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1""" 

2This class is defined to override standard pickle functionality 

3 

4The goals of it follow: 

5-Serialize lambdas and nested functions to compiled byte code 

6-Deal with main module correctly 

7-Deal with other non-serializable objects 

8 

9It does not include an unpickler, as standard python unpickling suffices. 

10 

11This module was extracted from the `cloud` package, developed by `PiCloud, Inc. 

12<https://web.archive.org/web/20140626004012/http://www.picloud.com/>`_. 

13 

14Copyright (c) 2012, Regents of the University of California. 

15Copyright (c) 2009 `PiCloud, Inc. <https://web.archive.org/web/20140626004012/http://www.picloud.com/>`_. 

16All rights reserved. 

17 

18Redistribution and use in source and binary forms, with or without 

19modification, are permitted provided that the following conditions 

20are met: 

21 * Redistributions of source code must retain the above copyright 

22 notice, this list of conditions and the following disclaimer. 

23 * Redistributions in binary form must reproduce the above copyright 

24 notice, this list of conditions and the following disclaimer in the 

25 documentation and/or other materials provided with the distribution. 

26 * Neither the name of the University of California, Berkeley nor the 

27 names of its contributors may be used to endorse or promote 

28 products derived from this software without specific prior written 

29 permission. 

30 

31THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 

32"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 

33LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 

34A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 

35HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 

36SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 

37TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 

38PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 

39LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 

40NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 

41SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

42""" 

43 

44import builtins 

45import dis 

46import opcode 

47import platform 

48import sys 

49import types 

50import weakref 

51import uuid 

52import threading 

53import typing 

54import warnings 

55 

56from .compat import pickle 

57from collections import OrderedDict 

58from typing import ClassVar, Generic, Union, Tuple, Callable 

59from pickle import _getattribute 

60from importlib._bootstrap import _find_spec 

61 

62try: # pragma: no branch 

63 import typing_extensions as _typing_extensions 

64 from typing_extensions import Literal, Final 

65except ImportError: 

66 _typing_extensions = Literal = Final = None 

67 

68if sys.version_info >= (3, 8): 

69 from types import CellType 

70else: 

71 def f(): 

72 a = 1 

73 

74 def g(): 

75 return a 

76 return g 

77 CellType = type(f().__closure__[0]) 

78 

79 

80# cloudpickle is meant for inter process communication: we expect all 

81# communicating processes to run the same Python version hence we favor 

82# communication speed over compatibility: 

83DEFAULT_PROTOCOL = pickle.HIGHEST_PROTOCOL 

84 

85# Names of modules whose resources should be treated as dynamic. 

86_PICKLE_BY_VALUE_MODULES = set() 

87 

88# Track the provenance of reconstructed dynamic classes to make it possible to 

89# reconstruct instances from the matching singleton class definition when 

90# appropriate and preserve the usual "isinstance" semantics of Python objects. 

91_DYNAMIC_CLASS_TRACKER_BY_CLASS = weakref.WeakKeyDictionary() 

92_DYNAMIC_CLASS_TRACKER_BY_ID = weakref.WeakValueDictionary() 

93_DYNAMIC_CLASS_TRACKER_LOCK = threading.Lock() 

94 

95PYPY = platform.python_implementation() == "PyPy" 

96 

97builtin_code_type = None 

98if PYPY: 

99 # builtin-code objects only exist in pypy 

100 builtin_code_type = type(float.__new__.__code__) 

101 

102_extract_code_globals_cache = weakref.WeakKeyDictionary() 

103 

104 

105def _get_or_create_tracker_id(class_def): 

106 with _DYNAMIC_CLASS_TRACKER_LOCK: 

107 class_tracker_id = _DYNAMIC_CLASS_TRACKER_BY_CLASS.get(class_def) 

108 if class_tracker_id is None: 

109 class_tracker_id = uuid.uuid4().hex 

110 _DYNAMIC_CLASS_TRACKER_BY_CLASS[class_def] = class_tracker_id 

111 _DYNAMIC_CLASS_TRACKER_BY_ID[class_tracker_id] = class_def 

112 return class_tracker_id 

113 

114 

115def _lookup_class_or_track(class_tracker_id, class_def): 

116 if class_tracker_id is not None: 

117 with _DYNAMIC_CLASS_TRACKER_LOCK: 

118 class_def = _DYNAMIC_CLASS_TRACKER_BY_ID.setdefault( 

119 class_tracker_id, class_def) 

120 _DYNAMIC_CLASS_TRACKER_BY_CLASS[class_def] = class_tracker_id 

121 return class_def 

122 

123 

124def register_pickle_by_value(module): 

125 """Register a module to make it functions and classes picklable by value. 

