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1 | // Copyright (C) 2006 Douglas Gregor <doug.gregor -at- gmail.com> |
2 | ||
3 | // Use, modification and distribution is subject to the Boost Software | |
4 | // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
5 | // http://www.boost.org/LICENSE_1_0.txt) | |
6 | ||
7 | // Authors: Douglas Gregor | |
8 | ||
9 | /** @file serialize.hpp | |
10 | * | |
11 | * This file provides Boost.Serialization support for Python objects | |
12 | * within Boost.MPI. Python objects can be serialized in one of two | |
13 | * ways. The default serialization method involves using the Python | |
14 | * "pickle" module to pickle the Python objects, transmits the | |
15 | * pickled representation, and unpickles the result when | |
16 | * received. For C++ types that have been exposed to Python and | |
17 | * registered with register_serialized(), objects are directly | |
18 | * serialized for transmissing, skipping the pickling step. | |
19 | */ | |
20 | #ifndef BOOST_MPI_PYTHON_SERIALIZE_HPP | |
21 | #define BOOST_MPI_PYTHON_SERIALIZE_HPP | |
22 | ||
23 | #include <boost/mpi/python/config.hpp> | |
24 | ||
25 | #include <boost/python/object.hpp> | |
26 | #include <boost/python/str.hpp> | |
27 | #include <boost/python/extract.hpp> | |
28 | ||
29 | #include <memory> | |
30 | #include <map> | |
31 | ||
32 | #include <boost/function/function3.hpp> | |
33 | ||
34 | #include <boost/mpl/bool.hpp> | |
35 | #include <boost/mpl/if.hpp> | |
36 | ||
37 | #include <boost/serialization/split_free.hpp> | |
38 | #include <boost/serialization/array.hpp> | |
39 | ||
40 | #include <boost/assert.hpp> | |
41 | ||
42 | #include <boost/type_traits/is_fundamental.hpp> | |
43 | ||
44 | #define BOOST_MPI_PYTHON_FORWARD_ONLY | |
45 | #include <boost/mpi/python.hpp> | |
46 | ||
47 | /************************************************************************ | |
48 | * Boost.Python Serialization Section * | |
49 | ************************************************************************/ | |
50 | #if !defined(BOOST_NO_SFINAE) && !defined(BOOST_NO_IS_CONVERTIBLE) | |
51 | /** | |
52 | * @brief Declare IArchive and OArchive as a Boost.Serialization | |
53 | * archives that can be used for Python objects. | |
54 | * | |
55 | * This macro can only be expanded from the global namespace. It only | |
56 | * requires that Archiver be forward-declared. IArchiver and OArchiver | |
57 | * will only support Serialization of Python objects by pickling | |
58 | * them. If the Archiver type should also support "direct" | |
59 | * serialization (for C++ types), use | |
60 | * BOOST_PYTHON_DIRECT_SERIALIZATION_ARCHIVE instead. | |
61 | */ | |
62 | # define BOOST_PYTHON_SERIALIZATION_ARCHIVE(IArchiver, OArchiver) \ | |
63 | namespace boost { namespace python { namespace api { \ | |
64 | template<typename R, typename T> \ | |
65 | struct enable_binary< IArchiver , R, T> {}; \ | |
66 | \ | |
67 | template<typename R, typename T> \ | |
68 | struct enable_binary< OArchiver , R, T> {}; \ | |
69 | } } } | |
70 | # else | |
71 | # define BOOST_PYTHON_SERIALIZATION_ARCHIVE(IArchiver, OArchiver) | |
72 | #endif | |
73 | ||
74 | /** | |
75 | * @brief Declare IArchiver and OArchiver as a Boost.Serialization | |
76 | * archives that can be used for Python objects and C++ objects | |
77 | * wrapped in Python. | |
78 | * | |
79 | * This macro can only be expanded from the global namespace. It only | |
80 | * requires that IArchiver and OArchiver be forward-declared. However, | |
