2 * Copyright (C) 2004, 2005, 2007-2009, 2011 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2003 Internet Software Consortium.
5 * Permission to use, copy, modify, and/or distribute this software for any
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11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
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15 * PERFORMANCE OF THIS SOFTWARE.
18 /* $Id: rbt.c,v 1.146.278.2 2011-03-12 04:59:17 tbox Exp $ */
22 /* Principal Authors: DCL */
27 #include <isc/platform.h>
28 #include <isc/print.h>
29 #include <isc/refcount.h>
30 #include <isc/string.h>
34 * This define is so dns/name.h (included by dns/fixedname.h) uses more
35 * efficient macro calls instead of functions for a few operations.
37 #define DNS_NAME_USEINLINE 1
39 #include <dns/fixedname.h>
42 #include <dns/result.h>
44 #define RBT_MAGIC ISC_MAGIC('R', 'B', 'T', '+')
45 #define VALID_RBT(rbt) ISC_MAGIC_VALID(rbt, RBT_MAGIC)
48 * XXXDCL Since parent pointers were added in again, I could remove all of the
49 * chain junk, and replace with dns_rbt_firstnode, _previousnode, _nextnode,
50 * _lastnode. This would involve pretty major change to the API.
52 #define CHAIN_MAGIC ISC_MAGIC('0', '-', '0', '-')
53 #define VALID_CHAIN(chain) ISC_MAGIC_VALID(chain, CHAIN_MAGIC)
55 #define RBT_HASH_SIZE 64
59 #define RBT_HASH_SIZE 2 /*%< To give the reallocation code a workout. */
66 void (*data_deleter)(void *, void *);
68 unsigned int nodecount;
69 unsigned int hashsize;
70 dns_rbtnode_t ** hashtable;
77 * Elements of the rbtnode structure.
79 #define PARENT(node) ((node)->parent)
80 #define LEFT(node) ((node)->left)
81 #define RIGHT(node) ((node)->right)
82 #define DOWN(node) ((node)->down)
83 #define DATA(node) ((node)->data)
84 #define HASHNEXT(node) ((node)->hashnext)
85 #define HASHVAL(node) ((node)->hashval)
86 #define COLOR(node) ((node)->color)
87 #define NAMELEN(node) ((node)->namelen)
88 #define OLDNAMELEN(node) ((node)->oldnamelen)
89 #define OFFSETLEN(node) ((node)->offsetlen)
90 #define ATTRS(node) ((node)->attributes)
91 #define IS_ROOT(node) ISC_TF((node)->is_root == 1)
92 #define FINDCALLBACK(node) ISC_TF((node)->find_callback == 1)
95 * Structure elements from the rbtdb.c, not
96 * used as part of the rbt.c algorithms.
98 #define DIRTY(node) ((node)->dirty)
99 #define WILD(node) ((node)->wild)
100 #define LOCKNUM(node) ((node)->locknum)
103 * The variable length stuff stored after the node has the following
106 * <name_data>{1..255}<oldoffsetlen>{1}<offsets>{1..128}
108 * <name_data> contains the name of the node when it was created.
109 * <oldoffsetlen> contains the length of <offsets> when the node was created.
110 * <offsets> contains the offets into name for each label when the node was
114 #define NAME(node) ((unsigned char *)((node) + 1))
115 #define OFFSETS(node) (NAME(node) + OLDNAMELEN(node) + 1)
116 #define OLDOFFSETLEN(node) (OFFSETS(node)[-1])
118 #define NODE_SIZE(node) (sizeof(*node) + \
119 OLDNAMELEN(node) + OLDOFFSETLEN(node) + 1)
124 #define IS_RED(node) ((node) != NULL && (node)->color == RED)
125 #define IS_BLACK(node) ((node) == NULL || (node)->color == BLACK)
126 #define MAKE_RED(node) ((node)->color = RED)
127 #define MAKE_BLACK(node) ((node)->color = BLACK)
132 * The "ancestors" member of chains were removed, with their job now
133 * being wholly handled by parent pointers (which didn't exist, because
134 * of memory concerns, when chains were first implemented).
136 #define ADD_LEVEL(chain, node) \
137 (chain)->levels[(chain)->level_count++] = (node)
140 * The following macros directly access normally private name variables.
141 * These macros are used to avoid a lot of function calls in the critical
142 * path of the tree traversal code.
145 #define NODENAME(node, name) \
147 (name)->length = NAMELEN(node); \
148 (name)->labels = OFFSETLEN(node); \
149 (name)->ndata = NAME(node); \
150 (name)->offsets = OFFSETS(node); \
151 (name)->attributes = ATTRS(node); \
152 (name)->attributes |= DNS_NAMEATTR_READONLY; \
155 #ifdef DNS_RBT_USEHASH
157 inithash(dns_rbt_t *rbt);
163 * A little something to help out in GDB.
165 dns_name_t Name(dns_rbtnode_t *node);
167 Name(dns_rbtnode_t *node) {
170 dns_name_init(&name, NULL);
172 NODENAME(node, &name);
177 static void dns_rbt_printnodename(dns_rbtnode_t *node);
180 static inline dns_rbtnode_t *
181 find_up(dns_rbtnode_t *node) {
185 * Return the node in the level above the argument node that points
186 * to the level the argument node is in. If the argument node is in
187 * the top level, the return value is NULL.
189 for (root = node; ! IS_ROOT(root); root = PARENT(root))
192 return (PARENT(root));
196 * Forward declarations.
199 create_node(isc_mem_t *mctx, dns_name_t *name, dns_rbtnode_t **nodep);
201 #ifdef DNS_RBT_USEHASH
203 hash_node(dns_rbt_t *rbt, dns_rbtnode_t *node, dns_name_t *name);
205 unhash_node(dns_rbt_t *rbt, dns_rbtnode_t *node);
207 #define hash_node(rbt, node, name) (ISC_R_SUCCESS)
208 #define unhash_node(rbt, node)
212 rotate_left(dns_rbtnode_t *node, dns_rbtnode_t **rootp);
214 rotate_right(dns_rbtnode_t *node, dns_rbtnode_t **rootp);
217 dns_rbt_addonlevel(dns_rbtnode_t *node, dns_rbtnode_t *current, int order,
218 dns_rbtnode_t **rootp);
221 dns_rbt_deletefromlevel(dns_rbtnode_t *delete, dns_rbtnode_t **rootp);
224 dns_rbt_deletetree(dns_rbt_t *rbt, dns_rbtnode_t *node);
227 dns_rbt_deletetreeflat(dns_rbt_t *rbt, unsigned int quantum,
228 dns_rbtnode_t **nodep);
231 * Initialize a red/black tree of trees.
