virtio-scsi: suppress virtqueue kick during processing
[qemu.git] / qobject / qdict.c
1 /*
2 * QDict Module
3 *
4 * Copyright (C) 2009 Red Hat Inc.
5 *
6 * Authors:
7 * Luiz Capitulino <lcapitulino@redhat.com>
8 *
9 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
10 * See the COPYING.LIB file in the top-level directory.
11 */
12
13 #include "qemu/osdep.h"
14 #include "qapi/qmp/qint.h"
15 #include "qapi/qmp/qfloat.h"
16 #include "qapi/qmp/qdict.h"
17 #include "qapi/qmp/qbool.h"
18 #include "qapi/qmp/qstring.h"
19 #include "qapi/qmp/qobject.h"
20 #include "qapi/error.h"
21 #include "qemu/queue.h"
22 #include "qemu-common.h"
23 #include "qemu/cutils.h"
24
25 /**
26 * qdict_new(): Create a new QDict
27 *
28 * Return strong reference.
29 */
30 QDict *qdict_new(void)
31 {
32 QDict *qdict;
33
34 qdict = g_malloc0(sizeof(*qdict));
35 qobject_init(QOBJECT(qdict), QTYPE_QDICT);
36
37 return qdict;
38 }
39
40 /**
41 * qobject_to_qdict(): Convert a QObject into a QDict
42 */
43 QDict *qobject_to_qdict(const QObject *obj)
44 {
45 if (!obj || qobject_type(obj) != QTYPE_QDICT) {
46 return NULL;
47 }
48 return container_of(obj, QDict, base);
49 }
50
51 /**
52 * tdb_hash(): based on the hash agorithm from gdbm, via tdb
53 * (from module-init-tools)
54 */
55 static unsigned int tdb_hash(const char *name)
56 {
57 unsigned value; /* Used to compute the hash value. */
58 unsigned i; /* Used to cycle through random values. */
59
60 /* Set the initial value from the key size. */
61 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++)
62 value = (value + (((const unsigned char *)name)[i] << (i*5 % 24)));
63
64 return (1103515243 * value + 12345);
65 }
66
67 /**
68 * alloc_entry(): allocate a new QDictEntry
69 */
70 static QDictEntry *alloc_entry(const char *key, QObject *value)
71 {
72 QDictEntry *entry;
73
74 entry = g_malloc0(sizeof(*entry));
75 entry->key = g_strdup(key);
76 entry->value = value;
77
78 return entry;
79 }
80
81 /**
82 * qdict_entry_value(): Return qdict entry value
83 *
84 * Return weak reference.
85 */
86 QObject *qdict_entry_value(const QDictEntry *entry)
87 {
88 return entry->value;
89 }
90
91 /**
92 * qdict_entry_key(): Return qdict entry key
93 *
94 * Return a *pointer* to the string, it has to be duplicated before being
95 * stored.
96 */
97 const char *qdict_entry_key(const QDictEntry *entry)
98 {
99 return entry->key;
100 }
101
102 /**
103 * qdict_find(): List lookup function
104 */
105 static QDictEntry *qdict_find(const QDict *qdict,
106 const char *key, unsigned int bucket)
107 {
108 QDictEntry *entry;
109
110 QLIST_FOREACH(entry, &qdict->table[bucket], next)
111 if (!strcmp(entry->key, key))
112 return entry;
113
114 return NULL;
115 }
116
117 /**
118 * qdict_put_obj(): Put a new QObject into the dictionary
119 *
120 * Insert the pair 'key:value' into 'qdict', if 'key' already exists
121 * its 'value' will be replaced.
122 *
123 * This is done by freeing the reference to the stored QObject and
124 * storing the new one in the same entry.
125 *
126 * NOTE: ownership of 'value' is transferred to the QDict
127 */
128 void qdict_put_obj(QDict *qdict, const char *key, QObject *value)
129 {
130 unsigned int bucket;
131 QDictEntry *entry;
132
133 bucket = tdb_hash(key) % QDICT_BUCKET_MAX;
134 entry = qdict_find(qdict, key, bucket);
135 if (entry) {
136 /* replace key's value */
137 qobject_decref(entry->value);
138 entry->value = value;
139 } else {
140 /* allocate a new entry */
141 entry = alloc_entry(key, value);
142 QLIST_INSERT_HEAD(&qdict->table[bucket], entry, next);
143 qdict->size++;
144 }
145 }
146
147 /**
148 * qdict_get(): Lookup for a given 'key'
149 *
150 * Return a weak reference to the QObject associated with 'key' if
151 * 'key' is present in the dictionary, NULL otherwise.