81 | * note that you will also need to write | |
82 | * BOOST_PYTHON_DIRECT_SERIALIZATION_ARCHIVE_IMPL(IArchiver, | |
83 | * OArchiver) in one of your translation units. | |
84 | ||
85 | DPG PICK UP HERE | |
86 | */ | |
87 | #define BOOST_PYTHON_DIRECT_SERIALIZATION_ARCHIVE(IArchiver, OArchiver) \ | |
88 | BOOST_PYTHON_SERIALIZATION_ARCHIVE(IArchiver, OArchiver) \ | |
89 | namespace boost { namespace python { namespace detail { \ | |
90 | template<> \ | |
91 | BOOST_MPI_PYTHON_DECL direct_serialization_table< IArchiver , OArchiver >& \ | |
92 | get_direct_serialization_table< IArchiver , OArchiver >(); \ | |
93 | } \ | |
94 | \ | |
95 | template<> \ | |
96 | struct has_direct_serialization< IArchiver , OArchiver> : mpl::true_ { }; \ | |
97 | \ | |
98 | template<> \ | |
99 | struct output_archiver< IArchiver > { typedef OArchiver type; }; \ | |
100 | \ | |
101 | template<> \ | |
102 | struct input_archiver< OArchiver > { typedef IArchiver type; }; \ | |
103 | } } | |
104 | ||
105 | /** | |
106 | * @brief Define the implementation for Boost.Serialization archivers | |
107 | * that can be used for Python objects and C++ objects wrapped in | |
108 | * Python. | |
109 | * | |
110 | * This macro can only be expanded from the global namespace. It only | |
111 | * requires that IArchiver and OArchiver be forward-declared. Before | |
112 | * using this macro, you will need to declare IArchiver and OArchiver | |
113 | * as direct serialization archives with | |
114 | * BOOST_PYTHON_DIRECT_SERIALIZATION_ARCHIVE(IArchiver, OArchiver). | |
115 | */ | |
116 | #define BOOST_PYTHON_DIRECT_SERIALIZATION_ARCHIVE_IMPL(IArchiver, OArchiver) \ | |
117 | namespace boost { namespace python { namespace detail { \ | |
118 | template \ | |
119 | class BOOST_MPI_PYTHON_DECL direct_serialization_table< IArchiver , OArchiver >; \ | |
120 | \ | |
121 | template<> \ | |
122 | BOOST_MPI_PYTHON_DECL \ | |
123 | direct_serialization_table< IArchiver , OArchiver >& \ | |
124 | get_direct_serialization_table< IArchiver , OArchiver >( ) \ | |
125 | { \ | |
126 | static direct_serialization_table< IArchiver, OArchiver > table; \ | |
127 | return table; \ | |
128 | } \ | |
129 | } } } | |
130 | ||
131 | namespace boost { namespace python { | |
132 | ||
133 | /** | |
134 | * INTERNAL ONLY | |
135 | * | |
136 | * Provides access to the Python "pickle" module from within C++. | |
137 | */ | |
138 | class BOOST_MPI_PYTHON_DECL pickle { | |
139 | struct data_t; | |
140 | ||
141 | public: | |
142 | static str dumps(object obj, int protocol = -1); | |
143 | static object loads(str s); | |
144 | ||
145 | private: | |
146 | static void initialize_data(); | |
147 | ||
148 | static data_t* data; | |
149 | }; | |
150 | ||
151 | /** | |
152 | * @brief Whether the input/output archiver pair has "direct" | |
153 | * serialization for C++ objects exposed in Python. | |
154 | * | |
155 | * Users do not typically need to specialize this trait, as it will be | |
156 | * specialized as part of the macro | |
157 | * BOOST_PYTHON_DIRECT_SERIALIZATION_ARCHIVE. | |
158 | */ | |
159 | template<typename IArchiver, typename OArchiver> | |
160 | struct has_direct_serialization : mpl::false_ { }; | |
161 | ||
162 | /** | |
163 | * @brief A metafunction that determines the output archiver for the | |
164 | * given input archiver. | |
165 | * | |
166 | * Users do not typically need to specialize this trait, as it will be | |
167 | * specialized as part of the macro | |
168 | * BOOST_PYTHON_DIRECT_SERIALIZATION_ARCHIVE. | |
169 | */ | |
