1 /* Ordered Dictionary object implementation.
2
3 This implementation is necessarily explicitly equivalent to the pure Python
4 OrderedDict class in Lib/collections/__init__.py. The strategy there
5 involves using a doubly-linked-list to capture the order. We keep to that
6 strategy, using a lower-level linked-list.
7
8 About the Linked-List
9 =====================
10
11 For the linked list we use a basic doubly-linked-list. Using a circularly-
12 linked-list does have some benefits, but they don't apply so much here
13 since OrderedDict is focused on the ends of the list (for the most part).
14 Furthermore, there are some features of generic linked-lists that we simply
15 don't need for OrderedDict. Thus a simple custom implementation meets our
16 needs. Alternatives to our simple approach include the QCIRCLE_*
17 macros from BSD's queue.h, and the linux's list.h.
18
19 Getting O(1) Node Lookup
20 ------------------------
21
22 One invariant of Python's OrderedDict is that it preserves time complexity
23 of dict's methods, particularly the O(1) operations. Simply adding a
24 linked-list on top of dict is not sufficient here; operations for nodes in
25 the middle of the linked-list implicitly require finding the node first.
26 With a simple linked-list like we're using, that is an O(n) operation.
27 Consequently, methods like __delitem__() would change from O(1) to O(n),
28 which is unacceptable.
29
30 In order to preserve O(1) performance for node removal (finding nodes), we
31 must do better than just looping through the linked-list. Here are options
32 we've considered:
33
34 1. use a second dict to map keys to nodes (a la the pure Python version).
35 2. keep a simple hash table mirroring the order of dict's, mapping each key
36 to the corresponding node in the linked-list.
37 3. use a version of shared keys (split dict) that allows non-unicode keys.
38 4. have the value stored for each key be a (value, node) pair, and adjust
39 __getitem__(), get(), etc. accordingly.
40
41 The approach with the least performance impact (time and space) is #2,
42 mirroring the key order of dict's dk_entries with an array of node pointers.
43 While _Py_dict_lookup() does not give us the index into the array,
44 we make use of pointer arithmetic to get that index. An alternative would
45 be to refactor _Py_dict_lookup() to provide the index, explicitly exposing
46 the implementation detail. We could even just use a custom lookup function
47 for OrderedDict that facilitates our need. However, both approaches are
48 significantly more complicated than just using pointer arithmetic.
49
50 The catch with mirroring the hash table ordering is that we have to keep
51 the ordering in sync through any dict resizes. However, that order only
52 matters during node lookup. We can simply defer any potential resizing
53 until we need to do a lookup.
54
55 Linked-List Nodes
56 -----------------
57
58 The current implementation stores a pointer to the associated key only.
59 One alternative would be to store a pointer to the PyDictKeyEntry instead.
60 This would save one pointer de-reference per item, which is nice during
61 calls to values() and items(). However, it adds unnecessary overhead
62 otherwise, so we stick with just the key.
63
64 Linked-List API
65 ---------------
66
67 As noted, the linked-list implemented here does not have all the bells and
68 whistles. However, we recognize that the implementation may need to
69 change to accommodate performance improvements or extra functionality. To
70 that end, we use a simple API to interact with the linked-list. Here's a
71 summary of the methods/macros:
72
73 Node info:
74
75 * _odictnode_KEY(node)
76 * _odictnode_VALUE(od, node)
77 * _odictnode_PREV(node)
78 * _odictnode_NEXT(node)
79
80 Linked-List info:
81
82 * _odict_FIRST(od)
83 * _odict_LAST(od)
84 * _odict_EMPTY(od)
85 * _odict_FOREACH(od, node) - used in place of `for (node=...)`
86
87 For adding nodes:
88
89 * _odict_add_head(od, node)
90 * _odict_add_tail(od, node)
91 * _odict_add_new_node(od, key, hash)
92
93 For removing nodes:
94
95 * _odict_clear_node(od, node, key, hash)
96 * _odict_clear_nodes(od, clear_each)
97
98 Others:
99
100 * _odict_find_node_hash(od, key, hash)
101 * _odict_find_node(od, key)
102 * _odict_keys_equal(od1, od2)
103
104 And here's a look at how the linked-list relates to the OrderedDict API:
105
106 ============ === === ==== ==== ==== === ==== ===== ==== ==== === ==== === ===
107 method key val prev next mem 1st last empty iter find add rmv clr keq
108 ============ === === ==== ==== ==== === ==== ===== ==== ==== === ==== === ===
109 __del__ ~ X
110 __delitem__ free ~ node
111 __eq__ ~ X
112 __iter__ X X
113 __new__ X X
114 __reduce__ X ~ X
115 __repr__ X X X
116 __reversed__ X X
117 __setitem__ key
118 __sizeof__ size X
119 clear ~ ~ X
120 copy X X X
121 items X X X
122 keys X X
123 move_to_end X X X ~ h/t key
124 pop free key
125 popitem X X free X X node
126 setdefault ~ ? ~
127 values X X
128 ============ === === ==== ==== ==== === ==== ===== ==== ==== === ==== === ===
129
130 __delitem__ is the only method that directly relies on finding an arbitrary
131 node in the linked-list. Everything else is iteration or relates to the
132 ends of the linked-list.
133
134 Situation that Endangers Consistency
135 ------------------------------------
136 Using a raw linked-list for OrderedDict exposes a key situation that can
137 cause problems. If a node is stored in a variable, there is a chance that
138 the node may have been deallocated before the variable gets used, thus
139 potentially leading to a segmentation fault. A key place where this shows
140 up is during iteration through the linked list (via _odict_FOREACH or
141 otherwise).
142
143 A number of solutions are available to resolve this situation:
144
145 * defer looking up the node until as late as possible and certainly after
146 any code that could possibly result in a deletion;
147 * if the node is needed both before and after a point where the node might
148 be removed, do a check before using the node at the "after" location to
149 see if the node is still valid;
150 * like the last one, but simply pull the node again to ensure it's right;
151 * keep the key in the variable instead of the node and then look up the
152 node using the key at the point where the node is needed (this is what
153 we do for the iterators).
154
155 Another related problem, preserving consistent ordering during iteration,
156 is described below. That one is not exclusive to using linked-lists.
157
158
159 Challenges from Subclassing dict
160 ================================
161
162 OrderedDict subclasses dict, which is an unusual relationship between two
163 builtin types (other than the base object type). Doing so results in
164 some complication and deserves further explanation. There are two things
165 to consider here. First, in what circumstances or with what adjustments
166 can OrderedDict be used as a drop-in replacement for dict (at the C level)?
167 Second, how can the OrderedDict implementation leverage the dict
168 implementation effectively without introducing unnecessary coupling or
169 inefficiencies?
170
171 This second point is reflected here and in the implementation, so the
172 further focus is on the first point. It is worth noting that for
173 overridden methods, the dict implementation is deferred to as much as
174 possible. Furthermore, coupling is limited to as little as is reasonable.
175
176 Concrete API Compatibility
177 --------------------------
178
179 Use of the concrete C-API for dict (PyDict_*) with OrderedDict is
180 problematic. (See http://bugs.python.org/issue10977.) The concrete API
181 has a number of hard-coded assumptions tied to the dict implementation.
182 This is, in part, due to performance reasons, which is understandable
183 given the part dict plays in Python.
184
185 Any attempt to replace dict with OrderedDict for any role in the
186 interpreter (e.g. **kwds) faces a challenge. Such any effort must
187 recognize that the instances in affected locations currently interact with
188 the concrete API.
189
190 Here are some ways to address this challenge:
191
192 1. Change the relevant usage of the concrete API in CPython and add
193 PyDict_CheckExact() calls to each of the concrete API functions.
194 2. Adjust the relevant concrete API functions to explicitly accommodate
195 OrderedDict.
196 3. As with #1, add the checks, but improve the abstract API with smart fast
197 paths for dict and OrderedDict, and refactor CPython to use the abstract
198 API. Improvements to the abstract API would be valuable regardless.
199
200 Adding the checks to the concrete API would help make any interpreter
201 switch to OrderedDict less painful for extension modules. However, this
202 won't work. The equivalent C API call to `dict.__setitem__(obj, k, v)`
203 is 'PyDict_SetItem(obj, k, v)`. This illustrates how subclasses in C call
204 the base class's methods, since there is no equivalent of super() in the
205 C API. Calling into Python for parent class API would work, but some
206 extension modules already rely on this feature of the concrete API.
207
208 For reference, here is a breakdown of some of the dict concrete API:
209
210 ========================== ============= =======================
211 concrete API uses abstract API
212 ========================== ============= =======================
213 PyDict_Check PyMapping_Check
214 (PyDict_CheckExact) -
215 (PyDict_New) -
216 (PyDictProxy_New) -
217 PyDict_Clear -
218 PyDict_Contains PySequence_Contains
219 PyDict_Copy -
220 PyDict_SetItem PyObject_SetItem
221 PyDict_SetItemString PyMapping_SetItemString
222 PyDict_DelItem PyMapping_DelItem
223 PyDict_DelItemString PyMapping_DelItemString
224 PyDict_GetItem -
225 PyDict_GetItemWithError PyObject_GetItem
226 _PyDict_GetItemIdWithError -
227 PyDict_GetItemString PyMapping_GetItemString
228 PyDict_Items PyMapping_Items
229 PyDict_Keys PyMapping_Keys
230 PyDict_Values PyMapping_Values
231 PyDict_Size PyMapping_Size
232 PyMapping_Length
233 PyDict_Next PyIter_Next
234 _PyDict_Next -
235 PyDict_Merge -
236 PyDict_Update -
237 PyDict_MergeFromSeq2 -
238 PyDict_ClearFreeList -
239 - PyMapping_HasKeyString
240 - PyMapping_HasKey
241 ========================== ============= =======================
242
243
244 The dict Interface Relative to OrderedDict
245 ==========================================
246
247 Since OrderedDict subclasses dict, understanding the various methods and
248 attributes of dict is important for implementing OrderedDict.