152 */
153 QObject *qdict_get(const QDict *qdict, const char *key)
154 {
155 QDictEntry *entry;
156
157 entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
158 return (entry == NULL ? NULL : entry->value);
159 }
160
161 /**
162 * qdict_haskey(): Check if 'key' exists
163 *
164 * Return 1 if 'key' exists in the dict, 0 otherwise
165 */
166 int qdict_haskey(const QDict *qdict, const char *key)
167 {
168 unsigned int bucket = tdb_hash(key) % QDICT_BUCKET_MAX;
169 return (qdict_find(qdict, key, bucket) == NULL ? 0 : 1);
170 }
171
172 /**
173 * qdict_size(): Return the size of the dictionary
174 */
175 size_t qdict_size(const QDict *qdict)
176 {
177 return qdict->size;
178 }
179
180 /**
181 * qdict_get_obj(): Get a QObject of a specific type
182 */
183 static QObject *qdict_get_obj(const QDict *qdict, const char *key, QType type)
184 {
185 QObject *obj;
186
187 obj = qdict_get(qdict, key);
188 assert(obj != NULL);
189 assert(qobject_type(obj) == type);
190
191 return obj;
192 }
193
194 /**
195 * qdict_get_double(): Get an number mapped by 'key'
196 *
197 * This function assumes that 'key' exists and it stores a
198 * QFloat or QInt object.
199 *
200 * Return number mapped by 'key'.
201 */
202 double qdict_get_double(const QDict *qdict, const char *key)
203 {
204 QObject *obj = qdict_get(qdict, key);
205
206 assert(obj);
207 switch (qobject_type(obj)) {
208 case QTYPE_QFLOAT:
209 return qfloat_get_double(qobject_to_qfloat(obj));
210 case QTYPE_QINT:
211 return qint_get_int(qobject_to_qint(obj));
212 default:
213 abort();
214 }
215 }
216
217 /**
218 * qdict_get_int(): Get an integer mapped by 'key'
219 *
220 * This function assumes that 'key' exists and it stores a
221 * QInt object.
222 *
223 * Return integer mapped by 'key'.
224 */
225 int64_t qdict_get_int(const QDict *qdict, const char *key)
226 {
227 return qint_get_int(qobject_to_qint(qdict_get(qdict, key)));
228 }
229
230 /**
231 * qdict_get_bool(): Get a bool mapped by 'key'
232 *
233 * This function assumes that 'key' exists and it stores a
234 * QBool object.
235 *
236 * Return bool mapped by 'key'.
237 */
238 bool qdict_get_bool(const QDict *qdict, const char *key)
239 {
240 return qbool_get_bool(qobject_to_qbool(qdict_get(qdict, key)));
241 }
242
243 /**
244 * qdict_get_qlist(): Get the QList mapped by 'key'
245 *
246 * This function assumes that 'key' exists and it stores a
247 * QList object.
248 *
249 * Return QList mapped by 'key'.
250 */
251 QList *qdict_get_qlist(const QDict *qdict, const char *key)
252 {
253 return qobject_to_qlist(qdict_get_obj(qdict, key, QTYPE_QLIST));
254 }
255
256 /**
257 * qdict_get_qdict(): Get the QDict mapped by 'key'
258 *
259 * This function assumes that 'key' exists and it stores a
260 * QDict object.
261 *
262 * Return QDict mapped by 'key'.
263 */
264 QDict *qdict_get_qdict(const QDict *qdict, const char *key)
265 {
266 return qobject_to_qdict(qdict_get(qdict, key));
267 }
268
269 /**
270 * qdict_get_str(): Get a pointer to the stored string mapped
271 * by 'key'
272 *
273 * This function assumes that 'key' exists and it stores a
274 * QString object.
275 *
276 * Return pointer to the string mapped by 'key'.
277 */
278 const char *qdict_get_str(const QDict *qdict, const char *key)
279 {
280 return qstring_get_str(qobject_to_qstring(qdict_get(qdict, key)));
281 }
282
283 /**
284 * qdict_get_try_int(): Try to get integer mapped by 'key'
285 *
286 * Return integer mapped by 'key', if it is not present in
287 * the dictionary or if the stored object is not of QInt type
288 * 'def_value' will be returned.