234 dns_rbt_create(isc_mem_t *mctx, void (*deleter)(void *, void *),
235 void *deleter_arg, dns_rbt_t **rbtp)
237 #ifdef DNS_RBT_USEHASH
243 REQUIRE(mctx != NULL);
244 REQUIRE(rbtp != NULL && *rbtp == NULL);
245 REQUIRE(deleter == NULL ? deleter_arg == NULL : 1);
247 rbt = (dns_rbt_t *)isc_mem_get(mctx, sizeof(*rbt));
249 return (ISC_R_NOMEMORY);
252 rbt->data_deleter = deleter;
253 rbt->deleter_arg = deleter_arg;
256 rbt->hashtable = NULL;
259 #ifdef DNS_RBT_USEHASH
260 result = inithash(rbt);
261 if (result != ISC_R_SUCCESS) {
262 isc_mem_put(mctx, rbt, sizeof(*rbt));
267 rbt->magic = RBT_MAGIC;
271 return (ISC_R_SUCCESS);
275 * Deallocate a red/black tree of trees.
278 dns_rbt_destroy(dns_rbt_t **rbtp) {
279 RUNTIME_CHECK(dns_rbt_destroy2(rbtp, 0) == ISC_R_SUCCESS);
283 dns_rbt_destroy2(dns_rbt_t **rbtp, unsigned int quantum) {
286 REQUIRE(rbtp != NULL && VALID_RBT(*rbtp));
290 dns_rbt_deletetreeflat(rbt, quantum, &rbt->root);
291 if (rbt->root != NULL)
292 return (ISC_R_QUOTA);
294 INSIST(rbt->nodecount == 0);
296 if (rbt->hashtable != NULL)
297 isc_mem_put(rbt->mctx, rbt->hashtable,
298 rbt->hashsize * sizeof(dns_rbtnode_t *));
302 isc_mem_put(rbt->mctx, rbt, sizeof(*rbt));
304 return (ISC_R_SUCCESS);
308 dns_rbt_nodecount(dns_rbt_t *rbt) {
309 REQUIRE(VALID_RBT(rbt));
310 return (rbt->nodecount);
313 static inline isc_result_t
314 chain_name(dns_rbtnodechain_t *chain, dns_name_t *name,
315 isc_boolean_t include_chain_end)
318 isc_result_t result = ISC_R_SUCCESS;
321 dns_name_init(&nodename, NULL);
323 if (include_chain_end && chain->end != NULL) {
324 NODENAME(chain->end, &nodename);
325 result = dns_name_copy(&nodename, name, NULL);
326 if (result != ISC_R_SUCCESS)
329 dns_name_reset(name);
331 for (i = (int)chain->level_count - 1; i >= 0; i--) {
332 NODENAME(chain->levels[i], &nodename);
333 result = dns_name_concatenate(name, &nodename, name, NULL);
335 if (result != ISC_R_SUCCESS)
341 static inline isc_result_t
342 move_chain_to_last(dns_rbtnodechain_t *chain, dns_rbtnode_t *node) {
345 * Go as far right and then down as much as possible,
346 * as long as the rightmost node has a down pointer.
348 while (RIGHT(node) != NULL)
351 if (DOWN(node) == NULL)
354 ADD_LEVEL(chain, node);
360 return (ISC_R_SUCCESS);
364 * Add 'name' to tree, initializing its data pointer with 'data'.
368 dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
370 * Does this thing have too many variables or what?
372 dns_rbtnode_t **root, *parent, *child, *current, *new_current;
373 dns_name_t *add_name, *new_name, current_name, *prefix, *suffix;
374 dns_fixedname_t fixedcopy, fixedprefix, fixedsuffix, fnewname;
375 dns_offsets_t current_offsets;
376 dns_namereln_t compared;
377 isc_result_t result = ISC_R_SUCCESS;
378 dns_rbtnodechain_t chain;
379 unsigned int common_labels;
380 unsigned int nlabels, hlabels;
383 REQUIRE(VALID_RBT(rbt));
384 REQUIRE(dns_name_isabsolute(name));
385 REQUIRE(nodep != NULL && *nodep == NULL);
388 * Create a copy of the name so the original name structure is
391 dns_fixedname_init(&fixedcopy);
392 add_name = dns_fixedname_name(&fixedcopy);
393 dns_name_clone(name, add_name);
395 if (rbt->root == NULL) {
396 result = create_node(rbt->mctx, add_name, &new_current);
397 if (result == ISC_R_SUCCESS) {
399 new_current->is_root = 1;
400 rbt->root = new_current;
401 *nodep = new_current;
402 hash_node(rbt, new_current, name);
407 dns_rbtnodechain_init(&chain, rbt->mctx);
409 dns_fixedname_init(&fixedprefix);
410 dns_fixedname_init(&fixedsuffix);
411 prefix = dns_fixedname_name(&fixedprefix);
412 suffix = dns_fixedname_name(&fixedsuffix);
415 INSIST(IS_ROOT(*root));
419 dns_name_init(¤t_name, current_offsets);
420 dns_fixedname_init(&fnewname);
421 new_name = dns_fixedname_name(&fnewname);
422 nlabels = dns_name_countlabels(name);
428 NODENAME(current, ¤t_name);
429 compared = dns_name_fullcompare(add_name, ¤t_name,
430 &order, &common_labels);
432 if (compared == dns_namereln_equal) {
434 result = ISC_R_EXISTS;
439 if (compared == dns_namereln_none) {
443 child = LEFT(current);
445 } else if (order > 0) {
447 child = RIGHT(current);
453 * This name has some suffix in common with the
454 * name at the current node. If the name at
455 * the current node is shorter, that means the
456 * new name should be in a subtree. If the
457 * name at the current node is longer, that means
458 * the down pointer to this tree should point
459 * to a new tree that has the common suffix, and
460 * the non-common parts of these two names should
463 hlabels += common_labels;
464 if (compared == dns_namereln_subdomain) {
466 * All of the existing labels are in common,
467 * so the new name is in a subtree.
468 * Whack off the common labels for the
469 * not-in-common part to be searched for
472 dns_name_split(add_name, common_labels,
476 * Follow the down pointer (possibly NULL).
478 root = &DOWN(current);
480 INSIST(*root == NULL ||
482 PARENT(*root) == current));
485 child = DOWN(current);
486 ADD_LEVEL(&chain, current);
490 * The number of labels in common is fewer
491 * than the number of labels at the current
492 * node, so the current node must be adjusted
493 * to have just the common suffix, and a down
494 * pointer made to a new tree.
