Asterisk - The Open Source Telephony Project  21.4.1
astobj2_hash.c
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1 /*
2  * astobj2_hash - Hash table implementation for astobj2.
3  *
4  * Copyright (C) 2006 Marta Carbone, Luigi Rizzo - Univ. di Pisa, Italy
5  *
6  * See http://www.asterisk.org for more information about
7  * the Asterisk project. Please do not directly contact
8  * any of the maintainers of this project for assistance;
9  * the project provides a web site, mailing lists and IRC
10  * channels for your use.
11  *
12  * This program is free software, distributed under the terms of
13  * the GNU General Public License Version 2. See the LICENSE file
14  * at the top of the source tree.
15  */
16 
17 /*! \file
18  *
19  * \brief Hash table functions implementing astobj2 containers.
20  *
21  * \author Richard Mudgett <rmudgett@digium.com>
22  */
23 
24 #include "asterisk.h"
25 
26 #include "asterisk/_private.h"
27 #include "asterisk/astobj2.h"
28 #include "astobj2_private.h"
30 #include "asterisk/dlinkedlists.h"
31 #include "asterisk/utils.h"
32 
33 /*!
34  * A structure to create a linked list of entries,
35  * used within a bucket.
36  */
38  /*!
39  * \brief Items common to all container nodes.
40  * \note Must be first in the specific node struct.
41  */
43  /*! Next node links in the list. */
45  /*! Hash bucket holding the node. */
46  int my_bucket;
47 };
48 
49 struct hash_bucket {
50  /*! List of objects held in the bucket. */
52 #if defined(AO2_DEBUG)
53  /*! Number of elements currently in the bucket. */
54  int elements;
55  /*! Maximum number of elements in the bucket. */
56  int max_elements;
57 #endif /* defined(AO2_DEBUG) */
58 };
59 
60 /*!
61  * A hash container in addition to values common to all
62  * container types, stores the hash callback function, the
63  * number of hash buckets, and the hash bucket heads.
64  */
66  /*!
67  * \brief Items common to all containers.
68  * \note Must be first in the specific container struct.
69  */
71  ao2_hash_fn *hash_fn;
72  /*! Number of hash buckets in this container. */
73  int n_buckets;
74  /*! Hash bucket array of n_buckets. Variable size. */
75  struct hash_bucket buckets[0];
76 };
77 
78 /*! Traversal state to restart a hash container traversal. */
80  /*! Active sort function in the traversal if not NULL. */
82  /*! Saved comparison callback arg pointer. */
83  void *arg;
84  /*! Starting hash bucket */
86  /*! Stopping hash bucket */
88  /*! Saved search flags to control traversing the container. */
89  enum search_flags flags;
90  /*! TRUE if it is a descending search */
91  unsigned int descending:1;
92 };
93 
95  /*
96  * If we have a division by zero compile error here then there
97  * is not enough room for the state. Increase AO2_TRAVERSAL_STATE_SIZE.
98  */
99  char check[1 / (AO2_TRAVERSAL_STATE_SIZE / sizeof(struct hash_traversal_state))];
100 };
101 
102 /*!
103  * \internal
104  * \brief Create an empty copy of this container.
105  * \since 14.0.0
106  *
107  * \param self Container to operate upon.
108  * \param tag used for debugging.
109  * \param file Debug file name invoked from
110  * \param line Debug line invoked from
111  * \param func Debug function name invoked from
112  *
113  * \return empty-clone-container on success.
114  * \retval NULL on error.
115  */
116 static struct ao2_container *hash_ao2_alloc_empty_clone(struct ao2_container_hash *self,
117  const char *tag, const char *file, int line, const char *func)
118 {
119  if (!__is_ao2_object(self, file, line, func)) {
120  return NULL;
121  }
122 
123  return __ao2_container_alloc_hash(ao2_options_get(self), self->common.options,
124  self->n_buckets, self->hash_fn, self->common.sort_fn, self->common.cmp_fn,
125  tag, file, line, func);
126 }
127 
128 /*!
129  * \internal
130  * \brief Destroy a hash container list node.
131  * \since 12.0.0
132  *
133  * \param v_doomed Container node to destroy.
134  *
135  * \details
136  * The container node unlinks itself from the container as part
137  * of its destruction. The node must be destroyed while the
138  * container is already locked.
139  *
140  * \note The container must be locked when the node is
141  * unreferenced.
142  */
143 static void hash_ao2_node_destructor(void *v_doomed)
144 {
145  struct hash_bucket_node *doomed = v_doomed;
146 
147  if (doomed->common.is_linked) {
148  struct ao2_container_hash *my_container;
149  struct hash_bucket *bucket;
150 
151  /*
152  * Promote to write lock if not already there. Since
153  * adjust_lock() can potentially release and block waiting for a
154  * write lock, care must be taken to ensure that node references
155  * are released before releasing the container references.
156  *
157  * Node references held by an iterator can only be held while
158  * the iterator also holds a reference to the container. These
159  * node references must be unreferenced before the container can
160  * be unreferenced to ensure that the node will not get a
161  * negative reference and the destructor called twice for the
162  * same node.
163  */
164  my_container = (struct ao2_container_hash *) doomed->common.my_container;
165 #ifdef AST_DEVMODE
166  is_ao2_object(my_container);
167 #endif
168 
169  __adjust_lock(my_container, AO2_LOCK_REQ_WRLOCK, 1);
170 
171 #if defined(AO2_DEBUG)
172  if (!my_container->common.destroying
174  ast_log(LOG_ERROR, "Container integrity failed before node deletion.\n");
175  }
176 #endif /* defined(AO2_DEBUG) */
177  bucket = &my_container->buckets[doomed->my_bucket];
178  AST_DLLIST_REMOVE(&bucket->list, doomed, links);
179  AO2_DEVMODE_STAT(--my_container->common.nodes);
180  }
181 
182  /*
183  * We could have an object in the node if the container is being
184  * destroyed or the node had not been linked in yet.