126 

127 By default, functions and classes that are attributes of an importable 

128 module are to be pickled by reference, that is relying on re-importing 

129 the attribute from the module at load time. 

130 

131 If `register_pickle_by_value(module)` is called, all its functions and 

132 classes are subsequently to be pickled by value, meaning that they can 

133 be loaded in Python processes where the module is not importable. 

134 

135 This is especially useful when developing a module in a distributed 

136 execution environment: restarting the client Python process with the new 

137 source code is enough: there is no need to re-install the new version 

138 of the module on all the worker nodes nor to restart the workers. 

139 

140 Note: this feature is considered experimental. See the cloudpickle 

141 README.md file for more details and limitations. 

142 """ 

143 if not isinstance(module, types.ModuleType): 

144 raise ValueError( 

145 f"Input should be a module object, got {str(module)} instead" 

146 ) 

147 # In the future, cloudpickle may need a way to access any module registered 

148 # for pickling by value in order to introspect relative imports inside 

149 # functions pickled by value. (see 

150 # https://github.com/cloudpipe/cloudpickle/pull/417#issuecomment-873684633). 

151 # This access can be ensured by checking that module is present in 

152 # sys.modules at registering time and assuming that it will still be in 

153 # there when accessed during pickling. Another alternative would be to 

154 # store a weakref to the module. Even though cloudpickle does not implement 

155 # this introspection yet, in order to avoid a possible breaking change 

156 # later, we still enforce the presence of module inside sys.modules. 

157 if module.__name__ not in sys.modules: 

158 raise ValueError( 

159 f"{module} was not imported correctly, have you used an " 

160 f"`import` statement to access it?" 

161 ) 

162 _PICKLE_BY_VALUE_MODULES.add(module.__name__) 

163 

164 

165def unregister_pickle_by_value(module): 

166 """Unregister that the input module should be pickled by value.""" 

167 if not isinstance(module, types.ModuleType): 

168 raise ValueError( 

169 f"Input should be a module object, got {str(module)} instead" 

170 ) 

171 if module.__name__ not in _PICKLE_BY_VALUE_MODULES: 

172 raise ValueError(f"{module} is not registered for pickle by value") 

173 else: 

174 _PICKLE_BY_VALUE_MODULES.remove(module.__name__) 

175 

176 

177def list_registry_pickle_by_value(): 

178 return _PICKLE_BY_VALUE_MODULES.copy() 

179 

180 

181def _is_registered_pickle_by_value(module): 

182 module_name = module.__name__ 

183 if module_name in _PICKLE_BY_VALUE_MODULES: 

184 return True 

185 while True: 

186 parent_name = module_name.rsplit(".", 1)[0] 

187 if parent_name == module_name: 

188 break 

189 if parent_name in _PICKLE_BY_VALUE_MODULES: 

190 return True 

191 module_name = parent_name 

192 return False 

193 

194 

195def _whichmodule(obj, name): 

196 """Find the module an object belongs to. 

197 

198 This function differs from ``pickle.whichmodule`` in two ways: 

199 - it does not mangle the cases where obj's module is __main__ and obj was 

200 not found in any module. 

201 - Errors arising during module introspection are ignored, as those errors 

202 are considered unwanted side effects. 

203 """ 

204 if sys.version_info[:2] < (3, 7) and isinstance(obj, typing.TypeVar): # pragma: no branch # noqa 

205 # Workaround bug in old Python versions: prior to Python 3.7, 

206 # T.__module__ would always be set to "typing" even when the TypeVar T 

207 # would be defined in a different module. 

208 if name is not None and getattr(typing, name, None) is obj: 

209 # Built-in TypeVar defined in typing such as AnyStr 

210 return 'typing' 

211 else: 

212 # User defined or third-party TypeVar: __module__ attribute is 

213 # irrelevant, thus trigger a exhaustive search for obj in all 

214 # modules. 

215 module_name = None 

216 else: 

217 module_name = getattr(obj, '__module__', None) 

218 

219 if module_name is not None: 

220 return module_name 

221 # Protect the iteration by using a copy of sys.modules against dynamic 

222 # modules that trigger imports of other modules upon calls to getattr or 

223 # other threads importing at the same time. 