289 */
290 int64_t qdict_get_try_int(const QDict *qdict, const char *key,
291 int64_t def_value)
292 {
293 QInt *qint = qobject_to_qint(qdict_get(qdict, key));
294
295 return qint ? qint_get_int(qint) : def_value;
296 }
297
298 /**
299 * qdict_get_try_bool(): Try to get a bool mapped by 'key'
300 *
301 * Return bool mapped by 'key', if it is not present in the
302 * dictionary or if the stored object is not of QBool type
303 * 'def_value' will be returned.
304 */
305 bool qdict_get_try_bool(const QDict *qdict, const char *key, bool def_value)
306 {
307 QBool *qbool = qobject_to_qbool(qdict_get(qdict, key));
308
309 return qbool ? qbool_get_bool(qbool) : def_value;
310 }
311
312 /**
313 * qdict_get_try_str(): Try to get a pointer to the stored string
314 * mapped by 'key'
315 *
316 * Return a pointer to the string mapped by 'key', if it is not present
317 * in the dictionary or if the stored object is not of QString type
318 * NULL will be returned.
319 */
320 const char *qdict_get_try_str(const QDict *qdict, const char *key)
321 {
322 QString *qstr = qobject_to_qstring(qdict_get(qdict, key));
323
324 return qstr ? qstring_get_str(qstr) : NULL;
325 }
326
327 /**
328 * qdict_iter(): Iterate over all the dictionary's stored values.
329 *
330 * This function allows the user to provide an iterator, which will be
331 * called for each stored value in the dictionary.
332 */
333 void qdict_iter(const QDict *qdict,
334 void (*iter)(const char *key, QObject *obj, void *opaque),
335 void *opaque)
336 {
337 int i;
338 QDictEntry *entry;
339
340 for (i = 0; i < QDICT_BUCKET_MAX; i++) {
341 QLIST_FOREACH(entry, &qdict->table[i], next)
342 iter(entry->key, entry->value, opaque);
343 }
344 }
345
346 static QDictEntry *qdict_next_entry(const QDict *qdict, int first_bucket)
347 {
348 int i;
349
350 for (i = first_bucket; i < QDICT_BUCKET_MAX; i++) {
351 if (!QLIST_EMPTY(&qdict->table[i])) {
352 return QLIST_FIRST(&qdict->table[i]);
353 }
354 }
355
356 return NULL;
357 }
358
359 /**
360 * qdict_first(): Return first qdict entry for iteration.
361 */
362 const QDictEntry *qdict_first(const QDict *qdict)
363 {
364 return qdict_next_entry(qdict, 0);
365 }
366
367 /**
368 * qdict_next(): Return next qdict entry in an iteration.
369 */
370 const QDictEntry *qdict_next(const QDict *qdict, const QDictEntry *entry)
371 {
372 QDictEntry *ret;
373
374 ret = QLIST_NEXT(entry, next);
375 if (!ret) {
376 unsigned int bucket = tdb_hash(entry->key) % QDICT_BUCKET_MAX;
377 ret = qdict_next_entry(qdict, bucket + 1);
378 }
379
380 return ret;
381 }
382
383 /**
384 * qdict_clone_shallow(): Clones a given QDict. Its entries are not copied, but
385 * another reference is added.
386 */
387 QDict *qdict_clone_shallow(const QDict *src)
388 {
389 QDict *dest;
390 QDictEntry *entry;
391 int i;
392
393 dest = qdict_new();
394
395 for (i = 0; i < QDICT_BUCKET_MAX; i++) {
396 QLIST_FOREACH(entry, &src->table[i], next) {
397 qobject_incref(entry->value);
398 qdict_put_obj(dest, entry->key, entry->value);
399 }
400 }
401
402 return dest;
403 }
404
405 /**
406 * qentry_destroy(): Free all the memory allocated by a QDictEntry
407 */
408 static void qentry_destroy(QDictEntry *e)
409 {
410 assert(e != NULL);
411 assert(e->key != NULL);
412 assert(e->value != NULL);
413
414 qobject_decref(e->value);
415 g_free(e->key);
416 g_free(e);
417 }
418
419 /**
420 * qdict_del(): Delete a 'key:value' pair from the dictionary
421 *
422 * This will destroy all data allocated by this entry.
