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1""" 

2This is a modified version of the cloudpickle module. 

3Patches: 

4- https://github.com/numba/numba/pull/7388 

5 Avoid resetting class state of dynamic classes. 

6 

7Original module docstring: 

8 

9Pickler class to extend the standard pickle.Pickler functionality 

10 

11The main objective is to make it natural to perform distributed computing on 

12clusters (such as PySpark, Dask, Ray...) with interactively defined code 

13(functions, classes, ...) written in notebooks or console. 

14 

15In particular this pickler adds the following features: 

16- serialize interactively-defined or locally-defined functions, classes, 

17 enums, typevars, lambdas and nested functions to compiled byte code; 

18- deal with some other non-serializable objects in an ad-hoc manner where 

19 applicable. 

20 

21This pickler is therefore meant to be used for the communication between short 

22lived Python processes running the same version of Python and libraries. In 

23particular, it is not meant to be used for long term storage of Python objects. 

24 

25It does not include an unpickler, as standard Python unpickling suffices. 

26 

27This module was extracted from the `cloud` package, developed by `PiCloud, Inc. 

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

29 

30Copyright (c) 2012-now, CloudPickle developers and contributors. 

31Copyright (c) 2012, Regents of the University of California. 

32Copyright (c) 2009 `PiCloud, Inc. <https://web.archive.org/web/20140626004012/http://www.picloud.com/>`_. 

33All rights reserved. 

34 

35Redistribution and use in source and binary forms, with or without 

36modification, are permitted provided that the following conditions 

37are met: 

38 * Redistributions of source code must retain the above copyright 

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

40 * Redistributions in binary form must reproduce the above copyright 

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

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

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

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

45 products derived from this software without specific prior written 

46 permission. 

47 

48THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 

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

50LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 

51A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 

52HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 

53SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 

54TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 

55PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 

56LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 

57NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 

58SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

59""" 

60 

61import _collections_abc 

62from collections import ChainMap, OrderedDict 

63import abc 

64import builtins 

65import copyreg 

66import dataclasses 

67import dis 

68from enum import Enum 

69import io 

70import itertools 

71import logging 

72import opcode 

73import pickle 

74from pickle import _getattribute 

75import platform 

76import struct 

77import sys 

78import threading 

79import types 

80import typing 

81import uuid 

82import warnings 

83import weakref 

84 

85# The following import is required to be imported in the cloudpickle 

86# namespace to be able to load pickle files generated with older versions of 

87# cloudpickle. See: tests/test_backward_compat.py 

88from types import CellType # noqa: F401 

89 

90 

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

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

93# communication speed over compatibility: 

94DEFAULT_PROTOCOL = pickle.HIGHEST_PROTOCOL 

95 

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

97_PICKLE_BY_VALUE_MODULES = set() 

98 

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

100# reconstruct instances from the matching singleton class definition when 

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

102_DYNAMIC_CLASS_TRACKER_BY_CLASS = weakref.WeakKeyDictionary() 

103_DYNAMIC_CLASS_TRACKER_BY_ID = weakref.WeakValueDictionary() 

104_DYNAMIC_CLASS_TRACKER_LOCK = threading.Lock() 

105_DYNAMIC_CLASS_TRACKER_REUSING = weakref.WeakSet() 

106 

107PYPY = platform.python_implementation() == "PyPy" 

108 

109builtin_code_type = None 

110if PYPY: 

111 # builtin-code objects only exist in pypy 

112 builtin_code_type = type(float.__new__.__code__) 

113 

114_extract_code_globals_cache = weakref.WeakKeyDictionary() 

115 

116 

117def _get_or_create_tracker_id(class_def): 

118 with _DYNAMIC_CLASS_TRACKER_LOCK: 

119 class_tracker_id = _DYNAMIC_CLASS_TRACKER_BY_CLASS.get(class_def) 

120 if class_tracker_id is None: 

121 class_tracker_id = uuid.uuid4().hex 

122 _DYNAMIC_CLASS_TRACKER_BY_CLASS[class_def] = class_tracker_id 

123 _DYNAMIC_CLASS_TRACKER_BY_ID[class_tracker_id] = class_def 

124 return class_tracker_id 

125 

126 

127def _lookup_class_or_track(class_tracker_id, class_def): 

128 if class_tracker_id is not None: 

129 with _DYNAMIC_CLASS_TRACKER_LOCK: 

130 orig_class_def = class_def 

131 class_def = _DYNAMIC_CLASS_TRACKER_BY_ID.setdefault( 

132 class_tracker_id, class_def 

133 ) 

134 _DYNAMIC_CLASS_TRACKER_BY_CLASS[class_def] = class_tracker_id 

135 # Check if we are reusing a previous class_def 

136 if orig_class_def is not class_def: 

137 # Remember the class_def is being reused 

138 _DYNAMIC_CLASS_TRACKER_REUSING.add(class_def) 

139 return class_def 

140 

141 

142def register_pickle_by_value(module): 

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

144 

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

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

147 the attribute from the module at load time. 

148 

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

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

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

152 

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

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

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

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

157 

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

159 README.md file for more details and limitations. 

160 """ 

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

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

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

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

165 # functions pickled by value. (see 

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

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

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

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

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

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

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

173 if module.__name__ not in sys.modules: 

174 raise ValueError( 

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

176 "`import` statement to access it?" 

177 ) 

178 _PICKLE_BY_VALUE_MODULES.add(module.__name__) 

179 

180 

181def unregister_pickle_by_value(module): 

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

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

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

185 if module.__name__ not in _PICKLE_BY_VALUE_MODULES: 

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

187 else: 

188 _PICKLE_BY_VALUE_MODULES.remove(module.__name__) 

189 

190 

191def list_registry_pickle_by_value(): 

192 return _PICKLE_BY_VALUE_MODULES.copy() 

193 

194 

195def _is_registered_pickle_by_value(module): 

196 module_name = module.__name__ 

197 if module_name in _PICKLE_BY_VALUE_MODULES: 

198 return True 

199 while True: 

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

201 if parent_name == module_name: 

202 break 

203 if parent_name in _PICKLE_BY_VALUE_MODULES: 

204 return True 

205 module_name = parent_name 

206 return False 

207 

208 

209def _whichmodule(obj, name): 

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

211 

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

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

214 not found in any module. 

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

216 are considered unwanted side effects. 

217 """ 

218 module_name = getattr(obj, "__module__", None) 

219 

220 if module_name is not None: 

221 return module_name 

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

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

224 # other threads importing at the same time. 