224 for module_name, module in sys.modules.copy().items(): 

225 # Some modules such as coverage can inject non-module objects inside 

226 # sys.modules 

227 if ( 

228 module_name == '__main__' or 

229 module is None or 

230 not isinstance(module, types.ModuleType) 

231 ): 

232 continue 

233 try: 

234 if _getattribute(module, name)[0] is obj: 

235 return module_name 

236 except Exception: 

237 pass 

238 return None 

239 

240 

241def _should_pickle_by_reference(obj, name=None): 

242 """Test whether an function or a class should be pickled by reference 

243 

244 Pickling by reference means by that the object (typically a function or a 

245 class) is an attribute of a module that is assumed to be importable in the 

246 target Python environment. Loading will therefore rely on importing the 

247 module and then calling `getattr` on it to access the function or class. 

248 

249 Pickling by reference is the only option to pickle functions and classes 

250 in the standard library. In cloudpickle the alternative option is to 

251 pickle by value (for instance for interactively or locally defined 

252 functions and classes or for attributes of modules that have been 

253 explicitly registered to be pickled by value. 

254 """ 

255 if isinstance(obj, types.FunctionType) or issubclass(type(obj), type): 

256 module_and_name = _lookup_module_and_qualname(obj, name=name) 

257 if module_and_name is None: 

258 return False 

259 module, name = module_and_name 

260 return not _is_registered_pickle_by_value(module) 

261 

262 elif isinstance(obj, types.ModuleType): 

263 # We assume that sys.modules is primarily used as a cache mechanism for 

264 # the Python import machinery. Checking if a module has been added in 

265 # is sys.modules therefore a cheap and simple heuristic to tell us 

266 # whether we can assume that a given module could be imported by name 

267 # in another Python process. 

268 if _is_registered_pickle_by_value(obj): 

269 return False 

270 return obj.__name__ in sys.modules 

271 else: 

272 raise TypeError( 

273 "cannot check importability of {} instances".format( 

274 type(obj).__name__) 

275 ) 

276 

277 

278def _lookup_module_and_qualname(obj, name=None): 

279 if name is None: 

280 name = getattr(obj, '__qualname__', None) 

281 if name is None: # pragma: no cover 

282 # This used to be needed for Python 2.7 support but is probably not 

283 # needed anymore. However we keep the __name__ introspection in case 

284 # users of cloudpickle rely on this old behavior for unknown reasons. 

285 name = getattr(obj, '__name__', None) 

286 

287 module_name = _whichmodule(obj, name) 

288 

289 if module_name is None: 

290 # In this case, obj.__module__ is None AND obj was not found in any 

291 # imported module. obj is thus treated as dynamic. 

292 return None 

293 

294 if module_name == "__main__": 

295 return None 

296 

297 # Note: if module_name is in sys.modules, the corresponding module is 

298 # assumed importable at unpickling time. See #357 

299 module = sys.modules.get(module_name, None) 

300 if module is None: 

301 # The main reason why obj's module would not be imported is that this 

302 # module has been dynamically created, using for example 

303 # types.ModuleType. The other possibility is that module was removed 

304 # from sys.modules after obj was created/imported. But this case is not 

305 # supported, as the standard pickle does not support it either. 

306 return None 

307 

308 try: 

309 obj2, parent = _getattribute(module, name) 

310 except AttributeError: 

311 # obj was not found inside the module it points to 

312 return None 

313 if obj2 is not obj: 

314 return None 

315 return module, name 

316 

317 

318def _extract_code_globals(co): 

319 """ 

320 Find all globals names read or written to by codeblock co 

321 """ 

322 out_names = _extract_code_globals_cache.get(co) 

323 if out_names is None: 

324 # We use a dict with None values instead of a set to get a 

325 # deterministic order (assuming Python 3.6+) and avoid introducing 

326 # non-deterministic pickle bytes as a results. 

327 out_names = {name: None for name in _walk_global_ops(co)} 

328 

329 # Declaring a function inside another one using the "def ..." 

330 # syntax generates a constant code object corresponding to the one 

331 # of the nested function's As the nested function may itself need 

332 # global variables, we need to introspect its code, extract its 

333 # globals, (look for code object in it's co_consts attribute..) and 

334 # add the result to code_globals 

335 if co.co_consts: 

336 for const in co.co_consts: 

337 if isinstance(const, types.CodeType): 

338 out_names.update(_extract_code_globals(const)) 

339 

340 _extract_code_globals_cache[co] = out_names 

341 

342 return out_names 

343 

344 

345def _find_imported_submodules(code, top_level_dependencies): 

346 """ 

347 Find currently imported submodules used by a function. 

348 

349 Submodules used by a function need to be detected and referenced for the 

350 function to work correctly at depickling time. Because submodules can be 

351 referenced as attribute of their parent package (``package.submodule``), we 

352 need a special introspection technique that does not rely on GLOBAL-related 

353 opcodes to find references of them in a code object. 