423 */
424 void qdict_del(QDict *qdict, const char *key)
425 {
426 QDictEntry *entry;
427
428 entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
429 if (entry) {
430 QLIST_REMOVE(entry, next);
431 qentry_destroy(entry);
432 qdict->size--;
433 }
434 }
435
436 /**
437 * qdict_destroy_obj(): Free all the memory allocated by a QDict
438 */
439 void qdict_destroy_obj(QObject *obj)
440 {
441 int i;
442 QDict *qdict;
443
444 assert(obj != NULL);
445 qdict = qobject_to_qdict(obj);
446
447 for (i = 0; i < QDICT_BUCKET_MAX; i++) {
448 QDictEntry *entry = QLIST_FIRST(&qdict->table[i]);
449 while (entry) {
450 QDictEntry *tmp = QLIST_NEXT(entry, next);
451 QLIST_REMOVE(entry, next);
452 qentry_destroy(entry);
453 entry = tmp;
454 }
455 }
456
457 g_free(qdict);
458 }
459
460 /**
461 * qdict_copy_default(): If no entry mapped by 'key' exists in 'dst' yet, the
462 * value of 'key' in 'src' is copied there (and the refcount increased
463 * accordingly).
464 */
465 void qdict_copy_default(QDict *dst, QDict *src, const char *key)
466 {
467 QObject *val;
468
469 if (qdict_haskey(dst, key)) {
470 return;
471 }
472
473 val = qdict_get(src, key);
474 if (val) {
475 qobject_incref(val);
476 qdict_put_obj(dst, key, val);
477 }
478 }
479
480 /**
481 * qdict_set_default_str(): If no entry mapped by 'key' exists in 'dst' yet, a
482 * new QString initialised by 'val' is put there.
483 */
484 void qdict_set_default_str(QDict *dst, const char *key, const char *val)
485 {
486 if (qdict_haskey(dst, key)) {
487 return;
488 }
489
490 qdict_put(dst, key, qstring_from_str(val));
491 }
492
493 static void qdict_flatten_qdict(QDict *qdict, QDict *target,
494 const char *prefix);
495
496 static void qdict_flatten_qlist(QList *qlist, QDict *target, const char *prefix)
497 {
498 QObject *value;
499 const QListEntry *entry;
500 char *new_key;
501 int i;
502
503 /* This function is never called with prefix == NULL, i.e., it is always
504 * called from within qdict_flatten_q(list|dict)(). Therefore, it does not
505 * need to remove list entries during the iteration (the whole list will be
506 * deleted eventually anyway from qdict_flatten_qdict()). */
507 assert(prefix);
508
509 entry = qlist_first(qlist);
510
511 for (i = 0; entry; entry = qlist_next(entry), i++) {
512 value = qlist_entry_obj(entry);
513 new_key = g_strdup_printf("%s.%i", prefix, i);
514
515 if (qobject_type(value) == QTYPE_QDICT) {
516 qdict_flatten_qdict(qobject_to_qdict(value), target, new_key);
517 } else if (qobject_type(value) == QTYPE_QLIST) {
518 qdict_flatten_qlist(qobject_to_qlist(value), target, new_key);
519 } else {
520 /* All other types are moved to the target unchanged. */
521 qobject_incref(value);
522 qdict_put_obj(target, new_key, value);
523 }
524
525 g_free(new_key);
526 }
527 }
528
529 static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char *prefix)
530 {
531 QObject *value;
532 const QDictEntry *entry, *next;
533 char *new_key;
534 bool delete;
535
536 entry = qdict_first(qdict);
537
538 while (entry != NULL) {
539
540 next = qdict_next(qdict, entry);
541 value = qdict_entry_value(entry);
542 new_key = NULL;
543 delete = false;
544
545 if (prefix) {
546 new_key = g_strdup_printf("%s.%s", prefix, entry->key);
547 }
548
549 if (qobject_type(value) == QTYPE_QDICT) {
550 /* Entries of QDicts are processed recursively, the QDict object
551 * itself disappears. */
552 qdict_flatten_qdict(qobject_to_qdict(value), target,
553 new_key ? new_key : entry->key);
554 delete = true;
555 } else if (qobject_type(value) == QTYPE_QLIST) {
556 qdict_flatten_qlist(qobject_to_qlist(value), target,
557 new_key ? new_key : entry->key);
558 delete = true;
559 } else if (prefix) {
560 /* All other objects are moved to the target unchanged. */
561 qobject_incref(value);
562 qdict_put_obj(target, new_key, value);
563 delete = true;
564 }
565
566 g_free(new_key);
567
568 if (delete) {
569 qdict_del(qdict, entry->key);
570
571 /* Restart loop after modifying the iterated QDict */
572 entry = qdict_first(qdict);
573 continue;
574 }
575
576 entry = next;
577 }
578 }
579
580 /**
581 * qdict_flatten(): For each nested QDict with key x, all fields with key y
582 * are moved to this QDict and their key is renamed to "x.y". For each nested
583 * QList with key x, the field at index y is moved to this QDict with the key
584 * "x.y" (i.e., the reverse of what qdict_array_split() does).