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

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

227 # sys.modules 

228 if ( 

229 module_name == "__main__" 

230 or module is None 

231 or not isinstance(module, types.ModuleType) 

232 ): 

233 continue 

234 try: 

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

236 return module_name 

237 except Exception: 

238 pass 

239 return None 

240 

241 

242def _should_pickle_by_reference(obj, name=None): 

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

244 

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

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

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

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

249 

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

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

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

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

254 explicitly registered to be pickled by value. 

255 """ 

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

257 module_and_name = _lookup_module_and_qualname(obj, name=name) 

258 if module_and_name is None: 

259 return False 

260 module, name = module_and_name 

261 return not _is_registered_pickle_by_value(module) 

262 

263 elif isinstance(obj, types.ModuleType): 

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

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

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

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

268 # in another Python process. 

269 if _is_registered_pickle_by_value(obj): 

270 return False 

271 return obj.__name__ in sys.modules 

272 else: 

273 raise TypeError( 

274 "cannot check importability of {} instances".format(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 """Find all globals names read or written to by codeblock co.""" 

320 out_names = _extract_code_globals_cache.get(co) 

321 if out_names is None: 

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

323 # deterministic order and avoid introducing non-deterministic pickle 

324 # bytes as a results. 

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

326 

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

328 # generates a constant code object corresponding to the one of the 

329 # nested function's As the nested function may itself need global 

330 # variables, we need to introspect its code, extract its globals, (look 

331 # for code object in it's co_consts attribute..) and add the result to 

332 # code_globals 

333 if co.co_consts: 

334 for const in co.co_consts: 

335 if isinstance(const, types.CodeType): 

336 out_names.update(_extract_code_globals(const)) 

337 

338 _extract_code_globals_cache[co] = out_names 

339 

340 return out_names 

341 

342 

343def _find_imported_submodules(code, top_level_dependencies): 

344 """Find currently imported submodules used by a function. 

345 

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

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

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

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

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

351 

352 Example: 

353 ``` 

354 import concurrent.futures 

355 import cloudpickle 

356 def func(): 

357 x = concurrent.futures.ThreadPoolExecutor 

358 if __name__ == '__main__': 

359 cloudpickle.dumps(func) 

360 ``` 

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

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

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

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

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

366 not being imported 

367 """ 

368 

369 subimports = [] 

370 # check if any known dependency is an imported package 

371 for x in top_level_dependencies: 

372 if ( 

373 isinstance(x, types.ModuleType) 

374 and hasattr(x, "__package__") 

375 and x.__package__ 

376 ): 

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 

392# relevant opcodes 

393STORE_GLOBAL = opcode.opmap["STORE_GLOBAL"] 

394DELETE_GLOBAL = opcode.opmap["DELETE_GLOBAL"] 

395LOAD_GLOBAL = opcode.opmap["LOAD_GLOBAL"] 

396GLOBAL_OPS = (STORE_GLOBAL, DELETE_GLOBAL, LOAD_GLOBAL) 

397HAVE_ARGUMENT = dis.HAVE_ARGUMENT 

398EXTENDED_ARG = dis.EXTENDED_ARG 

399 

400 

401_BUILTIN_TYPE_NAMES = {} 

402for k, v in types.__dict__.items(): 

403 if type(v) is type: 

404 _BUILTIN_TYPE_NAMES[v] = k 

405 

406 

407def _builtin_type(name): 

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

409 # Backward compat to load pickle files generated with cloudpickle 

410 # < 1.3 even if loading pickle files from older versions is not 

411 # officially supported. 

412 return type 

413 return getattr(types, name) 

414 

415 

416def _walk_global_ops(code): 

417 """Yield referenced name for global-referencing instructions in code.""" 

418 for instr in dis.get_instructions(code): 

419 op = instr.opcode 

420 if op in GLOBAL_OPS: 

421 yield instr.argval 

422 

423 

424def _extract_class_dict(cls): 

425 """Retrieve a copy of the dict of a class without the inherited method.""" 

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

427 if len(cls.__bases__) == 1: 

428 inherited_dict = cls.__bases__[0].__dict__ 

429 else: 

430 inherited_dict = {} 

431 for base in reversed(cls.__bases__): 

432 inherited_dict.update(base.__dict__) 

433 to_remove = [] 

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

435 try: 

436 base_value = inherited_dict[name] 

437 if value is base_value: 

438 to_remove.append(name) 

439 except KeyError: 

440 pass 

441 for name in to_remove: 

442 clsdict.pop(name) 

443 return clsdict 

444 

445 

446def is_tornado_coroutine(func): 

447 """Return whether `func` is a Tornado coroutine function. 

448 

449 Running coroutines are not supported. 

450 """ 

451 warnings.warn( 

452 "is_tornado_coroutine is deprecated in cloudpickle 3.0 and will be " 

453 "removed in cloudpickle 4.0. Use tornado.gen.is_coroutine_function " 

454 "directly instead.", 

455 category=DeprecationWarning, 

456 ) 

457 if "tornado.gen" not in sys.modules: 

458 return False 

459 gen = sys.modules["tornado.gen"] 

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

461 # Tornado version is too old 

462 return False 

463 return gen.is_coroutine_function(func) 

464 

465 

466def subimport(name): 

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

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

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

470 # module. 

471 __import__(name) 

472 return sys.modules[name] 

473 

474 

475def dynamic_subimport(name, vars): 

476 mod = types.ModuleType(name) 

477 mod.__dict__.update(vars) 

478 mod.__dict__["__builtins__"] = builtins.__dict__ 

479 return mod 

480 

481 

482def _get_cell_contents(cell): 

483 try: 

484 return cell.cell_contents 

485 except ValueError: 

486 # Handle empty cells explicitly with a sentinel value. 

487 return _empty_cell_value 

488 

489 

490def instance(cls): 

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

492 

493 Parameters 

494 ---------- 

495 cls : type 

496 The class to create an instance of. 

497 

498 Returns 

499 ------- 

500 instance : cls 

501 A new instance of ``cls``. 

502 """ 

503 return cls() 

504 

505 

506@instance 

507class _empty_cell_value: 

508 """Sentinel for empty closures.""" 