354 

355 Example: 

356 ``` 

357 import concurrent.futures 

358 import cloudpickle 

359 def func(): 

360 x = concurrent.futures.ThreadPoolExecutor 

361 if __name__ == '__main__': 

362 cloudpickle.dumps(func) 

363 ``` 

364 The globals extracted by cloudpickle in the function's state include the 

365 concurrent package, but not its submodule (here, concurrent.futures), which 

366 is the module used by func. Find_imported_submodules will detect the usage 

367 of concurrent.futures. Saving this module alongside with func will ensure 

368 that calling func once depickled does not fail due to concurrent.futures 

369 not being imported 

370 """ 

371 

372 subimports = [] 

373 # check if any known dependency is an imported package 

374 for x in top_level_dependencies: 

375 if (isinstance(x, types.ModuleType) and 

376 hasattr(x, '__package__') and x.__package__): 

377 # check if the package has any currently loaded sub-imports 

378 prefix = x.__name__ + '.' 

379 # A concurrent thread could mutate sys.modules, 

380 # make sure we iterate over a copy to avoid exceptions 

381 for name in list(sys.modules): 

382 # Older versions of pytest will add a "None" module to 

383 # sys.modules. 

384 if name is not None and name.startswith(prefix): 

385 # check whether the function can address the sub-module 

386 tokens = set(name[len(prefix):].split('.')) 

387 if not tokens - set(code.co_names): 

388 subimports.append(sys.modules[name]) 

389 return subimports 

390 

391 

392def cell_set(cell, value): 

393 """Set the value of a closure cell. 

394 

395 The point of this function is to set the cell_contents attribute of a cell 

396 after its creation. This operation is necessary in case the cell contains a 

397 reference to the function the cell belongs to, as when calling the 

398 function's constructor 

399 ``f = types.FunctionType(code, globals, name, argdefs, closure)``, 

400 closure will not be able to contain the yet-to-be-created f. 

401 

402 In Python3.7, cell_contents is writeable, so setting the contents of a cell 

403 can be done simply using 

404 >>> cell.cell_contents = value 

405 

406 In earlier Python3 versions, the cell_contents attribute of a cell is read 

407 only, but this limitation can be worked around by leveraging the Python 3 

408 ``nonlocal`` keyword. 

409 

410 In Python2 however, this attribute is read only, and there is no 

411 ``nonlocal`` keyword. For this reason, we need to come up with more 

412 complicated hacks to set this attribute. 

413 

414 The chosen approach is to create a function with a STORE_DEREF opcode, 

415 which sets the content of a closure variable. Typically: 

416 

417 >>> def inner(value): 

418 ... lambda: cell # the lambda makes cell a closure 

419 ... cell = value # cell is a closure, so this triggers a STORE_DEREF 

420 

421 (Note that in Python2, A STORE_DEREF can never be triggered from an inner 

422 function. The function g for example here 

423 >>> def f(var): 

424 ... def g(): 

425 ... var += 1 

426 ... return g 

427 

428 will not modify the closure variable ``var```inplace, but instead try to 

429 load a local variable var and increment it. As g does not assign the local 

430 variable ``var`` any initial value, calling f(1)() will fail at runtime.) 

431 

432 Our objective is to set the value of a given cell ``cell``. So we need to 

433 somewhat reference our ``cell`` object into the ``inner`` function so that 

434 this object (and not the smoke cell of the lambda function) gets affected 

435 by the STORE_DEREF operation. 

436 

437 In inner, ``cell`` is referenced as a cell variable (an enclosing variable 

438 that is referenced by the inner function). If we create a new function 

439 cell_set with the exact same code as ``inner``, but with ``cell`` marked as 

440 a free variable instead, the STORE_DEREF will be applied on its closure - 

441 ``cell``, which we can specify explicitly during construction! The new 

442 cell_set variable thus actually sets the contents of a specified cell! 

443 

444 Note: we do not make use of the ``nonlocal`` keyword to set the contents of 

445 a cell in early python3 versions to limit possible syntax errors in case 

446 test and checker libraries decide to parse the whole file. 

