// // impl/connect.hpp // ~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // #ifndef ASIO_IMPL_CONNECT_HPP #define ASIO_IMPL_CONNECT_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include #include "asio/associator.hpp" #include "asio/detail/base_from_cancellation_state.hpp" #include "asio/detail/bind_handler.hpp" #include "asio/detail/handler_cont_helpers.hpp" #include "asio/detail/handler_tracking.hpp" #include "asio/detail/handler_type_requirements.hpp" #include "asio/detail/non_const_lvalue.hpp" #include "asio/detail/throw_error.hpp" #include "asio/detail/type_traits.hpp" #include "asio/error.hpp" #include "asio/post.hpp" #include "asio/detail/push_options.hpp" namespace asio { namespace detail { struct default_connect_condition { template bool operator()(const asio::error_code&, const Endpoint&) { return true; } }; template inline typename Protocol::endpoint deref_connect_result( Iterator iter, asio::error_code& ec) { return ec ? typename Protocol::endpoint() : *iter; } template struct legacy_connect_condition_helper : T { typedef char (*fallback_func_type)(...); operator fallback_func_type() const; }; template struct legacy_connect_condition_helper { R operator()(Arg1, Arg2) const; char operator()(...) const; }; template struct is_legacy_connect_condition { static char asio_connect_condition_check(char); static char (&asio_connect_condition_check(Iterator))[2]; static const bool value = sizeof(asio_connect_condition_check( (declval>())( declval(), declval()))) != 1; }; template inline Iterator call_connect_condition(ConnectCondition& connect_condition, const asio::error_code& ec, Iterator next, Iterator end, enable_if_t::value>* = 0) { if (next != end) return connect_condition(ec, next); return end; } template inline Iterator call_connect_condition(ConnectCondition& connect_condition, const asio::error_code& ec, Iterator next, Iterator end, enable_if_t::value>* = 0) { for (;next != end; ++next) if (connect_condition(ec, *next)) return next; return end; } } template typename Protocol::endpoint connect(basic_socket& s, const EndpointSequence& endpoints, constraint_t::value>) { asio::error_code ec; typename Protocol::endpoint result = connect(s, endpoints, ec); asio::detail::throw_error(ec, "connect"); return result; } template typename Protocol::endpoint connect(basic_socket& s, const EndpointSequence& endpoints, asio::error_code& ec, constraint_t::value>) { return detail::deref_connect_result( connect(s, endpoints.begin(), endpoints.end(), detail::default_connect_condition(), ec), ec); } #if !defined(ASIO_NO_DEPRECATED) template Iterator connect(basic_socket& s, Iterator begin, constraint_t::value>) { asio::error_code ec; Iterator result = connect(s, begin, ec); asio::detail::throw_error(ec, "connect"); return result; } template inline Iterator connect(basic_socket& s, Iterator begin, asio::error_code& ec, constraint_t::value>) { return connect(s, begin, Iterator(), detail::default_connect_condition(), ec); } #endif // !defined(ASIO_NO_DEPRECATED) template Iterator connect(basic_socket& s, Iterator begin, Iterator end) { asio::error_code ec; Iterator result = connect(s, begin, end, ec); asio::detail::throw_error(ec, "connect"); return result; } template inline Iterator connect(basic_socket& s, Iterator begin, Iterator end, asio::error_code& ec) { return connect(s, begin, end, detail::default_connect_condition(), ec); } template typename Protocol::endpoint connect(basic_socket& s, const EndpointSequence& endpoints, ConnectCondition connect_condition, constraint_t::value>) { asio::error_code ec; typename Protocol::endpoint result = connect( s, endpoints, connect_condition, ec); asio::detail::throw_error(ec, "connect"); return result; } template typename Protocol::endpoint connect(basic_socket& s, const EndpointSequence& endpoints, ConnectCondition connect_condition, asio::error_code& ec, constraint_t::value>) { return detail::deref_connect_result( connect(s, endpoints.begin(), endpoints.end(), connect_condition, ec), ec); } #if !defined(ASIO_NO_DEPRECATED) template Iterator connect(basic_socket& s, Iterator