Line data Source code
1 : /*! \file access.hpp
2 : \brief Access control and default construction */
3 : /*
4 : Copyright (c) 2014, Randolph Voorhies, Shane Grant
5 : All rights reserved.
6 :
7 : Redistribution and use in source and binary forms, with or without
8 : modification, are permitted provided that the following conditions are met:
9 : * Redistributions of source code must retain the above copyright
10 : notice, this list of conditions and the following disclaimer.
11 : * Redistributions in binary form must reproduce the above copyright
12 : notice, this list of conditions and the following disclaimer in the
13 : documentation and/or other materials provided with the distribution.
14 : * Neither the name of the copyright holder nor the
15 : names of its contributors may be used to endorse or promote products
16 : derived from this software without specific prior written permission.
17 :
18 : THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
19 : ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 : WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 : DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
22 : DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 : (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24 : LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25 : ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 : (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27 : SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 : */
29 : #ifndef CEREAL_ACCESS_HPP_
30 : #define CEREAL_ACCESS_HPP_
31 :
32 : #include <type_traits>
33 : #include <iostream>
34 : #include <cstdint>
35 : #include <functional>
36 :
37 : #include "cereal/macros.hpp"
38 : #include "cereal/specialize.hpp"
39 : #include "cereal/details/helpers.hpp"
40 :
41 : namespace cereal
42 : {
43 : // ######################################################################
44 : //! A class that allows cereal to load smart pointers to types that have no default constructor
45 : /*! If your class does not have a default constructor, cereal will not be able
46 : to load any smart pointers to it unless you overload LoadAndConstruct
47 : for your class, and provide an appropriate load_and_construct method. You can also
48 : choose to define a member static function instead of specializing this class.
49 :
50 : The specialization of LoadAndConstruct must be placed within the cereal namespace:
51 :
52 : @code{.cpp}
53 : struct MyType
54 : {
55 : MyType( int x ); // note: no default ctor
56 : int myX;
57 :
58 : // Define a serialize or load/save pair as you normally would
59 : template <class Archive>
60 : void serialize( Archive & ar )
61 : {
62 : ar( myX );
63 : }
64 : };
65 :
66 : // Provide a specialization for LoadAndConstruct for your type
67 : namespace cereal
68 : {
69 : template <> struct LoadAndConstruct<MyType>
70 : {
71 : // load_and_construct will be passed the archive that you will be loading
72 : // from as well as a construct object which you can use as if it were the
73 : // constructor for your type. cereal will handle all memory management for you.
74 : template <class Archive>
75 : static void load_and_construct( Archive & ar, cereal::construct<MyType> & construct )
76 : {
77 : int x;
78 : ar( x );
79 : construct( x );
80 : }
81 :
82 : // if you require versioning, simply add a const std::uint32_t as the final parameter, e.g.:
83 : // load_and_construct( Archive & ar, cereal::construct<MyType> & construct, std::uint32_t const version )
84 : };
85 : } // end namespace cereal
86 : @endcode
87 :
88 : Please note that just as in using external serialization functions, you cannot get
89 : access to non-public members of your class by befriending cereal::access. If you
90 : have the ability to modify the class you wish to serialize, it is recommended that you
91 : use member serialize functions and a static member load_and_construct function.
92 :
93 : load_and_construct functions, regardless of whether they are static members of your class or
94 : whether you create one in the LoadAndConstruct specialization, have the following signature:
95 :
96 : @code{.cpp}
97 : // generally Archive will be templated, but it can be specific if desired
98 : template <class Archive>
99 : static void load_and_construct( Archive & ar, cereal::construct<MyType> & construct );
100 : // with an optional last parameter specifying the version: const std::uint32_t version
101 : @endcode
102 :
103 : Versioning behaves the same way as it does for standard serialization functions.
104 :
105 : @tparam T The type to specialize for
106 : @ingroup Access */
107 : template <class T>
108 : struct LoadAndConstruct
109 : { };
110 :
111 : // forward decl for construct
112 : //! @cond PRIVATE_NEVERDEFINED
113 : namespace memory_detail{ template <class Ar, class T> struct LoadAndConstructLoadWrapper; }
114 : namespace boost_variant_detail{ template <class Ar, class T> struct LoadAndConstructLoadWrapper; }
115 : //! @endcond
116 :
117 : //! Used to construct types with no default constructor
118 : /*! When serializing a type that has no default constructor, cereal
119 : will attempt to call either the class static function load_and_construct
120 : or the appropriate template specialization of LoadAndConstruct. cereal
121 : will pass that function a reference to the archive as well as a reference
122 : to a construct object which should be used to perform the allocation once
123 : data has been appropriately loaded.
