keep the PID file locked for the lifetime of the process
[qemu.git] / 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 "qint.h"
14 #include "qfloat.h"
15 #include "qdict.h"
16 #include "qbool.h"
17 #include "qstring.h"
18 #include "qobject.h"
19 #include "qemu-queue.h"
20 #include "qemu-common.h"
21
22 static void qdict_destroy_obj(QObject *obj);
23
24 static const QType qdict_type = {
25 .code = QTYPE_QDICT,
26 .destroy = qdict_destroy_obj,
27 };
28
29 /**
30 * qdict_new(): Create a new QDict
31 *
32 * Return strong reference.
33 */
34 QDict *qdict_new(void)
35 {
36 QDict *qdict;
37
38 qdict = g_malloc0(sizeof(*qdict));
39 QOBJECT_INIT(qdict, &qdict_type);
40
41 return qdict;
42 }
43
44 /**
45 * qobject_to_qdict(): Convert a QObject into a QDict
46 */
47 QDict *qobject_to_qdict(const QObject *obj)
48 {
49 if (qobject_type(obj) != QTYPE_QDICT)
50 return NULL;
51
52 return container_of(obj, QDict, base);
53 }
54
55 /**
56 * tdb_hash(): based on the hash agorithm from gdbm, via tdb
57 * (from module-init-tools)
58 */
59 static unsigned int tdb_hash(const char *name)
60 {
61 unsigned value; /* Used to compute the hash value. */
62 unsigned i; /* Used to cycle through random values. */
63
64 /* Set the initial value from the key size. */
65 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++)
66 value = (value + (((const unsigned char *)name)[i] << (i*5 % 24)));
67
68 return (1103515243 * value + 12345);
69 }
70
71 /**
72 * alloc_entry(): allocate a new QDictEntry
73 */
74 static QDictEntry *alloc_entry(const char *key, QObject *value)
75 {
76 QDictEntry *entry;
77
78 entry = g_malloc0(sizeof(*entry));
79 entry->key = g_strdup(key);
80 entry->value = value;
81
82 return entry;
83 }
84
85 /**
86 * qdict_entry_value(): Return qdict entry value
87 *
88 * Return weak reference.
89 */
90 QObject *qdict_entry_value(const QDictEntry *entry)
91 {
92 return entry->value;
93 }
94
95 /**
96 * qdict_entry_key(): Return qdict entry key
97 *
98 * Return a *pointer* to the string, it has to be duplicated before being
99 * stored.
100 */
101 const char *qdict_entry_key(const QDictEntry *entry)
102 {
103 return entry->key;
104 }
105
106 /**
107 * qdict_find(): List lookup function
108 */
109 static QDictEntry *qdict_find(const QDict *qdict,
110 const char *key, unsigned int bucket)
111 {
112 QDictEntry *entry;
113
114 QLIST_FOREACH(entry, &qdict->table[bucket], next)
115 if (!strcmp(entry->key, key))
116 return entry;
117
118 return NULL;
119 }
120
121 /**
122 * qdict_put_obj(): Put a new QObject into the dictionary
123 *
124 * Insert the pair 'key:value' into 'qdict', if 'key' already exists
125 * its 'value' will be replaced.
126 *
127 * This is done by freeing the reference to the stored QObject and
128 * storing the new one in the same entry.
129 *
130 * NOTE: ownership of 'value' is transferred to the QDict
131 */
132 void qdict_put_obj(QDict *qdict, const char *key, QObject *value)
133 {
134 unsigned int bucket;
135 QDictEntry *entry;
136
137 bucket = tdb_hash(key) % QDICT_BUCKET_MAX;
138 entry = qdict_find(qdict, key, bucket);
139 if (entry) {
140 /* replace key's value */
141 qobject_decref(entry->value);
142 entry->value = value;
143 } else {
144 /* allocate a new entry */
145 entry = alloc_entry(key, value);
146 QLIST_INSERT_HEAD(&qdict->table[bucket], entry, next);
147 qdict->size++;
148 }
149 }
150
151 /**
152 * qdict_get(): Lookup for a given 'key'
153 *
154 * Return a weak reference to the QObject associated with 'key' if
155 * 'key' is present in the dictionary, NULL otherwise.