185  */
186  if (doomed->common.obj) {
187  __container_unlink_node(&doomed->common, AO2_UNLINK_NODE_UNLINK_OBJECT);
188  }
189 }
190 
191 /*!
192  * \internal
193  * \brief Create a new container node.
194  * \since 12.0.0
195  *
196  * \param self Container to operate upon.
197  * \param obj_new Object to put into the node.
198  * \param tag used for debugging.
199  * \param file Debug file name invoked from
200  * \param line Debug line invoked from
201  * \param func Debug function name invoked from
202  *
203  * \return initialized-node on success.
204  * \retval NULL on error.
205  */
206 static struct hash_bucket_node *hash_ao2_new_node(struct ao2_container_hash *self, void *obj_new, const char *tag, const char *file, int line, const char *func)
207 {
208  struct hash_bucket_node *node;
209  int i;
210 
211  node = ao2_alloc_options(sizeof(*node), hash_ao2_node_destructor,
213  if (!node) {
214  return NULL;
215  }
216 
217  i = abs(self->hash_fn(obj_new, OBJ_SEARCH_OBJECT) % self->n_buckets);
218 
219  __ao2_ref(obj_new, +1, tag ?: "Container node creation", file, line, func);
220  node->common.obj = obj_new;
221  node->common.my_container = (struct ao2_container *) self;
222  node->my_bucket = i;
223 
224  return node;
225 }
226 
227 /*!
228  * \internal
229  * \brief Insert a node into this container.
230  * \since 12.0.0
231  *
232  * \param self Container to operate upon.
233  * \param node Container node to insert into the container.
234  *
235  * \return \ref ao2_container_insert value.
236  */
237 static enum ao2_container_insert hash_ao2_insert_node(struct ao2_container_hash *self,
238  struct hash_bucket_node *node)
239 {
240  int cmp;
241  struct hash_bucket *bucket;
242  struct hash_bucket_node *cur;
243  ao2_sort_fn *sort_fn;
244  uint32_t options;
245 
246  bucket = &self->buckets[node->my_bucket];
247  sort_fn = self->common.sort_fn;
248  options = self->common.options;
249 
250  if (options & AO2_CONTAINER_ALLOC_OPT_INSERT_BEGIN) {
251  if (sort_fn) {
253  cmp = sort_fn(cur->common.obj, node->common.obj, OBJ_SEARCH_OBJECT);
254  if (cmp > 0) {
255  continue;
256  }
257  if (cmp < 0) {
260  }
261  switch (options & AO2_CONTAINER_ALLOC_OPT_DUPS_MASK) {
262  default:
264  break;
266  /* Reject all objects with the same key. */
269  if (cur->common.obj == node->common.obj) {
270  /* Reject inserting the same object */
272  }
273  break;
275  SWAP(cur->common.obj, node->common.obj);
276  ao2_ref(node, -1);
278  }
279  }
281  }
282  AST_DLLIST_INSERT_HEAD(&bucket->list, node, links);
283  } else {
284  if (sort_fn) {
285  AST_DLLIST_TRAVERSE_SAFE_BEGIN(&bucket->list, cur, links) {
286  cmp = sort_fn(cur->common.obj, node->common.obj, OBJ_SEARCH_OBJECT);
287  if (cmp < 0) {
288  continue;
289  }
290  if (cmp > 0) {
293  }
294  switch (options & AO2_CONTAINER_ALLOC_OPT_DUPS_MASK) {
295  default:
297  break;
299  /* Reject all objects with the same key. */
302  if (cur->common.obj == node->common.obj) {
303  /* Reject inserting the same object */
305  }
306  break;
308  SWAP(cur->common.obj, node->common.obj);
309  ao2_ref(node, -1);
311  }
312  }
314  }
315  AST_DLLIST_INSERT_TAIL(&bucket->list, node, links);
316  }
318 }
319 
320 /*!
321  * \internal
322  * \brief Find the first hash container node in a traversal.
323  * \since 12.0.0
324  *
325  * \param self Container to operate upon.
326  * \param flags search_flags to control traversing the container
327  * \param arg Comparison callback arg parameter.
328  * \param state Traversal state to restart hash container traversal.
329  *
330  * \return node-ptr of found node (Reffed).
331  * \retval NULL when no node found.
332  */
333 static struct hash_bucket_node *hash_ao2_find_first(struct ao2_container_hash *self, enum search_flags flags, void *arg, struct hash_traversal_state *state)
334 {
335  struct hash_bucket_node *node;
336  int bucket_cur;
337  int cmp;
338 
339  memset(state, 0, sizeof(*state));
340  state->arg = arg;
341  state->flags = flags;
342 
343  /* Determine traversal order. */
344  switch (flags & OBJ_ORDER_MASK) {
345  case OBJ_ORDER_POST:
347  state->descending = 1;
348  break;
349  case OBJ_ORDER_PRE:
350  case OBJ_ORDER_ASCENDING:
351  default:
352  break;
353  }
354 
355  /*
356  * If lookup by pointer or search key, run the hash and optional
357  * sort functions. Otherwise, traverse the whole container.
