xref: /openbmc/qemu/qobject/qdict.c (revision d709bbf3)
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/qnum.h"
15 #include "qapi/qmp/qdict.h"
16 #include "qapi/qmp/qbool.h"
17 #include "qapi/qmp/qnull.h"
18 #include "qapi/qmp/qstring.h"
19 #include "qobject-internal.h"
20 
21 /**
22  * qdict_new(): Create a new QDict
23  *
24  * Return strong reference.
25  */
qdict_new(void)26 QDict *qdict_new(void)
27 {
28     QDict *qdict;
29 
30     qdict = g_malloc0(sizeof(*qdict));
31     qobject_init(QOBJECT(qdict), QTYPE_QDICT);
32 
33     return qdict;
34 }
35 
36 /**
37  * tdb_hash(): based on the hash algorithm from gdbm, via tdb
38  * (from module-init-tools)
39  */
tdb_hash(const char * name)40 static unsigned int tdb_hash(const char *name)
41 {
42     unsigned value;    /* Used to compute the hash value.  */
43     unsigned   i;      /* Used to cycle through random values. */
44 
45     /* Set the initial value from the key size. */
46     for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) {
47         value = (value + (((const unsigned char *)name)[i] << (i * 5 % 24)));
48     }
49 
50     return (1103515243 * value + 12345);
51 }
52 
53 /**
54  * alloc_entry(): allocate a new QDictEntry
55  */
alloc_entry(const char * key,QObject * value)56 static QDictEntry *alloc_entry(const char *key, QObject *value)
57 {
58     QDictEntry *entry;
59 
60     entry = g_malloc0(sizeof(*entry));
61     entry->key = g_strdup(key);
62     entry->value = value;
63 
64     return entry;
65 }
66 
67 /**
68  * qdict_entry_value(): Return qdict entry value
69  *
70  * Return weak reference.
71  */
qdict_entry_value(const QDictEntry * entry)72 QObject *qdict_entry_value(const QDictEntry *entry)
73 {
74     return entry->value;
75 }
76 
77 /**
78  * qdict_entry_key(): Return qdict entry key
79  *
80  * Return a *pointer* to the string, it has to be duplicated before being
81  * stored.
82  */
qdict_entry_key(const QDictEntry * entry)83 const char *qdict_entry_key(const QDictEntry *entry)
84 {
85     return entry->key;
86 }
87 
88 /**
89  * qdict_find(): List lookup function
90  */
qdict_find(const QDict * qdict,const char * key,unsigned int bucket)91 static QDictEntry *qdict_find(const QDict *qdict,
92                               const char *key, unsigned int bucket)
93 {
94     QDictEntry *entry;
95 
96     QLIST_FOREACH(entry, &qdict->table[bucket], next)
97         if (!strcmp(entry->key, key)) {
98             return entry;
99         }
100 
101     return NULL;
102 }
103 
104 /**
105  * qdict_put_obj(): Put a new QObject into the dictionary
106  *
107  * Insert the pair 'key:value' into 'qdict', if 'key' already exists
108  * its 'value' will be replaced.
109  *
110  * This is done by freeing the reference to the stored QObject and
111  * storing the new one in the same entry.
112  *
113  * NOTE: ownership of 'value' is transferred to the QDict
114  */
qdict_put_obj(QDict * qdict,const char * key,QObject * value)115 void qdict_put_obj(QDict *qdict, const char *key, QObject *value)
116 {
117     unsigned int bucket;
118     QDictEntry *entry;
119 
120     bucket = tdb_hash(key) % QDICT_BUCKET_MAX;
121     entry = qdict_find(qdict, key, bucket);
122     if (entry) {
123         /* replace key's value */
124         qobject_unref(entry->value);
125         entry->value = value;
126     } else {
127         /* allocate a new entry */
128         entry = alloc_entry(key, value);
129         QLIST_INSERT_HEAD(&qdict->table[bucket], entry, next);
130         qdict->size++;
131     }
132 }
133 
qdict_put_int(QDict * qdict,const char * key,int64_t value)134 void qdict_put_int(QDict *qdict, const char *key, int64_t value)
135 {
136     qdict_put(qdict, key, qnum_from_int(value));
137 }
138 
qdict_put_bool(QDict * qdict,const char * key,bool value)139 void qdict_put_bool(QDict *qdict, const char *key, bool value)
140 {
141     qdict_put(qdict, key, qbool_from_bool(value));
142 }
143 
qdict_put_str(QDict * qdict,const char * key,const char * value)144 void qdict_put_str(QDict *qdict, const char *key, const char *value)
145 {
146     qdict_put(qdict, key, qstring_from_str(value));
147 }
148 
qdict_put_null(QDict * qdict,const char * key)149 void qdict_put_null(QDict *qdict, const char *key)
150 {
151     qdict_put(qdict, key, qnull());
152 }
153 
154 /**
155  * qdict_get(): Lookup for a given 'key'
156  *
157  * Return a weak reference to the QObject associated with 'key' if
158  * 'key' is present in the dictionary, NULL otherwise.
