boost/asio/ip/basic_resolver_iterator.hpp

   1 //
   2 // ip/basic_resolver_iterator.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2017 Christopher M. Kohlhoff (chris at kohlhoff dot com)
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 //
  10
  11 #ifndef BOOST_ASIO_IP_BASIC_RESOLVER_ITERATOR_HPP
  12 #define BOOST_ASIO_IP_BASIC_RESOLVER_ITERATOR_HPP
  13
  14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  15 # pragma once
  16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  17
  18 #include <boost/asio/detail/config.hpp>
  19 #include <cstddef>
  20 #include <cstring>
  21 #include <iterator>
  22 #include <string>
  23 #include <vector>
  24 #include <boost/asio/detail/shared_ptr.hpp>
  25 #include <boost/asio/detail/socket_ops.hpp>
  26 #include <boost/asio/detail/socket_types.hpp>
  27 #include <boost/asio/ip/basic_resolver_entry.hpp>
  28
  29 #if defined(BOOST_ASIO_WINDOWS_RUNTIME)
  30 # include <boost/asio/detail/winrt_utils.hpp>
  31 #endif // defined(BOOST_ASIO_WINDOWS_RUNTIME)
  32
  33 #include <boost/asio/detail/push_options.hpp>
  34
  35 namespace boost {
  36 namespace asio {
  37 namespace ip {
  38
  39 /// An iterator over the entries produced by a resolver.
  40 /**
  41  * The boost::asio::ip::basic_resolver_iterator class template is used to define
  42  * iterators over the results returned by a resolver.
  43  *
  44  * The iterator's value_type, obtained when the iterator is dereferenced, is:
  45  * @code const basic_resolver_entry<InternetProtocol> @endcode
  46  *
  47  * @par Thread Safety
  48  * @e Distinct @e objects: Safe.@n
  49  * @e Shared @e objects: Unsafe.
  50  */
  51 template <typename InternetProtocol>
  52 class basic_resolver_iterator
  53 {
  54 public:
  55   /// The type used for the distance between two iterators.
  56   typedef std::ptrdiff_t difference_type;
  57
  58   /// The type of the value pointed to by the iterator.
  59   typedef basic_resolver_entry<InternetProtocol> value_type;
  60
  61   /// The type of the result of applying operator->() to the iterator.
  62   typedef const basic_resolver_entry<InternetProtocol>* pointer;
  63
  64   /// The type of the result of applying operator*() to the iterator.
  65   typedef const basic_resolver_entry<InternetProtocol>& reference;
  66
  67   /// The iterator category.
  68   typedef std::forward_iterator_tag iterator_category;
  69
  70   /// Default constructor creates an end iterator.
  71   basic_resolver_iterator()
  72     : index_(0)
  73   {
  74   }
  75
  76   /// Create an iterator from an addrinfo list returned by getaddrinfo.
  77   static basic_resolver_iterator create(
  78       boost::asio::detail::addrinfo_type* address_info,
  79       const std::string& host_name, const std::string& service_name)
  80   {
  81     basic_resolver_iterator iter;
  82     if (!address_info)
  83       return iter;
  84
  85     std::string actual_host_name = host_name;
  86     if (address_info->ai_canonname)
  87       actual_host_name = address_info->ai_canonname;
  88
  89     iter.values_.reset(new values_type);
  90
  91     while (address_info)
  92     {
  93       if (address_info->ai_family == BOOST_ASIO_OS_DEF(AF_INET)
  94           || address_info->ai_family == BOOST_ASIO_OS_DEF(AF_INET6))
  95       {
  96         using namespace std; // For memcpy.
  97         typename InternetProtocol::endpoint endpoint;
  98         endpoint.resize(static_cast<std::size_t>(address_info->ai_addrlen));
  99         memcpy(endpoint.data(), address_info->ai_addr,
 100             address_info->ai_addrlen);
 101         iter.values_->push_back(
 102             basic_resolver_entry<InternetProtocol>(endpoint,
 103               actual_host_name, service_name));
 104       }
 105       address_info = address_info->ai_next;
 106     }
 107
 108     return iter;
 109   }
 110
 111   /// Create an iterator from an endpoint, host name and service name.
 112   static basic_resolver_iterator create(
 113       const typename InternetProtocol::endpoint& endpoint,
 114       const std::string& host_name, const std::string& service_name)
 115   {
 116     basic_resolver_iterator iter;
 117     iter.values_.reset(new values_type);
 118     iter.values_->push_back(
 119         basic_resolver_entry<InternetProtocol>(
 120           endpoint, host_name, service_name));
 121     return iter;
 122   }
 123
 124   /// Create an iterator from a sequence of endpoints, host and service name.
