tdesktop/Telegram/SourceFiles/rpl/consumer.h

637 lines
14 KiB
C++

/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.
For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#pragma once
#include <memory>
#include <gsl/gsl_assert>
#include <rpl/lifetime.h>
#include <rpl/details/callable.h>
// GCC 7.2 can't handle not type-erased consumers.
// It eats up 4GB RAM + 16GB swap on the unittest and dies.
// Clang and Visual C++ both handle it without such problems.
#if defined _DEBUG || defined COMPILER_GCC
#define RPL_CONSUMER_TYPE_ERASED_ALWAYS
#endif // _DEBUG || COMPILER_GCC
namespace rpl {
namespace details {
template <
typename Value,
typename Error,
typename OnNext,
typename OnError,
typename OnDone>
class consumer_handlers;
template <typename Value, typename Error>
class type_erased_handlers {
public:
virtual bool put_next(Value &&value) = 0;
virtual bool put_next_copy(const Value &value) = 0;
virtual void put_error(Error &&error) = 0;
virtual void put_error_copy(const Error &error) = 0;
virtual void put_done() = 0;
bool add_lifetime(lifetime &&lifetime);
template <typename Type, typename... Args>
Type *make_state(Args&& ...args);
void terminate();
virtual ~type_erased_handlers() = default;
protected:
lifetime _lifetime;
bool _terminated = false;
};
template <typename Handlers>
struct is_type_erased_handlers
: std::false_type {
};
template <typename Value, typename Error>
struct is_type_erased_handlers<type_erased_handlers<Value, Error>>
: std::true_type {
};
template <typename Handlers>
constexpr bool is_type_erased_handlers_v
= is_type_erased_handlers<Handlers>::value;
template <typename Value, typename Error, typename OnNext, typename OnError, typename OnDone>
class consumer_handlers final
: public type_erased_handlers<Value, Error> {
public:
template <
typename OnNextOther,
typename OnErrorOther,
typename OnDoneOther>
consumer_handlers(
OnNextOther &&next,
OnErrorOther &&error,
OnDoneOther &&done)
: _next(std::forward<OnNextOther>(next))
, _error(std::forward<OnErrorOther>(error))
, _done(std::forward<OnDoneOther>(done)) {
}
bool put_next(Value &&value) final override;
bool put_next_copy(const Value &value) final override;
void put_error(Error &&error) final override;
void put_error_copy(const Error &error) final override;
void put_done() final override;
private:
OnNext _next;
OnError _error;
OnDone _done;
};
template <typename Value, typename Error>
inline bool type_erased_handlers<Value, Error>::add_lifetime(
lifetime &&lifetime) {
if (_terminated) {
lifetime.destroy();
return false;
}
_lifetime.add(std::move(lifetime));
return true;
}
template <typename Value, typename Error>
template <typename Type, typename... Args>
inline Type *type_erased_handlers<Value, Error>::make_state(
Args&& ...args) {
if (_terminated) {
return nullptr;
}
return _lifetime.make_state<Type>(std::forward<Args>(args)...);
}
template <typename Value, typename Error>
inline void type_erased_handlers<Value, Error>::terminate() {
if (!_terminated) {
_terminated = true;
_lifetime.destroy();
}
}
template <
typename Value,
typename Error,
typename OnNext,
typename OnError,
typename OnDone>
bool consumer_handlers<
Value,
Error,
OnNext,
OnError,
OnDone
>::put_next(Value &&value) {
if (this->_terminated) {
return false;
}
auto handler = this->_next;
details::callable_invoke(std::move(handler), std::move(value));
return true;
}
template <
typename Value,
typename Error,
typename OnNext,
typename OnError,
typename OnDone>
bool consumer_handlers<
Value,
Error,
OnNext,
OnError,
OnDone
>::put_next_copy(const Value &value) {
if (this->_terminated) {
return false;
}
auto handler = this->_next;
details::const_ref_call_invoke(std::move(handler), value);
return true;
}
template <
typename Value,
typename Error,
typename OnNext,
typename OnError,
typename OnDone>
void consumer_handlers<
Value,
Error,
OnNext,
OnError,
OnDone
>::put_error(Error &&error) {
if (!this->_terminated) {
details::callable_invoke(
std::move(this->_error),
std::move(error));
this->terminate();
}
}
template <
typename Value,
typename Error,
typename OnNext,
typename OnError,
typename OnDone>
void consumer_handlers<
Value,
Error,
OnNext,
OnError,
OnDone
>::put_error_copy(const Error &error) {
if (!this->_terminated) {
details::const_ref_call_invoke(
std::move(this->_error),
error);
this->terminate();
}
}
template <
typename Value,
typename Error,
typename OnNext,
typename OnError,
typename OnDone>
void consumer_handlers<
Value,
Error,
OnNext,
OnError,
OnDone
>::put_done() {
if (!this->_terminated) {
std::move(this->_done)();
this->terminate();
}
}
} // namespace details
struct no_value {