124 :
125 : @code{.cpp}
126 : struct MyType
127 : {
128 : // note the lack of default constructor
129 : MyType( int xx, int yy );
130 :
131 : int x, y;
132 : double notInConstructor;
133 :
134 : template <class Archive>
135 : void serialize( Archive & ar )
136 : {
137 : ar( x, y );
138 : ar( notInConstructor );
139 : }
140 :
141 : template <class Archive>
142 : static void load_and_construct( Archive & ar, cereal::construct<MyType> & construct )
143 : {
144 : int x, y;
145 : ar( x, y );
146 :
147 : // use construct object to initialize with loaded data
148 : construct( x, y );
149 :
150 : // access to member variables and functions via -> operator
151 : ar( construct->notInConstructor );
152 :
153 : // could also do the above section by:
154 : double z;
155 : ar( z );
156 : construct->notInConstructor = z;
157 : }
158 : };
159 : @endcode
160 :
161 : @tparam T The class type being serialized
162 : */
163 : template <class T>
164 : class construct
165 : {
166 : public:
167 : //! Construct and initialize the type T with the given arguments
168 : /*! This will forward all arguments to the underlying type T,
169 : calling an appropriate constructor.
170 :
171 : Calling this function more than once will result in an exception
172 : being thrown.
173 :
174 : @param args The arguments to the constructor for T
175 : @throw Exception If called more than once */
176 : template <class ... Args>
177 : void operator()( Args && ... args );
178 : // implementation deferred due to reliance on cereal::access
179 :
180 : //! Get a reference to the initialized underlying object
181 : /*! This must be called after the object has been initialized.
182 :
183 : @return A reference to the initialized object
184 : @throw Exception If called before initialization */
185 1608 : T * operator->()
186 : {
187 1608 : if( !itsValid )
188 0 : throw Exception("Object must be initialized prior to accessing members");
189 :
190 1608 : return itsPtr;
191 : }
192 :
193 : //! Returns a raw pointer to the initialized underlying object
194 : /*! This is mainly intended for use with passing an instance of
195 : a constructed object to cereal::base_class.
196 :
197 : It is strongly recommended to avoid using this function in
198 : any other circumstance.
199 :
200 : @return A raw pointer to the initialized type */
201 4 : T * ptr()
202 : {
203 4 : return operator->();
204 : }
205 :
206 : private:
207 : template <class Ar, class TT> friend struct ::cereal::memory_detail::LoadAndConstructLoadWrapper;
208 : template <class Ar, class TT> friend struct ::cereal::boost_variant_detail::LoadAndConstructLoadWrapper;
209 :
210 11608 : construct( T * p ) : itsPtr( p ), itsEnableSharedRestoreFunction( [](){} ), itsValid( false ) {}
211 2400 : construct( T * p, std::function<void()> enableSharedFunc ) : // g++4.7 ice with default lambda to std func
212 2400 : itsPtr( p ), itsEnableSharedRestoreFunction( enableSharedFunc ), itsValid( false ) {}
213 : construct( construct const & ) = delete;
214 : construct & operator=( construct const & ) = delete;
215 :
216 : T * itsPtr;
217 : std::function<void()> itsEnableSharedRestoreFunction;
218 : bool itsValid;
219 : };
220 :
221 : // ######################################################################
222 : //! A class that can be made a friend to give cereal access to non public functions
223 : /*! If you desire non-public serialization functions within a class, cereal can only
224 : access these if you declare cereal::access a friend.
225 :
226 : @code{.cpp}
227 : class MyClass
228 : {
229 : private:
230 : friend class cereal::access; // gives access to the private serialize
231 :
232 : template <class Archive>
233 : void serialize( Archive & ar )
234 : {
235 : // some code
236 : }
237 : };
238 : @endcode
239 : @ingroup Access */
240 : class access
241 : {
242 : public:
243 : // ####### Standard Serialization ########################################
244 : template<class Archive, class T> inline
245 5141140 : static auto member_serialize(Archive & ar, T & t) -> decltype(t.CEREAL_SERIALIZE_FUNCTION_NAME(ar))
246 5141140 : { return t.CEREAL_SERIALIZE_FUNCTION_NAME(ar); }
247 :
248 : template<class Archive, class T> inline
249 844979 : static auto member_save(Archive & ar, T const & t) -> decltype(t.CEREAL_SAVE_FUNCTION_NAME(ar))
250 844979 : { return t.CEREAL_SAVE_FUNCTION_NAME(ar); }
251 :
252 : template<class Archive, class T> inline
253 : static auto member_save_non_const(Archive & ar, T & t) -> decltype(t.CEREAL_SAVE_FUNCTION_NAME(ar))
254 : { return t.CEREAL_SAVE_FUNCTION_NAME(ar); }
255 :
256 : template<class Archive, class T> inline
257 844979 : static auto member_load(Archive & ar, T & t) -> decltype(t.CEREAL_LOAD_FUNCTION_NAME(ar))
258 844979 : { return t.CEREAL_LOAD_FUNCTION_NAME(ar); }
259 :
260 : template<class Archive, class T> inline