447 """ 

448 

449 if sys.version_info[:2] >= (3, 7): # pragma: no branch 

450 cell.cell_contents = value 

451 else: 

452 _cell_set = types.FunctionType( 

453 _cell_set_template_code, {}, '_cell_set', (), (cell,),) 

454 _cell_set(value) 

455 

456 

457def _make_cell_set_template_code(): 

458 def _cell_set_factory(value): 

459 lambda: cell 

460 cell = value 

461 

462 co = _cell_set_factory.__code__ 

463 

464 _cell_set_template_code = types.CodeType( 

465 co.co_argcount, 

466 co.co_kwonlyargcount, # Python 3 only argument 

467 co.co_nlocals, 

468 co.co_stacksize, 

469 co.co_flags, 

470 co.co_code, 

471 co.co_consts, 

472 co.co_names, 

473 co.co_varnames, 

474 co.co_filename, 

475 co.co_name, 

476 co.co_firstlineno, 

477 co.co_lnotab, 

478 co.co_cellvars, # co_freevars is initialized with co_cellvars 

479 (), # co_cellvars is made empty 

480 ) 

481 return _cell_set_template_code 

482 

483 

484if sys.version_info[:2] < (3, 7): 

485 _cell_set_template_code = _make_cell_set_template_code() 

486 

487# relevant opcodes 

488STORE_GLOBAL = opcode.opmap['STORE_GLOBAL'] 

489DELETE_GLOBAL = opcode.opmap['DELETE_GLOBAL'] 

490LOAD_GLOBAL = opcode.opmap['LOAD_GLOBAL'] 

491GLOBAL_OPS = (STORE_GLOBAL, DELETE_GLOBAL, LOAD_GLOBAL) 

492HAVE_ARGUMENT = dis.HAVE_ARGUMENT 

493EXTENDED_ARG = dis.EXTENDED_ARG 

494 

495 

496_BUILTIN_TYPE_NAMES = {} 

497for k, v in types.__dict__.items(): 

498 if type(v) is type: 

499 _BUILTIN_TYPE_NAMES[v] = k 

500 

501 

502def _builtin_type(name): 

503 if name == "ClassType": # pragma: no cover 

504 # Backward compat to load pickle files generated with cloudpickle 

505 # < 1.3 even if loading pickle files from older versions is not 

506 # officially supported. 

507 return type 

508 return getattr(types, name) 

509 

510 

511def _walk_global_ops(code): 

512 """ 

513 Yield referenced name for all global-referencing instructions in *code*. 

514 """ 

515 for instr in dis.get_instructions(code): 

516 op = instr.opcode 

517 if op in GLOBAL_OPS: 

518 yield instr.argval 

519 

520 

521def _extract_class_dict(cls): 

522 """Retrieve a copy of the dict of a class without the inherited methods""" 

523 clsdict = dict(cls.__dict__) # copy dict proxy to a dict 

524 if len(cls.__bases__) == 1: 

525 inherited_dict = cls.__bases__[0].__dict__ 

526 else: 

527 inherited_dict = {} 

528 for base in reversed(cls.__bases__): 

529 inherited_dict.update(base.__dict__) 

530 to_remove = [] 

531 for name, value in clsdict.items(): 

532 try: 

533 base_value = inherited_dict[name] 

534 if value is base_value: 

535 to_remove.append(name) 

536 except KeyError: 

537 pass 

538 for name in to_remove: 

539 clsdict.pop(name) 

540 return clsdict 

541 

542 

543if sys.version_info[:2] < (3, 7): # pragma: no branch 

544 def _is_parametrized_type_hint(obj): 

545 # This is very cheap but might generate false positives. So try to 

546 # narrow it down is good as possible. 

547 type_module = getattr(type(obj), '__module__', None) 

548 from_typing_extensions = type_module == 'typing_extensions' 

549 from_typing = type_module == 'typing' 

550 

551 # general typing Constructs 

552 is_typing = getattr(obj, '__origin__', None) is not None 

553 

554 # typing_extensions.Literal 

555 is_literal = ( 

556 (getattr(obj, '__values__', None) is not None) 

557 and from_typing_extensions 

558 ) 

559 

560 # typing_extensions.Final 

561 is_final = ( 

562 (getattr(obj, '__type__', None) is not None) 

563 and from_typing_extensions 

564 ) 

565 

566 # typing.ClassVar 

567 is_classvar = ( 

568 (getattr(obj, '__type__', None) is not None) and from_typing 

569 ) 

570 

571 # typing.Union/Tuple for old Python 3.5 

572 is_union = getattr(obj, '__union_params__', None) is not None 

573 is_tuple = getattr(obj, '__tuple_params__', None) is not None 

574 is_callable = ( 

575 getattr(obj, '__result__', None) is not None and 

576 getattr(obj, '__args__', None) is not None 

577 ) 

578 return any((is_typing, is_literal, is_final, is_classvar, is_union, 

579 is_tuple, is_callable)) 