no_value() = delete;
};
struct no_error {
no_error() = delete;
};
struct empty_value {
};
struct empty_error {
};
template <
typename Value = empty_value,
typename Error = no_error,
typename Handlers = details::type_erased_handlers<Value, Error>>
class consumer;
namespace details {
template <typename Value, typename Error, typename Handlers>
class consumer_base {
static constexpr bool is_type_erased
= is_type_erased_handlers_v<Handlers>;
public:
template <
typename OnNext,
typename OnError,
typename OnDone>
consumer_base(
OnNext &&next,
OnError &&error,
OnDone &&done);
bool put_next(Value &&value) const;
bool put_next_copy(const Value &value) const;
bool put_next_forward(Value &&value) const {
return put_next(std::move(value));
}
bool put_next_forward(const Value &value) const {
return put_next_copy(value);
}
void put_error(Error &&error) const;
void put_error_copy(const Error &error) const;
void put_error_forward(Error &&error) const {
return put_error(std::move(error));
}
void put_error_forward(const Error &error) const {
return put_error_copy(error);
}
void put_done() const;
bool add_lifetime(lifetime &&lifetime) const;
template <typename Type, typename... Args>
Type *make_state(Args&& ...args) const;
void terminate() const;
auto terminator() const {
return [self = *this] {
self.terminate();
};
}
const details::type_erased_handlers<Value, Error> *comparable() const {
return _handlers.get();
}
private:
template <
typename OtherHandlers,
typename = std::enable_if_t<
std::is_base_of_v<Handlers, OtherHandlers>>>
consumer_base(const std::shared_ptr<OtherHandlers> &handlers)
: _handlers(handlers) {
}
template <
typename OtherHandlers,
typename = std::enable_if_t<
std::is_base_of_v<Handlers, OtherHandlers>>>
consumer_base(std::shared_ptr<OtherHandlers> &&handlers)
: _handlers(std::move(handlers)) {
}
mutable std::shared_ptr<Handlers> _handlers;
bool handlers_put_next(Value &&value) const {
if constexpr (is_type_erased) {
return _handlers->put_next(std::move(value));
} else {
return _handlers->Handlers::put_next(std::move(value));
}
}
bool handlers_put_next_copy(const Value &value) const {
if constexpr (is_type_erased) {
return _handlers->put_next_copy(value);
} else {
return _handlers->Handlers::put_next_copy(value);
}
}
std::shared_ptr<Handlers> take_handlers() const {
return std::exchange(_handlers, nullptr);
}
template <
typename OtherValue,
typename OtherError,
typename OtherHandlers>
friend class ::rpl::consumer;
};
template <typename Value, typename Error, typename Handlers>
template <typename OnNext, typename OnError, typename OnDone>
inline consumer_base<Value, Error, Handlers>::consumer_base(
OnNext &&next,
OnError &&error,
OnDone &&done)
: _handlers(std::make_shared<consumer_handlers<
Value,
Error,
std::decay_t<OnNext>,
std::decay_t<OnError>,
std::decay_t<OnDone>>>(
std::forward<OnNext>(next),
std::forward<OnError>(error),
std::forward<OnDone>(done))) {
}
template <typename Value, typename Error, typename Handlers>
inline bool consumer_base<Value, Error, Handlers>::put_next(
Value &&value) const {
if (_handlers) {
if (handlers_put_next(std::move(value))) {
return true;
}
_handlers = nullptr;
}
return false;
}
template <typename Value, typename Error, typename Handlers>
inline bool consumer_base<Value, Error, Handlers>::put_next_copy(
const Value &value) const {
if (_handlers) {
if (handlers_put_next_copy(value)) {
return true;
}
_handlers = nullptr;
}
return false;
}
template <typename Value, typename Error, typename Handlers>
inline void consumer_base<Value, Error, Handlers>::put_error(
Error &&error) const {
if (_handlers) {
if constexpr (is_type_erased) {
take_handlers()->put_error(std::move(error));
} else {
take_handlers()->Handlers::put_error(std::move(error));
}
}
}
template <typename Value, typename Error, typename Handlers>
inline void consumer_base<Value, Error, Handlers>::put_error_copy(
const Error &error) const {
if (_handlers) {
if constexpr (is_type_erased) {
take_handlers()->put_error_copy(error);
} else {
take_handlers()->Handlers::put_error_copy(error);
}
}
}
template <typename Value, typename Error, typename Handlers>
inline void consumer_base<Value, Error, Handlers>::put_done() const {
if (_handlers) {
if constexpr (is_type_erased) {
take_handlers()->put_done();
} else {
take_handlers()->Handlers::put_done();
}
}
}
template <typename Value, typename Error, typename Handlers>
inline bool consumer_base<Value, Error, Handlers>::add_lifetime(
lifetime &&lifetime) const {
if (!_handlers) {
lifetime.destroy();
return false;
}
if (_handlers->add_lifetime(std::move(lifetime))) {
return true;
}