261 1200 : static auto member_save_minimal(Archive const & ar, T const & t) -> decltype(t.CEREAL_SAVE_MINIMAL_FUNCTION_NAME(ar))
262 1200 : { return t.CEREAL_SAVE_MINIMAL_FUNCTION_NAME(ar); }
263 :
264 : template<class Archive, class T> inline
265 : static auto member_save_minimal_non_const(Archive const & ar, T & t) -> decltype(t.CEREAL_SAVE_MINIMAL_FUNCTION_NAME(ar))
266 : { return t.CEREAL_SAVE_MINIMAL_FUNCTION_NAME(ar); }
267 :
268 : template<class Archive, class T, class U> inline
269 1200 : static auto member_load_minimal(Archive const & ar, T & t, U && u) -> decltype(t.CEREAL_LOAD_MINIMAL_FUNCTION_NAME(ar, std::forward<U>(u)))
270 1200 : { return t.CEREAL_LOAD_MINIMAL_FUNCTION_NAME(ar, std::forward<U>(u)); }
271 :
272 : // ####### Versioned Serialization #######################################
273 : template<class Archive, class T> inline
274 4000 : static auto member_serialize(Archive & ar, T & t, const std::uint32_t version ) -> decltype(t.CEREAL_SERIALIZE_FUNCTION_NAME(ar, version))
275 4000 : { return t.CEREAL_SERIALIZE_FUNCTION_NAME(ar, version); }
276 :
277 : template<class Archive, class T> inline
278 1200 : static auto member_save(Archive & ar, T const & t, const std::uint32_t version ) -> decltype(t.CEREAL_SAVE_FUNCTION_NAME(ar, version))
279 1200 : { return t.CEREAL_SAVE_FUNCTION_NAME(ar, version); }
280 :
281 : template<class Archive, class T> inline
282 : static auto member_save_non_const(Archive & ar, T & t, const std::uint32_t version ) -> decltype(t.CEREAL_SAVE_FUNCTION_NAME(ar, version))
283 : { return t.CEREAL_SAVE_FUNCTION_NAME(ar, version); }
284 :
285 : template<class Archive, class T> inline
286 1200 : static auto member_load(Archive & ar, T & t, const std::uint32_t version ) -> decltype(t.CEREAL_LOAD_FUNCTION_NAME(ar, version))
287 1200 : { return t.CEREAL_LOAD_FUNCTION_NAME(ar, version); }
288 :
289 : template<class Archive, class T> inline
290 800 : static auto member_save_minimal(Archive const & ar, T const & t, const std::uint32_t version) -> decltype(t.CEREAL_SAVE_MINIMAL_FUNCTION_NAME(ar, version))
291 800 : { return t.CEREAL_SAVE_MINIMAL_FUNCTION_NAME(ar, version); }
292 :
293 : template<class Archive, class T> inline
294 : static auto member_save_minimal_non_const(Archive const & ar, T & t, const std::uint32_t version) -> decltype(t.CEREAL_SAVE_MINIMAL_FUNCTION_NAME(ar, version))
295 : { return t.CEREAL_SAVE_MINIMAL_FUNCTION_NAME(ar, version); }
296 :
297 : template<class Archive, class T, class U> inline
298 800 : static auto member_load_minimal(Archive const & ar, T & t, U && u, const std::uint32_t version) -> decltype(t.CEREAL_LOAD_MINIMAL_FUNCTION_NAME(ar, std::forward<U>(u), version))
299 800 : { return t.CEREAL_LOAD_MINIMAL_FUNCTION_NAME(ar, std::forward<U>(u), version); }
300 :
301 : // ####### Other Functionality ##########################################
302 : // for detecting inheritance from enable_shared_from_this
303 : template <class T> inline
304 : static auto shared_from_this(T & t) -> decltype(t.shared_from_this());
305 :
306 : // for placement new
307 : template <class T, class ... Args> inline
308 8004 : static void construct( T *& ptr, Args && ... args )
309 : {
310 8004 : new (ptr) T( std::forward<Args>( args )... );
311 8004 : }
312 :
313 : // for non-placement new with a default constructor
314 : template <class T> inline
315 85608 : static T * construct()
316 : {
317 85608 : return new T();
318 : }
319 :
320 : template <class T> inline
321 : static std::false_type load_and_construct(...)
322 : { return std::false_type(); }
323 :
324 : template<class T, class Archive> inline
325 5200 : static auto load_and_construct(Archive & ar, ::cereal::construct<T> & construct) -> decltype(T::load_and_construct(ar, construct))
326 : {
327 5200 : T::load_and_construct( ar, construct );
328 4800 : }
329 :
330 : template<class T, class Archive> inline
331 800 : static auto load_and_construct(Archive & ar, ::cereal::construct<T> & construct, const std::uint32_t version) -> decltype(T::load_and_construct(ar, construct, version))
332 : {
333 800 : T::load_and_construct( ar, construct, version );
334 800 : }
335 : }; // end class access
336 :
337 : // ######################################################################
338 : // Deferred Implementation, see construct for more information
339 : template <class T> template <class ... Args> inline
340 8004 : void construct<T>::operator()( Args && ... args )
341 : {
342 8004 : if( itsValid )
343 0 : throw Exception("Attempting to construct an already initialized object");
344 :
345 8004 : ::cereal::access::construct( itsPtr, std::forward<Args>( args )... );
346 8004 : itsEnableSharedRestoreFunction();
347 8004 : itsValid = true;
348 8004 : }
349 : } // namespace cereal
350 :
351 : #endif // CEREAL_ACCESS_HPP_
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