580 

581 def _create_parametrized_type_hint(origin, args): 

582 return origin[args] 

583else: 

584 _is_parametrized_type_hint = None 

585 _create_parametrized_type_hint = None 

586 

587 

588def parametrized_type_hint_getinitargs(obj): 

589 # The distorted type check sematic for typing construct becomes: 

590 # ``type(obj) is type(TypeHint)``, which means "obj is a 

591 # parametrized TypeHint" 

592 if type(obj) is type(Literal): # pragma: no branch 

593 initargs = (Literal, obj.__values__) 

594 elif type(obj) is type(Final): # pragma: no branch 

595 initargs = (Final, obj.__type__) 

596 elif type(obj) is type(ClassVar): 

597 initargs = (ClassVar, obj.__type__) 

598 elif type(obj) is type(Generic): 

599 initargs = (obj.__origin__, obj.__args__) 

600 elif type(obj) is type(Union): 

601 initargs = (Union, obj.__args__) 

602 elif type(obj) is type(Tuple): 

603 initargs = (Tuple, obj.__args__) 

604 elif type(obj) is type(Callable): 

605 (*args, result) = obj.__args__ 

606 if len(args) == 1 and args[0] is Ellipsis: 

607 args = Ellipsis 

608 else: 

609 args = list(args) 

610 initargs = (Callable, (args, result)) 

611 else: # pragma: no cover 

612 raise pickle.PicklingError( 

613 f"Cloudpickle Error: Unknown type {type(obj)}" 

614 ) 

615 return initargs 

616 

617 

618# Tornado support 

619 

620def is_tornado_coroutine(func): 

621 """ 

622 Return whether *func* is a Tornado coroutine function. 

623 Running coroutines are not supported. 

624 """ 

625 if 'tornado.gen' not in sys.modules: 

626 return False 

627 gen = sys.modules['tornado.gen'] 

628 if not hasattr(gen, "is_coroutine_function"): 

629 # Tornado version is too old 

630 return False 

631 return gen.is_coroutine_function(func) 

632 

633 

634def _rebuild_tornado_coroutine(func): 

635 from tornado import gen 

636 return gen.coroutine(func) 

637 

638 

639# including pickles unloading functions in this namespace 

640load = pickle.load 

641loads = pickle.loads 

642 

643 

644def subimport(name): 

645 # We cannot do simply: `return __import__(name)`: Indeed, if ``name`` is 

646 # the name of a submodule, __import__ will return the top-level root module 

647 # of this submodule. For instance, __import__('os.path') returns the `os` 

648 # module. 

649 __import__(name) 

650 return sys.modules[name] 

651 

652 

653def dynamic_subimport(name, vars): 

654 mod = types.ModuleType(name) 

655 mod.__dict__.update(vars) 

656 mod.__dict__['__builtins__'] = builtins.__dict__ 

657 return mod 

658 

659 

660def _gen_ellipsis(): 

661 return Ellipsis 

662 

663 

664def _gen_not_implemented(): 

665 return NotImplemented 

666 

667 

668def _get_cell_contents(cell): 

669 try: 

670 return cell.cell_contents 

671 except ValueError: 

672 # sentinel used by ``_fill_function`` which will leave the cell empty 

673 return _empty_cell_value 

674 

675 

676def instance(cls): 

677 """Create a new instance of a class. 

678 

679 Parameters 

680 ---------- 

681 cls : type 

682 The class to create an instance of. 

683 

684 Returns 

685 ------- 

686 instance : cls 

687 A new instance of ``cls``. 

688 """ 

689 return cls() 

690 

691 

692@instance 

693class _empty_cell_value: 

694 """sentinel for empty closures 

695 """ 

696 @classmethod 

697 def __reduce__(cls): 

698 return cls.__name__ 

699 

700 

701def _fill_function(*args): 

702 """Fills in the rest of function data into the skeleton function object 

703 

704 The skeleton itself is create by _make_skel_func(). 

705 """ 

706 if len(args) == 2: 

707 func = args[0] 

708 state = args[1] 

709 elif len(args) == 5: 

710 # Backwards compat for cloudpickle v0.4.0, after which the `module` 

711 # argument was introduced 

712 func = args[0] 

713 keys = ['globals', 'defaults', 'dict', 'closure_values'] 

714 state = dict(zip(keys, args[1:])) 

715 elif len(args) == 6: 

716 # Backwards compat for cloudpickle v0.4.1, after which the function 

717 # state was passed as a dict to the _fill_function it-self. 

