aboutsummaryrefslogtreecommitdiff
path: root/qobject/qdict.c
blob: 42ec4c0d2c142985e77b4d8466d5bbc4e2714a48 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
/*
 * QDict Module
 *
 * Copyright (C) 2009 Red Hat Inc.
 *
 * Authors:
 *  Luiz Capitulino <lcapitulino@redhat.com>
 *
 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 * See the COPYING.LIB file in the top-level directory.
 */

#include "qapi/qmp/qint.h"
#include "qapi/qmp/qfloat.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qbool.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qmp/qobject.h"
#include "qemu/queue.h"
#include "qemu-common.h"

static void qdict_destroy_obj(QObject *obj);

static const QType qdict_type = {
    .code = QTYPE_QDICT,
    .destroy = qdict_destroy_obj,
};

/**
 * qdict_new(): Create a new QDict
 *
 * Return strong reference.
 */
QDict *qdict_new(void)
{
    QDict *qdict;

    qdict = g_malloc0(sizeof(*qdict));
    QOBJECT_INIT(qdict, &qdict_type);

    return qdict;
}

/**
 * qobject_to_qdict(): Convert a QObject into a QDict
 */
QDict *qobject_to_qdict(const QObject *obj)
{
    if (qobject_type(obj) != QTYPE_QDICT)
        return NULL;

    return container_of(obj, QDict, base);
}

/**
 * tdb_hash(): based on the hash agorithm from gdbm, via tdb
 * (from module-init-tools)
 */
static unsigned int tdb_hash(const char *name)
{
    unsigned value;	/* Used to compute the hash value.  */
    unsigned   i;	/* Used to cycle through random values. */

    /* Set the initial value from the key size. */
    for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++)
        value = (value + (((const unsigned char *)name)[i] << (i*5 % 24)));

    return (1103515243 * value + 12345);
}

/**
 * alloc_entry(): allocate a new QDictEntry
 */
static QDictEntry *alloc_entry(const char *key, QObject *value)
{
    QDictEntry *entry;

    entry = g_malloc0(sizeof(*entry));
    entry->key = g_strdup(key);
    entry->value = value;

    return entry;
}

/**
 * qdict_entry_value(): Return qdict entry value
 *
 * Return weak reference.
 */
QObject *qdict_entry_value(const QDictEntry *entry)
{
    return entry->value;
}

/**
 * qdict_entry_key(): Return qdict entry key
 *
 * Return a *pointer* to the string, it has to be duplicated before being
 * stored.
 */
const char *qdict_entry_key(const QDictEntry *entry)
{
    return entry->key;
}

/**
 * qdict_find(): List lookup function
 */
static QDictEntry *qdict_find(const QDict *qdict,
                              const char *key, unsigned int bucket)
{
    QDictEntry *entry;

    QLIST_FOREACH(entry, &qdict->table[bucket], next)
        if (!strcmp(entry->key, key))
            return entry;

    return NULL;
}

/**
 * qdict_put_obj(): Put a new QObject into the dictionary
 *
 * Insert the pair 'key:value' into 'qdict', if 'key' already exists
 * its 'value' will be replaced.
 *
 * This is done by freeing the reference to the stored QObject and
 * storing the new one in the same entry.
 *
 * NOTE: ownership of 'value' is transferred to the QDict
 */
void qdict_put_obj(QDict *qdict, const char *key, QObject *value)
{
    unsigned int bucket;
    QDictEntry *entry;

    bucket = tdb_hash(key) % QDICT_BUCKET_MAX;
    entry = qdict_find(qdict, key, bucket);
    if (entry) {
        /* replace key's value */
        qobject_decref(entry->value);
        entry->value = value;
    } else {
        /* allocate a new entry */
        entry = alloc_entry(key, value);
        QLIST_INSERT_HEAD(&qdict->table[bucket], entry, next);
        qdict->size++;
    }
}

/**
 * qdict_get(): Lookup for a given 'key'
 *
 * Return a weak reference to the QObject associated with 'key' if
 * 'key' is present in the dictionary, NULL otherwise.
 */
QObject *qdict_get(const QDict *qdict, const char *key)
{
    QDictEntry *entry;

    entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
    return (entry == NULL ? NULL : entry->value);
}

/**
 * qdict_haskey(): Check if 'key' exists
 *
 * Return 1 if 'key' exists in the dict, 0 otherwise
 */
int qdict_haskey(const QDict *qdict, const char *key)
{
    unsigned int bucket = tdb_hash(key) % QDICT_BUCKET_MAX;
    return (qdict_find(qdict, key, bucket) == NULL ? 0 : 1);
}

/**
 * qdict_size(): Return the size of the dictionary
 */
size_t qdict_size(const QDict *qdict)
{
    return qdict->size;
}