497 INSIST(compared == dns_namereln_commonancestor
498 || compared == dns_namereln_contains);
501 * Ensure the number of levels in the tree
502 * does not exceed the number of logical
503 * levels allowed by DNSSEC.
505 * XXXDCL need a better error result?
507 * XXXDCL Since chain ancestors were removed,
508 * no longer used by dns_rbt_addonlevel(),
509 * this is the only real use of chains in the
510 * function. It could be done instead with
511 * a simple integer variable, but I am pressed
514 if (chain.level_count ==
515 (sizeof(chain.levels) /
516 sizeof(*chain.levels))) {
517 result = ISC_R_NOSPACE;
522 * Split the name into two parts, a prefix
523 * which is the not-in-common parts of the
524 * two names and a suffix that is the common
527 dns_name_split(¤t_name, common_labels,
529 result = create_node(rbt->mctx, suffix,
532 if (result != ISC_R_SUCCESS)
536 * Reproduce the tree attributes of the
539 new_current->is_root = current->is_root;
540 if (current->nsec == DNS_RBT_NSEC_HAS_NSEC)
541 new_current->nsec = DNS_RBT_NSEC_NORMAL;
543 new_current->nsec = current->nsec;
544 PARENT(new_current) = PARENT(current);
545 LEFT(new_current) = LEFT(current);
546 RIGHT(new_current) = RIGHT(current);
547 COLOR(new_current) = COLOR(current);
550 * Fix pointers that were to the current node.
552 if (parent != NULL) {
553 if (LEFT(parent) == current)
554 LEFT(parent) = new_current;
556 RIGHT(parent) = new_current;
558 if (LEFT(new_current) != NULL)
559 PARENT(LEFT(new_current)) =
561 if (RIGHT(new_current) != NULL)
562 PARENT(RIGHT(new_current)) =
564 if (*root == current)
567 NAMELEN(current) = prefix->length;
568 OFFSETLEN(current) = prefix->labels;
571 * Set up the new root of the next level.
572 * By definition it will not be the top
573 * level tree, so clear DNS_NAMEATTR_ABSOLUTE.
575 current->is_root = 1;
576 PARENT(current) = new_current;
577 DOWN(new_current) = current;
578 root = &DOWN(new_current);
580 ADD_LEVEL(&chain, new_current);
582 LEFT(current) = NULL;
583 RIGHT(current) = NULL;
586 ATTRS(current) &= ~DNS_NAMEATTR_ABSOLUTE;
589 dns_name_getlabelsequence(name,
592 hash_node(rbt, new_current, new_name);
595 dns_name_countlabels(add_name)) {
597 * The name has been added by pushing
598 * the not-in-common parts down to
601 *nodep = new_current;
602 return (ISC_R_SUCCESS);
606 * The current node has no data,
607 * because it is just a placeholder.
608 * Its data pointer is already NULL
609 * from create_node()), so there's
610 * nothing more to do to it.
614 * The not-in-common parts of the new
615 * name will be inserted into the new
616 * level following this loop (unless
617 * result != ISC_R_SUCCESS, which
618 * is tested after the loop ends).
620 dns_name_split(add_name, common_labels,
630 } while (child != NULL);
632 if (result == ISC_R_SUCCESS)
633 result = create_node(rbt->mctx, add_name, &new_current);
635 if (result == ISC_R_SUCCESS) {
636 dns_rbt_addonlevel(new_current, current, order, root);
638 *nodep = new_current;
639 hash_node(rbt, new_current, name);
646 * Add a name to the tree of trees, associating it with some data.
649 dns_rbt_addname(dns_rbt_t *rbt, dns_name_t *name, void *data) {
653 REQUIRE(VALID_RBT(rbt));
654 REQUIRE(dns_name_isabsolute(name));
658 result = dns_rbt_addnode(rbt, name, &node);
661 * dns_rbt_addnode will report the node exists even when
662 * it does not have data associated with it, but the
663 * dns_rbt_*name functions all behave depending on whether
664 * there is data associated with a node.
666 if (result == ISC_R_SUCCESS ||
667 (result == ISC_R_EXISTS && DATA(node) == NULL)) {
669 result = ISC_R_SUCCESS;
676 * Find the node for "name" in the tree of trees.
679 dns_rbt_findnode(dns_rbt_t *rbt, dns_name_t *name, dns_name_t *foundname,
680 dns_rbtnode_t **node, dns_rbtnodechain_t *chain,
681 unsigned int options, dns_rbtfindcallback_t callback,
684 dns_rbtnode_t *current, *last_compared, *current_root;
685 dns_rbtnodechain_t localchain;
686 dns_name_t *search_name, current_name, *callback_name;
687 dns_fixedname_t fixedcallbackname, fixedsearchname;
688 dns_namereln_t compared;
689 isc_result_t result, saved_result;
690 unsigned int common_labels;
691 unsigned int hlabels = 0;
694 REQUIRE(VALID_RBT(rbt));
695 REQUIRE(dns_name_isabsolute(name));
696 REQUIRE(node != NULL && *node == NULL);
697 REQUIRE((options & (DNS_RBTFIND_NOEXACT | DNS_RBTFIND_NOPREDECESSOR))
698 != (DNS_RBTFIND_NOEXACT | DNS_RBTFIND_NOPREDECESSOR));
701 * If there is a chain it needs to appear to be in a sane state,
702 * otherwise a chain is still needed to generate foundname and
706 options |= DNS_RBTFIND_NOPREDECESSOR;
708 dns_rbtnodechain_init(chain, rbt->mctx);
710 dns_rbtnodechain_reset(chain);
712 if (rbt->root == NULL)
713 return (ISC_R_NOTFOUND);
716 * Appease GCC about variables it incorrectly thinks are
717 * possibly used uninitialized.
719 compared = dns_namereln_none;
720 last_compared = NULL;
724 dns_fixedname_init(&fixedcallbackname);
725 callback_name = dns_fixedname_name(&fixedcallbackname);
728 * search_name is the name segment being sought in each tree level.
729 * By using a fixedname, the search_name will definitely have offsets
730 * for use by any splitting.
731 * By using dns_name_clone, no name data should be copied thanks to
732 * the lack of bitstring labels.