358  */
359  switch (flags & OBJ_SEARCH_MASK) {
360  case OBJ_SEARCH_OBJECT:
361  case OBJ_SEARCH_KEY:
362  /* we know hash can handle this case */
363  bucket_cur = abs(self->hash_fn(arg, flags & OBJ_SEARCH_MASK)
364  % self->n_buckets);
365  state->sort_fn = self->common.sort_fn;
366  break;
368  /* scan all buckets for partial key matches */
369  bucket_cur = -1;
370  state->sort_fn = self->common.sort_fn;
371  break;
372  default:
373  /* don't know, let's scan all buckets */
374  bucket_cur = -1;
375  state->sort_fn = NULL;
376  break;
377  }
378 
379  if (state->descending) {
380  /*
381  * Determine the search boundaries of a descending traversal.
382  *
383  * bucket_cur downto state->bucket_last
384  */
385  if (bucket_cur < 0) {
386  bucket_cur = self->n_buckets - 1;
387  state->bucket_last = 0;
388  } else {
389  state->bucket_last = bucket_cur;
390  }
391  state->bucket_start = bucket_cur;
392 
393  /* For each bucket */
394  for (; state->bucket_last <= bucket_cur; --bucket_cur) {
395  /* For each node in the bucket. */
396  for (node = AST_DLLIST_LAST(&self->buckets[bucket_cur].list);
397  node;
398  node = AST_DLLIST_PREV(node, links)) {
399  if (!node->common.obj) {
400  /* Node is empty */
401  continue;
402  }
403 
404  if (state->sort_fn) {
405  /* Filter node through the sort_fn */
406  cmp = state->sort_fn(node->common.obj, arg, flags & OBJ_SEARCH_MASK);
407  if (cmp > 0) {
408  continue;
409  }
410  if (cmp < 0) {
411  /* No more nodes in this bucket are possible to match. */
412  break;
413  }
414  }
415 
416  /* We have the first traversal node */
417  ao2_ref(node, +1);
418  return node;
419  }
420  }
421  } else {
422  /*
423  * Determine the search boundaries of an ascending traversal.
424  *
425  * bucket_cur to state->bucket_last-1
426  */
427  if (bucket_cur < 0) {
428  bucket_cur = 0;
429  state->bucket_last = self->n_buckets;
430  } else {
431  state->bucket_last = bucket_cur + 1;
432  }
433  state->bucket_start = bucket_cur;
434 
435  /* For each bucket */
436  for (; bucket_cur < state->bucket_last; ++bucket_cur) {
437  /* For each node in the bucket. */
438  for (node = AST_DLLIST_FIRST(&self->buckets[bucket_cur].list);
439  node;
440  node = AST_DLLIST_NEXT(node, links)) {
441  if (!node->common.obj) {
442  /* Node is empty */
443  continue;
444  }
445 
446  if (state->sort_fn) {
447  /* Filter node through the sort_fn */
448  cmp = state->sort_fn(node->common.obj, arg, flags & OBJ_SEARCH_MASK);
449  if (cmp < 0) {
450  continue;
451  }
452  if (cmp > 0) {
453  /* No more nodes in this bucket are possible to match. */
454  break;
455  }
456  }
457 
458  /* We have the first traversal node */
459  ao2_ref(node, +1);
460  return node;
461  }
462  }
463  }
464 
465  return NULL;
466 }
467 
468 /*!
469  * \internal
470  * \brief Find the next hash container node in a traversal.
471  * \since 12.0.0
472  *
473  * \param self Container to operate upon.
474  * \param state Traversal state to restart hash container traversal.
475  * \param prev Previous node returned by the traversal search functions.
476  * The ref ownership is passed back to this function.
477  *
478  * \return node-ptr of found node (Reffed).
479  * \retval NULL when no node found.
480  */
481 static struct hash_bucket_node *hash_ao2_find_next(struct ao2_container_hash *self, struct hash_traversal_state *state, struct hash_bucket_node *prev)
482 {
483  struct hash_bucket_node *node;
484  void *arg;
485  enum search_flags flags;
486  int bucket_cur;
487  int cmp;
488 
489  arg = state->arg;
490  flags = state->flags;
491  bucket_cur = prev->my_bucket;
492  node = prev;
493 
494  /*
495  * This function is structured the same as hash_ao2_find_first()
496  * intentionally. We are resuming the search loops from
497  * hash_ao2_find_first() in order to find the next node. The
498  * search loops must be resumed where hash_ao2_find_first()
499  * returned with the first node.
500  */
501  if (state->descending) {
502  goto hash_descending_resume;
503 
504  /* For each bucket */
505  for (; state->bucket_last <= bucket_cur; --bucket_cur) {
506  /* For each node in the bucket. */
507  for (node = AST_DLLIST_LAST(&self->buckets[bucket_cur].list);
508  node;
509  node = AST_DLLIST_PREV(node, links)) {
510  if (!node->common.obj) {
511  /* Node is empty */
512  continue;
513  }
514 
515  if (state->sort_fn) {
516  /* Filter node through the sort_fn */
517  cmp = state->sort_fn(node->common.obj, arg, flags & OBJ_SEARCH_MASK);
518  if (cmp > 0) {
519  continue;
520  }
521  if (cmp < 0) {
522  /* No more nodes in this bucket are possible to match. */
523  break;
524  }
525  }
526 
527  /* We have the next traversal node */
528  ao2_ref(node, +1);
529 
530  /*
531  * Dereferencing the prev node may result in our next node
532  * object being removed by another thread. This could happen if
533  * the container uses RW locks and the container was read
534  * locked.