/**
 * qdict_get_obj(): Get a QObject of a specific type
 */
static QObject *qdict_get_obj(const QDict *qdict, const char *key,
                              qtype_code type)
{
    QObject *obj;

    obj = qdict_get(qdict, key);
    assert(obj != NULL);
    assert(qobject_type(obj) == type);

    return obj;
}

/**
 * qdict_get_double(): Get an number mapped by 'key'
 *
 * This function assumes that 'key' exists and it stores a
 * QFloat or QInt object.
 *
 * Return number mapped by 'key'.
 */
double qdict_get_double(const QDict *qdict, const char *key)
{
    QObject *obj = qdict_get(qdict, key);

    assert(obj);
    switch (qobject_type(obj)) {
    case QTYPE_QFLOAT:
        return qfloat_get_double(qobject_to_qfloat(obj));
    case QTYPE_QINT:
        return qint_get_int(qobject_to_qint(obj));
    default:
        abort();
    }
}

/**
 * qdict_get_int(): Get an integer mapped by 'key'
 *
 * This function assumes that 'key' exists and it stores a
 * QInt object.
 *
 * Return integer mapped by 'key'.
 */
int64_t qdict_get_int(const QDict *qdict, const char *key)
{
    QObject *obj = qdict_get_obj(qdict, key, QTYPE_QINT);
    return qint_get_int(qobject_to_qint(obj));
}

/**
 * qdict_get_bool(): Get a bool mapped by 'key'
 *
 * This function assumes that 'key' exists and it stores a
 * QBool object.
 *
 * Return bool mapped by 'key'.
 */
int qdict_get_bool(const QDict *qdict, const char *key)
{
    QObject *obj = qdict_get_obj(qdict, key, QTYPE_QBOOL);
    return qbool_get_int(qobject_to_qbool(obj));
}

/**
 * qdict_get_qlist(): Get the QList mapped by 'key'
 *
 * This function assumes that 'key' exists and it stores a
 * QList object.
 *
 * Return QList mapped by 'key'.
 */
QList *qdict_get_qlist(const QDict *qdict, const char *key)
{
    return qobject_to_qlist(qdict_get_obj(qdict, key, QTYPE_QLIST));
}

/**
 * qdict_get_qdict(): Get the QDict mapped by 'key'
 *
 * This function assumes that 'key' exists and it stores a
 * QDict object.
 *
 * Return QDict mapped by 'key'.
 */
QDict *qdict_get_qdict(const QDict *qdict, const char *key)
{
    return qobject_to_qdict(qdict_get_obj(qdict, key, QTYPE_QDICT));
}

/**
 * qdict_get_str(): Get a pointer to the stored string mapped
 * by 'key'
 *
 * This function assumes that 'key' exists and it stores a
 * QString object.
 *
 * Return pointer to the string mapped by 'key'.
 */
const char *qdict_get_str(const QDict *qdict, const char *key)
{
    QObject *obj = qdict_get_obj(qdict, key, QTYPE_QSTRING);
    return qstring_get_str(qobject_to_qstring(obj));
}

/**
 * qdict_get_try_int(): Try to get integer mapped by 'key'
 *
 * Return integer mapped by 'key', if it is not present in
 * the dictionary or if the stored object is not of QInt type
 * 'def_value' will be returned.
 */
int64_t qdict_get_try_int(const QDict *qdict, const char *key,
                          int64_t def_value)
{
    QObject *obj;

    obj = qdict_get(qdict, key);
    if (!obj || qobject_type(obj) != QTYPE_QINT)
        return def_value;

    return qint_get_int(qobject_to_qint(obj));
}

/**
 * qdict_get_try_bool(): Try to get a bool mapped by 'key'
 *
 * Return bool mapped by 'key', if it is not present in the
 * dictionary or if the stored object is not of QBool type
 * 'def_value' will be returned.
 */
int qdict_get_try_bool(const QDict *qdict, const char *key, int def_value)
{
    QObject *obj;

    obj = qdict_get(qdict, key);
    if (!obj || qobject_type(obj) != QTYPE_QBOOL)
        return def_value;

    return qbool_get_int(qobject_to_qbool(obj));
}

/**
 * qdict_get_try_str(): Try to get a pointer to the stored string
 * mapped by 'key'
 *
 * Return a pointer to the string mapped by 'key', if it is not present
 * in the dictionary or if the stored object is not of QString type
 * NULL will be returned.
 */
const char *qdict_get_try_str(const QDict *qdict, const char *key)
{
    QObject *obj;

    obj = qdict_get(qdict, key);
    if (!obj || qobject_type(obj) != QTYPE_QSTRING)
        return NULL;