734 dns_fixedname_init(&fixedsearchname);
735 search_name = dns_fixedname_name(&fixedsearchname);
736 dns_name_clone(name, search_name);
738 dns_name_init(¤t_name, NULL);
740 saved_result = ISC_R_SUCCESS;
742 current_root = rbt->root;
744 while (current != NULL) {
745 NODENAME(current, ¤t_name);
746 compared = dns_name_fullcompare(search_name, ¤t_name,
747 &order, &common_labels);
748 last_compared = current;
750 if (compared == dns_namereln_equal)
753 if (compared == dns_namereln_none) {
754 #ifdef DNS_RBT_USEHASH
755 dns_name_t hash_name;
756 dns_rbtnode_t *hnode;
757 dns_rbtnode_t *up_current;
758 unsigned int nlabels;
759 unsigned int tlabels = 1;
763 * If there is no hash table, hashing can't be done.
765 if (rbt->hashtable == NULL)
769 * The case of current != current_root, that
770 * means a left or right pointer was followed,
771 * only happens when the algorithm fell through to
772 * the traditional binary search because of a
773 * bitstring label. Since we dropped the bitstring
774 * support, this should not happen.
776 INSIST(current == current_root);
778 nlabels = dns_name_countlabels(search_name);
781 * current_root is the root of the current level, so
782 * it's parent is the same as it's "up" pointer.
784 up_current = PARENT(current_root);
785 dns_name_init(&hash_name, NULL);
789 * Hash includes tail.
791 dns_name_getlabelsequence(name,
795 hash = dns_name_fullhash(&hash_name, ISC_FALSE);
796 dns_name_getlabelsequence(search_name,
798 tlabels, &hash_name);
800 for (hnode = rbt->hashtable[hash % rbt->hashsize];
802 hnode = hnode->hashnext)
804 dns_name_t hnode_name;
806 if (hash != HASHVAL(hnode))
808 if (find_up(hnode) != up_current)
810 dns_name_init(&hnode_name, NULL);
811 NODENAME(hnode, &hnode_name);
812 if (dns_name_equal(&hnode_name, &hash_name))
819 * This is an optimization. If hashing found
820 * the right node, the next call to
821 * dns_name_fullcompare() would obviously
822 * return _equal or _subdomain. Determine
823 * which of those would be the case by
824 * checking if the full name was hashed. Then
825 * make it look like dns_name_fullcompare
826 * was called and jump to the right place.
828 if (tlabels == nlabels) {
829 compared = dns_namereln_equal;
832 common_labels = tlabels;
833 compared = dns_namereln_subdomain;
838 if (tlabels++ < nlabels)
842 * All of the labels have been tried against the hash
843 * table. Since we dropped the support of bitstring
844 * labels, the name isn't in the table.
850 #endif /* DNS_RBT_USEHASH */
852 * Standard binary search tree movement.
855 current = LEFT(current);
857 current = RIGHT(current);
861 * The names have some common suffix labels.
863 * If the number in common are equal in length to
864 * the current node's name length, then follow the
865 * down pointer and search in the new tree.
867 if (compared == dns_namereln_subdomain) {
870 * Whack off the current node's common parts
871 * for the name to search in the next level.
873 dns_name_split(search_name, common_labels,
875 hlabels += common_labels;
877 * This might be the closest enclosing name.
879 if (DATA(current) != NULL ||
880 (options & DNS_RBTFIND_EMPTYDATA) != 0)
884 * Point the chain to the next level. This
885 * needs to be done before 'current' is pointed
886 * there because the callback in the next
887 * block of code needs the current 'current',
888 * but in the event the callback requests that
889 * the search be stopped then the
890 * DNS_R_PARTIALMATCH code at the end of this
891 * function needs the chain pointed to the
894 ADD_LEVEL(chain, current);
897 * The caller may want to interrupt the
898 * downward search when certain special nodes
899 * are traversed. If this is a special node,
900 * the callback is used to learn what the
901 * caller wants to do.
903 if (callback != NULL &&
904 FINDCALLBACK(current)) {
905 result = chain_name(chain,
908 if (result != ISC_R_SUCCESS) {
909 dns_rbtnodechain_reset(chain);
913 result = (callback)(current,
916 if (result != DNS_R_CONTINUE) {
917 saved_result = result;
919 * Treat this node as if it
920 * had no down pointer.
928 * Finally, head to the next tree level.
930 current = DOWN(current);
931 current_root = current;
935 * Though there are labels in common, the
936 * entire name at this node is not common
937 * with the search name so the search
938 * name does not exist in the tree.
940 INSIST(compared == dns_namereln_commonancestor
941 || compared == dns_namereln_contains);
949 * If current is not NULL, NOEXACT is not disallowing exact matches,
950 * and either the node has data or an empty node is ok, return
951 * ISC_R_SUCCESS to indicate an exact match.
953 if (current != NULL && (options & DNS_RBTFIND_NOEXACT) == 0 &&
954 (DATA(current) != NULL ||
955 (options & DNS_RBTFIND_EMPTYDATA) != 0)) {
957 * Found an exact match.
959 chain->end = current;
960 chain->level_matches = chain->level_count;
962 if (foundname != NULL)
963 result = chain_name(chain, foundname, ISC_TRUE);
965 result = ISC_R_SUCCESS;
967 if (result == ISC_R_SUCCESS) {
969 result = saved_result;
974 * Did not find an exact match (or did not want one).
978 * ... but found a partially matching superdomain.
979 * Unwind the chain to the partial match node
980 * to set level_matches to the level above the node,
981 * and then to derive the name.
983 * chain->level_count is guaranteed to be at least 1
984 * here because by definition of finding a superdomain,
985 * the chain is pointed to at least the first subtree.
987 chain->level_matches = chain->level_count - 1;
989 while (chain->levels[chain->level_matches] != *node) {
990 INSIST(chain->level_matches > 0);
991 chain->level_matches--;
994 if (foundname != NULL) {
995 unsigned int saved_count = chain->level_count;
997 chain->level_count = chain->level_matches + 1;
999 result = chain_name(chain, foundname,
1002 chain->level_count = saved_count;
1004 result = ISC_R_SUCCESS;
1006 if (result == ISC_R_SUCCESS)
1007 result = DNS_R_PARTIALMATCH;
1010 result = ISC_R_NOTFOUND;
1012 if (current != NULL) {
1014 * There was an exact match but either
1015 * DNS_RBTFIND_NOEXACT was set, or
1016 * DNS_RBTFIND_EMPTYDATA was set and the node had no
1017 * data. A policy decision was made to set the
1018 * chain to the exact match, but this is subject
1019 * to change if it becomes apparent that something
1020 * else would be more useful. It is important that
1021 * this case is handled here, because the predecessor
1022 * setting code below assumes the match was not exact.
