...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu , C++ Coding Standards

// ~~~~~~~~~~~~~~~~~~~~~~~~~~~ // 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 BOOST_ASIO_DETAIL_RESOLVER_SERVICE_HPP #define BOOST_ASIO_DETAIL_RESOLVER_SERVICE_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include < boost/asio/detail/config.hpp > #if !defined(BOOST_ASIO_WINDOWS_RUNTIME) #include < boost/asio/ip/basic_resolver_query.hpp > #include < boost/asio/ip/basic_resolver_results.hpp > #include < boost/asio/detail/concurrency_hint.hpp > #include < boost/asio/detail/memory.hpp > #include < boost/asio/detail/resolve_endpoint_op.hpp > #include < boost/asio/detail/resolve_query_op.hpp > #include < boost/asio/detail/resolver_service_base.hpp > #include < boost/asio/detail/push_options.hpp > namespace boost { namespace asio { namespace detail { template <typename Protocol> class resolver_service : public execution_context_service_base<resolver_service<Protocol> >, public resolver_service_base public: // The implementation type of the resolver. A cancellation token is used to // indicate to the background thread that the operation has been cancelled. typedef socket_ops::shared_cancel_token_type implementation_type; // The endpoint type. typedef typename Protocol::endpoint endpoint_type; // The query type. typedef boost::asio::ip::basic_resolver_query<Protocol> query_type; // The results type. typedef boost::asio::ip::basic_resolver_results<Protocol> results_type; // Constructor. resolver_service(execution_context& context) : execution_context_service_base<resolver_service<Protocol> >(context), resolver_service_base(context) // Destroy all user-defined handler objects owned by the service. void shutdown() this->base_shutdown(); // Perform any fork-related housekeeping. void notify_fork(execution_context::fork_event fork_ev) this->base_notify_fork(fork_ev); // Resolve a query to a list of entries. results_type resolve(implementation_type&, const query_type& qry, boost::system::error_code& ec) boost::asio::detail::addrinfo_type* address_info = 0; socket_ops::getaddrinfo(qry.host_name().c_str(), qry.service_name().c_str(), qry.hints(), &address_info, ec); auto_addrinfo auto_address_info(address_info); BOOST_ASIO_ERROR_LOCATION(ec); return ec ? results_type() : results_type::create( address_info, qry.host_name(), qry.service_name()); // Asynchronously resolve a query to a list of entries. template <typename Handler, typename IoExecutor> void async_resolve(implementation_type& impl, const query_type& qry, Handler& handler, const IoExecutor& io_ex) // Allocate and construct an operation to wrap the handler. typedef resolve_query_op<Protocol, Handler, IoExecutor> op; typename op::ptr p = { boost::asio::detail::addressof(handler), op::ptr::allocate(handler), 0 }; p.p = new (p.v) op(impl, qry, scheduler_, handler, io_ex); BOOST_ASIO_HANDLER_CREATION((scheduler_.context(), *p.p, "resolver", &impl, 0, "async_resolve")); start_resolve_op(p.p); p.v = p.p = 0; // Resolve an endpoint to a list of entries. results_type resolve(implementation_type&, const endpoint_type& endpoint, boost::system::error_code& ec) char host_name[NI_MAXHOST]; char service_name[NI_MAXSERV]; socket_ops::sync_getnameinfo(endpoint.data(), endpoint.size(), host_name, NI_MAXHOST, service_name, NI_MAXSERV, endpoint.protocol().type(), ec); BOOST_ASIO_ERROR_LOCATION(ec); return ec ? results_type() : results_type::create( endpoint, host_name, service_name); // Asynchronously resolve an endpoint to a list of entries. template <typename Handler, typename IoExecutor> void async_resolve(implementation_type& impl, const endpoint_type& endpoint, Handler& handler, const IoExecutor& io_ex) // Allocate and construct an operation to wrap the handler. typedef resolve_endpoint_op<Protocol, Handler, IoExecutor> op; typename op::ptr p = { boost::asio::detail::addressof(handler), op::ptr::allocate(handler), 0 }; p.p = new (p.v) op(impl, endpoint, scheduler_, handler, io_ex); BOOST_ASIO_HANDLER_CREATION((scheduler_.context(), *p.p, "resolver", &impl, 0, "async_resolve")); start_resolve_op(p.p); p.v = p.p = 0; } // namespace detail } // namespace asio } // namespace boost #include < boost/asio/detail/pop_options.hpp > #endif // !defined(BOOST_ASIO_WINDOWS_RUNTIME) #endif // BOOST_ASIO_DETAIL_RESOLVER_SERVICE_HPP