249
250 Relevant Type Slots
251 -------------------
252
253 ================= ================ =================== ================
254 slot attribute object dict
255 ================= ================ =================== ================
256 tp_dealloc - object_dealloc dict_dealloc
257 tp_repr __repr__ object_repr dict_repr
258 sq_contains __contains__ - dict_contains
259 mp_length __len__ - dict_length
260 mp_subscript __getitem__ - dict_subscript
261 mp_ass_subscript __setitem__ - dict_ass_sub
262 __delitem__
263 tp_hash __hash__ _Py_HashPointer ..._HashNotImpl
264 tp_str __str__ object_str -
265 tp_getattro __getattribute__ ..._GenericGetAttr (repeated)
266 __getattr__
267 tp_setattro __setattr__ ..._GenericSetAttr (disabled)
268 tp_doc __doc__ (literal) dictionary_doc
269 tp_traverse - - dict_traverse
270 tp_clear - - dict_tp_clear
271 tp_richcompare __eq__ object_richcompare dict_richcompare
272 __ne__
273 tp_weaklistoffset (__weakref__) - -
274 tp_iter __iter__ - dict_iter
275 tp_dictoffset (__dict__) - -
276 tp_init __init__ object_init dict_init
277 tp_alloc - PyType_GenericAlloc (repeated)
278 tp_new __new__ object_new dict_new
279 tp_free - PyObject_Del PyObject_GC_Del
280 ================= ================ =================== ================
281
282 Relevant Methods
283 ----------------
284
285 ================ =================== ===============
286 method object dict
287 ================ =================== ===============
288 __reduce__ object_reduce -
289 __sizeof__ object_sizeof dict_sizeof
290 clear - dict_clear
291 copy - dict_copy
292 fromkeys - dict_fromkeys
293 get - dict_get
294 items - dictitems_new
295 keys - dictkeys_new
296 pop - dict_pop
297 popitem - dict_popitem
298 setdefault - dict_setdefault
299 update - dict_update
300 values - dictvalues_new
301 ================ =================== ===============
302
303
304 Pure Python OrderedDict
305 =======================
306
307 As already noted, compatibility with the pure Python OrderedDict
308 implementation is a key goal of this C implementation. To further that
309 goal, here's a summary of how OrderedDict-specific methods are implemented
310 in collections/__init__.py. Also provided is an indication of which
311 methods directly mutate or iterate the object, as well as any relationship
312 with the underlying linked-list.
313
314 ============= ============== == ================ === === ====
315 method impl used ll uses inq mut iter
316 ============= ============== == ================ === === ====
317 __contains__ dict - - X
318 __delitem__ OrderedDict Y dict.__delitem__ X
319 __eq__ OrderedDict N OrderedDict ~
320 dict.__eq__
321 __iter__
322 __getitem__ dict - - X
323 __iter__ OrderedDict Y - X
324 __init__ OrderedDict N update
325 __len__ dict - - X
326 __ne__ MutableMapping - __eq__ ~
327 __reduce__ OrderedDict N OrderedDict ~
328 __iter__
329 __getitem__
330 __repr__ OrderedDict N __class__ ~
331 items
332 __reversed__ OrderedDict Y - X
333 __setitem__ OrderedDict Y __contains__ X
334 dict.__setitem__
335 __sizeof__ OrderedDict Y __len__ ~
336 __dict__
337 clear OrderedDict Y dict.clear X
338 copy OrderedDict N __class__
339 __init__
340 fromkeys OrderedDict N __setitem__
341 get dict - - ~
342 items MutableMapping - ItemsView X
343 keys MutableMapping - KeysView X
344 move_to_end OrderedDict Y - X
345 pop OrderedDict N __contains__ X
346 __getitem__
347 __delitem__
348 popitem OrderedDict Y dict.pop X
349 setdefault OrderedDict N __contains__ ~
350 __getitem__
351 __setitem__
352 update MutableMapping - __setitem__ ~
353 values MutableMapping - ValuesView X
354 ============= ============== == ================ === === ====
355
356 __reversed__ and move_to_end are both exclusive to OrderedDict.
357
358
359 C OrderedDict Implementation
360 ============================
361
362 ================= ================
363 slot impl
364 ================= ================
365 tp_dealloc odict_dealloc
366 tp_repr odict_repr
367 mp_ass_subscript odict_ass_sub
368 tp_doc odict_doc
369 tp_traverse odict_traverse
370 tp_clear odict_tp_clear
371 tp_richcompare odict_richcompare
372 tp_weaklistoffset (offset)
373 tp_iter odict_iter
374 tp_dictoffset (offset)
375 tp_init odict_init
376 tp_alloc (repeated)
377 ================= ================
378
379 ================= ================
380 method impl
381 ================= ================
382 __reduce__ odict_reduce
383 __sizeof__ odict_sizeof
384 clear odict_clear
385 copy odict_copy
386 fromkeys odict_fromkeys
387 items odictitems_new
388 keys odictkeys_new
389 pop odict_pop
390 popitem odict_popitem
391 setdefault odict_setdefault
392 update odict_update
393 values odictvalues_new
394 ================= ================
395
396 Inherited unchanged from object/dict:
397
398 ================ ==========================
399 method type field
400 ================ ==========================
401 - tp_free
402 __contains__ tp_as_sequence.sq_contains
403 __getattr__ tp_getattro
404 __getattribute__ tp_getattro
405 __getitem__ tp_as_mapping.mp_subscript
406 __hash__ tp_hash
407 __len__ tp_as_mapping.mp_length
408 __setattr__ tp_setattro
409 __str__ tp_str
410 get -
411 ================ ==========================
412
413
414 Other Challenges
415 ================
416
417 Preserving Ordering During Iteration
418 ------------------------------------
419 During iteration through an OrderedDict, it is possible that items could
420 get added, removed, or reordered. For a linked-list implementation, as
421 with some other implementations, that situation may lead to undefined
422 behavior. The documentation for dict mentions this in the `iter()` section
423 of http://docs.python.org/3.4/library/stdtypes.html#dictionary-view-objects.
424 In this implementation we follow dict's lead (as does the pure Python
425 implementation) for __iter__(), keys(), values(), and items().
426
427 For internal iteration (using _odict_FOREACH or not), there is still the
428 risk that not all nodes that we expect to be seen in the loop actually get
429 seen. Thus, we are careful in each of those places to ensure that they
430 are. This comes, of course, at a small price at each location. The
431 solutions are much the same as those detailed in the `Situation that
432 Endangers Consistency` section above.
433
434
435 Potential Optimizations
436 =======================
437
438 * Allocate the nodes as a block via od_fast_nodes instead of individually.
439 - Set node->key to NULL to indicate the node is not-in-use.
440 - Add _odict_EXISTS()?
441 - How to maintain consistency across resizes? Existing node pointers
442 would be invalidated after a resize, which is particularly problematic
443 for the iterators.
444 * Use a more stream-lined implementation of update() and, likely indirectly,
445 __init__().
446
447 */
448
449 /* TODO
450
451 sooner:
452 - reentrancy (make sure everything is at a thread-safe state when calling
453 into Python). I've already checked this multiple times, but want to
454 make one more pass.
455 - add unit tests for reentrancy?
456
457 later:
458 - make the dict views support the full set API (the pure Python impl does)
459 - implement a fuller MutableMapping API in C?
460 - move the MutableMapping implementation to abstract.c?
461 - optimize mutablemapping_update
462 - use PyObject_Malloc (small object allocator) for odict nodes?
463 - support subclasses better (e.g. in odict_richcompare)
464
465 */
466
467 #include "Python.h"
468 #include "pycore_call.h" // _PyObject_CallNoArgs()
469 #include "pycore_object.h" // _PyObject_GC_UNTRACK()
470 #include "pycore_dict.h" // _Py_dict_lookup()
471 #include <stddef.h> // offsetof()
472
473 #include "clinic/odictobject.c.h"
474
475 /*[clinic input]
476 class OrderedDict "PyODictObject *" "&PyODict_Type"
477 [clinic start generated code]*/
478 /*[clinic end generated code: output=da39a3ee5e6b4b0d input=ca0641cf6143d4af]*/
479
480
481 typedef struct _odictnode _ODictNode;
482
483 /* PyODictObject */
484 struct _odictobject {
485 PyDictObject od_dict; /* the underlying dict */
486 _ODictNode *od_first; /* first node in the linked list, if any */
487 _ODictNode *od_last; /* last node in the linked list, if any */
488 /* od_fast_nodes, od_fast_nodes_size and od_resize_sentinel are managed
489 * by _odict_resize().