535  */
536  ao2_ref(prev, -1);
537  if (node->common.obj) {
538  return node;
539  }
540  prev = node;
541 
542 hash_descending_resume:;
543  }
544  }
545  } else {
546  goto hash_ascending_resume;
547 
548  /* For each bucket */
549  for (; bucket_cur < state->bucket_last; ++bucket_cur) {
550  /* For each node in the bucket. */
551  for (node = AST_DLLIST_FIRST(&self->buckets[bucket_cur].list);
552  node;
553  node = AST_DLLIST_NEXT(node, links)) {
554  if (!node->common.obj) {
555  /* Node is empty */
556  continue;
557  }
558 
559  if (state->sort_fn) {
560  /* Filter node through the sort_fn */
561  cmp = state->sort_fn(node->common.obj, arg, flags & OBJ_SEARCH_MASK);
562  if (cmp < 0) {
563  continue;
564  }
565  if (cmp > 0) {
566  /* No more nodes in this bucket are possible to match. */
567  break;
568  }
569  }
570 
571  /* We have the next traversal node */
572  ao2_ref(node, +1);
573 
574  /*
575  * Dereferencing the prev node may result in our next node
576  * object being removed by another thread. This could happen if
577  * the container uses RW locks and the container was read
578  * locked.
579  */
580  ao2_ref(prev, -1);
581  if (node->common.obj) {
582  return node;
583  }
584  prev = node;
585 
586 hash_ascending_resume:;
587  }
588  }
589  }
590 
591  /* No more nodes in the container left to traverse. */
592  ao2_ref(prev, -1);
593  return NULL;
594 }
595 
596 /*!
597  * \internal
598  * \brief Find the next non-empty iteration node in the container.
599  * \since 12.0.0
600  *
601  * \param self Container to operate upon.
602  * \param node Previous node returned by the iterator.
603  * \param flags search_flags to control iterating the container.
604  * Only AO2_ITERATOR_DESCENDING is useful by the method.
605  *
606  * \note The container is already locked.
607  *
608  * \return node on success.
609  * \retval NULL on error or no more nodes in the container.
610  */
611 static struct hash_bucket_node *hash_ao2_iterator_next(struct ao2_container_hash *self, struct hash_bucket_node *node, enum ao2_iterator_flags flags)
612 {
613  int cur_bucket;
614 
615  if (flags & AO2_ITERATOR_DESCENDING) {
616  if (node) {
617  cur_bucket = node->my_bucket;
618 
619  /* Find next non-empty node. */
620  for (;;) {
621  node = AST_DLLIST_PREV(node, links);
622  if (!node) {
623  break;
624  }
625  if (node->common.obj) {
626  /* Found a non-empty node. */
627  return node;
628  }
629  }
630  } else {
631  /* Find first non-empty node. */
632  cur_bucket = self->n_buckets;
633  }
634 
635  /* Find a non-empty node in the remaining buckets */
636  while (0 <= --cur_bucket) {
637  node = AST_DLLIST_LAST(&self->buckets[cur_bucket].list);
638  while (node) {
639  if (node->common.obj) {
640  /* Found a non-empty node. */
641  return node;
642  }
643  node = AST_DLLIST_PREV(node, links);
644  }
645  }
646  } else {
647  if (node) {
648  cur_bucket = node->my_bucket;
649 
650  /* Find next non-empty node. */
651  for (;;) {
652  node = AST_DLLIST_NEXT(node, links);
653  if (!node) {
654  break;
655  }
656  if (node->common.obj) {
657  /* Found a non-empty node. */
658  return node;
659  }
660  }
661  } else {
662  /* Find first non-empty node. */
663  cur_bucket = -1;
664  }
665 
666  /* Find a non-empty node in the remaining buckets */
667  while (++cur_bucket < self->n_buckets) {
668  node = AST_DLLIST_FIRST(&self->buckets[cur_bucket].list);
669  while (node) {
670  if (node->common.obj) {
671  /* Found a non-empty node. */
672  return node;
673  }
674  node = AST_DLLIST_NEXT(node, links);
675  }
676  }
677  }
678 
679  /* No more nodes to visit in the container. */
680  return NULL;
681 }
682 
683 #if defined(AO2_DEBUG)
684 /*!
685  * \internal
686  * \brief Increment the hash container linked object statistic.
687  * \since 12.0.0
688  *
689  * \param hash Container to operate upon.
690  * \param hash_node Container node linking object to.
691  */
692 static void hash_ao2_link_node_stat(struct ao2_container *hash, struct ao2_container_node *hash_node)
693 {
694  struct ao2_container_hash *self = (struct ao2_container_hash *) hash;
695  struct hash_bucket_node *node = (struct hash_bucket_node *) hash_node;
696  int i = node->my_bucket;
697 
698  ++self->buckets[i].elements;
699  if (self->buckets[i].max_elements < self->buckets[i].elements) {
700  self->buckets[i].max_elements = self->buckets[i].elements;
701  }
702 }
703 #endif /* defined(AO2_DEBUG) */
704 
705 #if defined(AO2_DEBUG)
706 /*!
707  * \internal
708  * \brief Decrement the hash container linked object statistic.
709  * \since 12.0.0
710  *
711  * \param hash Container to operate upon.
712  * \param hash_node Container node unlinking object from.
713  */
714 static void hash_ao2_unlink_node_stat(struct ao2_container *hash, struct ao2_container_node *hash_node)
715 {
716  struct ao2_container_hash *self = (struct ao2_container_hash *) hash;
717  struct hash_bucket_node *node = (struct hash_bucket_node *) hash_node;
718 
719  --self->buckets[node->my_bucket].elements;
720 }
721 #endif /* defined(AO2_DEBUG) */
722 
723 /*!
724  * \internal
725  *
726  * \brief Destroy this container.
727  * \since 12.0.0
728  *
729  * \param self Container to operate upon.
