boost/asio/ip/basic_resolver.hpp
//
// ip/basic_resolver.hpp
// ~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2015 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 BOOST_ASIO_IP_BASIC_RESOLVER_HPP
#define BOOST_ASIO_IP_BASIC_RESOLVER_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include <boost/asio/detail/config.hpp>
#include <boost/asio/basic_io_object.hpp>
#include <boost/asio/detail/handler_type_requirements.hpp>
#include <boost/asio/detail/throw_error.hpp>
#include <boost/asio/error.hpp>
#include <boost/asio/ip/basic_resolver_iterator.hpp>
#include <boost/asio/ip/basic_resolver_query.hpp>
#include <boost/asio/ip/resolver_service.hpp>
#include <boost/asio/detail/push_options.hpp>
namespace boost {
namespace asio {
namespace ip {
/// Provides endpoint resolution functionality.
/**
* The basic_resolver class template provides the ability to resolve a query
* to a list of endpoints.
*
* @par Thread Safety
* @e Distinct @e objects: Safe.@n
* @e Shared @e objects: Unsafe.
*/
template <typename InternetProtocol,
typename ResolverService = resolver_service<InternetProtocol> >
class basic_resolver
: public basic_io_object<ResolverService>
{
public:
/// The protocol type.
typedef InternetProtocol protocol_type;
/// The endpoint type.
typedef typename InternetProtocol::endpoint endpoint_type;
/// The query type.
typedef basic_resolver_query<InternetProtocol> query;
/// The iterator type.
typedef basic_resolver_iterator<InternetProtocol> iterator;
/// Constructor.
/**
* This constructor creates a basic_resolver.
*
* @param io_service The io_service object that the resolver will use to
* dispatch handlers for any asynchronous operations performed on the timer.
*/
explicit basic_resolver(boost::asio::io_service& io_service)
: basic_io_object<ResolverService>(io_service)
{
}
/// Cancel any asynchronous operations that are waiting on the resolver.
/**
* This function forces the completion of any pending asynchronous
* operations on the host resolver. The handler for each cancelled operation
* will be invoked with the boost::asio::error::operation_aborted error code.
*/
void cancel()
{
return this->service.cancel(this->implementation);
}
/// Perform forward resolution of a query to a list of entries.
/**
* This function is used to resolve a query into a list of endpoint entries.
*
* @param q A query object that determines what endpoints will be returned.
*
* @returns A forward-only iterator that can be used to traverse the list
* of endpoint entries.
*
* @throws boost::system::system_error Thrown on failure.
*
* @note A default constructed iterator represents the end of the list.
*
* A successful call to this function is guaranteed to return at least one
* entry.
*/
iterator resolve(const query& q)
{
boost::system::error_code ec;
iterator i = this->service.resolve(this->implementation, q, ec);
boost::asio::detail::throw_error(ec, "resolve");
return i;
}
/// Perform forward resolution of a query to a list of entries.
/**
* This function is used to resolve a query into a list of endpoint entries.
*
* @param q A query object that determines what endpoints will be returned.
*
* @param ec Set to indicate what error occurred, if any.
*
* @returns A forward-only iterator that can be used to traverse the list
* of endpoint entries. Returns a default constructed iterator if an error
* occurs.
*
* @note A default constructed iterator represents the end of the list.
*
* A successful call to this function is guaranteed to return at least one
* entry.
*/
iterator resolve(const query& q, boost::system::error_code& ec)
{
return this->service.resolve(this->implementation, q, ec);
}
/// Asynchronously perform forward resolution of a query to a list of entries.
/**
* This function is used to asynchronously resolve a query into a list of
* endpoint entries.
*
* @param q A query object that determines what endpoints will be returned.
*
* @param handler The handler to be called when the resolve operation
* completes. Copies will be made of the handler as required. The function
* signature of the handler must be:
* @code void handler(
* const boost::system::error_code& error, // Result of operation.
* resolver::iterator iterator // Forward-only iterator that can
* // be used to traverse the list
* // of endpoint entries.