490 * Note that we rely on implementation details of dict for both. */
491 _ODictNode **od_fast_nodes; /* hash table that mirrors the dict table */
492 Py_ssize_t od_fast_nodes_size;
493 void *od_resize_sentinel; /* changes if odict should be resized */
494
495 size_t od_state; /* incremented whenever the LL changes */
496 PyObject *od_inst_dict; /* OrderedDict().__dict__ */
497 PyObject *od_weakreflist; /* holds weakrefs to the odict */
498 };
499
500
501 /* ----------------------------------------------
502 * odict keys (a simple doubly-linked list)
503 */
504
505 struct _odictnode {
506 PyObject *key;
507 Py_hash_t hash;
508 _ODictNode *next;
509 _ODictNode *prev;
510 };
511
512 #define _odictnode_KEY(node) \
513 (node->key)
514 #define _odictnode_HASH(node) \
515 (node->hash)
516 /* borrowed reference */
517 #define _odictnode_VALUE(node, od) \
518 PyODict_GetItemWithError((PyObject *)od, _odictnode_KEY(node))
519 #define _odictnode_PREV(node) (node->prev)
520 #define _odictnode_NEXT(node) (node->next)
521
522 #define _odict_FIRST(od) (((PyODictObject *)od)->od_first)
523 #define _odict_LAST(od) (((PyODictObject *)od)->od_last)
524 #define _odict_EMPTY(od) (_odict_FIRST(od) == NULL)
525 #define _odict_FOREACH(od, node) \
526 for (node = _odict_FIRST(od); node != NULL; node = _odictnode_NEXT(node))
527
528 /* Return the index into the hash table, regardless of a valid node. */
529 static Py_ssize_t
530 _odict_get_index_raw(PyODictObject *od, PyObject *key, Py_hash_t hash)
531 {
532 PyObject *value = NULL;
533 PyDictKeysObject *keys = ((PyDictObject *)od)->ma_keys;
534 Py_ssize_t ix;
535
536 ix = _Py_dict_lookup((PyDictObject *)od, key, hash, &value);
537 if (ix == DKIX_EMPTY) {
538 return keys->dk_nentries; /* index of new entry */
539 }
540 if (ix < 0)
541 return -1;
542 /* We use pointer arithmetic to get the entry's index into the table. */
543 return ix;
544 }
545
546 #define ONE ((Py_ssize_t)1)
547
548 /* Replace od->od_fast_nodes with a new table matching the size of dict's. */
549 static int
550 _odict_resize(PyODictObject *od)
551 {
552 Py_ssize_t size, i;
553 _ODictNode **fast_nodes, *node;
554
555 /* Initialize a new "fast nodes" table. */
556 size = ONE << (((PyDictObject *)od)->ma_keys->dk_log2_size);
557 fast_nodes = PyMem_NEW(_ODictNode *, size);
558 if (fast_nodes == NULL) {
559 PyErr_NoMemory();
560 return -1;
561 }
562 for (i = 0; i < size; i++)
563 fast_nodes[i] = NULL;
564
565 /* Copy the current nodes into the table. */
566 _odict_FOREACH(od, node) {
567 i = _odict_get_index_raw(od, _odictnode_KEY(node),
568 _odictnode_HASH(node));
569 if (i < 0) {
570 PyMem_Free(fast_nodes);
571 return -1;
572 }
573 fast_nodes[i] = node;
574 }
575
576 /* Replace the old fast nodes table. */
577 PyMem_Free(od->od_fast_nodes);
578 od->od_fast_nodes = fast_nodes;
579 od->od_fast_nodes_size = size;
580 od->od_resize_sentinel = ((PyDictObject *)od)->ma_keys;
581 return 0;
582 }
583
584 /* Return the index into the hash table, regardless of a valid node. */
585 static Py_ssize_t
586 _odict_get_index(PyODictObject *od, PyObject *key, Py_hash_t hash)
587 {
588 PyDictKeysObject *keys;
589
590 assert(key != NULL);
591 keys = ((PyDictObject *)od)->ma_keys;
592
593 /* Ensure od_fast_nodes and dk_entries are in sync. */
594 if (od->od_resize_sentinel != keys ||
595 od->od_fast_nodes_size != (ONE << (keys->dk_log2_size))) {
596 int resize_res = _odict_resize(od);
597 if (resize_res < 0)
598 return -1;
599 }
600
601 return _odict_get_index_raw(od, key, hash);
602 }
603
604 /* Returns NULL if there was some error or the key was not found. */
605 static _ODictNode *
606 _odict_find_node_hash(PyODictObject *od, PyObject *key, Py_hash_t hash)
607 {
608 Py_ssize_t index;
609
610 if (_odict_EMPTY(od))
611 return NULL;
612 index = _odict_get_index(od, key, hash);
613 if (index < 0)
614 return NULL;
615 assert(od->od_fast_nodes != NULL);
616 return od->od_fast_nodes[index];
617 }
618
619 static _ODictNode *
620 _odict_find_node(PyODictObject *od, PyObject *key)
621 {
622 Py_ssize_t index;
623 Py_hash_t hash;
624
625 if (_odict_EMPTY(od))
626 return NULL;
627 hash = PyObject_Hash(key);
628 if (hash == -1)
629 return NULL;
630 index = _odict_get_index(od, key, hash);
631 if (index < 0)
632 return NULL;
633 assert(od->od_fast_nodes != NULL);
634 return od->od_fast_nodes[index];
635 }
636
637 static void
638 _odict_add_head(PyODictObject *od, _ODictNode *node)
639 {
640 _odictnode_PREV(node) = NULL;
641 _odictnode_NEXT(node) = _odict_FIRST(od);
642 if (_odict_FIRST(od) == NULL)
643 _odict_LAST(od) = node;
644 else
645 _odictnode_PREV(_odict_FIRST(od)) = node;
646 _odict_FIRST(od) = node;
647 od->od_state++;
648 }
649
650 static void
651 _odict_add_tail(PyODictObject *od, _ODictNode *node)
652 {
653 _odictnode_PREV(node) = _odict_LAST(od);
654 _odictnode_NEXT(node) = NULL;
655 if (_odict_LAST(od) == NULL)
656 _odict_FIRST(od) = node;
657 else
658 _odictnode_NEXT(_odict_LAST(od)) = node;
659 _odict_LAST(od) = node;
660 od->od_state++;
661 }
662
663 /* adds the node to the end of the list */
664 static int
665 _odict_add_new_node(PyODictObject *od, PyObject *key, Py_hash_t hash)
666 {
667 Py_ssize_t i;
668 _ODictNode *node;
669
670 Py_INCREF(key);
671 i = _odict_get_index(od, key, hash);
672 if (i < 0) {
673 if (!PyErr_Occurred())
674 PyErr_SetObject(PyExc_KeyError, key);
675 Py_DECREF(key);
676 return -1;
677 }
678 assert(od->od_fast_nodes != NULL);
679 if (od->od_fast_nodes[i] != NULL) {
680 /* We already have a node for the key so there's no need to add one. */
681 Py_DECREF(key);
682 return 0;
683 }
684
685 /* must not be added yet */
686 node = (_ODictNode *)PyMem_Malloc(sizeof(_ODictNode));
687 if (node == NULL) {
688 Py_DECREF(key);
689 PyErr_NoMemory();
690 return -1;
691 }
692
693 _odictnode_KEY(node) = key;
694 _odictnode_HASH(node) = hash;
695 _odict_add_tail(od, node);
696 od->od_fast_nodes[i] = node;
697 return 0;
698 }
699
700 /* Putting the decref after the free causes problems. */
701 #define _odictnode_DEALLOC(node) \
702 do { \
703 Py_DECREF(_odictnode_KEY(node)); \
704 PyMem_Free((void *)node); \
705 } while (0)
706
707 /* Repeated calls on the same node are no-ops. */
708 static void
709 _odict_remove_node(PyODictObject *od, _ODictNode *node)
710 {
711 if (_odict_FIRST(od) == node)
712 _odict_FIRST(od) = _odictnode_NEXT(node);
713 else if (_odictnode_PREV(node) != NULL)
714 _odictnode_NEXT(_odictnode_PREV(node)) = _odictnode_NEXT(node);
715
716 if (_odict_LAST(od) == node)
717 _odict_LAST(od) = _odictnode_PREV(node);
718 else if (_odictnode_NEXT(node) != NULL)
719 _odictnode_PREV(_odictnode_NEXT(node)) = _odictnode_PREV(node);
720
721 _odictnode_PREV(node) = NULL;
722 _odictnode_NEXT(node) = NULL;
723 od->od_state++;
724 }
725
726 /* If someone calls PyDict_DelItem() directly on an OrderedDict, we'll
727 get all sorts of problems here. In PyODict_DelItem we make sure to
728 call _odict_clear_node first.
729
730 This matters in the case of colliding keys. Suppose we add 3 keys:
731 [A, B, C], where the hash of C collides with A and the next possible
732 index in the hash table is occupied by B. If we remove B then for C
733 the dict's looknode func will give us the old index of B instead of
734 the index we got before deleting B. However, the node for C in
735 od_fast_nodes is still at the old dict index of C. Thus to be sure
736 things don't get out of sync, we clear the node in od_fast_nodes
737 *before* calling PyDict_DelItem.
738
739 The same must be done for any other OrderedDict operations where
740 we modify od_fast_nodes.
741 */
742 static int
743 _odict_clear_node(PyODictObject *od, _ODictNode *node, PyObject *key,
744 Py_hash_t hash)
745 {
746 Py_ssize_t i;
747
748 assert(key != NULL);
749 if (_odict_EMPTY(od)) {
750 /* Let later code decide if this is a KeyError. */
751 return 0;
752 }
753
754 i = _odict_get_index(od, key, hash);
755 if (i < 0)
756 return PyErr_Occurred() ? -1 : 0;
757
758 assert(od->od_fast_nodes != NULL);
759 if (node == NULL)
760 node = od->od_fast_nodes[i];
761 assert(node == od->od_fast_nodes[i]);
762 if (node == NULL) {
763 /* Let later code decide if this is a KeyError. */
764 return 0;
765 }
766
767 // Now clear the node.