730  */
731 static void hash_ao2_destroy(struct ao2_container_hash *self)
732 {
733  int idx;
734 
735  /* Check that the container no longer has any nodes */
736  for (idx = self->n_buckets; idx--;) {
737  if (!AST_DLLIST_EMPTY(&self->buckets[idx].list)) {
738  ast_log(LOG_ERROR, "Node ref leak. Hash container still has nodes!\n");
739  ast_assert(0);
740  break;
741  }
742  }
743 }
744 
745 #if defined(AO2_DEBUG)
746 /*!
747  * \internal
748  * \brief Display contents of the specified container.
749  * \since 12.0.0
750  *
751  * \param self Container to dump.
752  * \param where User data needed by prnt to determine where to put output.
753  * \param prnt Print output callback function to use.
754  * \param prnt_obj Callback function to print the given object's key. (NULL if not available)
755  */
756 static void hash_ao2_dump(struct ao2_container_hash *self, void *where, ao2_prnt_fn *prnt, ao2_prnt_obj_fn *prnt_obj)
757 {
758 #define FORMAT "%6s, %16s, %16s, %16s, %16s, %s\n"
759 #define FORMAT2 "%6d, %16p, %16p, %16p, %16p, "
760 
761  int bucket;
762  int suppressed_buckets = 0;
763  struct hash_bucket_node *node;
764 
765  prnt(where, "Number of buckets: %d\n\n", self->n_buckets);
766 
767  prnt(where, FORMAT, "Bucket", "Node", "Prev", "Next", "Obj", "Key");
768  for (bucket = 0; bucket < self->n_buckets; ++bucket) {
769  node = AST_DLLIST_FIRST(&self->buckets[bucket].list);
770  if (node) {
771  suppressed_buckets = 0;
772  do {
773  prnt(where, FORMAT2,
774  bucket,
775  node,
776  AST_DLLIST_PREV(node, links),
777  AST_DLLIST_NEXT(node, links),
778  node->common.obj);
779  if (node->common.obj && prnt_obj) {
780  prnt_obj(node->common.obj, where, prnt);
781  }
782  prnt(where, "\n");
783 
784  node = AST_DLLIST_NEXT(node, links);
785  } while (node);
786  } else if (!suppressed_buckets) {
787  suppressed_buckets = 1;
788  prnt(where, "...\n");
789  }
790  }
791 
792 #undef FORMAT
793 #undef FORMAT2
794 }
795 #endif /* defined(AO2_DEBUG) */
796 
797 #if defined(AO2_DEBUG)
798 /*!
799  * \internal
800  * \brief Display statistics of the specified container.
801  * \since 12.0.0
802  *
803  * \param self Container to display statistics.
804  * \param where User data needed by prnt to determine where to put output.
805  * \param prnt Print output callback function to use.
806  *
807  * \note The container is already locked for reading.
808  */
809 static void hash_ao2_stats(struct ao2_container_hash *self, void *where, ao2_prnt_fn *prnt)
810 {
811 #define FORMAT "%10.10s %10.10s %10.10s\n"
812 #define FORMAT2 "%10d %10d %10d\n"
813 
814  int bucket;
815  int suppressed_buckets = 0;
816 
817  prnt(where, "Number of buckets: %d\n\n", self->n_buckets);
818 
819  prnt(where, FORMAT, "Bucket", "Objects", "Max");
820  for (bucket = 0; bucket < self->n_buckets; ++bucket) {
821  if (self->buckets[bucket].max_elements) {
822  suppressed_buckets = 0;
823  prnt(where, FORMAT2, bucket, self->buckets[bucket].elements,
824  self->buckets[bucket].max_elements);
825  } else if (!suppressed_buckets) {
826  suppressed_buckets = 1;
827  prnt(where, "...\n");
828  }
829  }
830 
831 #undef FORMAT
832 #undef FORMAT2
833 }
834 #endif /* defined(AO2_DEBUG) */
835 
836 #if defined(AO2_DEBUG)
837 /*!
838  * \internal
839  * \brief Perform an integrity check on the specified container.
840  * \since 12.0.0
841  *
842  * \param self Container to check integrity.
843  *
844  * \note The container is already locked for reading.
845  *
846  * \retval 0 on success.
847  * \retval -1 on error.