159  */
qdict_get(const QDict * qdict,const char * key)160 QObject *qdict_get(const QDict *qdict, const char *key)
161 {
162     QDictEntry *entry;
163 
164     entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
165     return (entry == NULL ? NULL : entry->value);
166 }
167 
168 /**
169  * qdict_haskey(): Check if 'key' exists
170  *
171  * Return 1 if 'key' exists in the dict, 0 otherwise
172  */
qdict_haskey(const QDict * qdict,const char * key)173 int qdict_haskey(const QDict *qdict, const char *key)
174 {
175     unsigned int bucket = tdb_hash(key) % QDICT_BUCKET_MAX;
176     return (qdict_find(qdict, key, bucket) == NULL ? 0 : 1);
177 }
178 
179 /**
180  * qdict_size(): Return the size of the dictionary
181  */
qdict_size(const QDict * qdict)182 size_t qdict_size(const QDict *qdict)
183 {
184     return qdict->size;
185 }
186 
187 /**
188  * qdict_get_double(): Get an number mapped by 'key'
189  *
190  * This function assumes that 'key' exists and it stores a QNum.
191  *
192  * Return number mapped by 'key'.
193  */
qdict_get_double(const QDict * qdict,const char * key)194 double qdict_get_double(const QDict *qdict, const char *key)
195 {
196     return qnum_get_double(qobject_to(QNum, qdict_get(qdict, key)));
197 }
198 
199 /**
200  * qdict_get_int(): Get an integer mapped by 'key'
201  *
202  * This function assumes that 'key' exists and it stores a
203  * QNum representable as int.
204  *
205  * Return integer mapped by 'key'.
206  */
qdict_get_int(const QDict * qdict,const char * key)207 int64_t qdict_get_int(const QDict *qdict, const char *key)
208 {
209     return qnum_get_int(qobject_to(QNum, qdict_get(qdict, key)));
210 }
211 
212 /**
213  * qdict_get_bool(): Get a bool mapped by 'key'
214  *
215  * This function assumes that 'key' exists and it stores a
216  * QBool object.
217  *
218  * Return bool mapped by 'key'.
219  */
qdict_get_bool(const QDict * qdict,const char * key)220 bool qdict_get_bool(const QDict *qdict, const char *key)
221 {
222     return qbool_get_bool(qobject_to(QBool, qdict_get(qdict, key)));
223 }
224 
225 /**
226  * qdict_get_qlist(): If @qdict maps @key to a QList, return it, else NULL.
227  */
qdict_get_qlist(const QDict * qdict,const char * key)228 QList *qdict_get_qlist(const QDict *qdict, const char *key)
229 {
230     return qobject_to(QList, qdict_get(qdict, key));
231 }
232 
233 /**
234  * qdict_get_qdict(): If @qdict maps @key to a QDict, return it, else NULL.
235  */
qdict_get_qdict(const QDict * qdict,const char * key)236 QDict *qdict_get_qdict(const QDict *qdict, const char *key)
237 {
238     return qobject_to(QDict, qdict_get(qdict, key));
239 }
240 
241 /**
242  * qdict_get_str(): Get a pointer to the stored string mapped
243  * by 'key'
244  *
245  * This function assumes that 'key' exists and it stores a
246  * QString object.
247  *
248  * Return pointer to the string mapped by 'key'.
249  */
qdict_get_str(const QDict * qdict,const char * key)250 const char *qdict_get_str(const QDict *qdict, const char *key)
251 {
252     return qstring_get_str(qobject_to(QString, qdict_get(qdict, key)));
253 }
254 
255 /**
256  * qdict_get_try_int(): Try to get integer mapped by 'key'
257  *
258  * Return integer mapped by 'key', if it is not present in the
259  * dictionary or if the stored object is not a QNum representing an
260  * integer, 'def_value' will be returned.
261  */
qdict_get_try_int(const QDict * qdict,const char * key,int64_t def_value)262 int64_t qdict_get_try_int(const QDict *qdict, const char *key,
263                           int64_t def_value)
264 {
265     QNum *qnum = qobject_to(QNum, qdict_get(qdict, key));
266     int64_t val;
267 
268     if (!qnum || !qnum_get_try_int(qnum, &val)) {
269         return def_value;
270     }
271 
272     return val;
273 }
274 
275 /**
276  * qdict_get_try_bool(): Try to get a bool mapped by 'key'
277  *
278  * Return bool mapped by 'key', if it is not present in the
279  * dictionary or if the stored object is not of QBool type
280  * 'def_value' will be returned.
281  */
qdict_get_try_bool(const QDict * qdict,const char * key,bool def_value)282 bool qdict_get_try_bool(const QDict *qdict, const char *key, bool def_value)
283 {
284     QBool *qbool = qobject_to(QBool, qdict_get(qdict, key));
285 
286     return qbool ? qbool_get_bool(qbool) : def_value;
287 }
288 
289 /**
290  * qdict_get_try_str(): Try to get a pointer to the stored string
291  * mapped by 'key'
292  *
293  * Return a pointer to the string mapped by 'key', if it is not present
294  * in the dictionary or if the stored object is not of QString type
295  * NULL will be returned.
