cobalt/io/resolver.hpp

0001 //
0002 // Copyright (c) 2025 Klemens Morgenstern (klemens.morgenstern@gmx.net)
0003 //
0004 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007
0008
0009 #ifndef BOOST_COBALT_RESOLVER_HPP
0010 #define BOOST_COBALT_RESOLVER_HPP
0011
0012 #include <boost/cobalt/io/detail/config.hpp>
0013 #include <boost/cobalt/io/endpoint.hpp>
0014 #include <boost/cobalt/io/ops.hpp>
0015 #include <boost/cobalt/op.hpp>
0016 #include <boost/cobalt/promise.hpp>
0017
0018 #include <boost/asio/ip/tcp.hpp>
0019 #include <boost/system/result.hpp>
0020
0021 namespace boost::cobalt::io
0022 {
0023
0024 struct BOOST_SYMBOL_VISIBLE resolver
0025 {
0026   using flags = asio::ip::resolver_base::flags;
0027
0028   resolver(const executor & exec = this_thread::get_executor());
0029   resolver(resolver && ) = delete;
0030
0031   void cancel();
0032
0033  private:
0034   struct BOOST_COBALT_IO_DECL resolve_op_ final : op<system::error_code, endpoint_sequence>
0035   {
0036     void initiate(completion_handler<system::error_code, endpoint_sequence> h) override;
0037
0038     resolve_op_(asio::ip::basic_resolver<protocol_type, executor> & resolver,
0039                 std::string_view host, std::string_view service, flags flags_ = {})
0040         : resolver_(resolver), host_(host), service_(service), flags_(flags_) {}
0041     ~resolve_op_() = default;
0042    private:
0043     asio::ip::basic_resolver<protocol_type, executor> & resolver_;
0044     std::string_view host_;
0045     std::string_view service_;
0046     flags flags_;
0047   };
0048
0049  public:
0050   [[nodiscard]] auto resolve(std::string_view host, std::string_view service,
0051                              flags flags_ = {})
0052   {
0053     return resolve_op_{resolver_, host, service, flags_};
0054   }
0055
0056  private:
0057   asio::ip::basic_resolver<protocol_type, executor> resolver_;
0058 };
0059
0060 struct BOOST_COBALT_IO_DECL lookup final : op<system::error_code, endpoint_sequence>
0061 {
0062   lookup(std::string_view host, std::string_view service,
0063          const executor & exec = this_thread::get_executor(),
0064          resolver::flags flags_ = {})
0065       : host_(host), service_(service), resolver_{exec}, flags_{flags_} {}
0066
0067   void initiate(completion_handler<system::error_code, endpoint_sequence> h) final override;
0068   ~lookup() = default;
0069  private:
0070   std::string_view host_;
0071   std::string_view service_;
0072   asio::ip::basic_resolver<protocol_type, executor> resolver_;
0073   resolver::flags flags_;
0074 };
0075
0076 }
0077
0078 #endif //BOOST_COBALT_RESOLVER_HPP