848  */
849 static int hash_ao2_integrity(struct ao2_container_hash *self)
850 {
851  int bucket_exp;
852  int bucket;
853  int count_obj;
854  int count_total_obj;
855  int count_total_node;
856  void *obj_last;
857  struct hash_bucket_node *node;
858  struct hash_bucket_node *prev;
859  struct hash_bucket_node *next;
860 
861  count_total_obj = 0;
862  count_total_node = 0;
863 
864  /* For each bucket in the container. */
865  for (bucket = 0; bucket < self->n_buckets; ++bucket) {
866  if (!AST_DLLIST_FIRST(&self->buckets[bucket].list)
867  && !AST_DLLIST_LAST(&self->buckets[bucket].list)) {
868  /* The bucket list is empty. */
869  continue;
870  }
871 
872  count_obj = 0;
873  obj_last = NULL;
874 
875  /* Check bucket list links and nodes. */
876  node = AST_DLLIST_LAST(&self->buckets[bucket].list);
877  if (!node) {
878  ast_log(LOG_ERROR, "Bucket %d list tail is NULL when it should not be!\n",
879  bucket);
880  return -1;
881  }
882  if (AST_DLLIST_NEXT(node, links)) {
883  ast_log(LOG_ERROR, "Bucket %d list tail node is not the last node!\n",
884  bucket);
885  return -1;
886  }
887  node = AST_DLLIST_FIRST(&self->buckets[bucket].list);
888  if (!node) {
889  ast_log(LOG_ERROR, "Bucket %d list head is NULL when it should not be!\n",
890  bucket);
891  return -1;
892  }
893  if (AST_DLLIST_PREV(node, links)) {
894  ast_log(LOG_ERROR, "Bucket %d list head node is not the first node!\n",
895  bucket);
896  return -1;
897  }
898  for (; node; node = next) {
899  /* Check backward link. */
900  prev = AST_DLLIST_PREV(node, links);
901  if (prev) {
902  if (prev == node) {
903  ast_log(LOG_ERROR, "Bucket %d list node's prev pointer points to itself!\n",
904  bucket);
905  return -1;
906  }
907  if (node != AST_DLLIST_NEXT(prev, links)) {
908  ast_log(LOG_ERROR, "Bucket %d list node's prev node does not link back!\n",
909  bucket);
910  return -1;
911  }
912  } else if (node != AST_DLLIST_FIRST(&self->buckets[bucket].list)) {
913  ast_log(LOG_ERROR, "Bucket %d backward list chain is broken!\n",
914  bucket);
915  return -1;
916  }
917 
918  /* Check forward link. */
919  next = AST_DLLIST_NEXT(node, links);
920  if (next) {
921  if (next == node) {
922  ast_log(LOG_ERROR, "Bucket %d list node's next pointer points to itself!\n",
923  bucket);
924  return -1;
925  }
926  if (node != AST_DLLIST_PREV(next, links)) {
927  ast_log(LOG_ERROR, "Bucket %d list node's next node does not link back!\n",
928  bucket);
929  return -1;
930  }
931  } else if (node != AST_DLLIST_LAST(&self->buckets[bucket].list)) {
932  ast_log(LOG_ERROR, "Bucket %d forward list chain is broken!\n",
933  bucket);
934  return -1;
935  }
936 
937  if (bucket != node->my_bucket) {
938  ast_log(LOG_ERROR, "Bucket %d node claims to be in bucket %d!\n",
939  bucket, node->my_bucket);
940  return -1;
941  }
942 
943  ++count_total_node;
944  if (!node->common.obj) {
945  /* Node is empty. */
946  continue;
947  }
948  ++count_obj;
949 
950  /* Check container hash key for expected bucket. */
951  bucket_exp = abs(self->hash_fn(node->common.obj, OBJ_SEARCH_OBJECT)
952  % self->n_buckets);
953  if (bucket != bucket_exp) {
954  ast_log(LOG_ERROR, "Bucket %d node hashes to bucket %d!\n",
955  bucket, bucket_exp);
956  return -1;
957  }
958 
959  /* Check sort if configured. */
960  if (self->common.sort_fn) {
961  if (obj_last
962  && self->common.sort_fn(obj_last, node->common.obj, OBJ_SEARCH_OBJECT) > 0) {
963  ast_log(LOG_ERROR, "Bucket %d nodes out of sorted order!\n",
964  bucket);
965  return -1;
966  }
967  obj_last = node->common.obj;
968  }
969  }
970 
971  /* Check bucket obj count statistic. */
972  if (count_obj != self->buckets[bucket].elements) {
973  ast_log(LOG_ERROR, "Bucket %d object count of %d does not match stat of %d!\n",
974  bucket, count_obj, self->buckets[bucket].elements);
975  return -1;
976  }
977 
978  /* Accumulate found object counts. */
979  count_total_obj += count_obj;
980  }
981 
982  /* Check total obj count. */
983  if (count_total_obj != ao2_container_count(&self->common)) {
984  ast_log(LOG_ERROR,
985  "Total object count of %d does not match ao2_container_count() of %d!\n",
986  count_total_obj, ao2_container_count(&self->common));
987  return -1;
988  }
989 
990  /* Check total node count. */
991  if (count_total_node != self->common.nodes) {
992  ast_log(LOG_ERROR, "Total node count of %d does not match stat of %d!\n",
993  count_total_node, self->common.nodes);
994  return -1;
995  }
996 
997  return 0;
998 }
999 #endif /* defined(AO2_DEBUG) */
1000 
1001 /*! Hash container virtual method table. */
1002 static const struct ao2_container_methods v_table_hash = {
1003  .alloc_empty_clone = (ao2_container_alloc_empty_clone_fn) hash_ao2_alloc_empty_clone,
1004  .new_node = (ao2_container_new_node_fn) hash_ao2_new_node,
1005  .insert = (ao2_container_insert_fn) hash_ao2_insert_node,
1006  .traverse_first = (ao2_container_find_first_fn) hash_ao2_find_first,
1007  .traverse_next = (ao2_container_find_next_fn) hash_ao2_find_next,
1008  .iterator_next = (ao2_iterator_next_fn) hash_ao2_iterator_next,
1009  .destroy = (ao2_container_destroy_fn) hash_ao2_destroy,
1010 #if defined(AO2_DEBUG)
1011  .link_stat = hash_ao2_link_node_stat,
1012  .unlink_stat = hash_ao2_unlink_node_stat,
1013  .dump = (ao2_container_display) hash_ao2_dump,
1014  .stats = (ao2_container_statistics) hash_ao2_stats,
1015  .integrity = (ao2_container_integrity) hash_ao2_integrity,
1016 #endif /* defined(AO2_DEBUG) */
1017 };
1018 
1019 /*!
1020  * \brief always zero hash function
1021  *
1022  * it is convenient to have a hash function that always returns 0.
1023  * This is basically used when we want to have a container that is
1024  * a simple linked list.