509 

510 @classmethod 

511 def __reduce__(cls): 

512 return cls.__name__ 

513 

514 

515def _make_function(code, globals, name, argdefs, closure): 

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

517 globals["__builtins__"] = __builtins__ 

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

519 

520 

521def _make_empty_cell(): 

522 if False: 

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

524 cell = None 

525 raise AssertionError("this route should not be executed") 

526 

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

528 

529 

530def _make_cell(value=_empty_cell_value): 

531 cell = _make_empty_cell() 

532 if value is not _empty_cell_value: 

533 cell.cell_contents = value 

534 return cell 

535 

536 

537def _make_skeleton_class( 

538 type_constructor, name, bases, type_kwargs, class_tracker_id, extra 

539): 

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

541 

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

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

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

545 class id will also reuse this class definition. 

546 

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

548 forward compatibility shall the need arise. 

549 """ 

550 skeleton_class = types.new_class( 

551 name, bases, {"metaclass": type_constructor}, lambda ns: ns.update(type_kwargs) 

552 ) 

553 return _lookup_class_or_track(class_tracker_id, skeleton_class) 

554 

555 

556def _make_skeleton_enum( 

557 bases, name, qualname, members, module, class_tracker_id, extra 

558): 

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

560 

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

562 EnumMeta._create_. 

563 

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

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

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

567 class id will also reuse this enum definition. 

568 

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

570 forward compatibility shall the need arise. 

571 """ 

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

573 # the list of base classes: 

574 enum_base = bases[-1] 

575 metacls = enum_base.__class__ 

576 classdict = metacls.__prepare__(name, bases) 

577 

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

579 classdict[member_name] = member_value 

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

581 enum_class.__module__ = module 

582 enum_class.__qualname__ = qualname 

583 

584 return _lookup_class_or_track(class_tracker_id, enum_class) 

585 

586 

587def _make_typevar(name, bound, constraints, covariant, contravariant, class_tracker_id): 

588 tv = typing.TypeVar( 

589 name, 

590 *constraints, 

591 bound=bound, 

592 covariant=covariant, 

593 contravariant=contravariant, 

594 ) 

595 return _lookup_class_or_track(class_tracker_id, tv) 

596 

597 

598def _decompose_typevar(obj): 

599 return ( 

600 obj.__name__, 

601 obj.__bound__, 

602 obj.__constraints__, 

603 obj.__covariant__, 

604 obj.__contravariant__, 

605 _get_or_create_tracker_id(obj), 

606 ) 

607 

608 

609def _typevar_reduce(obj): 

610 # TypeVar instances require the module information hence why we 

611 # are not using the _should_pickle_by_reference directly 

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

613 

614 if module_and_name is None: 

615 return (_make_typevar, _decompose_typevar(obj)) 

616 elif _is_registered_pickle_by_value(module_and_name[0]): 

617 return (_make_typevar, _decompose_typevar(obj)) 

618 

619 return (getattr, module_and_name) 

620 

621 

622def _get_bases(typ): 

623 if "__orig_bases__" in getattr(typ, "__dict__", {}): 

624 # For generic types (see PEP 560) 

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

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

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

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

629 bases_attr = "__orig_bases__" 

630 else: 

631 # For regular class objects 

632 bases_attr = "__bases__" 

633 return getattr(typ, bases_attr) 

634 

635 

636def _make_dict_keys(obj, is_ordered=False): 

637 if is_ordered: 

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

639 else: 

640 return dict.fromkeys(obj).keys() 

641 

642 

643def _make_dict_values(obj, is_ordered=False): 

644 if is_ordered: 

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

646 else: 

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

648 

649 

650def _make_dict_items(obj, is_ordered=False): 

651 if is_ordered: 

652 return OrderedDict(obj).items() 

653 else: 

654 return obj.items() 

655 

656 

657# COLLECTION OF OBJECTS __getnewargs__-LIKE METHODS 

658# ------------------------------------------------- 

659 

660 

661def _class_getnewargs(obj): 

662 type_kwargs = {} 

663 if "__module__" in obj.__dict__: 

664 type_kwargs["__module__"] = obj.__module__ 

665 

666 __dict__ = obj.__dict__.get("__dict__", None) 

667 if isinstance(__dict__, property): 

668 type_kwargs["__dict__"] = __dict__ 

669 

670 return ( 

671 type(obj), 

672 obj.__name__, 

673 _get_bases(obj), 

674 type_kwargs, 

675 _get_or_create_tracker_id(obj), 

676 None, 

677 ) 

678 

679 

680def _enum_getnewargs(obj): 

681 members = {e.name: e.value for e in obj} 

682 return ( 

683 obj.__bases__, 

684 obj.__name__, 

685 obj.__qualname__, 

686 members, 

687 obj.__module__, 

688 _get_or_create_tracker_id(obj), 

689 None, 

690 ) 

691 

692 

693# COLLECTION OF OBJECTS RECONSTRUCTORS 

694# ------------------------------------ 

695def _file_reconstructor(retval): 

696 return retval 

697 

698 

699# COLLECTION OF OBJECTS STATE GETTERS 

700# ----------------------------------- 

701 

702 

703def _function_getstate(func): 

704 # - Put func's dynamic attributes (stored in func.__dict__) in state. These 

705 # attributes will be restored at unpickling time using 

706 # f.__dict__.update(state) 

707 # - Put func's members into slotstate. Such attributes will be restored at 

708 # unpickling time by iterating over slotstate and calling setattr(func, 

709 # slotname, slotvalue) 

710 slotstate = { 

711 "__name__": func.__name__, 

712 "__qualname__": func.__qualname__, 

713 "__annotations__": func.__annotations__, 

714 "__kwdefaults__": func.__kwdefaults__, 

715 "__defaults__": func.__defaults__, 

716 "__module__": func.__module__, 

717 "__doc__": func.__doc__, 

718 "__closure__": func.__closure__, 

719 } 

720 

721 f_globals_ref = _extract_code_globals(func.__code__) 

722 f_globals = {k: func.__globals__[k] for k in f_globals_ref if k in func.__globals__} 

723 

724 if func.__closure__ is not None: 

725 closure_values = list(map(_get_cell_contents, func.__closure__)) 

726 else: 

727 closure_values = () 

728 

729 # Extract currently-imported submodules used by func. Storing these modules 

730 # in a smoke _cloudpickle_subimports attribute of the object's state will 

731 # trigger the side effect of importing these modules at unpickling time 

732 # (which is necessary for func to work correctly once depickled) 

733 slotstate["_cloudpickle_submodules"] = _find_imported_submodules( 

734 func.__code__, itertools.chain(f_globals.values(), closure_values) 

735 ) 

736 slotstate["__globals__"] = f_globals 

737 

738 state = func.__dict__ 

739 return state, slotstate 

740 

741 

742def _class_getstate(obj): 

743 clsdict = _extract_class_dict(obj) 

744 clsdict.pop("__weakref__", None) 

745 

746 if issubclass(type(obj), abc.ABCMeta): 

747 # If obj is an instance of an ABCMeta subclass, don't pickle the 

748 # cache/negative caches populated during isinstance/issubclass 

749 # checks, but pickle the list of registered subclasses of obj. 