    return qstring_get_str(qobject_to_qstring(obj));
}

/**
 * qdict_iter(): Iterate over all the dictionary's stored values.
 *
 * This function allows the user to provide an iterator, which will be
 * called for each stored value in the dictionary.
 */
void qdict_iter(const QDict *qdict,
                void (*iter)(const char *key, QObject *obj, void *opaque),
                void *opaque)
{
    int i;
    QDictEntry *entry;

    for (i = 0; i < QDICT_BUCKET_MAX; i++) {
        QLIST_FOREACH(entry, &qdict->table[i], next)
            iter(entry->key, entry->value, opaque);
    }
}

static QDictEntry *qdict_next_entry(const QDict *qdict, int first_bucket)
{
    int i;

    for (i = first_bucket; i < QDICT_BUCKET_MAX; i++) {
        if (!QLIST_EMPTY(&qdict->table[i])) {
            return QLIST_FIRST(&qdict->table[i]);
        }
    }

    return NULL;
}

/**
 * qdict_first(): Return first qdict entry for iteration.
 */
const QDictEntry *qdict_first(const QDict *qdict)
{
    return qdict_next_entry(qdict, 0);
}

/**
 * qdict_next(): Return next qdict entry in an iteration.
 */
const QDictEntry *qdict_next(const QDict *qdict, const QDictEntry *entry)
{
    QDictEntry *ret;

    ret = QLIST_NEXT(entry, next);
    if (!ret) {
        unsigned int bucket = tdb_hash(entry->key) % QDICT_BUCKET_MAX;
        ret = qdict_next_entry(qdict, bucket + 1);
    }

    return ret;
}

/**
 * qdict_clone_shallow(): Clones a given QDict. Its entries are not copied, but
 * another reference is added.
 */
QDict *qdict_clone_shallow(const QDict *src)
{
    QDict *dest;
    QDictEntry *entry;
    int i;

    dest = qdict_new();

    for (i = 0; i < QDICT_BUCKET_MAX; i++) {
        QLIST_FOREACH(entry, &src->table[i], next) {
            qobject_incref(entry->value);
            qdict_put_obj(dest, entry->key, entry->value);
        }
    }

    return dest;
}

/**
 * qentry_destroy(): Free all the memory allocated by a QDictEntry
 */
static void qentry_destroy(QDictEntry *e)
{
    assert(e != NULL);
    assert(e->key != NULL);
    assert(e->value != NULL);

    qobject_decref(e->value);
    g_free(e->key);
    g_free(e);
}

/**
 * qdict_del(): Delete a 'key:value' pair from the dictionary
 *
 * This will destroy all data allocated by this entry.
 */
void qdict_del(QDict *qdict, const char *key)
{
    QDictEntry *entry;

    entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
    if (entry) {
        QLIST_REMOVE(entry, next);
        qentry_destroy(entry);
        qdict->size--;
    }
}

/**
 * qdict_destroy_obj(): Free all the memory allocated by a QDict
 */
static void qdict_destroy_obj(QObject *obj)
{
    int i;
    QDict *qdict;

    assert(obj != NULL);
    qdict = qobject_to_qdict(obj);

    for (i = 0; i < QDICT_BUCKET_MAX; i++) {
        QDictEntry *entry = QLIST_FIRST(&qdict->table[i]);
        while (entry) {
            QDictEntry *tmp = QLIST_NEXT(entry, next);
            QLIST_REMOVE(entry, next);
            qentry_destroy(entry);
            entry = tmp;
        }
    }

    g_free(qdict);
}

static void qdict_flatten_qdict(QDict *qdict, QDict *target,
                                const char *prefix);

static void qdict_flatten_qlist(QList *qlist, QDict *target, const char *prefix)
{
    QObject *value;
    const QListEntry *entry;
    char *new_key;
    int i;

    /* This function is never called with prefix == NULL, i.e., it is always
     * called from within qdict_flatten_q(list|dict)(). Therefore, it does not
     * need to remove list entries during the iteration (the whole list will be
     * deleted eventually anyway from qdict_flatten_qdict()). */
    assert(prefix);

    entry = qlist_first(qlist);

    for (i = 0; entry; entry = qlist_next(entry), i++) {
        value = qlist_entry_obj(entry);
        new_key = g_strdup_printf("%s.%i", prefix, i);

        if (qobject_type(value) == QTYPE_QDICT) {
            qdict_flatten_qdict(qobject_to_qdict(value), target, new_key);
        } else if (qobject_type(value) == QTYPE_QLIST) {
            qdict_flatten_qlist(qobject_to_qlist(value), target, new_key);
        } else {
            /* All other types are moved to the target unchanged. */
            qobject_incref(value);
            qdict_put_obj(target, new_key, value);
        }

        g_free(new_key);
    }
}

static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char *prefix)
{
    QObject *value;
    const QDictEntry *entry, *next;
    char *new_key;
    bool delete;