170 | template<typename IArchiver> struct output_archiver { }; | |
171 | ||
172 | /** | |
173 | * @brief A metafunction that determines the input archiver for the | |
174 | * given output archiver. | |
175 | * | |
176 | * Users do not typically need to specialize this trait, as it will be | |
177 | * specialized as part of the macro | |
178 | * BOOST_PYTHON_DIRECT_SERIALIZATION_ARCHIVE. | |
179 | * | |
180 | */ | |
181 | template<typename OArchiver> struct input_archiver { }; | |
182 | ||
183 | namespace detail { | |
184 | ||
185 | /** | |
186 | * INTERNAL ONLY | |
187 | * | |
188 | * This class contains the direct-serialization code for the given | |
189 | * IArchiver/OArchiver pair. It is intended to be used as a | |
190 | * singleton class, and will be accessed when (de-)serializing a | |
191 | * Boost.Python object with an archiver that supports direct | |
192 | * serializations. Do not create instances of this class directly: | |
193 | * instead, use get_direct_serialization_table. | |
194 | */ | |
195 | template<typename IArchiver, typename OArchiver> | |
196 | class BOOST_MPI_PYTHON_DECL direct_serialization_table | |
197 | { | |
198 | public: | |
199 | typedef boost::function3<void, OArchiver&, const object&, const unsigned int> | |
200 | saver_t; | |
201 | typedef boost::function3<void, IArchiver&, object&, const unsigned int> | |
202 | loader_t; | |
203 | ||
204 | typedef std::map<PyTypeObject*, std::pair<int, saver_t> > savers_t; | |
205 | typedef std::map<int, loader_t> loaders_t; | |
206 | ||
207 | /** | |
208 | * Retrieve the saver (serializer) associated with the Python | |
209 | * object @p obj. | |
210 | * | |
211 | * @param obj The object we want to save. Only its (Python) type | |
212 | * is important. | |
213 | * | |
214 | * @param descriptor The value of the descriptor associated to | |
215 | * the returned saver. Will be set to zero if no saver was found | |
216 | * for @p obj. | |
217 | * | |
218 | * @returns a function object that can be used to serialize this | |
219 | * object (and other objects of the same type), if possible. If | |
220 | * no saver can be found, returns an empty function object.. | |
221 | */ | |
222 | saver_t saver(const object& obj, int& descriptor) | |
223 | { | |
224 | typename savers_t::iterator pos = savers.find(obj.ptr()->ob_type); | |
225 | if (pos != savers.end()) { | |
226 | descriptor = pos->second.first; | |
227 | return pos->second.second; | |
228 | } | |
229 | else { | |
230 | descriptor = 0; | |
231 | return saver_t(); | |
232 | } | |
233 | } | |
234 | ||
235 | /** | |
236 | * Retrieve the loader (deserializer) associated with the given | |
237 | * descriptor. | |
238 | * | |
239 | * @param descriptor The descriptor number provided by saver() | |
240 | * when determining the saver for this type. | |
241 | * | |
242 | * @returns a function object that can be used to deserialize an | |
243 | * object whose type is the same as that corresponding to the | |
244 | * descriptor. If the descriptor is unknown, the return value | |
245 | * will be an empty function object. | |
246 | */ | |
247 | loader_t loader(int descriptor) | |
248 | { | |
249 | typename loaders_t::iterator pos = loaders.find(descriptor); | |
250 | if (pos != loaders.end()) | |
251 | return pos->second; | |
252 | else | |
253 | return loader_t(); | |
254 | } | |
255 | ||
256 | /** | |
257 | * Register the type T for direct serialization. | |
258 | * | |
259 | * @param value A sample value of the type @c T. This may be used | |
260 | * to compute the Python type associated with the C++ type @c T. | |