 125   template <typename EndpointIterator>
 126   static basic_resolver_iterator create(
 127       EndpointIterator begin, EndpointIterator end,
 128       const std::string& host_name, const std::string& service_name)
 129   {
 130     basic_resolver_iterator iter;
 131     if (begin != end)
 132     {
 133       iter.values_.reset(new values_type);
 134       for (EndpointIterator ep_iter = begin; ep_iter != end; ++ep_iter)
 135       {
 136         iter.values_->push_back(
 137             basic_resolver_entry<InternetProtocol>(
 138               *ep_iter, host_name, service_name));
 139       }
 140     }
 141     return iter;
 142   }
 143
 144 #if defined(BOOST_ASIO_WINDOWS_RUNTIME)
 145   /// Create an iterator from a Windows Runtime list of EndpointPair objects.
 146   static basic_resolver_iterator create(
 147       Windows::Foundation::Collections::IVectorView<
 148         Windows::Networking::EndpointPair^>^ endpoints,
 149       const boost::asio::detail::addrinfo_type& hints,
 150       const std::string& host_name, const std::string& service_name)
 151   {
 152     basic_resolver_iterator iter;
 153     if (endpoints->Size)
 154     {
 155       iter.values_.reset(new values_type);
 156       for (unsigned int i = 0; i < endpoints->Size; ++i)
 157       {
 158         auto pair = endpoints->GetAt(i);
 159
 160         if (hints.ai_family == BOOST_ASIO_OS_DEF(AF_INET)
 161             && pair->RemoteHostName->Type
 162               != Windows::Networking::HostNameType::Ipv4)
 163           continue;
 164
 165         if (hints.ai_family == BOOST_ASIO_OS_DEF(AF_INET6)
 166             && pair->RemoteHostName->Type
 167               != Windows::Networking::HostNameType::Ipv6)
 168           continue;
 169
 170         iter.values_->push_back(
 171             basic_resolver_entry<InternetProtocol>(
 172               typename InternetProtocol::endpoint(
 173                 ip::address::from_string(
 174                   boost::asio::detail::winrt_utils::string(
 175                     pair->RemoteHostName->CanonicalName)),
 176                 boost::asio::detail::winrt_utils::integer(
 177                   pair->RemoteServiceName)),
 178               host_name, service_name));
 179       }
 180     }
 181     return iter;
 182   }
 183 #endif // defined(BOOST_ASIO_WINDOWS_RUNTIME)
 184
 185   /// Dereference an iterator.
 186   const basic_resolver_entry<InternetProtocol>& operator*() const
 187   {
 188     return dereference();
 189   }
 190
 191   /// Dereference an iterator.
 192   const basic_resolver_entry<InternetProtocol>* operator->() const
 193   {
 194     return &dereference();
 195   }
 196
 197   /// Increment operator (prefix).
 198   basic_resolver_iterator& operator++()
 199   {
 200     increment();
 201     return *this;
 202   }
 203
 204   /// Increment operator (postfix).
 205   basic_resolver_iterator operator++(int)
 206   {
 207     basic_resolver_iterator tmp(*this);
 208     ++*this;
 209     return tmp;
 210   }
 211
 212   /// Test two iterators for equality.
 213   friend bool operator==(const basic_resolver_iterator& a,
 214       const basic_resolver_iterator& b)
 215   {
 216     return a.equal(b);
 217   }
 218
 219   /// Test two iterators for inequality.
 220   friend bool operator!=(const basic_resolver_iterator& a,
 221       const basic_resolver_iterator& b)
 222   {
 223     return !a.equal(b);
 224   }
 225
 226 private:
 227   void increment()
 228   {
 229     if (++index_ == values_->size())
 230     {
 231       // Reset state to match a default constructed end iterator.
 232       values_.reset();
 233       index_ = 0;
 234     }
 235   }
 236
 237   bool equal(const basic_resolver_iterator& other) const
 238   {
 239     if (!values_ && !other.values_)
 240       return true;
 241     if (values_ != other.values_)
 242       return false;
 243     return index_ == other.index_;
 244   }
 245
 246   const basic_resolver_entry<InternetProtocol>& dereference() const
 247   {
 248     return (*values_)[index_];
 249   }
 250
 251   typedef std::vector<basic_resolver_entry<InternetProtocol> > values_type;
 252   boost::asio::detail::shared_ptr<values_type> values_;
 253   std::size_t index_;
 254 };
 255
 256 } // namespace ip
 257 } // namespace asio
 258 } // namespace boost
 259
 260 #include <boost/asio/detail/pop_options.hpp>
 261
 262 #endif // BOOST_ASIO_IP_BASIC_RESOLVER_ITERATOR_HPP