585 * This operation is applied recursively for nested QDicts and QLists.
586 */
587 void qdict_flatten(QDict *qdict)
588 {
589 qdict_flatten_qdict(qdict, qdict, NULL);
590 }
591
592 /* extract all the src QDict entries starting by start into dst */
593 void qdict_extract_subqdict(QDict *src, QDict **dst, const char *start)
594
595 {
596 const QDictEntry *entry, *next;
597 const char *p;
598
599 *dst = qdict_new();
600 entry = qdict_first(src);
601
602 while (entry != NULL) {
603 next = qdict_next(src, entry);
604 if (strstart(entry->key, start, &p)) {
605 qobject_incref(entry->value);
606 qdict_put_obj(*dst, p, entry->value);
607 qdict_del(src, entry->key);
608 }
609 entry = next;
610 }
611 }
612
613 static int qdict_count_prefixed_entries(const QDict *src, const char *start)
614 {
615 const QDictEntry *entry;
616 int count = 0;
617
618 for (entry = qdict_first(src); entry; entry = qdict_next(src, entry)) {
619 if (strstart(entry->key, start, NULL)) {
620 if (count == INT_MAX) {
621 return -ERANGE;
622 }
623 count++;
624 }
625 }
626
627 return count;
628 }
629
630 /**
631 * qdict_array_split(): This function moves array-like elements of a QDict into
632 * a new QList. Every entry in the original QDict with a key "%u" or one
633 * prefixed "%u.", where %u designates an unsigned integer starting at 0 and
634 * incrementally counting up, will be moved to a new QDict at index %u in the
635 * output QList with the key prefix removed, if that prefix is "%u.". If the
636 * whole key is just "%u", the whole QObject will be moved unchanged without
637 * creating a new QDict. The function terminates when there is no entry in the
638 * QDict with a prefix directly (incrementally) following the last one; it also
639 * returns if there are both entries with "%u" and "%u." for the same index %u.
640 * Example: {"0.a": 42, "0.b": 23, "1.x": 0, "4.y": 1, "o.o": 7, "2": 66}
641 * (or {"1.x": 0, "4.y": 1, "0.a": 42, "o.o": 7, "0.b": 23, "2": 66})
642 * => [{"a": 42, "b": 23}, {"x": 0}, 66]
643 * and {"4.y": 1, "o.o": 7} (remainder of the old QDict)
644 */
645 void qdict_array_split(QDict *src, QList **dst)
646 {
647 unsigned i;
648
649 *dst = qlist_new();
650
651 for (i = 0; i < UINT_MAX; i++) {
652 QObject *subqobj;
653 bool is_subqdict;
654 QDict *subqdict;
655 char indexstr[32], prefix[32];
656 size_t snprintf_ret;
657
658 snprintf_ret = snprintf(indexstr, 32, "%u", i);
659 assert(snprintf_ret < 32);
660
661 subqobj = qdict_get(src, indexstr);
662
663 snprintf_ret = snprintf(prefix, 32, "%u.", i);
664 assert(snprintf_ret < 32);
665
666 /* Overflow is the same as positive non-zero results */
667 is_subqdict = qdict_count_prefixed_entries(src, prefix);
668
669 // There may be either a single subordinate object (named "%u") or
670 // multiple objects (each with a key prefixed "%u."), but not both.