261 | * | |
262 | * @param type The Python type associated with the C++ type @c | |
263 | * T. If not provided, it will be computed from the same value @p | |
264 | * value. | |
265 | */ | |
266 | template<typename T> | |
267 | void register_type(const T& value = T(), PyTypeObject* type = 0) | |
268 | { | |
269 | // If the user did not provide us with a Python type, figure it | |
270 | // out for ourselves. | |
271 | if (!type) { | |
272 | object obj(value); | |
273 | type = obj.ptr()->ob_type; | |
274 | } | |
275 | ||
276 | register_type(default_saver<T>(), default_loader<T>(type), value, type); | |
277 | } | |
278 | ||
279 | /** | |
280 | * Register the type T for direct serialization. | |
281 | * | |
282 | * @param saver A function object that will serialize a | |
283 | * Boost.Python object (that represents a C++ object of type @c | |
284 | * T) to an @c OArchive. | |
285 | * | |
286 | * @param loader A function object that will deserialize from an | |
287 | * @c IArchive into a Boost.Python object that represents a C++ | |
288 | * object of type @c T. | |
289 | * | |
290 | * @param value A sample value of the type @c T. This may be used | |
291 | * to compute the Python type associated with the C++ type @c T. | |
292 | * | |
293 | * @param type The Python type associated with the C++ type @c | |
294 | * T. If not provided, it will be computed from the same value @p | |
295 | * value. | |
296 | */ | |
297 | template<typename T> | |
298 | void register_type(const saver_t& saver, const loader_t& loader, | |
299 | const T& value = T(), PyTypeObject* type = 0) | |
300 | { | |
301 | // If the user did not provide us with a Python type, figure it | |
302 | // out for ourselves. | |
303 | if (!type) { | |
304 | object obj(value); | |
305 | type = obj.ptr()->ob_type; | |
306 | } | |
307 | ||
308 | int descriptor = savers.size() + 1; | |
309 | if (savers.find(type) != savers.end()) | |
310 | return; | |
311 | ||
312 | savers[type] = std::make_pair(descriptor, saver); | |
313 | loaders[descriptor] = loader; | |
314 | } | |
315 | ||
316 | protected: | |
317 | template<typename T> | |
318 | struct default_saver { | |
319 | void operator()(OArchiver& ar, const object& obj, const unsigned int) { | |
320 | T value = extract<T>(obj)(); | |
321 | ar << value; | |
322 | } | |
323 | }; | |
324 | ||
325 | template<typename T> | |
326 | struct default_loader { | |
327 | default_loader(PyTypeObject* type) : type(type) { } | |
328 | ||
329 | void operator()(IArchiver& ar, object& obj, const unsigned int) { | |
330 | // If we can, extract the object in place. | |
331 | if (!is_fundamental<T>::value && obj && obj.ptr()->ob_type == type) { | |
332 | ar >> extract<T&>(obj)(); | |
333 | } else { | |
334 | T value; | |
335 | ar >> value; | |
336 | obj = object(value); | |
337 | } | |
338 | } | |
339 | ||
340 | private: | |
341 | PyTypeObject* type; | |
342 | }; | |
343 | ||
344 | savers_t savers; | |
345 | loaders_t loaders; | |
346 | }; | |
347 | ||
348 | /** | |
349 | * @brief Retrieve the direct-serialization table for an | |
350 | * IArchiver/OArchiver pair. | |
351 | * | |
352 | * This function is responsible for returning a reference to the | |
353 | * singleton direct-serialization table. Its primary template is | |
354 | * left undefined, to force the use of an explicit specialization | |
355 | * with a definition in a single translation unit. Use the macro | |
356 | * BOOST_PYTHON_DIRECT_SERIALIZATION_ARCHIVE_IMPL to define this | |
357 | * explicit specialization. | |