718 func = args[0] 

719 keys = ['globals', 'defaults', 'dict', 'module', 'closure_values'] 

720 state = dict(zip(keys, args[1:])) 

721 else: 

722 raise ValueError(f'Unexpected _fill_value arguments: {args!r}') 

723 

724 # - At pickling time, any dynamic global variable used by func is 

725 # serialized by value (in state['globals']). 

726 # - At unpickling time, func's __globals__ attribute is initialized by 

727 # first retrieving an empty isolated namespace that will be shared 

728 # with other functions pickled from the same original module 

729 # by the same CloudPickler instance and then updated with the 

730 # content of state['globals'] to populate the shared isolated 

731 # namespace with all the global variables that are specifically 

732 # referenced for this function. 

733 func.__globals__.update(state['globals']) 

734 

735 func.__defaults__ = state['defaults'] 

736 func.__dict__ = state['dict'] 

737 if 'annotations' in state: 

738 func.__annotations__ = state['annotations'] 

739 if 'doc' in state: 

740 func.__doc__ = state['doc'] 

741 if 'name' in state: 

742 func.__name__ = state['name'] 

743 if 'module' in state: 

744 func.__module__ = state['module'] 

745 if 'qualname' in state: 

746 func.__qualname__ = state['qualname'] 

747 if 'kwdefaults' in state: 

748 func.__kwdefaults__ = state['kwdefaults'] 

749 # _cloudpickle_subimports is a set of submodules that must be loaded for 

750 # the pickled function to work correctly at unpickling time. Now that these 

751 # submodules are depickled (hence imported), they can be removed from the 

752 # object's state (the object state only served as a reference holder to 

753 # these submodules) 

754 if '_cloudpickle_submodules' in state: 

755 state.pop('_cloudpickle_submodules') 

756 

757 cells = func.__closure__ 

758 if cells is not None: 

759 for cell, value in zip(cells, state['closure_values']): 

760 if value is not _empty_cell_value: 

761 cell_set(cell, value) 

762 

763 return func 

764 

765 

766def _make_function(code, globals, name, argdefs, closure): 

767 # Setting __builtins__ in globals is needed for nogil CPython. 

768 globals["__builtins__"] = __builtins__ 

769 return types.FunctionType(code, globals, name, argdefs, closure) 

770 

771 

772def _make_empty_cell(): 

773 if False: 

774 # trick the compiler into creating an empty cell in our lambda 

775 cell = None 

776 raise AssertionError('this route should not be executed') 

777 

778 return (lambda: cell).__closure__[0] 

779 

780 

781def _make_cell(value=_empty_cell_value): 

782 cell = _make_empty_cell() 

783 if value is not _empty_cell_value: 

784 cell_set(cell, value) 

785 return cell 

786 

787 

788def _make_skel_func(code, cell_count, base_globals=None): 

789 """ Creates a skeleton function object that contains just the provided 

790 code and the correct number of cells in func_closure. All other 

791 func attributes (e.g. func_globals) are empty. 

792 """ 

793 # This function is deprecated and should be removed in cloudpickle 1.7 

794 warnings.warn( 

795 "A pickle file created using an old (<=1.4.1) version of cloudpickle " 

796 "is currently being loaded. This is not supported by cloudpickle and " 

797 "will break in cloudpickle 1.7", category=UserWarning 

798 ) 

799 # This is backward-compatibility code: for cloudpickle versions between 

800 # 0.5.4 and 0.7, base_globals could be a string or None. base_globals 

801 # should now always be a dictionary. 

802 if base_globals is None or isinstance(base_globals, str): 

803 base_globals = {} 

804 

805 base_globals['__builtins__'] = __builtins__ 

806 

807 closure = ( 

808 tuple(_make_empty_cell() for _ in range(cell_count)) 

809 if cell_count >= 0 else 

810 None 

811 ) 

812 return types.FunctionType(code, base_globals, None, None, closure) 

813 

814 

815def _make_skeleton_class(type_constructor, name, bases, type_kwargs, 

816 class_tracker_id, extra): 

817 """Build dynamic class with an empty __dict__ to be filled once memoized 

818 

819 If class_tracker_id is not None, try to lookup an existing class definition 

820 matching that id. If none is found, track a newly reconstructed class 

821 definition under that id so that other instances stemming from the same 

822 class id will also reuse this class definition. 

823 

824 The "extra" variable is meant to be a dict (or None) that can be used for 

825 forward compatibility shall the need arise. 

