
callback();
});
return make_cancelled();
}
std::unique_lock<std::mutex> _(m_data->mutex);
if (m_data->result.has_value()) {
return make_cancelled();
}
return Promise([data = m_data, callback](auto fwdStateToNextPromise) {
data->callback = [fwdStateToNextPromise, callback](auto&& state) {
if (state.index() == STATE_CANCELLED_INDEX) {
callback();
}
fwdStateToNextPromise(state);
};
});
}
void resolve(Value&& value) {
invoke_callback(State(std::in_place_index<STATE_VALUE_INDEX>, std::move(value)), m_data);
}
void reject(Error&& error) {
invoke_callback(State(std::in_place_index<STATE_ERROR_INDEX>, std::move(error)), m_data);
}
void cancel() {
m_data->cancelled = true;
invoke_callback(State(std::in_place_index<STATE_CANCELLED_INDEX>, CancelledState()), m_data);
}
/**
* Returns a filter for listening to this `Promise` through the Geode
* Events system. Useful for example for using `Promise`s on layers,
* which may be removed from the node tree before the `Promise`
* finishes and as such calling a `then` callback that captures the
* layer would then read undefined memory
*/
PromiseEventFilter<T, E, P> listen();
private:
struct Data final {
std::mutex mutex;
OnStateChange callback;
std::optional<std::variant<Value, Error>> result;
std::atomic_bool cancelled;
};
std::shared_ptr<Data> m_data;
template <class T2 = Value, class E2 = Error, class P2 = Progress>
static Promise<T2, E2, P2> make_cancelled() {
auto ret = Promise<T2, E2, P2>();
ret.cancel();
return std::move(ret);
}
static void invoke_callback(State&& state, std::shared_ptr<Data> data) {
if (data->cancelled) return;
std::unique_lock<std::mutex> _(data->mutex);
if (data->callback) {
data->callback(State(state));
}
// Store the state to let future installed callbacks be immediately resolved
if (state.index() == STATE_VALUE_INDEX) {
data->result = std::variant<Value, Error>(std::in_place_index<0>, std::get<0>(std::move(state)));
}
else if (state.index() == STATE_ERROR_INDEX) {
data->result = std::variant<Value, Error>(std::in_place_index<1>, std::get<1>(std::move(state)));
}
else if (state.index() == STATE_CANCELLED_INDEX) {
data->cancelled = true;
}
}
static void invoke_source(utils::MiniFunction<void(OnStateChange)>&& source, std::shared_ptr<Data> data) {
source([data](auto&& state) {
invoke_callback(std::move(state), data);
});
}
};
/**
* Wraps a `Promise` in the Geode Event system for easier consumption.
* Useful for example for layers, where just regularly waiting for the
* `Promise` could run into issues if the layer is freed from memory;
* whereas with event listeners being RAII, they are automatically
* removed from layers, avoiding use-after-free errors
*/
template <class T = impl::DefaultValue, class E = impl::DefaultError, class P = impl::DefaultProgress>
class PromiseEvent : public Event {
protected:
size_t m_id;
std::variant<T, E, P> m_value;
PromiseEvent(size_t id, std::variant<T, E, P>&& value) : m_id(id), m_value(value) {}
friend class Promise<T, E, P>;
friend class PromiseEventFilter<T, E, P>;
public:
T const* getResolve() const { return std::get_if<0>(&m_value); }
E const* getReject() const { return std::get_if<1>(&m_value); }
P const* getProgress() const { return std::get_if<2>(&m_value); }
bool isFinally() const { return m_value.index() != 2; }
};
template <class T, class E, class P>
class PromiseEventFilter : public EventFilter<PromiseEvent<T, E, P>> {
public:
using Callback = void(PromiseEvent<T, E, P>*);
protected:
size_t m_id;
friend class Promise<T, E, P>;
PromiseEventFilter(size_t id) : m_id(id) {}
public:
PromiseEventFilter() : m_id(0) {}
ListenerResult handle(utils::MiniFunction<Callback> fn, PromiseEvent<T, E, P>* event) {
// log::debug("Event mod filter: {}, {}, {}, {}", m_mod, static_cast<int>(m_type), event->getMod(), static_cast<int>(event->getType()));
if (m_id == event->m_id) {
fn(event);
}
return ListenerResult::Propagate;
}
};
template <class T, class E, class P>
PromiseEventFilter<T, E, P> Promise<T, E, P>::listen() {
// After 4 billion promises this will overflow and start producing
// the same IDs again, so technically if some promise takes
// literally forever then this could cause issues later on
static size_t ID_COUNTER = 0;
// Reserve 0 for PromiseEventFilter not listening to anything
if (ID_COUNTER == 0) {
ID_COUNTER += 1;
}
size_t id = ++ID_COUNTER;
this
->then([id](auto&& value) {
PromiseEvent<T, E, P>(id, std::variant<T, E, P> { std::in_place_index<0>, std::forward<T>(value) }).post();
})
.expect([id](auto&& error) {
PromiseEvent<T, E, P>(id, std::variant<T, E, P> { std::in_place_index<1>, std::forward<E>(error) }).post();
})
.progress([id](auto&& prog) {
PromiseEvent<T, E, P>(id, std::variant<T, E, P> { std::in_place_index<2>, std::forward<P>(prog) }).post();
});
return PromiseEventFilter<T, E, P>(id);
}
}