296  */
qdict_get_try_str(const QDict * qdict,const char * key)297 const char *qdict_get_try_str(const QDict *qdict, const char *key)
298 {
299     QString *qstr = qobject_to(QString, qdict_get(qdict, key));
300 
301     return qstr ? qstring_get_str(qstr) : NULL;
302 }
303 
qdict_next_entry(const QDict * qdict,int first_bucket)304 static QDictEntry *qdict_next_entry(const QDict *qdict, int first_bucket)
305 {
306     int i;
307 
308     for (i = first_bucket; i < QDICT_BUCKET_MAX; i++) {
309         if (!QLIST_EMPTY(&qdict->table[i])) {
310             return QLIST_FIRST(&qdict->table[i]);
311         }
312     }
313 
314     return NULL;
315 }
316 
317 /**
318  * qdict_first(): Return first qdict entry for iteration.
319  */
qdict_first(const QDict * qdict)320 const QDictEntry *qdict_first(const QDict *qdict)
321 {
322     return qdict_next_entry(qdict, 0);
323 }
324 
325 /**
326  * qdict_next(): Return next qdict entry in an iteration.
327  */
qdict_next(const QDict * qdict,const QDictEntry * entry)328 const QDictEntry *qdict_next(const QDict *qdict, const QDictEntry *entry)
329 {
330     QDictEntry *ret;
331 
332     ret = QLIST_NEXT(entry, next);
333     if (!ret) {
334         unsigned int bucket = tdb_hash(entry->key) % QDICT_BUCKET_MAX;
335         ret = qdict_next_entry(qdict, bucket + 1);
336     }
337 
338     return ret;
339 }
340 
341 /**
342  * qdict_clone_shallow(): Clones a given QDict. Its entries are not copied, but
343  * another reference is added.
344  */
qdict_clone_shallow(const QDict * src)345 QDict *qdict_clone_shallow(const QDict *src)
346 {
347     QDict *dest;
348     QDictEntry *entry;
349     int i;
350 
351     dest = qdict_new();
352 
353     for (i = 0; i < QDICT_BUCKET_MAX; i++) {
354         QLIST_FOREACH(entry, &src->table[i], next) {
355             qdict_put_obj(dest, entry->key, qobject_ref(entry->value));
356         }
357     }
358 
359     return dest;
360 }
361 
362 /**
363  * qentry_destroy(): Free all the memory allocated by a QDictEntry
364  */
qentry_destroy(QDictEntry * e)365 static void qentry_destroy(QDictEntry *e)
366 {
367     assert(e != NULL);
368     assert(e->key != NULL);
369     assert(e->value != NULL);
370 
371     qobject_unref(e->value);
372     g_free(e->key);
373     g_free(e);
374 }
375 
376 /**
377  * qdict_del(): Delete a 'key:value' pair from the dictionary
378  *
379  * This will destroy all data allocated by this entry.
380  */
qdict_del(QDict * qdict,const char * key)381 void qdict_del(QDict *qdict, const char *key)
382 {
383     QDictEntry *entry;
384 
385     entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
386     if (entry) {
387         QLIST_REMOVE(entry, next);
388         qentry_destroy(entry);
389         qdict->size--;
390     }
391 }
392 
393 /**
394  * qdict_is_equal(): Test whether the two QDicts are equal
395  *
396  * Here, equality means whether they contain the same keys and whether
397  * the respective values are in turn equal (i.e. invoking
398  * qobject_is_equal() on them yields true).
399  */
qdict_is_equal(const QObject * x,const QObject * y)400 bool qdict_is_equal(const QObject *x, const QObject *y)
401 {
402     const QDict *dict_x = qobject_to(QDict, x);
403     const QDict *dict_y = qobject_to(QDict, y);
404     const QDictEntry *e;
405 
406     if (qdict_size(dict_x) != qdict_size(dict_y)) {
407         return false;
408     }
409 
410     for (e = qdict_first(dict_x); e; e = qdict_next(dict_x, e)) {
411         const QObject *obj_x = qdict_entry_value(e);
412         const QObject *obj_y = qdict_get(dict_y, qdict_entry_key(e));
413 
414         if (!qobject_is_equal(obj_x, obj_y)) {
415             return false;
416         }
417     }
418 
419     return true;
420 }
421 
422 /**
423  * qdict_destroy_obj(): Free all the memory allocated by a QDict
424  */
qdict_destroy_obj(QObject * obj)425 void qdict_destroy_obj(QObject *obj)
426 {
427     int i;
428     QDict *qdict;
429 
430     assert(obj != NULL);
431     qdict = qobject_to(QDict, obj);
432 
433     for (i = 0; i < QDICT_BUCKET_MAX; i++) {
434         QDictEntry *entry = QLIST_FIRST(&qdict->table[i]);
435         while (entry) {
436             QDictEntry *tmp = QLIST_NEXT(entry, next);
437             QLIST_REMOVE(entry, next);
438             qentry_destroy(entry);
439             entry = tmp;
440         }
441     }
442 
443     g_free(qdict);
444 }
445 
qdict_unref(QDict * q)446 void qdict_unref(QDict *q)
447 {
448     qobject_unref(q);
449 }
450