358 | */ | |
359 | template<typename IArchiver, typename OArchiver> | |
360 | direct_serialization_table<IArchiver, OArchiver>& | |
361 | get_direct_serialization_table(); | |
362 | } // end namespace detail | |
363 | ||
364 | /** | |
365 | * @brief Register the type T for direct serialization. | |
366 | * | |
367 | * The @c register_serialized function registers a C++ type for direct | |
368 | * serialization with the given @c IArchiver/@c OArchiver pair. Direct | |
369 | * serialization elides the use of the Python @c pickle package when | |
370 | * serializing Python objects that represent C++ values. Direct | |
371 | * serialization can be beneficial both to improve serialization | |
372 | * performance (Python pickling can be very inefficient) and to permit | |
373 | * serialization for Python-wrapped C++ objects that do not support | |
374 | * pickling. | |
375 | * | |
376 | * @param value A sample value of the type @c T. This may be used | |
377 | * to compute the Python type associated with the C++ type @c T. | |
378 | * | |
379 | * @param type The Python type associated with the C++ type @c | |
380 | * T. If not provided, it will be computed from the same value @p | |
381 | * value. | |
382 | */ | |
383 | template<typename IArchiver, typename OArchiver, typename T> | |
384 | void | |
385 | register_serialized(const T& value = T(), PyTypeObject* type = 0) | |
386 | { | |
387 | detail::direct_serialization_table<IArchiver, OArchiver>& table = | |
388 | detail::get_direct_serialization_table<IArchiver, OArchiver>(); | |
389 | table.register_type(value, type); | |
390 | } | |
391 | ||
392 | namespace detail { | |
393 | ||
394 | /// Save a Python object by pickling it. | |
395 | template<typename Archiver> | |
396 | void | |
397 | save_impl(Archiver& ar, const boost::python::object& obj, | |
398 | const unsigned int /*version*/, | |
399 | mpl::false_ /*has_direct_serialization*/) | |
400 | { | |
401 | boost::python::str py_string = boost::python::pickle::dumps(obj); | |
402 | int len = boost::python::extract<int>(py_string.attr("__len__")()); | |
403 | const char* string = boost::python::extract<const char*>(py_string); | |
404 | ar << len << boost::serialization::make_array(string, len); | |
405 | } | |
406 | ||
407 | /// Try to save a Python object by directly serializing it; fall back | |
408 | /// on pickling if required. | |
409 | template<typename Archiver> | |
410 | void | |
411 | save_impl(Archiver& ar, const boost::python::object& obj, | |
412 | const unsigned int version, | |
413 | mpl::true_ /*has_direct_serialization*/) | |
414 | { | |
415 | typedef Archiver OArchiver; | |
416 | typedef typename input_archiver<OArchiver>::type IArchiver; | |
417 | typedef typename direct_serialization_table<IArchiver, OArchiver>::saver_t | |
418 | saver_t; | |
419 | ||
420 | direct_serialization_table<IArchiver, OArchiver>& table = | |
421 | get_direct_serialization_table<IArchiver, OArchiver>(); | |
422 | ||
423 | int descriptor = 0; | |
424 | if (saver_t saver = table.saver(obj, descriptor)) { | |
425 | ar << descriptor; | |
426 | saver(ar, obj, version); | |
427 | } else { | |
428 | // Pickle it | |
429 | ar << descriptor; | |
430 | detail::save_impl(ar, obj, version, mpl::false_()); | |
431 | } | |
432 | } | |
433 | ||
434 | /// Load a Python object by unpickling it | |
435 | template<typename Archiver> | |
436 | void | |
437 | load_impl(Archiver& ar, boost::python::object& obj, | |
438 | const unsigned int /*version*/, | |
439 | mpl::false_ /*has_direct_serialization*/) | |