671 if (!subqobj == !is_subqdict) {
672 break;
673 }
674
675 if (is_subqdict) {
676 qdict_extract_subqdict(src, &subqdict, prefix);
677 assert(qdict_size(subqdict) > 0);
678 } else {
679 qobject_incref(subqobj);
680 qdict_del(src, indexstr);
681 }
682
683 qlist_append_obj(*dst, subqobj ?: QOBJECT(subqdict));
684 }
685 }
686
687 /**
688 * qdict_split_flat_key:
689 * @key: the key string to split
690 * @prefix: non-NULL pointer to hold extracted prefix
691 * @suffix: non-NULL pointer to remaining suffix
692 *
693 * Given a flattened key such as 'foo.0.bar', split it into two parts
694 * at the first '.' separator. Allows double dot ('..') to escape the
695 * normal separator.
696 *
697 * e.g.
698 * 'foo.0.bar' -> prefix='foo' and suffix='0.bar'
699 * 'foo..0.bar' -> prefix='foo.0' and suffix='bar'
700 *
701 * The '..' sequence will be unescaped in the returned 'prefix'
702 * string. The 'suffix' string will be left in escaped format, so it
703 * can be fed back into the qdict_split_flat_key() key as the input
704 * later.
705 *
706 * The caller is responsible for freeing the string returned in @prefix
707 * using g_free().
708 */
709 static void qdict_split_flat_key(const char *key, char **prefix,
710 const char **suffix)
711 {
712 const char *separator;
713 size_t i, j;
714
715 /* Find first '.' separator, but if there is a pair '..'
716 * that acts as an escape, so skip over '..' */
717 separator = NULL;
718 do {
719 if (separator) {
720 separator += 2;
721 } else {
722 separator = key;
723 }
724 separator = strchr(separator, '.');
725 } while (separator && separator[1] == '.');
726
727 if (separator) {
728 *prefix = g_strndup(key, separator - key);
729 *suffix = separator + 1;
730 } else {
731 *prefix = g_strdup(key);
732 *suffix = NULL;
733 }
734
735 /* Unescape the '..' sequence into '.' */
736 for (i = 0, j = 0; (*prefix)[i] != '\0'; i++, j++) {
737 if ((*prefix)[i] == '.') {
738 assert((*prefix)[i + 1] == '.');
739 i++;
740 }
741 (*prefix)[j] = (*prefix)[i];
742 }
743 (*prefix)[j] = '\0';
744 }
745
746 /**
747 * qdict_is_list:
748 * @maybe_list: dict to check if keys represent list elements.
749 *
750 * Determine whether all keys in @maybe_list are valid list elements.
751 * If @maybe_list is non-zero in length and all the keys look like
752 * valid list indexes, this will return 1. If @maybe_list is zero
753 * length or all keys are non-numeric then it will return 0 to indicate
754 * it is a normal qdict. If there is a mix of numeric and non-numeric
755 * keys, or the list indexes are non-contiguous, an error is reported.
756 *
757 * Returns: 1 if a valid list, 0 if a dict, -1 on error
758 */
759 static int qdict_is_list(QDict *maybe_list, Error **errp)
760 {
761 const QDictEntry *ent;
762 ssize_t len = 0;
763 ssize_t max = -1;
764 int is_list = -1;
765 int64_t val;
766
767 for (ent = qdict_first(maybe_list); ent != NULL;
768 ent = qdict_next(maybe_list, ent)) {
769
770 if (qemu_strtoll(ent->key, NULL, 10, &val) == 0) {
771 if (is_list == -1) {
772 is_list = 1;
773 } else if (!is_list) {
774 error_setg(errp,
775 "Cannot mix list and non-list keys");
776 return -1;
777 }
778 len++;
779 if (val > max) {
780 max = val;
781 }
782 } else {
783 if (is_list == -1) {
784 is_list = 0;
785 } else if (is_list) {
786 error_setg(errp,
787 "Cannot mix list and non-list keys");
788 return -1;
789 }
790 }
791 }
792
793 if (is_list == -1) {
794 assert(!qdict_size(maybe_list));
795 is_list = 0;
796 }
797
798 /* NB this isn't a perfect check - e.g. it won't catch
799 * a list containing '1', '+1', '01', '3', but that
800 * does not matter - we've still proved that the
801 * input is a list. It is up the caller to do a
802 * stricter check if desired */
803 if (len != (max + 1)) {
804 error_setg(errp, "List indices are not contiguous, "
805 "saw %zd elements but %zd largest index",
806 len, max);
807 return -1;
808 }
809
810 return is_list;
811 }
812
813 /**
814 * qdict_crumple:
815 * @src: the original flat dictionary (only scalar values) to crumple
816 *
817 * Takes a flat dictionary whose keys use '.' separator to indicate
818 * nesting, and values are scalars, and crumples it into a nested
819 * structure.