768 od->od_fast_nodes[i] = NULL;
769 _odict_remove_node(od, node);
770 _odictnode_DEALLOC(node);
771 return 0;
772 }
773
774 static void
775 _odict_clear_nodes(PyODictObject *od)
776 {
777 _ODictNode *node, *next;
778
779 PyMem_Free(od->od_fast_nodes);
780 od->od_fast_nodes = NULL;
781 od->od_fast_nodes_size = 0;
782 od->od_resize_sentinel = NULL;
783
784 node = _odict_FIRST(od);
785 _odict_FIRST(od) = NULL;
786 _odict_LAST(od) = NULL;
787 while (node != NULL) {
788 next = _odictnode_NEXT(node);
789 _odictnode_DEALLOC(node);
790 node = next;
791 }
792 }
793
794 /* There isn't any memory management of nodes past this point. */
795 #undef _odictnode_DEALLOC
796
797 static int
798 _odict_keys_equal(PyODictObject *a, PyODictObject *b)
799 {
800 _ODictNode *node_a, *node_b;
801
802 node_a = _odict_FIRST(a);
803 node_b = _odict_FIRST(b);
804 while (1) {
805 if (node_a == NULL && node_b == NULL)
806 /* success: hit the end of each at the same time */
807 return 1;
808 else if (node_a == NULL || node_b == NULL)
809 /* unequal length */
810 return 0;
811 else {
812 int res = PyObject_RichCompareBool(
813 (PyObject *)_odictnode_KEY(node_a),
814 (PyObject *)_odictnode_KEY(node_b),
815 Py_EQ);
816 if (res < 0)
817 return res;
818 else if (res == 0)
819 return 0;
820
821 /* otherwise it must match, so move on to the next one */
822 node_a = _odictnode_NEXT(node_a);
823 node_b = _odictnode_NEXT(node_b);
824 }
825 }
826 }
827
828
829 /* ----------------------------------------------
830 * OrderedDict mapping methods
831 */
832
833 /* mp_ass_subscript: __setitem__() and __delitem__() */
834
835 static int
836 odict_mp_ass_sub(PyODictObject *od, PyObject *v, PyObject *w)
837 {
838 if (w == NULL)
839 return PyODict_DelItem((PyObject *)od, v);
840 else
841 return PyODict_SetItem((PyObject *)od, v, w);
842 }
843
844 /* tp_as_mapping */
845
846 static PyMappingMethods odict_as_mapping = {
847 0, /*mp_length*/
848 0, /*mp_subscript*/
849 (objobjargproc)odict_mp_ass_sub, /*mp_ass_subscript*/
850 };
851
852
853 /* ----------------------------------------------
854 * OrderedDict number methods
855 */
856
857 static int mutablemapping_update_arg(PyObject*, PyObject*);
858
859 static PyObject *
860 odict_or(PyObject *left, PyObject *right)
861 {
862 PyTypeObject *type;
863 PyObject *other;
864 if (PyODict_Check(left)) {
865 type = Py_TYPE(left);
866 other = right;
867 }
868 else {
869 type = Py_TYPE(right);
870 other = left;
871 }
872 if (!PyDict_Check(other)) {
873 Py_RETURN_NOTIMPLEMENTED;
874 }
875 PyObject *new = PyObject_CallOneArg((PyObject*)type, left);
876 if (!new) {
877 return NULL;
878 }
879 if (mutablemapping_update_arg(new, right) < 0) {
880 Py_DECREF(new);
881 return NULL;
882 }
883 return new;
884 }
885
886 static PyObject *
887 odict_inplace_or(PyObject *self, PyObject *other)
888 {
889 if (mutablemapping_update_arg(self, other) < 0) {
890 return NULL;
891 }
892 Py_INCREF(self);
893 return self;
894 }
895
896 /* tp_as_number */
897
898 static PyNumberMethods odict_as_number = {
899 .nb_or = odict_or,
900 .nb_inplace_or = odict_inplace_or,
901 };
902
903
904 /* ----------------------------------------------
905 * OrderedDict methods
906 */
907
908 /* fromkeys() */
909
910 /*[clinic input]
911 @classmethod
912 OrderedDict.fromkeys
913
914 iterable as seq: object
915 value: object = None
916
917 Create a new ordered dictionary with keys from iterable and values set to value.
918 [clinic start generated code]*/
919
920 static PyObject *
921 OrderedDict_fromkeys_impl(PyTypeObject *type, PyObject *seq, PyObject *value)
922 /*[clinic end generated code: output=c10390d452d78d6d input=1a0476c229c597b3]*/
923 {
924 return _PyDict_FromKeys((PyObject *)type, seq, value);
925 }
926
927 /* __sizeof__() */
928
929 /* OrderedDict.__sizeof__() does not have a docstring. */
930 PyDoc_STRVAR(odict_sizeof__doc__, "");
931
932 static PyObject *
933 odict_sizeof(PyODictObject *od, PyObject *Py_UNUSED(ignored))
934 {
935 Py_ssize_t res = _PyDict_SizeOf((PyDictObject *)od);
936 res += sizeof(_ODictNode *) * od->od_fast_nodes_size; /* od_fast_nodes */
937 if (!_odict_EMPTY(od)) {
938 res += sizeof(_ODictNode) * PyODict_SIZE(od); /* linked-list */
939 }
940 return PyLong_FromSsize_t(res);
941 }
942
943 /* __reduce__() */
944
945 PyDoc_STRVAR(odict_reduce__doc__, "Return state information for pickling");
946
947 static PyObject *
948 odict_reduce(register PyODictObject *od, PyObject *Py_UNUSED(ignored))
949 {
950 PyObject *state, *result = NULL;
951 PyObject *items_iter, *items, *args = NULL;
952
953 /* capture any instance state */
954 state = _PyObject_GetState((PyObject *)od);
955 if (state == NULL)
956 goto Done;
957
958 /* build the result */
959 args = PyTuple_New(0);
960 if (args == NULL)
961 goto Done;
962
963 items = PyObject_CallMethodNoArgs((PyObject *)od, &_Py_ID(items));
964 if (items == NULL)
965 goto Done;
966
967 items_iter = PyObject_GetIter(items);
968 Py_DECREF(items);
969 if (items_iter == NULL)
970 goto Done;
971
972 result = PyTuple_Pack(5, Py_TYPE(od), args, state, Py_None, items_iter);
973 Py_DECREF(items_iter);
974
975 Done:
976 Py_XDECREF(state);
977 Py_XDECREF(args);
978
979 return result;
980 }
981
982 /* setdefault(): Skips __missing__() calls. */
983
984
985 /*[clinic input]
986 OrderedDict.setdefault
987
988 key: object
989 default: object = None
990
991 Insert key with a value of default if key is not in the dictionary.
992
993 Return the value for key if key is in the dictionary, else default.
994 [clinic start generated code]*/
995
996 static PyObject *
997 OrderedDict_setdefault_impl(PyODictObject *self, PyObject *key,
998 PyObject *default_value)
999 /*[clinic end generated code: output=97537cb7c28464b6 input=38e098381c1efbc6]*/
1000 {
1001 PyObject *result = NULL;
1002
1003 if (PyODict_CheckExact(self)) {
1004 result = PyODict_GetItemWithError(self, key); /* borrowed */
1005 if (result == NULL) {
1006 if (PyErr_Occurred())
1007 return NULL;
1008 assert(_odict_find_node(self, key) == NULL);
1009 if (PyODict_SetItem((PyObject *)self, key, default_value) >= 0) {
1010 result = default_value;
1011 Py_INCREF(result);
1012 }
1013 }
1014 else {
1015 Py_INCREF(result);
1016 }
1017 }
1018 else {
1019 int exists = PySequence_Contains((PyObject *)self, key);
1020 if (exists < 0) {
1021 return NULL;
1022 }
1023 else if (exists) {
1024 result = PyObject_GetItem((PyObject *)self, key);
1025 }
1026 else if (PyObject_SetItem((PyObject *)self, key, default_value) >= 0) {
1027 result = default_value;
1028 Py_INCREF(result);
1029 }
1030 }
1031
1032 return result;
1033 }
1034
1035 /* pop() */
1036
1037 static PyObject *
1038 _odict_popkey_hash(PyObject *od, PyObject *key, PyObject *failobj,
1039 Py_hash_t hash)
1040 {
1041 PyObject *value = NULL;
1042
1043 _ODictNode *node = _odict_find_node_hash((PyODictObject *)od, key, hash);
1044 if (node != NULL) {
1045 /* Pop the node first to avoid a possible dict resize (due to
1046 eval loop reentrancy) and complications due to hash collision
1047 resolution. */
1048 int res = _odict_clear_node((PyODictObject *)od, node, key, hash);
1049 if (res < 0) {
1050 return NULL;
1051 }
1052 /* Now delete the value from the dict. */
1053 value = _PyDict_Pop_KnownHash(od, key, hash, failobj);
1054 }
1055 else if (value == NULL && !PyErr_Occurred()) {
1056 /* Apply the fallback value, if necessary. */
1057 if (failobj) {
1058 value = failobj;
1059 Py_INCREF(failobj);
1060 }
1061 else {
1062 PyErr_SetObject(PyExc_KeyError, key);
1063 }
1064 }
1065
1066 return value;
1067 }
1068
1069 /* Skips __missing__() calls. */
1070 /*[clinic input]
1071 OrderedDict.pop
1072
1073 key: object
1074 default: object = NULL
1075
1076 od.pop(key[,default]) -> v, remove specified key and return the corresponding value.
1077
1078 If the key is not found, return the default if given; otherwise,
1079 raise a KeyError.
1080 [clinic start generated code]*/
1081
1082 static PyObject *
1083 OrderedDict_pop_impl(PyODictObject *self, PyObject *key,
1084 PyObject *default_value)
1085 /*[clinic end generated code: output=7a6447d104e7494b input=7efe36601007dff7]*/
1086 {
1087 Py_hash_t hash = PyObject_Hash(key);
1088 if (hash == -1)
1089 return NULL;
1090 return _odict_popkey_hash((PyObject *)self, key, default_value, hash);
1091 }
1092
1093
1094 /* popitem() */
1095
1096 /*[clinic input]
