sled/3party/rxcpp/operators/rx-retry.hpp
2024-03-14 20:50:17 +08:00

122 lines
3.8 KiB
C++

// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
#pragma once
/*! \file rx-retry.hpp
\brief Retry this observable for the given number of times.
\tparam Count the type of the counter (optional)
\param t the total number of tries (optional), i.e. retry(2) means one normal try, before an error occurs, and one retry. If not specified, infinitely retries the source observable. Specifying 0 returns immediately without subscribing
\return An observable that mirrors the source observable, resubscribing to it if it calls on_error up to a specified number of retries.
\sample
\snippet retry.cpp retry count sample
\snippet output.txt retry count sample
*/
#if !defined(RXCPP_OPERATORS_RX_RETRY_HPP)
#define RXCPP_OPERATORS_RX_RETRY_HPP
#include "../rx-includes.hpp"
#include "rx-retry-repeat-common.hpp"
namespace rxcpp {
namespace operators {
namespace detail {
template<class... AN>
struct retry_invalid_arguments {};
template<class... AN>
struct retry_invalid : public rxo::operator_base<retry_invalid_arguments<AN...>> {
using type = observable<retry_invalid_arguments<AN...>, retry_invalid<AN...>>;
};
template<class... AN>
using retry_invalid_t = typename retry_invalid<AN...>::type;
// Contain retry variations in a namespace
namespace retry {
struct event_handlers {
template <typename State>
static inline void on_error(State& state, rxu::error_ptr& e) {
state->update();
// Use specialized predicate for finite/infinte case
if (state->completed_predicate()) {
state->out.on_error(e);
} else {
state->do_subscribe();
}
}
template <typename State>
static inline void on_completed(State& state) {
state->out.on_completed();
}
};
// Finite repeat case (explicitely limited with the number of times)
template <class T, class Observable, class Count>
using finite = ::rxcpp::operators::detail::retry_repeat_common::finite
<event_handlers, T, Observable, Count>;
// Infinite repeat case
template <class T, class Observable>
using infinite = ::rxcpp::operators::detail::retry_repeat_common::infinite
<event_handlers, T, Observable>;
}
} // detail
/*! @copydoc rx-retry.hpp
*/
template<class... AN>
auto retry(AN&&... an)
-> operator_factory<retry_tag, AN...> {
return operator_factory<retry_tag, AN...>(std::make_tuple(std::forward<AN>(an)...));
}
}
template<>
struct member_overload<retry_tag>
{
template<class Observable,
class Enabled = rxu::enable_if_all_true_type_t<is_observable<Observable>>,
class SourceValue = rxu::value_type_t<Observable>,
class Retry = rxo::detail::retry::infinite<SourceValue, rxu::decay_t<Observable>>,
class Value = rxu::value_type_t<Retry>,
class Result = observable<Value, Retry>
>
static Result member(Observable&& o) {
return Result(Retry(std::forward<Observable>(o)));
}
template<class Observable,
class Count,
class Enabled = rxu::enable_if_all_true_type_t<is_observable<Observable>>,
class SourceValue = rxu::value_type_t<Observable>,
class Retry = rxo::detail::retry::finite<SourceValue, rxu::decay_t<Observable>, rxu::decay_t<Count>>,
class Value = rxu::value_type_t<Retry>,
class Result = observable<Value, Retry>
>
static Result member(Observable&& o, Count&& c) {
return Result(Retry(std::forward<Observable>(o), std::forward<Count>(c)));
}
template<class... AN>
static operators::detail::retry_invalid_t<AN...> member(const AN&...) {
std::terminate();
return {};
static_assert(sizeof...(AN) == 10000, "retry takes (optional Count)");
}
};
}
#endif