156 */
157 QObject *qdict_get(const QDict *qdict, const char *key)
158 {
159 QDictEntry *entry;
160
161 entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
162 return (entry == NULL ? NULL : entry->value);
163 }
164
165 /**
166 * qdict_haskey(): Check if 'key' exists
167 *
168 * Return 1 if 'key' exists in the dict, 0 otherwise
169 */
170 int qdict_haskey(const QDict *qdict, const char *key)
171 {
172 unsigned int bucket = tdb_hash(key) % QDICT_BUCKET_MAX;
173 return (qdict_find(qdict, key, bucket) == NULL ? 0 : 1);
174 }
175
176 /**
177 * qdict_size(): Return the size of the dictionary
178 */
179 size_t qdict_size(const QDict *qdict)
180 {
181 return qdict->size;
182 }
183
184 /**
185 * qdict_get_obj(): Get a QObject of a specific type
186 */
187 static QObject *qdict_get_obj(const QDict *qdict, const char *key,
188 qtype_code type)
189 {
190 QObject *obj;
191
192 obj = qdict_get(qdict, key);
193 assert(obj != NULL);
194 assert(qobject_type(obj) == type);
195
196 return obj;
197 }
198
199 /**
200 * qdict_get_double(): Get an number mapped by 'key'
201 *
202 * This function assumes that 'key' exists and it stores a
203 * QFloat or QInt object.
204 *
205 * Return number mapped by 'key'.
206 */
207 double qdict_get_double(const QDict *qdict, const char *key)
208 {
209 QObject *obj = qdict_get(qdict, key);
210
211 assert(obj);
212 switch (qobject_type(obj)) {
213 case QTYPE_QFLOAT:
214 return qfloat_get_double(qobject_to_qfloat(obj));
215 case QTYPE_QINT:
216 return qint_get_int(qobject_to_qint(obj));
217 default:
218 abort();
219 }
220 }
221
222 /**
223 * qdict_get_int(): Get an integer mapped by 'key'
224 *
225 * This function assumes that 'key' exists and it stores a
226 * QInt object.
227 *
228 * Return integer mapped by 'key'.
229 */
230 int64_t qdict_get_int(const QDict *qdict, const char *key)
231 {
232 QObject *obj = qdict_get_obj(qdict, key, QTYPE_QINT);
233 return qint_get_int(qobject_to_qint(obj));
234 }
235
236 /**
237 * qdict_get_bool(): Get a bool mapped by 'key'
238 *
239 * This function assumes that 'key' exists and it stores a
240 * QBool object.
241 *
242 * Return bool mapped by 'key'.
243 */
244 int qdict_get_bool(const QDict *qdict, const char *key)
245 {
246 QObject *obj = qdict_get_obj(qdict, key, QTYPE_QBOOL);
247 return qbool_get_int(qobject_to_qbool(obj));
248 }
249
250 /**
251 * qdict_get_qlist(): Get the QList mapped by 'key'
252 *
253 * This function assumes that 'key' exists and it stores a
254 * QList object.
255 *
256 * Return QList mapped by 'key'.
257 */
258 QList *qdict_get_qlist(const QDict *qdict, const char *key)
259 {
260 return qobject_to_qlist(qdict_get_obj(qdict, key, QTYPE_QLIST));
261 }
262
263 /**
264 * qdict_get_qdict(): Get the QDict mapped by 'key'
265 *
266 * This function assumes that 'key' exists and it stores a
267 * QDict object.
268 *
269 * Return QDict mapped by 'key'.
270 */
271 QDict *qdict_get_qdict(const QDict *qdict, const char *key)
272 {
273 return qobject_to_qdict(qdict_get_obj(qdict, key, QTYPE_QDICT));
274 }
275
276 /**
277 * qdict_get_str(): Get a pointer to the stored string mapped
278 * by 'key'
279 *
280 * This function assumes that 'key' exists and it stores a
281 * QString object.
282 *
283 * Return pointer to the string mapped by 'key'.
284 */
285 const char *qdict_get_str(const QDict *qdict, const char *key)
286 {
287 QObject *obj = qdict_get_obj(qdict, key, QTYPE_QSTRING);
288 return qstring_get_str(qobject_to_qstring(obj));
289 }
290
291 /**
292 * qdict_get_try_int(): Try to get integer mapped by 'key'
293 *
294 * Return integer mapped by 'key', if it is not present in
295 * the dictionary or if the stored object is not of QInt type
296 * 'def_value' will be returned.
297 */
298 int64_t qdict_get_try_int(const QDict *qdict, const char *key,
299 int64_t def_value)
300 {
301 QObject *obj;
302
303 obj = qdict_get(qdict, key);
304 if (!obj || qobject_type(obj) != QTYPE_QINT)
305 return def_value;
306
307 return qint_get_int(qobject_to_qint(obj));
308 }
309
310 /**
311 * qdict_get_try_bool(): Try to get a bool mapped by 'key'
312 *
313 * Return bool mapped by 'key', if it is not present in the
314 * dictionary or if the stored object is not of QBool type
315 * 'def_value' will be returned.