1024 INSIST(((options & DNS_RBTFIND_NOEXACT) != 0) ||
1025 ((options & DNS_RBTFIND_EMPTYDATA) == 0 &&
1026 DATA(current) == NULL));
1027 chain->end = current;
1029 } else if ((options & DNS_RBTFIND_NOPREDECESSOR) != 0) {
1031 * Ensure the chain points nowhere.
1037 * Since there was no exact match, the chain argument
1038 * needs to be pointed at the DNSSEC predecessor of
1041 if (compared == dns_namereln_subdomain) {
1043 * Attempted to follow a down pointer that was
1044 * NULL, which means the searched for name was
1045 * a subdomain of a terminal name in the tree.
1046 * Since there are no existing subdomains to
1047 * order against, the terminal name is the
1050 INSIST(chain->level_count > 0);
1051 INSIST(chain->level_matches <
1052 chain->level_count);
1054 chain->levels[--chain->level_count];
1057 isc_result_t result2;
1060 * Point current to the node that stopped
1063 * With the hashing modification that has been
1064 * added to the algorithm, the stop node of a
1065 * standard binary search is not known. So it
1066 * has to be found. There is probably a more
1067 * clever way of doing this.
1069 * The assignment of current to NULL when
1070 * the relationship is *not* dns_namereln_none,
1071 * even though it later gets set to the same
1072 * last_compared anyway, is simply to not push
1073 * the while loop in one more level of
1076 if (compared == dns_namereln_none)
1077 current = last_compared;
1081 while (current != NULL) {
1082 NODENAME(current, ¤t_name);
1083 compared = dns_name_fullcompare(
1090 last_compared = current;
1093 * Standard binary search movement.
1096 current = LEFT(current);
1098 current = RIGHT(current);
1102 current = last_compared;
1105 * Reached a point within a level tree that
1106 * positively indicates the name is not
1107 * present, but the stop node could be either
1108 * less than the desired name (order > 0) or
1109 * greater than the desired name (order < 0).
1111 * If the stop node is less, it is not
1112 * necessarily the predecessor. If the stop
1113 * node has a down pointer, then the real
1114 * predecessor is at the end of a level below
1115 * (not necessarily the next level).
1116 * Move down levels until the rightmost node
1117 * does not have a down pointer.
1119 * When the stop node is greater, it is
1120 * the successor. All the logic for finding
1121 * the predecessor is handily encapsulated
1122 * in dns_rbtnodechain_prev. In the event
1123 * that the search name is less than anything
1124 * else in the tree, the chain is reset.
1125 * XXX DCL What is the best way for the caller
1126 * to know that the search name has
1132 if (DOWN(current) != NULL) {
1133 ADD_LEVEL(chain, current);
1136 move_chain_to_last(chain,
1139 if (result2 != ISC_R_SUCCESS)
1143 * Ah, the pure and simple
1144 * case. The stop node is the
1147 chain->end = current;
1152 chain->end = current;
1154 result2 = dns_rbtnodechain_prev(chain,
1157 if (result2 == ISC_R_SUCCESS ||
1158 result2 == DNS_R_NEWORIGIN)
1160 else if (result2 == ISC_R_NOMORE)
1162 * There is no predecessor.
1164 dns_rbtnodechain_reset(chain);
1173 ENSURE(*node == NULL || DNS_RBTNODE_VALID(*node));
1179 * Get the data pointer associated with 'name'.
1182 dns_rbt_findname(dns_rbt_t *rbt, dns_name_t *name, unsigned int options,
1183 dns_name_t *foundname, void **data) {
1184 dns_rbtnode_t *node = NULL;
1185 isc_result_t result;
1187 REQUIRE(data != NULL && *data == NULL);
1189 result = dns_rbt_findnode(rbt, name, foundname, &node, NULL,
1190 options, NULL, NULL);
1193 (DATA(node) != NULL || (options & DNS_RBTFIND_EMPTYDATA) != 0))
1196 result = ISC_R_NOTFOUND;
1202 * Delete a name from the tree of trees.
1205 dns_rbt_deletename(dns_rbt_t *rbt, dns_name_t *name, isc_boolean_t recurse) {
1206 dns_rbtnode_t *node = NULL;
1207 isc_result_t result;
1209 REQUIRE(VALID_RBT(rbt));
1210 REQUIRE(dns_name_isabsolute(name));
1213 * First, find the node.
1215 * When searching, the name might not have an exact match:
1216 * consider a.b.a.com, b.b.a.com and c.b.a.com as the only
1217 * elements of a tree, which would make layer 1 a single
1218 * node tree of "b.a.com" and layer 2 a three node tree of
1219 * a, b, and c. Deleting a.com would find only a partial depth
1220 * match in the first layer. Should it be a requirement that
1221 * that the name to be deleted have data? For now, it is.
1223 * ->dirty, ->locknum and ->references are ignored; they are
1224 * solely the province of rbtdb.c.
1226 result = dns_rbt_findnode(rbt, name, NULL, &node, NULL,
1227 DNS_RBTFIND_NOOPTIONS, NULL, NULL);
1229 if (result == ISC_R_SUCCESS) {
1230 if (DATA(node) != NULL)
1231 result = dns_rbt_deletenode(rbt, node, recurse);
1233 result = ISC_R_NOTFOUND;
1235 } else if (result == DNS_R_PARTIALMATCH)
1236 result = ISC_R_NOTFOUND;
1242 * Remove a node from the tree of trees.
1244 * NOTE WELL: deletion is *not* symmetric with addition; that is, reversing
1245 * a sequence of additions to be deletions will not generally get the
1246 * tree back to the state it started in. For example, if the addition
1247 * of "b.c" caused the node "a.b.c" to be split, pushing "a" to its own level,
1248 * then the subsequent deletion of "b.c" will not cause "a" to be pulled up,
1249 * restoring "a.b.c". The RBT *used* to do this kind of rejoining, but it
1250 * turned out to be a bad idea because it could corrupt an active nodechain
1251 * that had "b.c" as one of its levels -- and the RBT has no idea what
1252 * nodechains are in use by callers, so it can't even *try* to helpfully
1253 * fix them up (which would probably be doomed to failure anyway).
1255 * Similarly, it is possible to leave the tree in a state where a supposedly
1256 * deleted node still exists. The first case of this is obvious; take
1257 * the tree which has "b.c" on one level, pointing to "a". Now deleted "b.c".
1258 * It was just established in the previous paragraph why we can't pull "a"
1259 * back up to its parent level. But what happens when "a" then gets deleted?
1260 * "b.c" is left hanging around without data or children. This condition
1261 * is actually pretty easy to detect, but ... should it really be removed?