440 | { | |
441 | int len; | |
442 | ar >> len; | |
443 | ||
444 | std::auto_ptr<char> string(new char[len]); | |
445 | ar >> boost::serialization::make_array(string.get(), len); | |
446 | boost::python::str py_string(string.get(), len); | |
447 | obj = boost::python::pickle::loads(py_string); | |
448 | } | |
449 | ||
450 | /// Try to load a Python object by directly deserializing it; fall back | |
451 | /// on unpickling if required. | |
452 | template<typename Archiver> | |
453 | void | |
454 | load_impl(Archiver& ar, boost::python::object& obj, | |
455 | const unsigned int version, | |
456 | mpl::true_ /*has_direct_serialization*/) | |
457 | { | |
458 | typedef Archiver IArchiver; | |
459 | typedef typename output_archiver<IArchiver>::type OArchiver; | |
460 | typedef typename direct_serialization_table<IArchiver, OArchiver>::loader_t | |
461 | loader_t; | |
462 | ||
463 | direct_serialization_table<IArchiver, OArchiver>& table = | |
464 | get_direct_serialization_table<IArchiver, OArchiver>(); | |
465 | ||
466 | int descriptor; | |
467 | ar >> descriptor; | |
468 | ||
469 | if (descriptor) { | |
470 | loader_t loader = table.loader(descriptor); | |
471 | BOOST_ASSERT(loader); | |
472 | ||
473 | loader(ar, obj, version); | |
474 | } else { | |
475 | // Unpickle it | |
476 | detail::load_impl(ar, obj, version, mpl::false_()); | |
477 | } | |
478 | } | |
479 | ||
480 | } // end namespace detail | |
481 | ||
482 | template<typename Archiver> | |
483 | void | |
484 | save(Archiver& ar, const boost::python::object& obj, | |
485 | const unsigned int version) | |
486 | { | |
487 | typedef Archiver OArchiver; | |
488 | typedef typename input_archiver<OArchiver>::type IArchiver; | |
489 | ||
490 | detail::save_impl(ar, obj, version, | |
491 | has_direct_serialization<IArchiver, OArchiver>()); | |
492 | } | |
493 | ||
494 | template<typename Archiver> | |
495 | void | |
496 | load(Archiver& ar, boost::python::object& obj, | |
497 | const unsigned int version) | |
498 | { | |
499 | typedef Archiver IArchiver; | |
500 | typedef typename output_archiver<IArchiver>::type OArchiver; | |
501 | ||
502 | detail::load_impl(ar, obj, version, | |
503 | has_direct_serialization<IArchiver, OArchiver>()); | |
504 | } | |
505 | ||
506 | template<typename Archive> | |
507 | inline void | |
508 | serialize(Archive& ar, boost::python::object& obj, const unsigned int version) | |
509 | { | |
510 | boost::serialization::split_free(ar, obj, version); | |
511 | } | |
512 | ||
513 | } } // end namespace boost::python | |
514 | ||
515 | /************************************************************************ | |
516 | * Boost.MPI-Specific Section * | |
517 | ************************************************************************/ | |
518 | namespace boost { namespace mpi { | |
519 | class packed_iarchive; | |
520 | class packed_oarchive; | |
521 | } } // end namespace boost::mpi | |
522 | ||
523 | BOOST_PYTHON_DIRECT_SERIALIZATION_ARCHIVE( | |
524 | ::boost::mpi::packed_iarchive, | |
525 | ::boost::mpi::packed_oarchive) | |
526 | ||
527 | namespace boost { namespace mpi { namespace python { | |
528 | ||
529 | template<typename T> | |
530 | void | |
531 | register_serialized(const T& value, PyTypeObject* type) | |
532 | { | |
533 | using boost::python::register_serialized; | |
534 | register_serialized<packed_iarchive, packed_oarchive>(value, type); | |
535 | } | |
536 | ||
537 | } } } // end namespace boost::mpi::python | |
538 | ||
539 | #endif // BOOST_MPI_PYTHON_SERIALIZE_HPP |