xref: /openbmc/qemu/qobject/qdict.c (revision 1be5a765c08cee3a9587c8a8d3fc2ea247b13f9c)
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