1262 * Is a chain pointing to it? An iterator? Who knows! (Note that the
1263 * references structure member cannot be looked at because it is private to
1264 * rbtdb.) This is ugly and makes me unhappy, but after hours of trying to
1265 * make it more aesthetically proper and getting nowhere, this is the way it
1266 * is going to stay until such time as it proves to be a *real* problem.
1268 * Finally, for reference, note that the original routine that did node
1269 * joining was called join_nodes(). It has been excised, living now only
1270 * in the CVS history, but comments have been left behind that point to it just
1271 * in case someone wants to muck with this some more.
1273 * The one positive aspect of all of this is that joining used to have a
1274 * case where it might fail. Without trying to join, now this function always
1275 * succeeds. It still returns isc_result_t, though, so the API wouldn't change.
1278 dns_rbt_deletenode(dns_rbt_t *rbt, dns_rbtnode_t *node, isc_boolean_t recurse)
1280 dns_rbtnode_t *parent;
1282 REQUIRE(VALID_RBT(rbt));
1283 REQUIRE(DNS_RBTNODE_VALID(node));
1285 if (DOWN(node) != NULL) {
1287 RUNTIME_CHECK(dns_rbt_deletetree(rbt, DOWN(node))
1290 if (DATA(node) != NULL && rbt->data_deleter != NULL)
1291 rbt->data_deleter(DATA(node), rbt->deleter_arg);
1295 * Since there is at least one node below this one and
1296 * no recursion was requested, the deletion is
1297 * complete. The down node from this node might be all
1298 * by itself on a single level, so join_nodes() could
1299 * be used to collapse the tree (with all the caveats
1300 * of the comment at the start of this function).
1302 return (ISC_R_SUCCESS);
1307 * Note the node that points to the level of the node that is being
1308 * deleted. If the deleted node is the top level, parent will be set
1311 parent = find_up(node);
1314 * This node now has no down pointer (either because it didn't
1315 * have one to start, or because it was recursively removed).
1316 * So now the node needs to be removed from this level.
1318 dns_rbt_deletefromlevel(node, parent == NULL ? &rbt->root :
1321 if (DATA(node) != NULL && rbt->data_deleter != NULL)
1322 rbt->data_deleter(DATA(node), rbt->deleter_arg);
1324 unhash_node(rbt, node);
1325 #if DNS_RBT_USEMAGIC
1328 dns_rbtnode_refdestroy(node);
1329 isc_mem_put(rbt->mctx, node, NODE_SIZE(node));
1333 * There are now two special cases that can exist that would
1334 * not have existed if the tree had been created using only
1335 * the names that now exist in it. (This is all related to
1336 * join_nodes() as described in this function's introductory comment.)
1337 * Both cases exist when the deleted node's parent (the node
1338 * that pointed to the deleted node's level) is not null but
1339 * it has no data: parent != NULL && DATA(parent) == NULL.
1341 * The first case is that the deleted node was the last on its level:
1342 * DOWN(parent) == NULL. This case can only exist if the parent was
1343 * previously deleted -- and so now, apparently, the parent should go
1344 * away. That can't be done though because there might be external
1345 * references to it, such as through a nodechain.
1347 * The other case also involves a parent with no data, but with the
1348 * deleted node being the next-to-last node instead of the last:
1349 * LEFT(DOWN(parent)) == NULL && RIGHT(DOWN(parent)) == NULL.
1350 * Presumably now the remaining node on the level should be joined
1351 * with the parent, but it's already been described why that can't be
1356 * This function never fails.
1358 return (ISC_R_SUCCESS);
1362 dns_rbt_namefromnode(dns_rbtnode_t *node, dns_name_t *name) {
1364 REQUIRE(DNS_RBTNODE_VALID(node));
1365 REQUIRE(name != NULL);
1366 REQUIRE(name->offsets == NULL);
1368 NODENAME(node, name);
1372 dns_rbt_fullnamefromnode(dns_rbtnode_t *node, dns_name_t *name) {
1374 isc_result_t result;
1376 REQUIRE(DNS_RBTNODE_VALID(node));
1377 REQUIRE(name != NULL);
1378 REQUIRE(name->buffer != NULL);
1380 dns_name_init(¤t, NULL);
1381 dns_name_reset(name);
1384 INSIST(node != NULL);
1386 NODENAME(node, ¤t);
1388 result = dns_name_concatenate(name, ¤t, name, NULL);
1389 if (result != ISC_R_SUCCESS)
1392 node = find_up(node);
1393 } while (! dns_name_isabsolute(name));
1399 dns_rbt_formatnodename(dns_rbtnode_t *node, char *printname, unsigned int size)
1401 dns_fixedname_t fixedname;
1403 isc_result_t result;
1405 REQUIRE(DNS_RBTNODE_VALID(node));
1406 REQUIRE(printname != NULL);
1408 dns_fixedname_init(&fixedname);
1409 name = dns_fixedname_name(&fixedname);
1410 result = dns_rbt_fullnamefromnode(node, name);
1411 if (result == ISC_R_SUCCESS)
1412 dns_name_format(name, printname, size);
1414 snprintf(printname, size, "<error building name: %s>",
1415 dns_result_totext(result));
1421 create_node(isc_mem_t *mctx, dns_name_t *name, dns_rbtnode_t **nodep) {
1422 dns_rbtnode_t *node;
1423 isc_region_t region;
1424 unsigned int labels;
1426 REQUIRE(name->offsets != NULL);
1428 dns_name_toregion(name, ®ion);
1429 labels = dns_name_countlabels(name);
1433 * Allocate space for the node structure, the name, and the offsets.
1435 node = (dns_rbtnode_t *)isc_mem_get(mctx, sizeof(*node) +
1436 region.length + labels + 1);
1439 return (ISC_R_NOMEMORY);
1442 PARENT(node) = NULL;
1447 #ifdef DNS_RBT_USEHASH
1448 HASHNEXT(node) = NULL;
1452 ISC_LINK_INIT(node, deadlink);
1457 dns_rbtnode_refinit(node, 0);
1458 node->find_callback = 0;
1459 node->nsec = DNS_RBT_NSEC_NORMAL;
1464 * The following is stored to make reconstructing a name from the
1465 * stored value in the node easy: the length of the name, the number
1466 * of labels, whether the name is absolute or not, the name itself,
1467 * and the name's offsets table.
1470 * The offsets table could be made smaller by eliminating the
1471 * first offset, which is always 0. This requires changes to
1474 * Note: OLDOFFSETLEN *must* be assigned *after* OLDNAMELEN is assigned
1475 * as it uses OLDNAMELEN.