1097 OrderedDict.popitem
1098
1099 last: bool = True
1100
1101 Remove and return a (key, value) pair from the dictionary.
1102
1103 Pairs are returned in LIFO order if last is true or FIFO order if false.
1104 [clinic start generated code]*/
1105
1106 static PyObject *
1107 OrderedDict_popitem_impl(PyODictObject *self, int last)
1108 /*[clinic end generated code: output=98e7d986690d49eb input=d992ac5ee8305e1a]*/
1109 {
1110 PyObject *key, *value, *item = NULL;
1111 _ODictNode *node;
1112
1113 /* pull the item */
1114
1115 if (_odict_EMPTY(self)) {
1116 PyErr_SetString(PyExc_KeyError, "dictionary is empty");
1117 return NULL;
1118 }
1119
1120 node = last ? _odict_LAST(self) : _odict_FIRST(self);
1121 key = _odictnode_KEY(node);
1122 Py_INCREF(key);
1123 value = _odict_popkey_hash((PyObject *)self, key, NULL, _odictnode_HASH(node));
1124 if (value == NULL)
1125 return NULL;
1126 item = PyTuple_Pack(2, key, value);
1127 Py_DECREF(key);
1128 Py_DECREF(value);
1129 return item;
1130 }
1131
1132 /* keys() */
1133
1134 /* MutableMapping.keys() does not have a docstring. */
1135 PyDoc_STRVAR(odict_keys__doc__, "");
1136
1137 static PyObject * odictkeys_new(PyObject *od, PyObject *Py_UNUSED(ignored)); /* forward */
1138
1139 /* values() */
1140
1141 /* MutableMapping.values() does not have a docstring. */
1142 PyDoc_STRVAR(odict_values__doc__, "");
1143
1144 static PyObject * odictvalues_new(PyObject *od, PyObject *Py_UNUSED(ignored)); /* forward */
1145
1146 /* items() */
1147
1148 /* MutableMapping.items() does not have a docstring. */
1149 PyDoc_STRVAR(odict_items__doc__, "");
1150
1151 static PyObject * odictitems_new(PyObject *od, PyObject *Py_UNUSED(ignored)); /* forward */
1152
1153 /* update() */
1154
1155 /* MutableMapping.update() does not have a docstring. */
1156 PyDoc_STRVAR(odict_update__doc__, "");
1157
1158 /* forward */
1159 static PyObject * mutablemapping_update(PyObject *, PyObject *, PyObject *);
1160
1161 #define odict_update mutablemapping_update
1162
1163 /* clear() */
1164
1165 PyDoc_STRVAR(odict_clear__doc__,
1166 "od.clear() -> None. Remove all items from od.");
1167
1168 static PyObject *
1169 odict_clear(register PyODictObject *od, PyObject *Py_UNUSED(ignored))
1170 {
1171 PyDict_Clear((PyObject *)od);
1172 _odict_clear_nodes(od);
1173 Py_RETURN_NONE;
1174 }
1175
1176 /* copy() */
1177
1178 /* forward */
1179 static int _PyODict_SetItem_KnownHash(PyObject *, PyObject *, PyObject *,
1180 Py_hash_t);
1181
1182 PyDoc_STRVAR(odict_copy__doc__, "od.copy() -> a shallow copy of od");
1183
1184 static PyObject *
1185 odict_copy(register PyODictObject *od, PyObject *Py_UNUSED(ignored))
1186 {
1187 _ODictNode *node;
1188 PyObject *od_copy;
1189
1190 if (PyODict_CheckExact(od))
1191 od_copy = PyODict_New();
1192 else
1193 od_copy = _PyObject_CallNoArgs((PyObject *)Py_TYPE(od));
1194 if (od_copy == NULL)
1195 return NULL;
1196
1197 if (PyODict_CheckExact(od)) {
1198 _odict_FOREACH(od, node) {
1199 PyObject *key = _odictnode_KEY(node);
1200 PyObject *value = _odictnode_VALUE(node, od);
1201 if (value == NULL) {
1202 if (!PyErr_Occurred())
1203 PyErr_SetObject(PyExc_KeyError, key);
1204 goto fail;
1205 }
1206 if (_PyODict_SetItem_KnownHash((PyObject *)od_copy, key, value,
1207 _odictnode_HASH(node)) != 0)
1208 goto fail;
1209 }
1210 }
1211 else {
1212 _odict_FOREACH(od, node) {
1213 int res;
1214 PyObject *value = PyObject_GetItem((PyObject *)od,
1215 _odictnode_KEY(node));
1216 if (value == NULL)
1217 goto fail;
1218 res = PyObject_SetItem((PyObject *)od_copy,
1219 _odictnode_KEY(node), value);
1220 Py_DECREF(value);
1221 if (res != 0)
1222 goto fail;
1223 }
1224 }
1225 return od_copy;
1226
1227 fail:
1228 Py_DECREF(od_copy);
1229 return NULL;
1230 }
1231
1232 /* __reversed__() */
1233
1234 PyDoc_STRVAR(odict_reversed__doc__, "od.__reversed__() <==> reversed(od)");
1235
1236 #define _odict_ITER_REVERSED 1
1237 #define _odict_ITER_KEYS 2
1238 #define _odict_ITER_VALUES 4
1239 #define _odict_ITER_ITEMS (_odict_ITER_KEYS|_odict_ITER_VALUES)
1240
1241 /* forward */
1242 static PyObject * odictiter_new(PyODictObject *, int);
1243
1244 static PyObject *
1245 odict_reversed(PyODictObject *od, PyObject *Py_UNUSED(ignored))
1246 {
1247 return odictiter_new(od, _odict_ITER_KEYS|_odict_ITER_REVERSED);
1248 }
1249
1250
1251 /* move_to_end() */
1252
1253 /*[clinic input]
1254 OrderedDict.move_to_end
1255
1256 key: object
1257 last: bool = True
1258
1259 Move an existing element to the end (or beginning if last is false).
1260
1261 Raise KeyError if the element does not exist.
1262 [clinic start generated code]*/
1263
1264 static PyObject *
1265 OrderedDict_move_to_end_impl(PyODictObject *self, PyObject *key, int last)
1266 /*[clinic end generated code: output=fafa4c5cc9b92f20 input=d6ceff7132a2fcd7]*/
1267 {
1268 _ODictNode *node;
1269
1270 if (_odict_EMPTY(self)) {
1271 PyErr_SetObject(PyExc_KeyError, key);
1272 return NULL;
1273 }
1274 node = last ? _odict_LAST(self) : _odict_FIRST(self);
1275 if (key != _odictnode_KEY(node)) {
1276 node = _odict_find_node(self, key);
1277 if (node == NULL) {
1278 if (!PyErr_Occurred())
1279 PyErr_SetObject(PyExc_KeyError, key);
1280 return NULL;
1281 }
1282 if (last) {
1283 /* Only move if not already the last one. */
1284 if (node != _odict_LAST(self)) {
1285 _odict_remove_node(self, node);
1286 _odict_add_tail(self, node);
1287 }
1288 }
1289 else {
1290 /* Only move if not already the first one. */
1291 if (node != _odict_FIRST(self)) {
1292 _odict_remove_node(self, node);
1293 _odict_add_head(self, node);
1294 }
1295 }
1296 }
1297 Py_RETURN_NONE;
1298 }
1299
1300
1301 /* tp_methods */
1302
1303 static PyMethodDef odict_methods[] = {
1304
1305 /* overridden dict methods */
1306 ORDEREDDICT_FROMKEYS_METHODDEF
1307 {"__sizeof__", (PyCFunction)odict_sizeof, METH_NOARGS,
1308 odict_sizeof__doc__},
1309 {"__reduce__", (PyCFunction)odict_reduce, METH_NOARGS,
1310 odict_reduce__doc__},
1311 ORDEREDDICT_SETDEFAULT_METHODDEF
1312 ORDEREDDICT_POP_METHODDEF
1313 ORDEREDDICT_POPITEM_METHODDEF
1314 {"keys", odictkeys_new, METH_NOARGS,
1315 odict_keys__doc__},
1316 {"values", odictvalues_new, METH_NOARGS,
1317 odict_values__doc__},
1318 {"items", odictitems_new, METH_NOARGS,
1319 odict_items__doc__},
1320 {"update", _PyCFunction_CAST(odict_update), METH_VARARGS | METH_KEYWORDS,
1321 odict_update__doc__},
1322 {"clear", (PyCFunction)odict_clear, METH_NOARGS,
1323 odict_clear__doc__},
1324 {"copy", (PyCFunction)odict_copy, METH_NOARGS,
1325 odict_copy__doc__},
1326
1327 /* new methods */
1328 {"__reversed__", (PyCFunction)odict_reversed, METH_NOARGS,
1329 odict_reversed__doc__},
1330 ORDEREDDICT_MOVE_TO_END_METHODDEF
1331
1332 {NULL, NULL} /* sentinel */
1333 };
1334
1335
1336 /* ----------------------------------------------
1337 * OrderedDict members
1338 */
1339
1340 /* tp_getset */
1341
1342 static PyGetSetDef odict_getset[] = {
1343 {"__dict__", PyObject_GenericGetDict, PyObject_GenericSetDict},
1344 {NULL}
1345 };
1346
1347 /* ----------------------------------------------
1348 * OrderedDict type slot methods
1349 */
1350
1351 /* tp_dealloc */
1352
1353 static void
1354 odict_dealloc(PyODictObject *self)
1355 {
1356 PyObject_GC_UnTrack(self);
1357 Py_TRASHCAN_BEGIN(self, odict_dealloc)
1358
1359 Py_XDECREF(self->od_inst_dict);
1360 if (self->od_weakreflist != NULL)
1361 PyObject_ClearWeakRefs((PyObject *)self);
1362
1363 _odict_clear_nodes(self);
1364 PyDict_Type.tp_dealloc((PyObject *)self);
1365
1366 Py_TRASHCAN_END
1367 }
1368
1369 /* tp_repr */
1370
1371 static PyObject *
1372 odict_repr(PyODictObject *self)
1373 {
1374 int i;
1375 PyObject *pieces = NULL, *result = NULL;
1376
1377 if (PyODict_SIZE(self) == 0)
1378 return PyUnicode_FromFormat("%s()", _PyType_Name(Py_TYPE(self)));
1379
1380 i = Py_ReprEnter((PyObject *)self);
1381 if (i != 0) {
1382 return i > 0 ? PyUnicode_FromString("...") : NULL;
1383 }
1384
1385 if (PyODict_CheckExact(self)) {
1386 Py_ssize_t count = 0;