    entry = qdict_first(qdict);

    while (entry != NULL) {

        next = qdict_next(qdict, entry);
        value = qdict_entry_value(entry);
        new_key = NULL;
        delete = false;

        if (prefix) {
            new_key = g_strdup_printf("%s.%s", prefix, entry->key);
        }

        if (qobject_type(value) == QTYPE_QDICT) {
            /* Entries of QDicts are processed recursively, the QDict object
             * itself disappears. */
            qdict_flatten_qdict(qobject_to_qdict(value), target,
                                new_key ? new_key : entry->key);
            delete = true;
        } else if (qobject_type(value) == QTYPE_QLIST) {
            qdict_flatten_qlist(qobject_to_qlist(value), target,
                                new_key ? new_key : entry->key);
            delete = true;
        } else if (prefix) {
            /* All other objects are moved to the target unchanged. */
            qobject_incref(value);
            qdict_put_obj(target, new_key, value);
            delete = true;
        }

        g_free(new_key);

        if (delete) {
            qdict_del(qdict, entry->key);

            /* Restart loop after modifying the iterated QDict */
            entry = qdict_first(qdict);
            continue;
        }

        entry = next;
    }
}

/**
 * qdict_flatten(): For each nested QDict with key x, all fields with key y
 * are moved to this QDict and their key is renamed to "x.y". For each nested
 * QList with key x, the field at index y is moved to this QDict with the key
 * "x.y" (i.e., the reverse of what qdict_array_split() does).
 * This operation is applied recursively for nested QDicts and QLists.
 */
void qdict_flatten(QDict *qdict)
{
    qdict_flatten_qdict(qdict, qdict, NULL);
}

/* extract all the src QDict entries starting by start into dst */
void qdict_extract_subqdict(QDict *src, QDict **dst, const char *start)

{
    const QDictEntry *entry, *next;
    const char *p;

    *dst = qdict_new();
    entry = qdict_first(src);

    while (entry != NULL) {
        next = qdict_next(src, entry);
        if (strstart(entry->key, start, &p)) {
            qobject_incref(entry->value);
            qdict_put_obj(*dst, p, entry->value);
            qdict_del(src, entry->key);
        }
        entry = next;
    }
}

static bool qdict_has_prefixed_entries(const QDict *src, const char *start)
{
    const QDictEntry *entry;

    for (entry = qdict_first(src); entry; entry = qdict_next(src, entry)) {
        if (strstart(entry->key, start, NULL)) {
            return true;
        }
    }

    return false;
}

/**
 * qdict_array_split(): This function moves array-like elements of a QDict into
 * a new QList. Every entry in the original QDict with a key "%u" or one
 * prefixed "%u.", where %u designates an unsigned integer starting at 0 and
 * incrementally counting up, will be moved to a new QDict at index %u in the
 * output QList with the key prefix removed, if that prefix is "%u.". If the
 * whole key is just "%u", the whole QObject will be moved unchanged without
 * creating a new QDict. The function terminates when there is no entry in the
 * QDict with a prefix directly (incrementally) following the last one; it also
 * returns if there are both entries with "%u" and "%u." for the same index %u.
 * Example: {"0.a": 42, "0.b": 23, "1.x": 0, "4.y": 1, "o.o": 7, "2": 66}
 *      (or {"1.x": 0, "4.y": 1, "0.a": 42, "o.o": 7, "0.b": 23, "2": 66})
 *       => [{"a": 42, "b": 23}, {"x": 0}, 66]
 *      and {"4.y": 1, "o.o": 7} (remainder of the old QDict)
 */
void qdict_array_split(QDict *src, QList **dst)
{
    unsigned i;

    *dst = qlist_new();

    for (i = 0; i < UINT_MAX; i++) {
        QObject *subqobj;
        bool is_subqdict;
        QDict *subqdict;
        char indexstr[32], prefix[32];
        size_t snprintf_ret;

        snprintf_ret = snprintf(indexstr, 32, "%u", i);
        assert(snprintf_ret < 32);

        subqobj = qdict_get(src, indexstr);

        snprintf_ret = snprintf(prefix, 32, "%u.", i);
        assert(snprintf_ret < 32);

        is_subqdict = qdict_has_prefixed_entries(src, prefix);

        // There may be either a single subordinate object (named "%u") or
        // multiple objects (each with a key prefixed "%u."), but not both.
        if (!subqobj == !is_subqdict) {
            break;
        }

        if (is_subqdict) {
            qdict_extract_subqdict(src, &subqdict, prefix);
            assert(qdict_size(subqdict) > 0);
        } else {
            qobject_incref(subqobj);
            qdict_del(src, indexstr);
        }

        qlist_append_obj(*dst, subqobj ?: QOBJECT(subqdict));
    }
}