* ); @endcode
* Regardless of whether the asynchronous operation completes immediately or
* not, the handler will not be invoked from within this function. Invocation
* of the handler will be performed in a manner equivalent to using
* boost::asio::io_service::post().
*
* @note A default constructed iterator represents the end of the list.
*
* A successful resolve operation is guaranteed to pass at least one entry to
* the handler.
*/
template <typename ResolveHandler>
BOOST_ASIO_INITFN_RESULT_TYPE(ResolveHandler,
void (boost::system::error_code, iterator))
async_resolve(const query& q,
BOOST_ASIO_MOVE_ARG(ResolveHandler) handler)
{
// If you get an error on the following line it means that your handler does
// not meet the documented type requirements for a ResolveHandler.
BOOST_ASIO_RESOLVE_HANDLER_CHECK(
ResolveHandler, handler, iterator) type_check;
return this->service.async_resolve(this->implementation, q,
BOOST_ASIO_MOVE_CAST(ResolveHandler)(handler));
}
/// Perform reverse resolution of an endpoint to a list of entries.
/**
* This function is used to resolve an endpoint into a list of endpoint
* entries.
*
* @param e An endpoint object that determines what endpoints will be
* returned.
*
* @returns A forward-only iterator that can be used to traverse the list
* of endpoint entries.
*
* @throws boost::system::system_error Thrown on failure.
*
* @note A default constructed iterator represents the end of the list.
*
* A successful call to this function is guaranteed to return at least one
* entry.
*/
iterator resolve(const endpoint_type& e)
{
boost::system::error_code ec;
iterator i = this->service.resolve(this->implementation, e, ec);
boost::asio::detail::throw_error(ec, "resolve");
return i;
}
/// Perform reverse resolution of an endpoint to a list of entries.
/**
* This function is used to resolve an endpoint into a list of endpoint
* entries.
*
* @param e An endpoint object that determines what endpoints will be
* returned.
*
* @param ec Set to indicate what error occurred, if any.
*
* @returns A forward-only iterator that can be used to traverse the list
* of endpoint entries. Returns a default constructed iterator if an error
* occurs.
*
* @note A default constructed iterator represents the end of the list.
*
* A successful call to this function is guaranteed to return at least one
* entry.
*/
iterator resolve(const endpoint_type& e, boost::system::error_code& ec)
{
return this->service.resolve(this->implementation, e, ec);
}
/// Asynchronously perform reverse resolution of an endpoint to a list of
/// entries.
/**
* This function is used to asynchronously resolve an endpoint into a list of
* endpoint entries.
*
* @param e An endpoint object that determines what endpoints will be
* returned.
*
* @param handler The handler to be called when the resolve operation
* completes. Copies will be made of the handler as required. The function
* signature of the handler must be:
* @code void handler(
* const boost::system::error_code& error, // Result of operation.
* resolver::iterator iterator // Forward-only iterator that can
* // be used to traverse the list
* // of endpoint entries.
* ); @endcode
* Regardless of whether the asynchronous operation completes immediately or
* not, the handler will not be invoked from within this function. Invocation
* of the handler will be performed in a manner equivalent to using
* boost::asio::io_service::post().
*
* @note A default constructed iterator represents the end of the list.
*
* A successful resolve operation is guaranteed to pass at least one entry to
* the handler.
*/
template <typename ResolveHandler>
BOOST_ASIO_INITFN_RESULT_TYPE(ResolveHandler,
void (boost::system::error_code, iterator))
async_resolve(const endpoint_type& e,
BOOST_ASIO_MOVE_ARG(ResolveHandler) handler)
{
// If you get an error on the following line it means that your handler does
// not meet the documented type requirements for a ResolveHandler.
BOOST_ASIO_RESOLVE_HANDLER_CHECK(
ResolveHandler, handler, iterator) type_check;
return this->service.async_resolve(this->implementation, e,
BOOST_ASIO_MOVE_CAST(ResolveHandler)(handler));
}
};
} // namespace ip
} // namespace asio
} // namespace boost
#include <boost/asio/detail/pop_options.hpp>
#endif // BOOST_ASIO_IP_BASIC_RESOLVER_HPP