1387 _ODictNode *node;
1388 pieces = PyList_New(PyODict_SIZE(self));
1389 if (pieces == NULL)
1390 goto Done;
1391
1392 _odict_FOREACH(self, node) {
1393 PyObject *pair;
1394 PyObject *key = _odictnode_KEY(node);
1395 PyObject *value = _odictnode_VALUE(node, self);
1396 if (value == NULL) {
1397 if (!PyErr_Occurred())
1398 PyErr_SetObject(PyExc_KeyError, key);
1399 goto Done;
1400 }
1401 pair = PyTuple_Pack(2, key, value);
1402 if (pair == NULL)
1403 goto Done;
1404
1405 if (count < PyList_GET_SIZE(pieces))
1406 PyList_SET_ITEM(pieces, count, pair); /* steals reference */
1407 else {
1408 if (PyList_Append(pieces, pair) < 0) {
1409 Py_DECREF(pair);
1410 goto Done;
1411 }
1412 Py_DECREF(pair);
1413 }
1414 count++;
1415 }
1416 if (count < PyList_GET_SIZE(pieces)) {
1417 Py_SET_SIZE(pieces, count);
1418 }
1419 }
1420 else {
1421 PyObject *items = PyObject_CallMethodNoArgs(
1422 (PyObject *)self, &_Py_ID(items));
1423 if (items == NULL)
1424 goto Done;
1425 pieces = PySequence_List(items);
1426 Py_DECREF(items);
1427 if (pieces == NULL)
1428 goto Done;
1429 }
1430
1431 result = PyUnicode_FromFormat("%s(%R)",
1432 _PyType_Name(Py_TYPE(self)), pieces);
1433
1434 Done:
1435 Py_XDECREF(pieces);
1436 Py_ReprLeave((PyObject *)self);
1437 return result;
1438 }
1439
1440 /* tp_doc */
1441
1442 PyDoc_STRVAR(odict_doc,
1443 "Dictionary that remembers insertion order");
1444
1445 /* tp_traverse */
1446
1447 static int
1448 odict_traverse(PyODictObject *od, visitproc visit, void *arg)
1449 {
1450 _ODictNode *node;
1451
1452 Py_VISIT(od->od_inst_dict);
1453 _odict_FOREACH(od, node) {
1454 Py_VISIT(_odictnode_KEY(node));
1455 }
1456 return PyDict_Type.tp_traverse((PyObject *)od, visit, arg);
1457 }
1458
1459 /* tp_clear */
1460
1461 static int
1462 odict_tp_clear(PyODictObject *od)
1463 {
1464 Py_CLEAR(od->od_inst_dict);
1465 PyDict_Clear((PyObject *)od);
1466 _odict_clear_nodes(od);
1467 return 0;
1468 }
1469
1470 /* tp_richcompare */
1471
1472 static PyObject *
1473 odict_richcompare(PyObject *v, PyObject *w, int op)
1474 {
1475 if (!PyODict_Check(v) || !PyDict_Check(w)) {
1476 Py_RETURN_NOTIMPLEMENTED;
1477 }
1478
1479 if (op == Py_EQ || op == Py_NE) {
1480 PyObject *res, *cmp;
1481 int eq;
1482
1483 cmp = PyDict_Type.tp_richcompare(v, w, op);
1484 if (cmp == NULL)
1485 return NULL;
1486 if (!PyODict_Check(w))
1487 return cmp;
1488 if (op == Py_EQ && cmp == Py_False)
1489 return cmp;
1490 if (op == Py_NE && cmp == Py_True)
1491 return cmp;
1492 Py_DECREF(cmp);
1493
1494 /* Try comparing odict keys. */
1495 eq = _odict_keys_equal((PyODictObject *)v, (PyODictObject *)w);
1496 if (eq < 0)
1497 return NULL;
1498
1499 res = (eq == (op == Py_EQ)) ? Py_True : Py_False;
1500 Py_INCREF(res);
1501 return res;
1502 } else {
1503 Py_RETURN_NOTIMPLEMENTED;
1504 }
1505 }
1506
1507 /* tp_iter */
1508
1509 static PyObject *
1510 odict_iter(PyODictObject *od)
1511 {
1512 return odictiter_new(od, _odict_ITER_KEYS);
1513 }
1514
1515 /* tp_init */
1516
1517 static int
1518 odict_init(PyObject *self, PyObject *args, PyObject *kwds)
1519 {
1520 PyObject *res;
1521 Py_ssize_t len = PyObject_Length(args);
1522
1523 if (len == -1)
1524 return -1;
1525 if (len > 1) {
1526 const char *msg = "expected at most 1 arguments, got %zd";
1527 PyErr_Format(PyExc_TypeError, msg, len);
1528 return -1;
1529 }
1530
1531 /* __init__() triggering update() is just the way things are! */
1532 res = odict_update(self, args, kwds);
1533 if (res == NULL) {
1534 return -1;
1535 } else {
1536 Py_DECREF(res);
1537 return 0;
1538 }
1539 }
1540
1541 /* PyODict_Type */
1542
1543 PyTypeObject PyODict_Type = {
1544 PyVarObject_HEAD_INIT(&PyType_Type, 0)
1545 "collections.OrderedDict", /* tp_name */
1546 sizeof(PyODictObject), /* tp_basicsize */
1547 0, /* tp_itemsize */
1548 (destructor)odict_dealloc, /* tp_dealloc */
1549 0, /* tp_vectorcall_offset */
1550 0, /* tp_getattr */
1551 0, /* tp_setattr */
1552 0, /* tp_as_async */
1553 (reprfunc)odict_repr, /* tp_repr */
1554 &odict_as_number, /* tp_as_number */
1555 0, /* tp_as_sequence */
1556 &odict_as_mapping, /* tp_as_mapping */
1557 0, /* tp_hash */
1558 0, /* tp_call */
1559 0, /* tp_str */
1560 0, /* tp_getattro */
1561 0, /* tp_setattro */
1562 0, /* tp_as_buffer */
1563 Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,/* tp_flags */
1564 odict_doc, /* tp_doc */
1565 (traverseproc)odict_traverse, /* tp_traverse */
1566 (inquiry)odict_tp_clear, /* tp_clear */
1567 (richcmpfunc)odict_richcompare, /* tp_richcompare */
1568 offsetof(PyODictObject, od_weakreflist), /* tp_weaklistoffset */
1569 (getiterfunc)odict_iter, /* tp_iter */
1570 0, /* tp_iternext */
1571 odict_methods, /* tp_methods */
1572 0, /* tp_members */
1573 odict_getset, /* tp_getset */
1574 &PyDict_Type, /* tp_base */
1575 0, /* tp_dict */
1576 0, /* tp_descr_get */
1577 0, /* tp_descr_set */
1578 offsetof(PyODictObject, od_inst_dict), /* tp_dictoffset */
1579 (initproc)odict_init, /* tp_init */
1580 PyType_GenericAlloc, /* tp_alloc */
1581 0, /* tp_new */
1582 0, /* tp_free */
1583 };
1584
1585
1586 /* ----------------------------------------------
1587 * the public OrderedDict API
1588 */
1589
1590 PyObject *
1591 PyODict_New(void)
1592 {
1593 return PyDict_Type.tp_new(&PyODict_Type, NULL, NULL);
1594 }
1595
1596 static int
1597 _PyODict_SetItem_KnownHash(PyObject *od, PyObject *key, PyObject *value,
1598 Py_hash_t hash)
1599 {
1600 int res = _PyDict_SetItem_KnownHash(od, key, value, hash);
1601 if (res == 0) {
1602 res = _odict_add_new_node((PyODictObject *)od, key, hash);
1603 if (res < 0) {
1604 /* Revert setting the value on the dict */
1605 PyObject *exc, *val, *tb;
1606 PyErr_Fetch(&exc, &val, &tb);
1607 (void) _PyDict_DelItem_KnownHash(od, key, hash);
1608 _PyErr_ChainExceptions(exc, val, tb);
1609 }
1610 }
1611 return res;
1612 }
1613
1614 int
1615 PyODict_SetItem(PyObject *od, PyObject *key, PyObject *value)
1616 {
1617 Py_hash_t hash = PyObject_Hash(key);
1618 if (hash == -1)
1619 return -1;
1620 return _PyODict_SetItem_KnownHash(od, key, value, hash);
1621 }
1622
1623 int
1624 PyODict_DelItem(PyObject *od, PyObject *key)
1625 {
1626 int res;
1627 Py_hash_t hash = PyObject_Hash(key);
1628 if (hash == -1)
1629 return -1;
1630 res = _odict_clear_node((PyODictObject *)od, NULL, key, hash);
1631 if (res < 0)
1632 return -1;
1633 return _PyDict_DelItem_KnownHash(od, key, hash);
1634 }
1635
1636
1637 /* -------------------------------------------
1638 * The OrderedDict views (keys/values/items)
1639 */
1640
1641 typedef struct {
1642 PyObject_HEAD
1643 int kind;
1644 PyODictObject *di_odict;
1645 Py_ssize_t di_size;
1646 size_t di_state;
1647 PyObject *di_current;
1648 PyObject *di_result; /* reusable result tuple for iteritems */
1649 } odictiterobject;
1650
1651 static void
1652 odictiter_dealloc(odictiterobject *di)
1653 {
1654 _PyObject_GC_UNTRACK(di);
1655 Py_XDECREF(di->di_odict);
1656 Py_XDECREF(di->di_current);
1657 if ((di->kind & _odict_ITER_ITEMS) == _odict_ITER_ITEMS) {
1658 Py_DECREF(di->di_result);
1659 }
1660 PyObject_GC_Del(di);
1661 }
1662
1663 static int
1664 odictiter_traverse(odictiterobject *di, visitproc visit, void *arg)
1665 {
1666 Py_VISIT(di->di_odict);
1667 Py_VISIT(di->di_current); /* A key could be any type, not just str. */
1668 Py_VISIT(di->di_result);
1669 return 0;
1670 }
1671
1672 /* In order to protect against modifications during iteration, we track
1673 * the current key instead of the current node. */
1674 static PyObject *
1675 odictiter_nextkey(odictiterobject *di)
1676 {
1677 PyObject *key = NULL;
1678 _ODictNode *node;
1679 int reversed = di->kind & _odict_ITER_REVERSED;
1680
1681 if (di->di_odict == NULL)
1682 return NULL;
1683 if (di->di_current == NULL)
1684 goto done; /* We're already done. */
1685
1686 /* Check for unsupported changes. */
1687 if (di->di_odict->od_state != di->di_state) {
1688 PyErr_SetString(PyExc_RuntimeError,
1689 "OrderedDict mutated during iteration");
1690 goto done;
1691 }