1025  *
1026  * \retval 0
1027  */
1028 static int hash_zero(const void *user_obj, const int flags)
1029 {
1030  return 0;
1031 }
1032 
1033 /*!
1034  * \brief Initialize a hash container with the desired number of buckets.
1035  *
1036  * \param self Container to initialize.
1037  * \param options Container behaviour options (See enum ao2_container_opts)
1038  * \param n_buckets Number of buckets for hash
1039  * \param hash_fn Pointer to a function computing a hash value.
1040  * \param sort_fn Pointer to a sort function.
1041  * \param cmp_fn Pointer to a compare function used by ao2_find.
1042  *
1043  * \return A pointer to a struct container.
1044  */
1046  struct ao2_container_hash *self, unsigned int options, unsigned int n_buckets,
1047  ao2_hash_fn *hash_fn, ao2_sort_fn *sort_fn, ao2_callback_fn *cmp_fn)
1048 {
1049  if (!self) {
1050  return NULL;
1051  }
1052 
1053  self->common.v_table = &v_table_hash;
1054  self->common.sort_fn = sort_fn;
1055  self->common.cmp_fn = cmp_fn;
1056  self->common.options = options;
1057  self->hash_fn = hash_fn ? hash_fn : hash_zero;
1058  self->n_buckets = n_buckets;
1059 
1060 #ifdef AO2_DEBUG
1061  ast_atomic_fetchadd_int(&ao2.total_containers, 1);
1062 #endif /* defined(AO2_DEBUG) */
1063 
1064  return (struct ao2_container *) self;
1065 }
1066 
1067 struct ao2_container *__ao2_container_alloc_hash(unsigned int ao2_options,
1068  unsigned int container_options, unsigned int n_buckets, ao2_hash_fn *hash_fn,
1069  ao2_sort_fn *sort_fn, ao2_callback_fn *cmp_fn,
1070  const char *tag, const char *file, int line, const char *func)
1071 {
1072  unsigned int num_buckets;
1073  size_t container_size;
1074  struct ao2_container_hash *self;
1075 
1076  num_buckets = hash_fn ? n_buckets : 1;
1077  container_size = sizeof(struct ao2_container_hash) + num_buckets * sizeof(struct hash_bucket);
1078 
1079  self = __ao2_alloc(container_size, container_destruct, ao2_options,
1080  tag ?: __PRETTY_FUNCTION__, file, line, func);
1081  return hash_ao2_container_init(self, container_options, num_buckets, hash_fn,
1082  sort_fn, cmp_fn);
1083 }
1084 
1085 struct ao2_container *__ao2_container_alloc_list(unsigned int ao2_options,
1086  unsigned int container_options, ao2_sort_fn *sort_fn, ao2_callback_fn *cmp_fn,
1087  const char *tag, const char *file, int line, const char *func)
1088 {
1089  return __ao2_container_alloc_hash(ao2_options, container_options, 1, NULL,
1090  sort_fn, cmp_fn, tag, file, line, func);
1091 }
#define AST_DLLIST_TRAVERSE_SAFE_BEGIN(head, var, field)
Loops safely over (traverses) the entries in a list.
Definition: dlinkedlists.h:849
Definition: test_heap.c:38
struct ao2_container common
Items common to all containers.
Definition: astobj2_hash.c:70
struct ao2_container_node *(* ao2_iterator_next_fn)(struct ao2_container *self, struct ao2_container_node *prev, enum ao2_iterator_flags flags)
Find the next non-empty iteration node in the container.
void( ao2_prnt_fn)(void *where, const char *fmt,...)
Print output.
Definition: astobj2.h:1435
void( ao2_prnt_obj_fn)(void *v_obj, void *where, ao2_prnt_fn *prnt)
Print object key.
Definition: astobj2.h:1445
Asterisk main include file. File version handling, generic pbx functions.
int ao2_container_count(struct ao2_container *c)
Returns the number of elements in a container.
int( ao2_callback_fn)(void *obj, void *arg, int flags)
Type of a generic callback function.
Definition: astobj2.h:1226
#define AST_DLLIST_INSERT_HEAD(head, elm, field)
Inserts a list entry at the head of a list.
The arg parameter is a search key, but is not an object.
Definition: astobj2.h:1101
Common, private definitions for astobj2.
Allow objects with duplicate keys in container.
Definition: astobj2.h:1181
enum ao2_container_insert(* ao2_container_insert_fn)(struct ao2_container *self, struct ao2_container_node *node)
Insert a node into this container.
int( ao2_hash_fn)(const void *obj, int flags)
Definition: astobj2.h:1258
#define AST_DLLIST_TRAVERSE_BACKWARDS_SAFE_BEGIN(head, var, field)
Loops safely over (traverses) the entries in a list.
Definition: dlinkedlists.h:888
Assume that the ao2_container is already locked.
Definition: astobj2.h:1063
int(* ao2_container_integrity)(struct ao2_container *self)
Perform an integrity check on the specified container.
ao2_container_find_first_fn traverse_first
search_flags
Flags passed to ao2_callback_fn(), ao2_hash_fn(), and ao2_sort_fn() to modify behaviour.
Definition: astobj2.h:1034
#define AST_DLLIST_INSERT_AFTER_CURRENT(elm, field)
Inserts a list node after the current node during a traversal.
Definition: dlinkedlists.h:723
int ast_atomic_fetchadd_int(volatile int *p, int v)
Atomically add v to *p and return the previous value of *p.
Definition: lock.h:757
Insert objects at the beginning of the container. (Otherwise it is the opposite; insert at the end...
Definition: astobj2.h:1172
Utility functions.
Generic container node.