750 clsdict.pop("_abc_cache", None) 

751 clsdict.pop("_abc_negative_cache", None) 

752 clsdict.pop("_abc_negative_cache_version", None) 

753 registry = clsdict.pop("_abc_registry", None) 

754 if registry is None: 

755 # The abc caches and registered subclasses of a 

756 # class are bundled into the single _abc_impl attribute 

757 clsdict.pop("_abc_impl", None) 

758 (registry, _, _, _) = abc._get_dump(obj) 

759 

760 clsdict["_abc_impl"] = [subclass_weakref() for subclass_weakref in registry] 

761 else: 

762 # In the above if clause, registry is a set of weakrefs -- in 

763 # this case, registry is a WeakSet 

764 clsdict["_abc_impl"] = [type_ for type_ in registry] 

765 

766 if "__slots__" in clsdict: 

767 # pickle string length optimization: member descriptors of obj are 

768 # created automatically from obj's __slots__ attribute, no need to 

769 # save them in obj's state 

770 if isinstance(obj.__slots__, str): 

771 clsdict.pop(obj.__slots__) 

772 else: 

773 for k in obj.__slots__: 

774 clsdict.pop(k, None) 

775 

776 clsdict.pop("__dict__", None) # unpicklable property object 

777 

778 return (clsdict, {}) 

779 

780 

781def _enum_getstate(obj): 

782 clsdict, slotstate = _class_getstate(obj) 

783 

784 members = {e.name: e.value for e in obj} 

785 # Cleanup the clsdict that will be passed to _make_skeleton_enum: 

786 # Those attributes are already handled by the metaclass. 

787 for attrname in [ 

788 "_generate_next_value_", 

789 "_member_names_", 

790 "_member_map_", 

791 "_member_type_", 

792 "_value2member_map_", 

793 ]: 

794 clsdict.pop(attrname, None) 

795 for member in members: 

796 clsdict.pop(member) 

797 # Special handling of Enum subclasses 

798 return clsdict, slotstate 

799 

800 

801# COLLECTIONS OF OBJECTS REDUCERS 

802# ------------------------------- 

803# A reducer is a function taking a single argument (obj), and that returns a 

804# tuple with all the necessary data to re-construct obj. Apart from a few 

805# exceptions (list, dict, bytes, int, etc.), a reducer is necessary to 

806# correctly pickle an object. 

807# While many built-in objects (Exceptions objects, instances of the "object" 

808# class, etc), are shipped with their own built-in reducer (invoked using 

809# obj.__reduce__), some do not. The following methods were created to "fill 

810# these holes". 

811 

812 

813def _code_reduce(obj): 

814 """code object reducer.""" 

815 # If you are not sure about the order of arguments, take a look at help 

816 # of the specific type from types, for example: 

817 # >>> from types import CodeType 

818 # >>> help(CodeType) 

819 if hasattr(obj, "co_exceptiontable"): 

820 # Python 3.11 and later: there are some new attributes 

821 # related to the enhanced exceptions. 

822 args = ( 

823 obj.co_argcount, 

824 obj.co_posonlyargcount, 

825 obj.co_kwonlyargcount, 

826 obj.co_nlocals, 

827 obj.co_stacksize, 

828 obj.co_flags, 

829 obj.co_code, 

830 obj.co_consts, 

831 obj.co_names, 

832 obj.co_varnames, 

833 obj.co_filename, 

834 obj.co_name, 

835 obj.co_qualname, 

836 obj.co_firstlineno, 

837 obj.co_linetable, 

838 obj.co_exceptiontable, 

839 obj.co_freevars, 

840 obj.co_cellvars, 

841 ) 

842 elif hasattr(obj, "co_linetable"): 

843 # Python 3.10 and later: obj.co_lnotab is deprecated and constructor 

844 # expects obj.co_linetable instead. 

845 args = ( 

846 obj.co_argcount, 

847 obj.co_posonlyargcount, 

848 obj.co_kwonlyargcount, 

849 obj.co_nlocals, 

850 obj.co_stacksize, 

851 obj.co_flags, 

852 obj.co_code, 

853 obj.co_consts, 

854 obj.co_names, 

855 obj.co_varnames, 

856 obj.co_filename, 

857 obj.co_name, 

858 obj.co_firstlineno, 

859 obj.co_linetable, 

860 obj.co_freevars, 

861 obj.co_cellvars, 

862 ) 

863 elif hasattr(obj, "co_nmeta"): # pragma: no cover 

864 # "nogil" Python: modified attributes from 3.9 

865 args = ( 

866 obj.co_argcount, 

867 obj.co_posonlyargcount, 

868 obj.co_kwonlyargcount, 

869 obj.co_nlocals, 

870 obj.co_framesize, 

871 obj.co_ndefaultargs, 

872 obj.co_nmeta, 

873 obj.co_flags, 

874 obj.co_code, 

875 obj.co_consts, 

876 obj.co_varnames, 

877 obj.co_filename, 

878 obj.co_name, 

879 obj.co_firstlineno, 

880 obj.co_lnotab, 

881 obj.co_exc_handlers, 

882 obj.co_jump_table, 

883 obj.co_freevars, 

884 obj.co_cellvars, 

885 obj.co_free2reg, 

886 obj.co_cell2reg, 

887 ) 

888 else: 

889 # Backward compat for 3.8 and 3.9 

890 args = ( 

891 obj.co_argcount, 

892 obj.co_posonlyargcount, 

893 obj.co_kwonlyargcount, 

894 obj.co_nlocals, 

895 obj.co_stacksize, 

896 obj.co_flags, 

897 obj.co_code, 

898 obj.co_consts, 

899 obj.co_names, 

900 obj.co_varnames, 

901 obj.co_filename, 

902 obj.co_name, 

903 obj.co_firstlineno, 

904 obj.co_lnotab, 

905 obj.co_freevars, 

906 obj.co_cellvars, 

907 ) 

908 return types.CodeType, args 

909 

910 

911def _cell_reduce(obj): 

912 """Cell (containing values of a function's free variables) reducer.""" 