1692 if (di->di_size != PyODict_SIZE(di->di_odict)) {
1693 PyErr_SetString(PyExc_RuntimeError,
1694 "OrderedDict changed size during iteration");
1695 di->di_size = -1; /* Make this state sticky */
1696 return NULL;
1697 }
1698
1699 /* Get the key. */
1700 node = _odict_find_node(di->di_odict, di->di_current);
1701 if (node == NULL) {
1702 if (!PyErr_Occurred())
1703 PyErr_SetObject(PyExc_KeyError, di->di_current);
1704 /* Must have been deleted. */
1705 Py_CLEAR(di->di_current);
1706 return NULL;
1707 }
1708 key = di->di_current;
1709
1710 /* Advance to the next key. */
1711 node = reversed ? _odictnode_PREV(node) : _odictnode_NEXT(node);
1712 if (node == NULL) {
1713 /* Reached the end. */
1714 di->di_current = NULL;
1715 }
1716 else {
1717 di->di_current = _odictnode_KEY(node);
1718 Py_INCREF(di->di_current);
1719 }
1720
1721 return key;
1722
1723 done:
1724 Py_CLEAR(di->di_odict);
1725 return key;
1726 }
1727
1728 static PyObject *
1729 odictiter_iternext(odictiterobject *di)
1730 {
1731 PyObject *result, *value;
1732 PyObject *key = odictiter_nextkey(di); /* new reference */
1733
1734 if (key == NULL)
1735 return NULL;
1736
1737 /* Handle the keys case. */
1738 if (! (di->kind & _odict_ITER_VALUES)) {
1739 return key;
1740 }
1741
1742 value = PyODict_GetItem((PyObject *)di->di_odict, key); /* borrowed */
1743 if (value == NULL) {
1744 if (!PyErr_Occurred())
1745 PyErr_SetObject(PyExc_KeyError, key);
1746 Py_DECREF(key);
1747 goto done;
1748 }
1749 Py_INCREF(value);
1750
1751 /* Handle the values case. */
1752 if (!(di->kind & _odict_ITER_KEYS)) {
1753 Py_DECREF(key);
1754 return value;
1755 }
1756
1757 /* Handle the items case. */
1758 result = di->di_result;
1759
1760 if (Py_REFCNT(result) == 1) {
1761 /* not in use so we can reuse it
1762 * (the common case during iteration) */
1763 Py_INCREF(result);
1764 Py_DECREF(PyTuple_GET_ITEM(result, 0)); /* borrowed */
1765 Py_DECREF(PyTuple_GET_ITEM(result, 1)); /* borrowed */
1766 // bpo-42536: The GC may have untracked this result tuple. Since we're
1767 // recycling it, make sure it's tracked again:
1768 if (!_PyObject_GC_IS_TRACKED(result)) {
1769 _PyObject_GC_TRACK(result);
1770 }
1771 }
1772 else {
1773 result = PyTuple_New(2);
1774 if (result == NULL) {
1775 Py_DECREF(key);
1776 Py_DECREF(value);
1777 goto done;
1778 }
1779 }
1780
1781 PyTuple_SET_ITEM(result, 0, key); /* steals reference */
1782 PyTuple_SET_ITEM(result, 1, value); /* steals reference */
1783 return result;
1784
1785 done:
1786 Py_CLEAR(di->di_current);
1787 Py_CLEAR(di->di_odict);
1788 return NULL;
1789 }
1790
1791 /* No need for tp_clear because odictiterobject is not mutable. */
1792
1793 PyDoc_STRVAR(reduce_doc, "Return state information for pickling");
1794
1795 static PyObject *
1796 odictiter_reduce(odictiterobject *di, PyObject *Py_UNUSED(ignored))
1797 {
1798 /* copy the iterator state */
1799 odictiterobject tmp = *di;
1800 Py_XINCREF(tmp.di_odict);
1801 Py_XINCREF(tmp.di_current);
1802
1803 /* iterate the temporary into a list */
1804 PyObject *list = PySequence_List((PyObject*)&tmp);
1805 Py_XDECREF(tmp.di_odict);
1806 Py_XDECREF(tmp.di_current);
1807 if (list == NULL) {
1808 return NULL;
1809 }
1810 return Py_BuildValue("N(N)", _PyEval_GetBuiltin(&_Py_ID(iter)), list);
1811 }
1812
1813 static PyMethodDef odictiter_methods[] = {
1814 {"__reduce__", (PyCFunction)odictiter_reduce, METH_NOARGS, reduce_doc},
1815 {NULL, NULL} /* sentinel */
1816 };
1817
1818 PyTypeObject PyODictIter_Type = {
1819 PyVarObject_HEAD_INIT(&PyType_Type, 0)
1820 "odict_iterator", /* tp_name */
1821 sizeof(odictiterobject), /* tp_basicsize */
1822 0, /* tp_itemsize */
1823 /* methods */
1824 (destructor)odictiter_dealloc, /* tp_dealloc */
1825 0, /* tp_vectorcall_offset */
1826 0, /* tp_getattr */
1827 0, /* tp_setattr */
1828 0, /* tp_as_async */
1829 0, /* tp_repr */
1830 0, /* tp_as_number */
1831 0, /* tp_as_sequence */
1832 0, /* tp_as_mapping */
1833 0, /* tp_hash */
1834 0, /* tp_call */
1835 0, /* tp_str */
1836 PyObject_GenericGetAttr, /* tp_getattro */
1837 0, /* tp_setattro */
1838 0, /* tp_as_buffer */
1839 Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
1840 0, /* tp_doc */
1841 (traverseproc)odictiter_traverse, /* tp_traverse */
1842 0, /* tp_clear */
1843 0, /* tp_richcompare */
1844 0, /* tp_weaklistoffset */
1845 PyObject_SelfIter, /* tp_iter */
1846 (iternextfunc)odictiter_iternext, /* tp_iternext */
1847 odictiter_methods, /* tp_methods */
1848 0,
1849 };
1850
1851 static PyObject *
1852 odictiter_new(PyODictObject *od, int kind)
1853 {
1854 odictiterobject *di;
1855 _ODictNode *node;
1856 int reversed = kind & _odict_ITER_REVERSED;
1857
1858 di = PyObject_GC_New(odictiterobject, &PyODictIter_Type);
1859 if (di == NULL)
1860 return NULL;
1861
1862 if ((kind & _odict_ITER_ITEMS) == _odict_ITER_ITEMS) {
1863 di->di_result = PyTuple_Pack(2, Py_None, Py_None);
1864 if (di->di_result == NULL) {
1865 Py_DECREF(di);
1866 return NULL;
1867 }
1868 }
1869 else {
1870 di->di_result = NULL;
1871 }
1872
1873 di->kind = kind;
1874 node = reversed ? _odict_LAST(od) : _odict_FIRST(od);
1875 di->di_current = node ? _odictnode_KEY(node) : NULL;
1876 Py_XINCREF(di->di_current);
1877 di->di_size = PyODict_SIZE(od);
1878 di->di_state = od->od_state;
1879 di->di_odict = od;
1880 Py_INCREF(od);
1881
1882 _PyObject_GC_TRACK(di);
1883 return (PyObject *)di;
1884 }
1885
1886 /* keys() */
1887
1888 static PyObject *
1889 odictkeys_iter(_PyDictViewObject *dv)
1890 {
1891 if (dv->dv_dict == NULL) {
1892 Py_RETURN_NONE;
1893 }
1894 return odictiter_new((PyODictObject *)dv->dv_dict,
1895 _odict_ITER_KEYS);
1896 }
1897
1898 static PyObject *
1899 odictkeys_reversed(_PyDictViewObject *dv, PyObject *Py_UNUSED(ignored))
1900 {
1901 if (dv->dv_dict == NULL) {
1902 Py_RETURN_NONE;
1903 }
1904 return odictiter_new((PyODictObject *)dv->dv_dict,
1905 _odict_ITER_KEYS|_odict_ITER_REVERSED);
1906 }
1907
1908 static PyMethodDef odictkeys_methods[] = {
1909 {"__reversed__", (PyCFunction)odictkeys_reversed, METH_NOARGS, NULL},
1910 {NULL, NULL} /* sentinel */
1911 };
1912
1913 PyTypeObject PyODictKeys_Type = {
1914 PyVarObject_HEAD_INIT(&PyType_Type, 0)
1915 "odict_keys", /* tp_name */
1916 0, /* tp_basicsize */
1917 0, /* tp_itemsize */
1918 0, /* tp_dealloc */
1919 0, /* tp_vectorcall_offset */
1920 0, /* tp_getattr */
1921 0, /* tp_setattr */
1922 0, /* tp_as_async */
1923 0, /* tp_repr */
1924 0, /* tp_as_number */
1925 0, /* tp_as_sequence */
1926 0, /* tp_as_mapping */
1927 0, /* tp_hash */
1928 0, /* tp_call */
1929 0, /* tp_str */
1930 0, /* tp_getattro */
1931 0, /* tp_setattro */
1932 0, /* tp_as_buffer */
1933 0, /* tp_flags */
1934 0, /* tp_doc */
1935 0, /* tp_traverse */
1936 0, /* tp_clear */
1937 0, /* tp_richcompare */
1938 0, /* tp_weaklistoffset */
1939 (getiterfunc)odictkeys_iter, /* tp_iter */
1940 0, /* tp_iternext */
1941 odictkeys_methods, /* tp_methods */
1942 0, /* tp_members */
1943 0, /* tp_getset */
1944 &PyDictKeys_Type, /* tp_base */
1945 };
1946
1947 static PyObject *
1948 odictkeys_new(PyObject *od, PyObject *Py_UNUSED(ignored))
1949 {
1950 return _PyDictView_New(od, &PyODictKeys_Type);
1951 }
1952
1953 /* items() */
1954
1955 static PyObject *
1956 odictitems_iter(_PyDictViewObject *dv)
1957 {
1958 if (dv->dv_dict == NULL) {
1959 Py_RETURN_NONE;
1960 }
1961 return odictiter_new((PyODictObject *)dv->dv_dict,
1962 _odict_ITER_KEYS|_odict_ITER_VALUES);
1963 }
1964
1965 static PyObject *
1966 odictitems_reversed(_PyDictViewObject *dv, PyObject *Py_UNUSED(ignored))
1967 {
1968 if (dv->dv_dict == NULL) {
1969 Py_RETURN_NONE;
1970 }
1971 return odictiter_new((PyODictObject *)dv->dv_dict,
1972 _odict_ITER_KEYS|_odict_ITER_VALUES|_odict_ITER_REVERSED);
1973 }
1974
1975 static PyMethodDef odictitems_methods[] = {
1976 {"__reversed__", (PyCFunction)odictitems_reversed, METH_NOARGS, NULL},
1977 {NULL, NULL} /* sentinel */
1978 };
1979
1980 PyTypeObject PyODictItems_Type = {
1981 PyVarObject_HEAD_INIT(&PyType_Type, 0)