826 """ 

827 skeleton_class = types.new_class( 

828 name, bases, {'metaclass': type_constructor}, 

829 lambda ns: ns.update(type_kwargs) 

830 ) 

831 return _lookup_class_or_track(class_tracker_id, skeleton_class) 

832 

833 

834def _rehydrate_skeleton_class(skeleton_class, class_dict): 

835 """Put attributes from `class_dict` back on `skeleton_class`. 

836 

837 See CloudPickler.save_dynamic_class for more info. 

838 """ 

839 registry = None 

840 for attrname, attr in class_dict.items(): 

841 if attrname == "_abc_impl": 

842 registry = attr 

843 else: 

844 setattr(skeleton_class, attrname, attr) 

845 if registry is not None: 

846 for subclass in registry: 

847 skeleton_class.register(subclass) 

848 

849 return skeleton_class 

850 

851 

852def _make_skeleton_enum(bases, name, qualname, members, module, 

853 class_tracker_id, extra): 

854 """Build dynamic enum with an empty __dict__ to be filled once memoized 

855 

856 The creation of the enum class is inspired by the code of 

857 EnumMeta._create_. 

858 

859 If class_tracker_id is not None, try to lookup an existing enum definition 

860 matching that id. If none is found, track a newly reconstructed enum 

861 definition under that id so that other instances stemming from the same 

862 class id will also reuse this enum definition. 

863 

864 The "extra" variable is meant to be a dict (or None) that can be used for 

865 forward compatibility shall the need arise. 

866 """ 

867 # enums always inherit from their base Enum class at the last position in 

868 # the list of base classes: 

869 enum_base = bases[-1] 

870 metacls = enum_base.__class__ 

871 classdict = metacls.__prepare__(name, bases) 

872 

873 for member_name, member_value in members.items(): 

874 classdict[member_name] = member_value 

875 enum_class = metacls.__new__(metacls, name, bases, classdict) 

876 enum_class.__module__ = module 

877 enum_class.__qualname__ = qualname 

878 

879 return _lookup_class_or_track(class_tracker_id, enum_class) 

880 

881 

882def _make_typevar(name, bound, constraints, covariant, contravariant, 

883 class_tracker_id): 

884 tv = typing.TypeVar( 

885 name, *constraints, bound=bound, 

886 covariant=covariant, contravariant=contravariant 

887 ) 

888 if class_tracker_id is not None: 

889 return _lookup_class_or_track(class_tracker_id, tv) 

890 else: # pragma: nocover 

891 # Only for Python 3.5.3 compat. 

892 return tv 

893 

894 

895def _decompose_typevar(obj): 

896 return ( 

897 obj.__name__, obj.__bound__, obj.__constraints__, 

898 obj.__covariant__, obj.__contravariant__, 

899 _get_or_create_tracker_id(obj), 

900 ) 

901 

902 

903def _typevar_reduce(obj): 

904 # TypeVar instances require the module information hence why we 

905 # are not using the _should_pickle_by_reference directly 

906 module_and_name = _lookup_module_and_qualname(obj, name=obj.__name__) 

907 

908 if module_and_name is None: 

909 return (_make_typevar, _decompose_typevar(obj)) 

910 elif _is_registered_pickle_by_value(module_and_name[0]): 

911 return (_make_typevar, _decompose_typevar(obj)) 

912 

913 return (getattr, module_and_name) 

914 

915 

916def _get_bases(typ): 

917 if '__orig_bases__' in getattr(typ, '__dict__', {}): 

918 # For generic types (see PEP 560) 

919 # Note that simply checking `hasattr(typ, '__orig_bases__')` is not 

920 # correct. Subclasses of a fully-parameterized generic class does not 

921 # have `__orig_bases__` defined, but `hasattr(typ, '__orig_bases__')` 

922 # will return True because it's defined in the base class. 

923 bases_attr = '__orig_bases__' 

924 else: 

925 # For regular class objects 

926 bases_attr = '__bases__' 

927 return getattr(typ, bases_attr) 

928 

929 

930def _make_dict_keys(obj, is_ordered=False): 

931 if is_ordered: 

932 return OrderedDict.fromkeys(obj).keys() 

933 else: 

934 return dict.fromkeys(obj).keys() 

935 

936 

937def _make_dict_values(obj, is_ordered=False): 

938 if is_ordered: 

939 return OrderedDict((i, _) for i, _ in enumerate(obj)).values() 

940 else: 

941 return {i: _ for i, _ in enumerate(obj)}.values() 

942 

943 

944def _make_dict_items(obj, is_ordered=False): 

945 if is_ordered: 

946 return OrderedDict(obj).items() 

947 else: 

948 return obj.items()