913 try: 

914 obj.cell_contents 

915 except ValueError: # cell is empty 

916 return _make_empty_cell, () 

917 else: 

918 return _make_cell, (obj.cell_contents,) 

919 

920 

921def _classmethod_reduce(obj): 

922 orig_func = obj.__func__ 

923 return type(obj), (orig_func,) 

924 

925 

926def _file_reduce(obj): 

927 """Save a file.""" 

928 import io 

929 

930 if not hasattr(obj, "name") or not hasattr(obj, "mode"): 

931 raise pickle.PicklingError( 

932 "Cannot pickle files that do not map to an actual file" 

933 ) 

934 if obj is sys.stdout: 

935 return getattr, (sys, "stdout") 

936 if obj is sys.stderr: 

937 return getattr, (sys, "stderr") 

938 if obj is sys.stdin: 

939 raise pickle.PicklingError("Cannot pickle standard input") 

940 if obj.closed: 

941 raise pickle.PicklingError("Cannot pickle closed files") 

942 if hasattr(obj, "isatty") and obj.isatty(): 

943 raise pickle.PicklingError("Cannot pickle files that map to tty objects") 

944 if "r" not in obj.mode and "+" not in obj.mode: 

945 raise pickle.PicklingError( 

946 "Cannot pickle files that are not opened for reading: %s" % obj.mode 

947 ) 

948 

949 name = obj.name 

950 

951 retval = io.StringIO() 

952 

953 try: 

954 # Read the whole file 

955 curloc = obj.tell() 

956 obj.seek(0) 

957 contents = obj.read() 

958 obj.seek(curloc) 

959 except OSError as e: 

960 raise pickle.PicklingError( 

961 "Cannot pickle file %s as it cannot be read" % name 

962 ) from e 

963 retval.write(contents) 

964 retval.seek(curloc) 

965 

966 retval.name = name 

967 return _file_reconstructor, (retval,) 

968 

969 

970def _getset_descriptor_reduce(obj): 

971 return getattr, (obj.__objclass__, obj.__name__) 

972 

973 

974def _mappingproxy_reduce(obj): 

975 return types.MappingProxyType, (dict(obj),) 

976 

977 

978def _memoryview_reduce(obj): 

979 return bytes, (obj.tobytes(),) 

980 

981 

982def _module_reduce(obj): 

983 if _should_pickle_by_reference(obj): 

984 return subimport, (obj.__name__,) 

985 else: 

986 # Some external libraries can populate the "__builtins__" entry of a 

987 # module's `__dict__` with unpicklable objects (see #316). For that 

988 # reason, we do not attempt to pickle the "__builtins__" entry, and 

989 # restore a default value for it at unpickling time. 

990 state = obj.__dict__.copy() 

991 state.pop("__builtins__", None) 

992 return dynamic_subimport, (obj.__name__, state) 

993 

994 

995def _method_reduce(obj): 

996 return (types.MethodType, (obj.__func__, obj.__self__)) 

997 

998 

999def _logger_reduce(obj): 

1000 return logging.getLogger, (obj.name,) 

1001 

1002 

1003def _root_logger_reduce(obj): 

1004 return logging.getLogger, () 

1005 

1006 

1007def _property_reduce(obj): 

1008 return property, (obj.fget, obj.fset, obj.fdel, obj.__doc__) 

1009 

1010 

1011def _weakset_reduce(obj): 

1012 return weakref.WeakSet, (list(obj),) 

1013 

1014 

1015def _dynamic_class_reduce(obj): 

1016 """Save a class that can't be referenced as a module attribute. 

1017 

1018 This method is used to serialize classes that are defined inside 

1019 functions, or that otherwise can't be serialized as attribute lookups 

1020 from importable modules. 

1021 """ 

1022 if Enum is not None and issubclass(obj, Enum): 

1023 return ( 

1024 _make_skeleton_enum, 

1025 _enum_getnewargs(obj), 

1026 _enum_getstate(obj), 

1027 None, 

1028 None, 

1029 _class_setstate, 

1030 ) 

1031 else: 

1032 return ( 

1033 _make_skeleton_class, 

1034 _class_getnewargs(obj), 

1035 _class_getstate(obj), 

1036 None, 

1037 None, 

1038 _class_setstate, 

1039 ) 

1040 

1041 

1042def _class_reduce(obj): 

1043 """Select the reducer depending on the dynamic nature of the class obj.""" 

1044 if obj is type(None): # noqa 

1045 return type, (None,) 

1046 elif obj is type(Ellipsis): 

1047 return type, (Ellipsis,) 

1048 elif obj is type(NotImplemented): 

1049 return type, (NotImplemented,) 

1050 elif obj in _BUILTIN_TYPE_NAMES: 

1051 return _builtin_type, (_BUILTIN_TYPE_NAMES[obj],) 

1052 elif not _should_pickle_by_reference(obj): 

1053 return _dynamic_class_reduce(obj) 

1054 return NotImplemented 

1055 

1056 

1057def _dict_keys_reduce(obj): 

1058 # Safer not to ship the full dict as sending the rest might 

1059 # be unintended and could potentially cause leaking of 

1060 # sensitive information 

1061 return _make_dict_keys, (list(obj),) 

1062 

1063 

1064def _dict_values_reduce(obj): 

1065 # Safer not to ship the full dict as sending the rest might 

1066 # be unintended and could potentially cause leaking of 

1067 # sensitive information 

1068 return _make_dict_values, (list(obj),) 

1069 

1070 

1071def _dict_items_reduce(obj): 

1072 return _make_dict_items, (dict(obj),) 

1073 

1074 

1075def _odict_keys_reduce(obj): 

1076 # Safer not to ship the full dict as sending the rest might 

1077 # be unintended and could potentially cause leaking of 

1078 # sensitive information 

1079 return _make_dict_keys, (list(obj), True) 

1080 

1081 

1082def _odict_values_reduce(obj): 

1083 # Safer not to ship the full dict as sending the rest might 

1084 # be unintended and could potentially cause leaking of 

1085 # sensitive information 

1086 return _make_dict_values, (list(obj), True) 

1087 

1088 

1089def _odict_items_reduce(obj): 

1090 return _make_dict_items, (dict(obj), True) 

1091 

1092 

1093def _dataclass_field_base_reduce(obj): 

1094 return _get_dataclass_field_type_sentinel, (obj.name,) 

1095 

1096 

1097# COLLECTIONS OF OBJECTS STATE SETTERS 

1098# ------------------------------------ 

1099# state setters are called at unpickling time, once the object is created and 

1100# it has to be updated to how it was at unpickling time. 