1477 OLDNAMELEN(node) = NAMELEN(node) = region.length;
1478 OLDOFFSETLEN(node) = OFFSETLEN(node) = labels;
1479 ATTRS(node) = name->attributes;
1481 memcpy(NAME(node), region.base, region.length);
1482 memcpy(OFFSETS(node), name->offsets, labels);
1484 #if DNS_RBT_USEMAGIC
1485 node->magic = DNS_RBTNODE_MAGIC;
1489 return (ISC_R_SUCCESS);
1492 #ifdef DNS_RBT_USEHASH
1494 hash_add_node(dns_rbt_t *rbt, dns_rbtnode_t *node, dns_name_t *name) {
1497 HASHVAL(node) = dns_name_fullhash(name, ISC_FALSE);
1499 hash = HASHVAL(node) % rbt->hashsize;
1500 HASHNEXT(node) = rbt->hashtable[hash];
1502 rbt->hashtable[hash] = node;
1506 inithash(dns_rbt_t *rbt) {
1509 rbt->hashsize = RBT_HASH_SIZE;
1510 bytes = rbt->hashsize * sizeof(dns_rbtnode_t *);
1511 rbt->hashtable = isc_mem_get(rbt->mctx, bytes);
1513 if (rbt->hashtable == NULL)
1514 return (ISC_R_NOMEMORY);
1516 memset(rbt->hashtable, 0, bytes);
1518 return (ISC_R_SUCCESS);
1522 rehash(dns_rbt_t *rbt) {
1523 unsigned int oldsize;
1524 dns_rbtnode_t **oldtable;
1525 dns_rbtnode_t *node;
1529 oldsize = rbt->hashsize;
1530 oldtable = rbt->hashtable;
1531 rbt->hashsize = rbt->hashsize * 2 + 1;
1532 rbt->hashtable = isc_mem_get(rbt->mctx,
1533 rbt->hashsize * sizeof(dns_rbtnode_t *));
1534 if (rbt->hashtable == NULL) {
1535 rbt->hashtable = oldtable;
1536 rbt->hashsize = oldsize;
1540 for (i = 0; i < rbt->hashsize; i++)
1541 rbt->hashtable[i] = NULL;
1543 for (i = 0; i < oldsize; i++) {
1545 while (node != NULL) {
1546 hash = HASHVAL(node) % rbt->hashsize;
1547 oldtable[i] = HASHNEXT(node);
1548 HASHNEXT(node) = rbt->hashtable[hash];
1549 rbt->hashtable[hash] = node;
1554 isc_mem_put(rbt->mctx, oldtable, oldsize * sizeof(dns_rbtnode_t *));
1558 hash_node(dns_rbt_t *rbt, dns_rbtnode_t *node, dns_name_t *name) {
1560 REQUIRE(DNS_RBTNODE_VALID(node));
1562 if (rbt->nodecount >= (rbt->hashsize *3))
1565 hash_add_node(rbt, node, name);
1569 unhash_node(dns_rbt_t *rbt, dns_rbtnode_t *node) {
1570 unsigned int bucket;
1571 dns_rbtnode_t *bucket_node;
1573 REQUIRE(DNS_RBTNODE_VALID(node));
1575 if (rbt->hashtable != NULL) {
1576 bucket = HASHVAL(node) % rbt->hashsize;
1577 bucket_node = rbt->hashtable[bucket];
1579 if (bucket_node == node)
1580 rbt->hashtable[bucket] = HASHNEXT(node);
1582 while (HASHNEXT(bucket_node) != node) {
1583 INSIST(HASHNEXT(bucket_node) != NULL);
1584 bucket_node = HASHNEXT(bucket_node);
1586 HASHNEXT(bucket_node) = HASHNEXT(node);
1590 #endif /* DNS_RBT_USEHASH */
1593 rotate_left(dns_rbtnode_t *node, dns_rbtnode_t **rootp) {
1594 dns_rbtnode_t *child;
1596 REQUIRE(DNS_RBTNODE_VALID(node));
1597 REQUIRE(rootp != NULL);
1599 child = RIGHT(node);
1600 INSIST(child != NULL);
1602 RIGHT(node) = LEFT(child);
1603 if (LEFT(child) != NULL)
1604 PARENT(LEFT(child)) = node;
1608 PARENT(child) = PARENT(node);
1610 if (IS_ROOT(node)) {
1616 if (LEFT(PARENT(node)) == node)
1617 LEFT(PARENT(node)) = child;
1619 RIGHT(PARENT(node)) = child;
1622 PARENT(node) = child;
1626 rotate_right(dns_rbtnode_t *node, dns_rbtnode_t **rootp) {
1627 dns_rbtnode_t *child;
1629 REQUIRE(DNS_RBTNODE_VALID(node));
1630 REQUIRE(rootp != NULL);
1633 INSIST(child != NULL);
1635 LEFT(node) = RIGHT(child);
1636 if (RIGHT(child) != NULL)
1637 PARENT(RIGHT(child)) = node;
1638 RIGHT(child) = node;
1641 PARENT(child) = PARENT(node);
1643 if (IS_ROOT(node)) {
1649 if (LEFT(PARENT(node)) == node)
1650 LEFT(PARENT(node)) = child;
1652 RIGHT(PARENT(node)) = child;
1655 PARENT(node) = child;
1659 * This is the real workhorse of the insertion code, because it does the
1660 * true red/black tree on a single level.
1663 dns_rbt_addonlevel(dns_rbtnode_t *node, dns_rbtnode_t *current, int order,
1664 dns_rbtnode_t **rootp)
1666 dns_rbtnode_t *child, *root, *parent, *grandparent;
1667 dns_name_t add_name, current_name;
1668 dns_offsets_t add_offsets, current_offsets;
1670 REQUIRE(rootp != NULL);
1671 REQUIRE(DNS_RBTNODE_VALID(node) && LEFT(node) == NULL &&
1672 RIGHT(node) == NULL);
1673 REQUIRE(current != NULL);
1678 * First node of a level.
1682 PARENT(node) = current;
1690 dns_name_init(&add_name, add_offsets);
1691 NODENAME(node, &add_name);
1693 dns_name_init(¤t_name, current_offsets);
1694 NODENAME(current, ¤t_name);
1697 INSIST(LEFT(current) == NULL);
1698 LEFT(current) = node;
1700 INSIST(RIGHT(current) == NULL);
1701 RIGHT(current) = node;
1704 INSIST(PARENT(node) == NULL);
1705 PARENT(node) = current;
1709 while (node != root && IS_RED(PARENT(node))) {
1711 * XXXDCL could do away with separate parent and grandparent
1712 * variables. They are vestiges of the days before parent
1713 * pointers. However, they make the code a little clearer.