1982 "odict_items", /* tp_name */
1983 0, /* tp_basicsize */
1984 0, /* tp_itemsize */
1985 0, /* tp_dealloc */
1986 0, /* tp_vectorcall_offset */
1987 0, /* tp_getattr */
1988 0, /* tp_setattr */
1989 0, /* tp_as_async */
1990 0, /* tp_repr */
1991 0, /* tp_as_number */
1992 0, /* tp_as_sequence */
1993 0, /* tp_as_mapping */
1994 0, /* tp_hash */
1995 0, /* tp_call */
1996 0, /* tp_str */
1997 0, /* tp_getattro */
1998 0, /* tp_setattro */
1999 0, /* tp_as_buffer */
2000 0, /* tp_flags */
2001 0, /* tp_doc */
2002 0, /* tp_traverse */
2003 0, /* tp_clear */
2004 0, /* tp_richcompare */
2005 0, /* tp_weaklistoffset */
2006 (getiterfunc)odictitems_iter, /* tp_iter */
2007 0, /* tp_iternext */
2008 odictitems_methods, /* tp_methods */
2009 0, /* tp_members */
2010 0, /* tp_getset */
2011 &PyDictItems_Type, /* tp_base */
2012 };
2013
2014 static PyObject *
2015 odictitems_new(PyObject *od, PyObject *Py_UNUSED(ignored))
2016 {
2017 return _PyDictView_New(od, &PyODictItems_Type);
2018 }
2019
2020 /* values() */
2021
2022 static PyObject *
2023 odictvalues_iter(_PyDictViewObject *dv)
2024 {
2025 if (dv->dv_dict == NULL) {
2026 Py_RETURN_NONE;
2027 }
2028 return odictiter_new((PyODictObject *)dv->dv_dict,
2029 _odict_ITER_VALUES);
2030 }
2031
2032 static PyObject *
2033 odictvalues_reversed(_PyDictViewObject *dv, PyObject *Py_UNUSED(ignored))
2034 {
2035 if (dv->dv_dict == NULL) {
2036 Py_RETURN_NONE;
2037 }
2038 return odictiter_new((PyODictObject *)dv->dv_dict,
2039 _odict_ITER_VALUES|_odict_ITER_REVERSED);
2040 }
2041
2042 static PyMethodDef odictvalues_methods[] = {
2043 {"__reversed__", (PyCFunction)odictvalues_reversed, METH_NOARGS, NULL},
2044 {NULL, NULL} /* sentinel */
2045 };
2046
2047 PyTypeObject PyODictValues_Type = {
2048 PyVarObject_HEAD_INIT(&PyType_Type, 0)
2049 "odict_values", /* tp_name */
2050 0, /* tp_basicsize */
2051 0, /* tp_itemsize */
2052 0, /* tp_dealloc */
2053 0, /* tp_vectorcall_offset */
2054 0, /* tp_getattr */
2055 0, /* tp_setattr */
2056 0, /* tp_as_async */
2057 0, /* tp_repr */
2058 0, /* tp_as_number */
2059 0, /* tp_as_sequence */
2060 0, /* tp_as_mapping */
2061 0, /* tp_hash */
2062 0, /* tp_call */
2063 0, /* tp_str */
2064 0, /* tp_getattro */
2065 0, /* tp_setattro */
2066 0, /* tp_as_buffer */
2067 0, /* tp_flags */
2068 0, /* tp_doc */
2069 0, /* tp_traverse */
2070 0, /* tp_clear */
2071 0, /* tp_richcompare */
2072 0, /* tp_weaklistoffset */
2073 (getiterfunc)odictvalues_iter, /* tp_iter */
2074 0, /* tp_iternext */
2075 odictvalues_methods, /* tp_methods */
2076 0, /* tp_members */
2077 0, /* tp_getset */
2078 &PyDictValues_Type, /* tp_base */
2079 };
2080
2081 static PyObject *
2082 odictvalues_new(PyObject *od, PyObject *Py_UNUSED(ignored))
2083 {
2084 return _PyDictView_New(od, &PyODictValues_Type);
2085 }
2086
2087
2088 /* ----------------------------------------------
2089 MutableMapping implementations
2090
2091 Mapping:
2092
2093 ============ ===========
2094 method uses
2095 ============ ===========
2096 __contains__ __getitem__
2097 __eq__ items
2098 __getitem__ +
2099 __iter__ +
2100 __len__ +
2101 __ne__ __eq__
2102 get __getitem__
2103 items ItemsView
2104 keys KeysView
2105 values ValuesView
2106 ============ ===========
2107
2108 ItemsView uses __len__, __iter__, and __getitem__.
2109 KeysView uses __len__, __iter__, and __contains__.
2110 ValuesView uses __len__, __iter__, and __getitem__.
2111
2112 MutableMapping:
2113
2114 ============ ===========
2115 method uses
2116 ============ ===========
2117 __delitem__ +
2118 __setitem__ +
2119 clear popitem
2120 pop __getitem__
2121 __delitem__
2122 popitem __iter__
2123 _getitem__
2124 __delitem__
2125 setdefault __getitem__
2126 __setitem__
2127 update __setitem__
2128 ============ ===========
2129 */
2130
2131 static int
2132 mutablemapping_add_pairs(PyObject *self, PyObject *pairs)
2133 {
2134 PyObject *pair, *iterator, *unexpected;
2135 int res = 0;
2136
2137 iterator = PyObject_GetIter(pairs);
2138 if (iterator == NULL)
2139 return -1;
2140 PyErr_Clear();
2141
2142 while ((pair = PyIter_Next(iterator)) != NULL) {
2143 /* could be more efficient (see UNPACK_SEQUENCE in ceval.c) */
2144 PyObject *key = NULL, *value = NULL;
2145 PyObject *pair_iterator = PyObject_GetIter(pair);
2146 if (pair_iterator == NULL)
2147 goto Done;
2148
2149 key = PyIter_Next(pair_iterator);
2150 if (key == NULL) {
2151 if (!PyErr_Occurred())
2152 PyErr_SetString(PyExc_ValueError,
2153 "need more than 0 values to unpack");
2154 goto Done;
2155 }
2156
2157 value = PyIter_Next(pair_iterator);
2158 if (value == NULL) {
2159 if (!PyErr_Occurred())
2160 PyErr_SetString(PyExc_ValueError,
2161 "need more than 1 value to unpack");
2162 goto Done;
2163 }
2164
2165 unexpected = PyIter_Next(pair_iterator);
2166 if (unexpected != NULL) {
2167 Py_DECREF(unexpected);
2168 PyErr_SetString(PyExc_ValueError,
2169 "too many values to unpack (expected 2)");
2170 goto Done;
2171 }
2172 else if (PyErr_Occurred())
2173 goto Done;
2174
2175 res = PyObject_SetItem(self, key, value);
2176
2177 Done:
2178 Py_DECREF(pair);
2179 Py_XDECREF(pair_iterator);
2180 Py_XDECREF(key);
2181 Py_XDECREF(value);
2182 if (PyErr_Occurred())
2183 break;
2184 }
2185 Py_DECREF(iterator);
2186
2187 if (res < 0 || PyErr_Occurred() != NULL)
2188 return -1;
2189 else
2190 return 0;
2191 }
2192
2193 static int
2194 mutablemapping_update_arg(PyObject *self, PyObject *arg)
2195 {
2196 int res = 0;
2197 if (PyDict_CheckExact(arg)) {
2198 PyObject *items = PyDict_Items(arg);
2199 if (items == NULL) {
2200 return -1;
2201 }
2202 res = mutablemapping_add_pairs(self, items);
2203 Py_DECREF(items);
2204 return res;
2205 }
2206 PyObject *func;
2207 if (_PyObject_LookupAttr(arg, &_Py_ID(keys), &func) < 0) {
2208 return -1;
2209 }
2210 if (func != NULL) {
2211 PyObject *keys = _PyObject_CallNoArgs(func);
2212 Py_DECREF(func);
2213 if (keys == NULL) {
2214 return -1;
2215 }
2216 PyObject *iterator = PyObject_GetIter(keys);
2217 Py_DECREF(keys);
2218 if (iterator == NULL) {
2219 return -1;
2220 }
2221 PyObject *key;
2222 while (res == 0 && (key = PyIter_Next(iterator))) {
2223 PyObject *value = PyObject_GetItem(arg, key);
2224 if (value != NULL) {
2225 res = PyObject_SetItem(self, key, value);
2226 Py_DECREF(value);
2227 }
2228 else {
2229 res = -1;
2230 }
2231 Py_DECREF(key);
2232 }
2233 Py_DECREF(iterator);
2234 if (res != 0 || PyErr_Occurred()) {
2235 return -1;
2236 }
2237 return 0;
2238 }
2239 if (_PyObject_LookupAttr(arg, &_Py_ID(items), &func) < 0) {
2240 return -1;
2241 }
2242 if (func != NULL) {
2243 PyObject *items = _PyObject_CallNoArgs(func);
2244 Py_DECREF(func);
2245 if (items == NULL) {
2246 return -1;
2247 }
2248 res = mutablemapping_add_pairs(self, items);
2249 Py_DECREF(items);
2250 return res;
2251 }
2252 res = mutablemapping_add_pairs(self, arg);
2253 return res;
2254 }
2255
2256 static PyObject *
2257 mutablemapping_update(PyObject *self, PyObject *args, PyObject *kwargs)
2258 {
2259 int res;
2260 /* first handle args, if any */
2261 assert(args == NULL || PyTuple_Check(args));
2262 Py_ssize_t len = (args != NULL) ? PyTuple_GET_SIZE(args) : 0;
2263 if (len > 1) {
2264 const char *msg = "update() takes at most 1 positional argument (%zd given)";
2265 PyErr_Format(PyExc_TypeError, msg, len);
2266 return NULL;
2267 }
2268
2269 if (len) {
2270 PyObject *other = PyTuple_GET_ITEM(args, 0); /* borrowed reference */
2271 assert(other != NULL);
2272 Py_INCREF(other);
2273 res = mutablemapping_update_arg(self, other);
2274 Py_DECREF(other);
2275 if (res < 0) {
2276 return NULL;
2277 }
2278 }
2279
2280 /* now handle kwargs */
2281 assert(kwargs == NULL || PyDict_Check(kwargs));
2282 if (kwargs != NULL && PyDict_GET_SIZE(kwargs)) {
2283 PyObject *items = PyDict_Items(kwargs);
2284 if (items == NULL)
2285 return NULL;
2286 res = mutablemapping_add_pairs(self, items);
2287 Py_DECREF(items);
2288 if (res == -1)
2289 return NULL;
2290 }
2291
2292 Py_RETURN_NONE;
2293 }