1101 

1102 

1103def _function_setstate(obj, state): 

1104 """Update the state of a dynamic function. 

1105 

1106 As __closure__ and __globals__ are readonly attributes of a function, we 

1107 cannot rely on the native setstate routine of pickle.load_build, that calls 

1108 setattr on items of the slotstate. Instead, we have to modify them inplace. 

1109 """ 

1110 state, slotstate = state 

1111 obj.__dict__.update(state) 

1112 

1113 obj_globals = slotstate.pop("__globals__") 

1114 obj_closure = slotstate.pop("__closure__") 

1115 # _cloudpickle_subimports is a set of submodules that must be loaded for 

1116 # the pickled function to work correctly at unpickling time. Now that these 

1117 # submodules are depickled (hence imported), they can be removed from the 

1118 # object's state (the object state only served as a reference holder to 

1119 # these submodules) 

1120 slotstate.pop("_cloudpickle_submodules") 

1121 

1122 obj.__globals__.update(obj_globals) 

1123 obj.__globals__["__builtins__"] = __builtins__ 

1124 

1125 if obj_closure is not None: 

1126 for i, cell in enumerate(obj_closure): 

1127 try: 

1128 value = cell.cell_contents 

1129 except ValueError: # cell is empty 

1130 continue 

1131 obj.__closure__[i].cell_contents = value 

1132 

1133 for k, v in slotstate.items(): 

1134 setattr(obj, k, v) 

1135 

1136 

1137def _class_setstate(obj, state): 

1138 # Check if class is being reused and needs bypass setstate logic. 

1139 if obj in _DYNAMIC_CLASS_TRACKER_REUSING: 

1140 return obj 

1141 state, slotstate = state 

1142 registry = None 

1143 for attrname, attr in state.items(): 

1144 if attrname == "_abc_impl": 

1145 registry = attr 

1146 else: 

1147 setattr(obj, attrname, attr) 

1148 if registry is not None: 

1149 for subclass in registry: 

1150 obj.register(subclass) 

1151 

1152 return obj 

1153 

1154 

1155# COLLECTION OF DATACLASS UTILITIES 

1156# --------------------------------- 

1157# There are some internal sentinel values whose identity must be preserved when 

1158# unpickling dataclass fields. Each sentinel value has a unique name that we can 

1159# use to retrieve its identity at unpickling time. 

1160 

1161 

1162_DATACLASSE_FIELD_TYPE_SENTINELS = { 

1163 dataclasses._FIELD.name: dataclasses._FIELD, 

1164 dataclasses._FIELD_CLASSVAR.name: dataclasses._FIELD_CLASSVAR, 

1165 dataclasses._FIELD_INITVAR.name: dataclasses._FIELD_INITVAR, 

1166} 

1167 

1168 

1169def _get_dataclass_field_type_sentinel(name): 

1170 return _DATACLASSE_FIELD_TYPE_SENTINELS[name] 

1171 

1172 

1173class Pickler(pickle.Pickler): 

1174 # set of reducers defined and used by cloudpickle (private) 

1175 _dispatch_table = {} 

1176 _dispatch_table[classmethod] = _classmethod_reduce 

1177 _dispatch_table[io.TextIOWrapper] = _file_reduce 

1178 _dispatch_table[logging.Logger] = _logger_reduce 

1179 _dispatch_table[logging.RootLogger] = _root_logger_reduce 

1180 _dispatch_table[memoryview] = _memoryview_reduce 

1181 _dispatch_table[property] = _property_reduce 

1182 _dispatch_table[staticmethod] = _classmethod_reduce 

1183 _dispatch_table[CellType] = _cell_reduce 

1184 _dispatch_table[types.CodeType] = _code_reduce 

1185 _dispatch_table[types.GetSetDescriptorType] = _getset_descriptor_reduce 

1186 _dispatch_table[types.ModuleType] = _module_reduce 

1187 _dispatch_table[types.MethodType] = _method_reduce 

1188 _dispatch_table[types.MappingProxyType] = _mappingproxy_reduce 

1189 _dispatch_table[weakref.WeakSet] = _weakset_reduce 

1190 _dispatch_table[typing.TypeVar] = _typevar_reduce 

1191 _dispatch_table[_collections_abc.dict_keys] = _dict_keys_reduce 

1192 _dispatch_table[_collections_abc.dict_values] = _dict_values_reduce 

1193 _dispatch_table[_collections_abc.dict_items] = _dict_items_reduce 

1194 _dispatch_table[type(OrderedDict().keys())] = _odict_keys_reduce 

1195 _dispatch_table[type(OrderedDict().values())] = _odict_values_reduce 

1196 _dispatch_table[type(OrderedDict().items())] = _odict_items_reduce 

1197 _dispatch_table[abc.abstractmethod] = _classmethod_reduce 

1198 _dispatch_table[abc.abstractclassmethod] = _classmethod_reduce 

1199 _dispatch_table[abc.abstractstaticmethod] = _classmethod_reduce 

1200 _dispatch_table[abc.abstractproperty] = _property_reduce 

1201 _dispatch_table[dataclasses._FIELD_BASE] = _dataclass_field_base_reduce 

1202 

1203 dispatch_table = ChainMap(_dispatch_table, copyreg.dispatch_table) 

1204 

1205 # function reducers are defined as instance methods of cloudpickle.Pickler 

1206 # objects, as they rely on a cloudpickle.Pickler attribute (globals_ref) 

1207 def _dynamic_function_reduce(self, func): 

1208 """Reduce a function that is not pickleable via attribute lookup.""" 

1209 newargs = self._function_getnewargs(func) 

1210 state = _function_getstate(func) 

1211 return (_make_function, newargs, state, None, None, _function_setstate) 

1212 

1213 def _function_reduce(self, obj): 

1214 """Reducer for function objects. 

1215 

1216 If obj is a top-level attribute of a file-backed module, this reducer 

1217 returns NotImplemented, making the cloudpickle.Pickler fall back to 

1218 traditional pickle.Pickler routines to save obj. Otherwise, it reduces 

1219 obj using a custom cloudpickle reducer designed specifically to handle 

1220 dynamic functions. 