820 *
821 * To include a literal '.' in a key name, it must be escaped as '..'
822 *
823 * For example, an input of:
824 *
825 * { 'foo.0.bar': 'one', 'foo.0.wizz': '1',
826 * 'foo.1.bar': 'two', 'foo.1.wizz': '2' }
827 *
828 * will result in an output of:
829 *
830 * {
831 * 'foo': [
832 * { 'bar': 'one', 'wizz': '1' },
833 * { 'bar': 'two', 'wizz': '2' }
834 * ],
835 * }
836 *
837 * The following scenarios in the input dict will result in an
838 * error being returned:
839 *
840 * - Any values in @src are non-scalar types
841 * - If keys in @src imply that a particular level is both a
842 * list and a dict. e.g., "foo.0.bar" and "foo.eek.bar".
843 * - If keys in @src imply that a particular level is a list,
844 * but the indices are non-contiguous. e.g. "foo.0.bar" and
845 * "foo.2.bar" without any "foo.1.bar" present.
846 * - If keys in @src represent list indexes, but are not in
847 * the "%zu" format. e.g. "foo.+0.bar"
848 *
849 * Returns: either a QDict or QList for the nested data structure, or NULL
850 * on error
851 */
852 QObject *qdict_crumple(const QDict *src, Error **errp)
853 {
854 const QDictEntry *ent;
855 QDict *two_level, *multi_level = NULL;
856 QObject *dst = NULL, *child;
857 size_t i;
858 char *prefix = NULL;
859 const char *suffix = NULL;
860 int is_list;
861
862 two_level = qdict_new();
863
864 /* Step 1: split our totally flat dict into a two level dict */
865 for (ent = qdict_first(src); ent != NULL; ent = qdict_next(src, ent)) {
866 if (qobject_type(ent->value) == QTYPE_QDICT ||
867 qobject_type(ent->value) == QTYPE_QLIST) {
868 error_setg(errp, "Value %s is not a scalar",
869 ent->key);
870 goto error;
871 }
872
873 qdict_split_flat_key(ent->key, &prefix, &suffix);
874
875 child = qdict_get(two_level, prefix);
876 if (suffix) {
877 if (child) {
878 if (qobject_type(child) != QTYPE_QDICT) {
879 error_setg(errp, "Key %s prefix is already set as a scalar",
880 prefix);
881 goto error;
882 }
883 } else {
884 child = QOBJECT(qdict_new());
885 qdict_put_obj(two_level, prefix, child);
886 }
887 qobject_incref(ent->value);
888 qdict_put_obj(qobject_to_qdict(child), suffix, ent->value);
889 } else {
890 if (child) {
891 error_setg(errp, "Key %s prefix is already set as a dict",
892 prefix);
893 goto error;
894 }
895 qobject_incref(ent->value);
896 qdict_put_obj(two_level, prefix, ent->value);
897 }
898
899 g_free(prefix);
900 prefix = NULL;
901 }
902
903 /* Step 2: optionally process the two level dict recursively
904 * into a multi-level dict */
905 multi_level = qdict_new();
906 for (ent = qdict_first(two_level); ent != NULL;
907 ent = qdict_next(two_level, ent)) {
908
909 if (qobject_type(ent->value) == QTYPE_QDICT) {
910 child = qdict_crumple(qobject_to_qdict(ent->value), errp);
911 if (!child) {
912 goto error;
913 }
914
915 qdict_put_obj(multi_level, ent->key, child);
916 } else {
917 qobject_incref(ent->value);
918 qdict_put_obj(multi_level, ent->key, ent->value);
919 }
920 }
921 QDECREF(two_level);
922 two_level = NULL;
923
924 /* Step 3: detect if we need to turn our dict into list */
925 is_list = qdict_is_list(multi_level, errp);
926 if (is_list < 0) {
927 goto error;
928 }
929
930 if (is_list) {
931 dst = QOBJECT(qlist_new());
932
933 for (i = 0; i < qdict_size(multi_level); i++) {
934 char *key = g_strdup_printf("%zu", i);
935
936 child = qdict_get(multi_level, key);
937 g_free(key);
938
939 if (!child) {
940 error_setg(errp, "Missing list index %zu", i);
941 goto error;
942 }
943
944 qobject_incref(child);
945 qlist_append_obj(qobject_to_qlist(dst), child);
946 }
947 QDECREF(multi_level);
948 multi_level = NULL;
949 } else {
950 dst = QOBJECT(multi_level);
951 }
952
953 return dst;
954
955 error:
956 g_free(prefix);
957 QDECREF(multi_level);
958 QDECREF(two_level);
959 qobject_decref(dst);
960 return NULL;
961 }
962
963 /**
964 * qdict_array_entries(): Returns the number of direct array entries if the
965 * sub-QDict of src specified by the prefix in subqdict (or src itself for
966 * prefix == "") is valid as an array, i.e. the length of the created list if
967 * the sub-QDict would become empty after calling qdict_array_split() on it. If
968 * the array is not valid, -EINVAL is returned.