_handlers = nullptr;
return false;
}
template <typename Value, typename Error, typename Handlers>
template <typename Type, typename... Args>
inline Type *consumer_base<Value, Error, Handlers>::make_state(
Args&& ...args) const {
if (!_handlers) {
return nullptr;
}
if (auto result = _handlers->template make_state<Type>(
std::forward<Args>(args)...)) {
return result;
}
_handlers = nullptr;
return nullptr;
}
template <typename Value, typename Error, typename Handlers>
inline void consumer_base<Value, Error, Handlers>::terminate() const {
if (_handlers) {
std::exchange(_handlers, nullptr)->terminate();
}
}
template <typename Value, typename Error>
using consumer_base_type_erased = consumer_base<
Value,
Error,
details::type_erased_handlers<Value, Error>>;
template <typename Value, typename Error, typename Handlers>
constexpr bool is_specific_handlers_v = !std::is_same_v<
details::type_erased_handlers<Value, Error>,
Handlers
> && std::is_base_of_v<
details::type_erased_handlers<Value, Error>,
Handlers
>;
} // namespace details
template <typename Value, typename Error, typename Handlers>
class consumer final
: public details::consumer_base<Value, Error, Handlers> {
using parent_type = details::consumer_base<
Value,
Error,
Handlers>;
public:
using parent_type::parent_type;
};
template <typename Value, typename Error>
class consumer<Value, Error, details::type_erased_handlers<Value, Error>> final
: public details::consumer_base_type_erased<Value, Error> {
using parent_type = details::consumer_base_type_erased<
Value,
Error>;
public:
using parent_type::parent_type;
template <
typename Handlers,
typename = std::enable_if_t<
details::is_specific_handlers_v<Value, Error, Handlers>>>
consumer(const details::consumer_base<Value, Error, Handlers> &other)
: parent_type(other._handlers) {
}
template <
typename Handlers,
typename = std::enable_if_t<
details::is_specific_handlers_v<Value, Error, Handlers>>>
consumer(details::consumer_base<Value, Error, Handlers> &&other)
: parent_type(std::move(other._handlers)) {
}
template <
typename Handlers,
typename = std::enable_if_t<
details::is_specific_handlers_v<Value, Error, Handlers>>>
consumer &operator=(
const details::consumer_base<Value, Error, Handlers> &other) {
this->_handlers = other._handlers;
return *this;
}
template <
typename Handlers,
typename = std::enable_if_t<
details::is_specific_handlers_v<Value, Error, Handlers>>>
consumer &operator=(
details::consumer_base<Value, Error, Handlers> &&other) {
this->_handlers = std::move(other._handlers);
return *this;
}
};
template <
typename Value,
typename Error,
typename Handlers1,
typename Handlers2>
inline bool operator==(
const consumer<Value, Error, Handlers1> &a,
const consumer<Value, Error, Handlers2> &b) {
return a.comparable() == b.comparable();
}
template <
typename Value,
typename Error,
typename Handlers1,
typename Handlers2>
inline bool operator<(
const consumer<Value, Error, Handlers1> &a,
const consumer<Value, Error, Handlers2> &b) {
return a.comparable() < b.comparable();
}
template <
typename Value,
typename Error,
typename Handlers1,
typename Handlers2>
inline bool operator!=(
const consumer<Value, Error, Handlers1> &a,
const consumer<Value, Error, Handlers2> &b) {
return !(a == b);
}
template <
typename Value,
typename Error,
typename Handlers1,
typename Handlers2>
inline bool operator>(
const consumer<Value, Error, Handlers1> &a,
const consumer<Value, Error, Handlers2> &b) {
return b < a;
}
template <
typename Value,
typename Error,
typename Handlers1,
typename Handlers2>
inline bool operator<=(
const consumer<Value, Error, Handlers1> &a,
const consumer<Value, Error, Handlers2> &b) {
return !(b < a);
}
template <
typename Value,
typename Error,
typename Handlers1,
typename Handlers2>
inline bool operator>=(
const consumer<Value, Error, Handlers1> &a,
const consumer<Value, Error, Handlers2> &b) {
return !(a < b);
}
template <
typename Value,
typename Error,
typename OnNext,
typename OnError,
typename OnDone,
typename = std::enable_if_t<
details::is_callable_v<OnNext, Value> &&
details::is_callable_v<OnError, Error> &&
details::is_callable_v<OnDone>>>
#ifdef RPL_CONSUMER_TYPE_ERASED_ALWAYS
inline consumer<Value, Error> make_consumer(
#else // RPL_CONSUMER_TYPE_ERASED_ALWAYS
inline auto make_consumer(
#endif // !RPL_CONSUMER_TYPE_ERASED_ALWAYS
OnNext &&next,
OnError &&error,
OnDone &&done) {
return consumer<Value, Error, details::consumer_handlers<
Value,
Error,
std::decay_t<OnNext>,
std::decay_t<OnError>,
std::decay_t<OnDone>>>(
std::forward<OnNext>(next),
std::forward<OnError>(error),
std::forward<OnDone>(done));
}
} // namespace rpl