Traverse in ascending order (First to last container object)
Definition: astobj2.h:1121
int ao2_container_check(struct ao2_container *self, enum search_flags flags)
Perform an integrity check on the specified container.
static struct ao2_container * hash_ao2_container_init(struct ao2_container_hash *self, unsigned int options, unsigned int n_buckets, ao2_hash_fn *hash_fn, ao2_sort_fn *sort_fn, ao2_callback_fn *cmp_fn)
Initialize a hash container with the desired number of buckets.
#define AST_DLLIST_INSERT_TAIL(head, elm, field)
Appends a list entry to the tail of a list.
The arg parameter is a partial search key similar to OBJ_SEARCH_KEY.
Definition: astobj2.h:1116
#define AST_DLLIST_NEXT(elm, field)
Returns the next entry in the list after the given entry.
Definition: dlinkedlists.h:446
A set of macros to manage doubly-linked lists.
#define AST_DLLIST_HEAD_NOLOCK(name, type)
Defines a structure to be used to hold a list of specified type (with no lock).
Definition: dlinkedlists.h:212
static int hash_zero(const void *user_obj, const int flags)
always zero hash function
struct ao2_container_node *(* ao2_container_find_first_fn)(struct ao2_container *self, enum search_flags flags, void *arg, void *v_state)
Find the first container node in a traversal.
The ao2 container objects with duplicate keys option field mask.
Definition: astobj2.h:1177
#define ao2_ref(o, delta)
Reference/unreference an object and return the old refcount.
Definition: astobj2.h:459
Traverse in descending order (Last to first container object)
Definition: astobj2.h:1123
ao2_sort_fn * sort_fn
Definition: astobj2_hash.c:81
#define AST_DLLIST_INSERT_BEFORE_CURRENT(elm, field)
Inserts a list node before the current node during a traversal.
Definition: dlinkedlists.h:696
unsigned int descending
Definition: astobj2_hash.c:91
struct ao2_container_node common
Items common to all container nodes.
Definition: astobj2_hash.c:42
void(* ao2_container_destroy_fn)(struct ao2_container *self)
Destroy this container.
void(* ao2_container_statistics)(struct ao2_container *self, void *where, ao2_prnt_fn *prnt)
Display statistics of the specified container.
ao2_iterator_next_fn iterator_next
Traverse in pre-order (Node then children, for tree container)
Definition: astobj2.h:1132
enum search_flags flags
Definition: astobj2_hash.c:89
static const struct ao2_container_methods v_table_hash
unsigned int destroying
TRUE if the container is being destroyed.
#define AST_DLLIST_EMPTY(head)
Checks whether the specified list contains any entries.
Definition: dlinkedlists.h:469
Prototypes for public functions only of internal interest,.
#define AO2_TRAVERSAL_STATE_SIZE
#define AST_DLLIST_TRAVERSE_SAFE_END
Closes a safe loop traversal block.
Definition: dlinkedlists.h:913
The arg parameter is an object of the same type.
Definition: astobj2.h:1087
Replace objects with duplicate keys in container.
Definition: astobj2.h:1211
#define AST_DLLIST_TRAVERSE_BACKWARDS_SAFE_END
Closes a safe loop traversal block.
Definition: dlinkedlists.h:921
Traverse in post-order (Children then node, for tree container)
Definition: astobj2.h:1141
unsigned int ao2_options_get(void *obj)
Retrieve the ao2 options used to create the object.
Definition: astobj2.c:781
#define AST_DLLIST_PREV(elm, field)
Returns the previous entry in the list before the given entry.
Definition: dlinkedlists.h:457
Common, private definitions for astobj2 containers.
struct ao2_container *(* ao2_container_alloc_empty_clone_fn)(struct ao2_container *self, const char *tag, const char *file, int line, const char *func)
Create an empty copy of this container.
#define AST_DLLIST_REMOVE(head, elm, field)
Removes a specific entry from a list.
Reject objects with duplicate keys in container.
Definition: astobj2.h:1188
int( ao2_sort_fn)(const void *obj_left, const void *obj_right, int flags)
Type of generic container sort function.
Definition: astobj2.h:1276
Generic container type.
Search option field mask.
Definition: astobj2.h:1072
struct ao2_container * my_container
struct hash_bucket buckets[0]
Definition: astobj2_hash.c:75
ao2_iterator_flags
Definition: astobj2.h:1835
struct ao2_container_node *(* ao2_container_new_node_fn)(struct ao2_container *self, void *obj_new, const char *tag, const char *file, int line, const char *func)
Create a new container node.
#define AST_DLLIST_FIRST(head)
Returns the first entry contained in a list.
Definition: dlinkedlists.h:422
ao2_container_alloc_empty_clone_fn alloc_empty_clone
Create an empty copy of this container.
struct hash_bucket_node::@304 links
struct hash_bucket::@305 list
Reject duplicate objects in container.
Definition: astobj2.h:1201
ao2_callback_fn * cmp_fn
ao2_container_new_node_fn new_node
Traverse order option field mask.
Definition: astobj2.h:1119
#define AST_DLLIST_LAST(head)
Returns the last entry contained in a list.
Definition: dlinkedlists.h:431
struct ao2_container_node *(* ao2_container_find_next_fn)(struct ao2_container *self, void *v_state, struct ao2_container_node *prev)
Find the next container node in a traversal.
#define AST_DLLIST_ENTRY(type)
Declare previous/forward links inside a list entry.
Definition: dlinkedlists.h:413
void(* ao2_container_display)(struct ao2_container *self, void *where, ao2_prnt_fn *prnt, ao2_prnt_obj_fn *prnt_obj)
Display contents of the specified container.