969 */
970 int qdict_array_entries(QDict *src, const char *subqdict)
971 {
972 const QDictEntry *entry;
973 unsigned i;
974 unsigned entries = 0;
975 size_t subqdict_len = strlen(subqdict);
976
977 assert(!subqdict_len || subqdict[subqdict_len - 1] == '.');
978
979 /* qdict_array_split() loops until UINT_MAX, but as we want to return
980 * negative errors, we only have a signed return value here. Any additional
981 * entries will lead to -EINVAL. */
982 for (i = 0; i < INT_MAX; i++) {
983 QObject *subqobj;
984 int subqdict_entries;
985 char *prefix = g_strdup_printf("%s%u.", subqdict, i);
986
987 subqdict_entries = qdict_count_prefixed_entries(src, prefix);
988
989 /* Remove ending "." */
990 prefix[strlen(prefix) - 1] = 0;
991 subqobj = qdict_get(src, prefix);
992
993 g_free(prefix);
994
995 if (subqdict_entries < 0) {
996 return subqdict_entries;
997 }
998
999 /* There may be either a single subordinate object (named "%u") or
1000 * multiple objects (each with a key prefixed "%u."), but not both. */
1001 if (subqobj && subqdict_entries) {
1002 return -EINVAL;
1003 } else if (!subqobj && !subqdict_entries) {
1004 break;
1005 }
1006
1007 entries += subqdict_entries ? subqdict_entries : 1;
1008 }
1009
1010 /* Consider everything handled that isn't part of the given sub-QDict */
1011 for (entry = qdict_first(src); entry; entry = qdict_next(src, entry)) {
1012 if (!strstart(qdict_entry_key(entry), subqdict, NULL)) {
1013 entries++;
1014 }
1015 }
1016
1017 /* Anything left in the sub-QDict that wasn't handled? */
1018 if (qdict_size(src) != entries) {
1019 return -EINVAL;
1020 }
1021
1022 return i;
1023 }
1024
1025 /**
1026 * qdict_join(): Absorb the src QDict into the dest QDict, that is, move all
1027 * elements from src to dest.
1028 *
1029 * If an element from src has a key already present in dest, it will not be
1030 * moved unless overwrite is true.
1031 *
1032 * If overwrite is true, the conflicting values in dest will be discarded and
1033 * replaced by the corresponding values from src.
1034 *
1035 * Therefore, with overwrite being true, the src QDict will always be empty when
1036 * this function returns. If overwrite is false, the src QDict will be empty
1037 * iff there were no conflicts.
1038 */
1039 void qdict_join(QDict *dest, QDict *src, bool overwrite)
1040 {
1041 const QDictEntry *entry, *next;
1042
1043 entry = qdict_first(src);
1044 while (entry) {
1045 next = qdict_next(src, entry);
1046
1047 if (overwrite || !qdict_haskey(dest, entry->key)) {
1048 qobject_incref(entry->value);
1049 qdict_put_obj(dest, entry->key, entry->value);
1050 qdict_del(src, entry->key);
1051 }
1052
1053 entry = next;
1054 }
1055 }