aboutsummaryrefslogtreecommitdiffstats
path: root/qdict.c
blob: c6a5a425e5ccaa56b4e331f24f945ab8a5a804d3 (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
/*
 * QDict data type.
 *
 * Copyright (C) 2009 Red Hat Inc.
 *
 * Authors:
 *  Luiz Capitulino <lcapitulino@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 */

#include "qint.h"
#include "qdict.h"
#include "qbool.h"
#include "qstring.h"
#include "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 = qemu_mallocz(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 = qemu_mallocz(sizeof(*entry));
    entry->key = qemu_strdup(key);
    entry->value = value;

    return entry;
}

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

    QLIST_FOREACH(entry, &qdict->table[hash], 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 hash;
    QDictEntry *entry;

    hash = tdb_hash(key) % QDICT_HASH_SIZE;
    entry = qdict_find(qdict, key, hash);
    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[hash], 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_HASH_SIZE);
    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 hash = tdb_hash(key) % QDICT_HASH_SIZE;
    return (qdict_find(qdict, key, hash) == 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_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
 * 'err_value' will be returned.
 */
int64_t qdict_get_try_int(const QDict *qdict, const char *key,
                          int64_t err_value)
{
    QObject *obj;

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

    return qint_get_int(qobject_to_qint(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_HASH_SIZE; i++) {
        QLIST_FOREACH(entry, &qdict->table[i], next)
            iter(entry->key, entry->value, opaque);
    }
}

/**
 * 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);
    qemu_free(e->key);
    qemu_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_HASH_SIZE);
    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_HASH_SIZE; 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;
        }
    }

    qemu_free(qdict);
}