316 */
317 int qdict_get_try_bool(const QDict *qdict, const char *key, int def_value)
318 {
319 QObject *obj;
320
321 obj = qdict_get(qdict, key);
322 if (!obj || qobject_type(obj) != QTYPE_QBOOL)
323 return def_value;
324
325 return qbool_get_int(qobject_to_qbool(obj));
326 }
327
328 /**
329 * qdict_get_try_str(): Try to get a pointer to the stored string
330 * mapped by 'key'
331 *
332 * Return a pointer to the string mapped by 'key', if it is not present
333 * in the dictionary or if the stored object is not of QString type
334 * NULL will be returned.
335 */
336 const char *qdict_get_try_str(const QDict *qdict, const char *key)
337 {
338 QObject *obj;
339
340 obj = qdict_get(qdict, key);
341 if (!obj || qobject_type(obj) != QTYPE_QSTRING)
342 return NULL;
343
344 return qstring_get_str(qobject_to_qstring(obj));
345 }
346
347 /**
348 * qdict_iter(): Iterate over all the dictionary's stored values.
349 *
350 * This function allows the user to provide an iterator, which will be
351 * called for each stored value in the dictionary.
352 */
353 void qdict_iter(const QDict *qdict,
354 void (*iter)(const char *key, QObject *obj, void *opaque),
355 void *opaque)
356 {
357 int i;
358 QDictEntry *entry;
359
360 for (i = 0; i < QDICT_BUCKET_MAX; i++) {
361 QLIST_FOREACH(entry, &qdict->table[i], next)
362 iter(entry->key, entry->value, opaque);
363 }
364 }
365
366 static QDictEntry *qdict_next_entry(const QDict *qdict, int first_bucket)
367 {
368 int i;
369
370 for (i = first_bucket; i < QDICT_BUCKET_MAX; i++) {
371 if (!QLIST_EMPTY(&qdict->table[i])) {
372 return QLIST_FIRST(&qdict->table[i]);
373 }
374 }
375
376 return NULL;
377 }
378
379 /**
380 * qdict_first(): Return first qdict entry for iteration.
381 */
382 const QDictEntry *qdict_first(const QDict *qdict)
383 {
384 return qdict_next_entry(qdict, 0);
385 }
386
387 /**
388 * qdict_next(): Return next qdict entry in an iteration.
389 */
390 const QDictEntry *qdict_next(const QDict *qdict, const QDictEntry *entry)
391 {
392 QDictEntry *ret;
393
394 ret = QLIST_NEXT(entry, next);
395 if (!ret) {
396 unsigned int bucket = tdb_hash(entry->key) % QDICT_BUCKET_MAX;
397 ret = qdict_next_entry(qdict, bucket + 1);
398 }
399
400 return ret;
401 }
402
403 /**
404 * qentry_destroy(): Free all the memory allocated by a QDictEntry
405 */
406 static void qentry_destroy(QDictEntry *e)
407 {
408 assert(e != NULL);
409 assert(e->key != NULL);
410 assert(e->value != NULL);
411
412 qobject_decref(e->value);
413 g_free(e->key);
414 g_free(e);
415 }
416
417 /**
418 * qdict_del(): Delete a 'key:value' pair from the dictionary
419 *
420 * This will destroy all data allocated by this entry.
421 */
422 void qdict_del(QDict *qdict, const char *key)
423 {
424 QDictEntry *entry;
425
426 entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
427 if (entry) {
428 QLIST_REMOVE(entry, next);
429 qentry_destroy(entry);
430 qdict->size--;
431 }
432 }
433
434 /**
435 * qdict_destroy_obj(): Free all the memory allocated by a QDict
436 */
437 static void qdict_destroy_obj(QObject *obj)
438 {
439 int i;
440 QDict *qdict;
441
442 assert(obj != NULL);
443 qdict = qobject_to_qdict(obj);
444
445 for (i = 0; i < QDICT_BUCKET_MAX; i++) {
446 QDictEntry *entry = QLIST_FIRST(&qdict->table[i]);
447 while (entry) {
448 QDictEntry *tmp = QLIST_NEXT(entry, next);
449 QLIST_REMOVE(entry, next);
450 qentry_destroy(entry);
451 entry = tmp;
452 }
453 }
454
455 g_free(qdict);
456 }