begin, ConnectCondition connect_condition, constraint_t::value>) { asio::error_code ec; Iterator result = connect(s, begin, connect_condition, ec); asio::detail::throw_error(ec, "connect"); return result; } template inline Iterator connect(basic_socket& s, Iterator begin, ConnectCondition connect_condition, asio::error_code& ec, constraint_t::value>) { return connect(s, begin, Iterator(), connect_condition, ec); } #endif // !defined(ASIO_NO_DEPRECATED) template Iterator connect(basic_socket& s, Iterator begin, Iterator end, ConnectCondition connect_condition) { asio::error_code ec; Iterator result = connect(s, begin, end, connect_condition, ec); asio::detail::throw_error(ec, "connect"); return result; } template Iterator connect(basic_socket& s, Iterator begin, Iterator end, ConnectCondition connect_condition, asio::error_code& ec) { ec = asio::error_code(); for (Iterator iter = begin; iter != end; ++iter) { iter = (detail::call_connect_condition(connect_condition, ec, iter, end)); if (iter != end) { s.close(ec); s.connect(*iter, ec); if (!ec) return iter; } else break; } if (!ec) ec = asio::error::not_found; return end; } namespace detail { // Enable the empty base class optimisation for the connect condition. template class base_from_connect_condition { protected: explicit base_from_connect_condition( const ConnectCondition& connect_condition) : connect_condition_(connect_condition) { } template void check_condition(const asio::error_code& ec, Iterator& iter, Iterator& end) { iter = detail::call_connect_condition(connect_condition_, ec, iter, end); } private: ConnectCondition connect_condition_; }; // The default_connect_condition implementation is essentially a no-op. This // template specialisation lets us eliminate all costs associated with it. template <> class base_from_connect_condition { protected: explicit base_from_connect_condition(const default_connect_condition&) { } template void check_condition(const asio::error_code&, Iterator&, Iterator&) { } }; template class range_connect_op : public base_from_cancellation_state, base_from_connect_condition { public: range_connect_op(basic_socket& sock, const EndpointSequence& endpoints, const ConnectCondition& connect_condition, RangeConnectHandler& handler) : base_from_cancellation_state( handler, enable_partial_cancellation()), base_from_connect_condition(connect_condition), socket_(sock), endpoints_(endpoints), index_(0), start_(0), handler_(static_cast(handler)) { } range_connect_op(const range_connect_op& other) : base_from_cancellation_state(other), base_from_connect_condition(other), socket_(other.socket_), endpoints_(other.endpoints_), index_(other.index_), start_(other.start_), handler_(other.handler_) { } range_connect_op(range_connect_op&& other) : base_from_cancellation_state( static_cast&&>( other)), base_from_connect_condition(other), socket_(other.socket_), endpoints_(other.endpoints_), index_(other.index_), start_(other.start_), handler_(static_cast(other.handler_)) { } void operator()(asio::error_code ec, int start = 0) { this->process(ec, start, const_cast(endpoints_).begin(), const_cast(endpoints_).end()); } //private: template void process(asio::error_code ec, int start, Iterator begin, Iterator end) { Iterator iter = begin; std::advance(iter, index_); switch (start_ = start) { case 1: for (;;) { this->check_condition(ec, iter, end); index_ = std::distance(begin, iter); if (iter != end) { socket_.close(ec); ASIO_HANDLER_LOCATION((__FILE__, __LINE__, "async_connect")); socket_.async_connect(*iter, static_cast(*this)); return; } if (start) { ec = asio::error::not_found; ASIO_HANDLER_LOCATION((__FILE__, __LINE__, "async_connect")); asio::post(socket_.get_executor(), detail::bind_handler( static_cast(*this), ec)); return; } /* fall-through */ default: if (iter == end) break; if (!socket_.is_open()) { ec = asio::error::operation_aborted; break; } if (!ec) break; if (this->cancelled() != cancellation_type::none) { ec = asio::error::operation_aborted; break; } ++iter; ++index_; } static_cast(handler_)( static_cast(ec), static_cast( ec || iter == end ? typename Protocol::endpoint() : *iter)); } } basic_socket& socket_; EndpointSequence endpoints_; std::size_t index_; int start_; RangeConnectHandler handler_; }; template inline bool asio_handler_is_continuation( range_connect_op* this_handler) { return asio_handler_cont_helpers::is_continuation( this_handler->handler_); } template class initiate_async_range_connect { public: typedef Executor executor_type; explicit initiate_async_range_connect(basic_socket& s) : socket_(s) { } executor_type get_executor() const noexcept { return socket_.get_executor(); } template void operator()(RangeConnectHandler&& handler, const EndpointSequence& endpoints, const ConnectCondition& connect_condition) const { // If you get an error on the following line it means that your // handler does not meet the documented type requirements for an // RangeConnectHandler. ASIO_RANGE_CONNECT_HANDLER_CHECK(RangeConnectHandler, handler, typename Protocol::endpoint) type_check; non_const_lvalue handler2(handler); range_connect_op>(socket_, endpoints, connect_condition, handler2.value)(asio::error_code(), 1); } private: basic_socket& socket_; }; template class iterator_connect_op : public base_from_cancellation_state, base_from_connect_condition { public: iterator_connect_op(basic_socket& sock, const Iterator& begin, const Iterator& end, const ConnectCondition& connect_condition, IteratorConnectHandler& handler) : base_from_cancellation_state( handler, enable_partial_cancellation()), base_from_connect_condition(connect_condition), socket_(sock), iter_(begin), end_(end), start_(0), handler_(static_cast(handler)) { } iterator_connect_op(const iterator_connect_op& other) : base_from_cancellation_state(other), base_from_connect_condition(other), socket_(other.socket_), iter_(other.iter_), end_(other.end_), start_(other.start_), handler_(other.handler_) { } iterator_connect_op(iterator_connect_op&& other) : base_from_cancellation_state( static_cast&&>( other)), base_from_connect_condition(other), socket_(other.socket_), iter_(other.iter_), end_(other.end_), start_(other.start_), handler_(static_cast(other.handler_)) { } void operator()(asio::error_code ec, int start = 0) { switch (start_ = start) { case 1: for (;;) { this->check_condition(ec, iter_, end_); if (iter_ != end_) { socket_.close(ec); ASIO_HANDLER_LOCATION((__FILE__, __LINE__, "async_connect")); socket_.async_connect(*iter_, static_cast(*this)); return; } if (start) { ec = asio::error::not_found; ASIO_HANDLER_LOCATION((__FILE__, __LINE__, "async_connect")); asio::post(socket_.get_executor(), detail::bind_handler( static_cast(*this), ec)); return; } /* fall-through */ default: if (iter_ == end_) break; if (!socket_.is_open()) { ec = asio::error::operation_aborted; break; } if (!ec) break; if (this->cancelled() != cancellation_type::none) { ec = asio::error::operation_aborted; break; } ++iter_; } static_cast(handler_)( static_cast(ec), static_cast(iter_)); } } //private: basic_socket& socket_; Iterator iter_; Iterator end_; int start_; IteratorConnectHandler handler_; }; template inline bool asio_handler_is_continuation( iterator_connect_op* this_handler) { return asio_handler_cont_helpers::is_continuation( this_handler->handler_); } template class initiate_async_iterator_connect { public: typedef Executor executor_type; explicit initiate_async_iterator_connect( basic_socket& s) : socket_(s) { } executor_type get_executor() const noexcept { return socket_.get_executor(); } template void operator()(IteratorConnectHandler&& handler, Iterator begin, Iterator end, const ConnectCondition& connect_condition) const { // If you get an error on the following line it means that your // handler does not meet the documented type requirements for an // IteratorConnectHandler. ASIO_ITERATOR_CONNECT_HANDLER_CHECK( IteratorConnectHandler, handler, Iterator) type_check; non_const_lvalue handler2(handler); iterator_connect_op>(socket_, begin, end, connect_condition, handler2.value)(asio::error_code(), 1); } private: basic_socket& socket_; }; } // namespace detail #if !defined(GENERATING_DOCUMENTATION) template