1221 """ 

1222 if _should_pickle_by_reference(obj): 

1223 return NotImplemented 

1224 else: 

1225 return self._dynamic_function_reduce(obj) 

1226 

1227 def _function_getnewargs(self, func): 

1228 code = func.__code__ 

1229 

1230 # base_globals represents the future global namespace of func at 

1231 # unpickling time. Looking it up and storing it in 

1232 # cloudpickle.Pickler.globals_ref allow functions sharing the same 

1233 # globals at pickling time to also share them once unpickled, at one 

1234 # condition: since globals_ref is an attribute of a cloudpickle.Pickler 

1235 # instance, and that a new cloudpickle.Pickler is created each time 

1236 # cloudpickle.dump or cloudpickle.dumps is called, functions also need 

1237 # to be saved within the same invocation of 

1238 # cloudpickle.dump/cloudpickle.dumps (for example: 

1239 # cloudpickle.dumps([f1, f2])). There is no such limitation when using 

1240 # cloudpickle.Pickler.dump, as long as the multiple invocations are 

1241 # bound to the same cloudpickle.Pickler instance. 

1242 base_globals = self.globals_ref.setdefault(id(func.__globals__), {}) 

1243 

1244 if base_globals == {}: 

1245 # Add module attributes used to resolve relative imports 

1246 # instructions inside func. 

1247 for k in ["__package__", "__name__", "__path__", "__file__"]: 

1248 if k in func.__globals__: 

1249 base_globals[k] = func.__globals__[k] 

1250 

1251 # Do not bind the free variables before the function is created to 

1252 # avoid infinite recursion. 

1253 if func.__closure__ is None: 

1254 closure = None 

1255 else: 

1256 closure = tuple(_make_empty_cell() for _ in range(len(code.co_freevars))) 

1257 

1258 return code, base_globals, None, None, closure 

1259 

1260 def dump(self, obj): 

1261 try: 

1262 return super().dump(obj) 

1263 except RuntimeError as e: 

1264 if len(e.args) > 0 and "recursion" in e.args[0]: 

1265 msg = "Could not pickle object as excessively deep recursion required." 

1266 raise pickle.PicklingError(msg) from e 

1267 else: 

1268 raise 

1269 

1270 def __init__(self, file, protocol=None, buffer_callback=None): 

1271 if protocol is None: 

1272 protocol = DEFAULT_PROTOCOL 

1273 super().__init__(file, protocol=protocol, buffer_callback=buffer_callback) 

1274 # map functions __globals__ attribute ids, to ensure that functions 

1275 # sharing the same global namespace at pickling time also share 

1276 # their global namespace at unpickling time. 

1277 self.globals_ref = {} 

1278 self.proto = int(protocol) 

1279 

1280 if not PYPY: 

1281 # pickle.Pickler is the C implementation of the CPython pickler and 

1282 # therefore we rely on reduce_override method to customize the pickler 

1283 # behavior. 

1284 

1285 # `cloudpickle.Pickler.dispatch` is only left for backward 

1286 # compatibility - note that when using protocol 5, 

1287 # `cloudpickle.Pickler.dispatch` is not an extension of 

1288 # `pickle._Pickler.dispatch` dictionary, because `cloudpickle.Pickler` 

1289 # subclasses the C-implemented `pickle.Pickler`, which does not expose 

1290 # a `dispatch` attribute. Earlier versions of `cloudpickle.Pickler` 

1291 # used `cloudpickle.Pickler.dispatch` as a class-level attribute 

1292 # storing all reducers implemented by cloudpickle, but the attribute 

1293 # name was not a great choice given because it would collide with a 

1294 # similarly named attribute in the pure-Python `pickle._Pickler` 

1295 # implementation in the standard library. 

1296 dispatch = dispatch_table 

1297 

1298 # Implementation of the reducer_override callback, in order to 

1299 # efficiently serialize dynamic functions and classes by subclassing 

1300 # the C-implemented `pickle.Pickler`. 

1301 # TODO: decorrelate reducer_override (which is tied to CPython's 

1302 # implementation - would it make sense to backport it to pypy? - and 

1303 # pickle's protocol 5 which is implementation agnostic. Currently, the 

1304 # availability of both notions coincide on CPython's pickle, but it may 

1305 # not be the case anymore when pypy implements protocol 5. 

1306 

1307 def reducer_override(self, obj): 

1308 """Type-agnostic reducing callback for function and classes. 

1309 

1310 For performance reasons, subclasses of the C `pickle.Pickler` class 

1311 cannot register custom reducers for functions and classes in the 

1312 dispatch_table attribute. Reducers for such types must instead 

1313 implemented via the special `reducer_override` method. 

1314 

1315 Note that this method will be called for any object except a few 

1316 builtin-types (int, lists, dicts etc.), which differs from reducers 

1317 in the Pickler's dispatch_table, each of them being invoked for 

1318 objects of a specific type only. 

1319 

1320 This property comes in handy for classes: although most classes are 

1321 instances of the ``type`` metaclass, some of them can be instances 

1322 of other custom metaclasses (such as enum.EnumMeta for example). In 

1323 particular, the metaclass will likely not be known in advance, and 

1324 thus cannot be special-cased using an entry in the dispatch_table. 

1325 reducer_override, among other things, allows us to register a 

1326 reducer that will be called for any class, independently of its 

1327 type. 

1328 

1329 Notes: 

1330 

1331 * reducer_override has the priority over dispatch_table-registered 

1332 reducers. 

1333 * reducer_override can be used to fix other limitations of 

1334 cloudpickle for other types that suffered from type-specific 

1335 reducers, such as Exceptions. See 

1336 https://github.com/cloudpipe/cloudpickle/issues/248 

1337 """ 

1338 t = type(obj) 

1339 try: 

1340 is_anyclass = issubclass(t, type) 

1341 except TypeError: # t is not a class (old Boost; see SF #502085) 

1342 is_anyclass = False 

1343 

1344 if is_anyclass: 

1345 return _class_reduce(obj) 

1346 elif isinstance(obj, types.FunctionType): 

1347 return self._function_reduce(obj) 

1348 else: 

1349 # fallback to save_global, including the Pickler's 

1350 # dispatch_table 

1351 return NotImplemented 

1352 

1353 else: 

1354 # When reducer_override is not available, hack the pure-Python 

1355 # Pickler's types.FunctionType and type savers. Note: the type saver 

1356 # must override Pickler.save_global, because pickle.py contains a 

1357 # hard-coded call to save_global when pickling meta-classes. 

1358 dispatch = pickle.Pickler.dispatch.copy() 

1359 

1360 def _save_reduce_pickle5( 

1361 self, 

1362 func, 

1363 args, 

1364 state=None, 

1365 listitems=None, 

1366 dictitems=None, 

1367 state_setter=None, 

1368 obj=None, 

1369 ): 

1370 save = self.save 

1371 write = self.write 

1372 self.save_reduce( 

1373 func, 

1374 args, 

1375 state=None, 

1376 listitems=listitems, 

1377 dictitems=dictitems, 

1378 obj=obj, 

1379 ) 

1380 # backport of the Python 3.8 state_setter pickle operations 

1381 save(state_setter) 

1382 save(obj) # simple BINGET opcode as obj is already memoized. 

1383 save(state) 

1384 write(pickle.TUPLE2) 

1385 # Trigger a state_setter(obj, state) function call. 

1386 write(pickle.REDUCE) 

1387 # The purpose of state_setter is to carry-out an 

1388 # inplace modification of obj. We do not care about what the 

1389 # method might return, so its output is eventually removed from 

1390 # the stack. 

1391 write(pickle.POP) 

1392 

1393 def save_global(self, obj, name=None, pack=struct.pack): 

1394 """Main dispatch method. 

1395 

1396 The name of this method is somewhat misleading: all types get 

1397 dispatched here. 

1398 """ 

1399 if obj is type(None): # noqa 

1400 return self.save_reduce(type, (None,), obj=obj) 

1401 elif obj is type(Ellipsis): 

1402 return self.save_reduce(type, (Ellipsis,), obj=obj) 

1403 elif obj is type(NotImplemented): 

1404 return self.save_reduce(type, (NotImplemented,), obj=obj) 

1405 elif obj in _BUILTIN_TYPE_NAMES: 

1406 return self.save_reduce( 

1407 _builtin_type, (_BUILTIN_TYPE_NAMES[obj],), obj=obj 

1408 ) 

1409 

1410 if name is not None: 

1411 super().save_global(obj, name=name) 

1412 elif not _should_pickle_by_reference(obj, name=name): 

1413 self._save_reduce_pickle5(*_dynamic_class_reduce(obj), obj=obj) 

1414 else: 

1415 super().save_global(obj, name=name) 

1416 

1417 dispatch[type] = save_global 

1418 

1419 def save_function(self, obj, name=None): 

1420 """Registered with the dispatch to handle all function types. 

1421 

1422 Determines what kind of function obj is (e.g. lambda, defined at 

1423 interactive prompt, etc) and handles the pickling appropriately. 

1424 """ 

1425 if _should_pickle_by_reference(obj, name=name): 

1426 return super().save_global(obj, name=name) 

1427 elif PYPY and isinstance(obj.__code__, builtin_code_type): 

1428 return self.save_pypy_builtin_func(obj) 

1429 else: 

1430 return self._save_reduce_pickle5( 

1431 *self._dynamic_function_reduce(obj), obj=obj 

1432 ) 

1433 

1434 def save_pypy_builtin_func(self, obj): 

1435 """Save pypy equivalent of builtin functions. 

1436 

1437 PyPy does not have the concept of builtin-functions. Instead, 

1438 builtin-functions are simple function instances, but with a 

1439 builtin-code attribute. 

1440 Most of the time, builtin functions should be pickled by attribute. 

1441 But PyPy has flaky support for __qualname__, so some builtin 

1442 functions such as float.__new__ will be classified as dynamic. For 

1443 this reason only, we created this special routine. Because 

1444 builtin-functions are not expected to have closure or globals, 

1445 there is no additional hack (compared the one already implemented 

1446 in pickle) to protect ourselves from reference cycles. A simple 

1447 (reconstructor, newargs, obj.__dict__) tuple is save_reduced. Note 

1448 also that PyPy improved their support for __qualname__ in v3.6, so 

1449 this routing should be removed when cloudpickle supports only PyPy 

1450 3.6 and later. 

1451 """ 

1452 rv = ( 

1453 types.FunctionType, 

1454 (obj.__code__, {}, obj.__name__, obj.__defaults__, obj.__closure__), 

1455 obj.__dict__, 

1456 ) 

1457 self.save_reduce(*rv, obj=obj) 

1458 

1459 dispatch[types.FunctionType] = save_function 

1460 

1461 

1462# Shorthands similar to pickle.dump/pickle.dumps 

1463 

1464 

1465def dump(obj, file, protocol=None, buffer_callback=None): 

1466 """Serialize obj as bytes streamed into file 

1467 

1468 protocol defaults to cloudpickle.DEFAULT_PROTOCOL which is an alias to 

1469 pickle.HIGHEST_PROTOCOL. This setting favors maximum communication 

1470 speed between processes running the same Python version. 

1471 

1472 Set protocol=pickle.DEFAULT_PROTOCOL instead if you need to ensure 

1473 compatibility with older versions of Python (although this is not always 

1474 guaranteed to work because cloudpickle relies on some internal 

1475 implementation details that can change from one Python version to the 

1476 next). 

1477 """ 

1478 Pickler(file, protocol=protocol, buffer_callback=buffer_callback).dump(obj) 

1479 

1480 

1481def dumps(obj, protocol=None, buffer_callback=None): 

1482 """Serialize obj as a string of bytes allocated in memory 

1483 

1484 protocol defaults to cloudpickle.DEFAULT_PROTOCOL which is an alias to 

1485 pickle.HIGHEST_PROTOCOL. This setting favors maximum communication 

1486 speed between processes running the same Python version. 

1487 

1488 Set protocol=pickle.DEFAULT_PROTOCOL instead if you need to ensure 

1489 compatibility with older versions of Python (although this is not always 

1490 guaranteed to work because cloudpickle relies on some internal 

1491 implementation details that can change from one Python version to the 

1492 next). 

1493 """ 

1494 with io.BytesIO() as file: 

1495 cp = Pickler(file, protocol=protocol, buffer_callback=buffer_callback) 

1496 cp.dump(obj) 

1497 return file.getvalue() 

1498 

1499 

1500# Include pickles unloading functions in this namespace for convenience. 

1501load, loads = pickle.load, pickle.loads 

1502 

1503# Backward compat alias. 

1504CloudPickler = Pickler