1716 parent = PARENT(node);
1717 grandparent = PARENT(parent);
1719 if (parent == LEFT(grandparent)) {
1720 child = RIGHT(grandparent);
1721 if (child != NULL && IS_RED(child)) {
1724 MAKE_RED(grandparent);
1727 if (node == RIGHT(parent)) {
1728 rotate_left(parent, &root);
1730 parent = PARENT(node);
1731 grandparent = PARENT(parent);
1734 MAKE_RED(grandparent);
1735 rotate_right(grandparent, &root);
1738 child = LEFT(grandparent);
1739 if (child != NULL && IS_RED(child)) {
1742 MAKE_RED(grandparent);
1745 if (node == LEFT(parent)) {
1746 rotate_right(parent, &root);
1748 parent = PARENT(node);
1749 grandparent = PARENT(parent);
1752 MAKE_RED(grandparent);
1753 rotate_left(grandparent, &root);
1759 ENSURE(IS_ROOT(root));
1766 * This is the real workhorse of the deletion code, because it does the
1767 * true red/black tree on a single level.
1770 dns_rbt_deletefromlevel(dns_rbtnode_t *delete, dns_rbtnode_t **rootp) {
1771 dns_rbtnode_t *child, *sibling, *parent;
1772 dns_rbtnode_t *successor;
1774 REQUIRE(delete != NULL);
1777 * Verify that the parent history is (apparently) correct.
1779 INSIST((IS_ROOT(delete) && *rootp == delete) ||
1780 (! IS_ROOT(delete) &&
1781 (LEFT(PARENT(delete)) == delete ||
1782 RIGHT(PARENT(delete)) == delete)));
1786 if (LEFT(delete) == NULL) {
1787 if (RIGHT(delete) == NULL) {
1788 if (IS_ROOT(delete)) {
1790 * This is the only item in the tree.
1797 * This node has one child, on the right.
1799 child = RIGHT(delete);
1801 } else if (RIGHT(delete) == NULL)
1803 * This node has one child, on the left.
1805 child = LEFT(delete);
1807 dns_rbtnode_t holder, *tmp = &holder;
1810 * This node has two children, so it cannot be directly
1811 * deleted. Find its immediate in-order successor and
1812 * move it to this location, then do the deletion at the
1813 * old site of the successor.
1815 successor = RIGHT(delete);
1816 while (LEFT(successor) != NULL)
1817 successor = LEFT(successor);
1820 * The successor cannot possibly have a left child;
1821 * if there is any child, it is on the right.
1823 if (RIGHT(successor) != NULL)
1824 child = RIGHT(successor);
1827 * Swap the two nodes; it would be simpler to just replace
1828 * the value being deleted with that of the successor,
1829 * but this rigamarole is done so the caller has complete
1830 * control over the pointers (and memory allocation) of
1831 * all of nodes. If just the key value were removed from
1832 * the tree, the pointer to the node would be unchanged.
1836 * First, put the successor in the tree location of the
1837 * node to be deleted. Save its existing tree pointer
1838 * information, which will be needed when linking up
1839 * delete to the successor's old location.
1841 memcpy(tmp, successor, sizeof(dns_rbtnode_t));
1843 if (IS_ROOT(delete)) {
1845 successor->is_root = ISC_TRUE;
1846 delete->is_root = ISC_FALSE;
1849 if (LEFT(PARENT(delete)) == delete)
1850 LEFT(PARENT(delete)) = successor;
1852 RIGHT(PARENT(delete)) = successor;
1854 PARENT(successor) = PARENT(delete);
1855 LEFT(successor) = LEFT(delete);
1856 RIGHT(successor) = RIGHT(delete);
1857 COLOR(successor) = COLOR(delete);
1859 if (LEFT(successor) != NULL)
1860 PARENT(LEFT(successor)) = successor;
1861 if (RIGHT(successor) != successor)
1862 PARENT(RIGHT(successor)) = successor;
1865 * Now relink the node to be deleted into the
1866 * successor's previous tree location. PARENT(tmp)
1867 * is the successor's original parent.
1869 INSIST(! IS_ROOT(delete));
1871 if (PARENT(tmp) == delete) {
1873 * Node being deleted was successor's parent.
1875 RIGHT(successor) = delete;
1876 PARENT(delete) = successor;
1879 LEFT(PARENT(tmp)) = delete;
1880 PARENT(delete) = PARENT(tmp);
1884 * Original location of successor node has no left.
1886 LEFT(delete) = NULL;
1887 RIGHT(delete) = RIGHT(tmp);
1888 COLOR(delete) = COLOR(tmp);
1892 * Remove the node by removing the links from its parent.
1894 if (! IS_ROOT(delete)) {
1895 if (LEFT(PARENT(delete)) == delete)
1896 LEFT(PARENT(delete)) = child;
1898 RIGHT(PARENT(delete)) = child;
1901 PARENT(child) = PARENT(delete);
1905 * This is the root being deleted, and at this point
1906 * it is known to have just one child.
1910 PARENT(child) = PARENT(delete);
1914 * Fix color violations.
1916 if (IS_BLACK(delete)) {
1917 parent = PARENT(delete);
1919 while (child != *rootp && IS_BLACK(child)) {
1920 INSIST(child == NULL || ! IS_ROOT(child));
1922 if (LEFT(parent) == child) {
1923 sibling = RIGHT(parent);
1925 if (IS_RED(sibling)) {
1926 MAKE_BLACK(sibling);
1928 rotate_left(parent, rootp);
1929 sibling = RIGHT(parent);
1932 if (IS_BLACK(LEFT(sibling)) &&
1933 IS_BLACK(RIGHT(sibling))) {
1939 if (IS_BLACK(RIGHT(sibling))) {
1940 MAKE_BLACK(LEFT(sibling));
1942 rotate_right(sibling, rootp);
1943 sibling = RIGHT(parent);
1946 COLOR(sibling) = COLOR(parent);
1948 MAKE_BLACK(RIGHT(sibling));
1949 rotate_left(parent, rootp);
1955 * Child is parent's right child.
1956 * Everything is done the same as above,
1959 sibling = LEFT(parent);
1961 if (IS_RED(sibling)) {
1962 MAKE_BLACK(sibling);
1964 rotate_right(parent, rootp);
1965 sibling = LEFT(parent);
1968 if (IS_BLACK(LEFT(sibling)) &&
1969 IS_BLACK(RIGHT(sibling))) {
1974 if (IS_BLACK(LEFT(sibling))) {
1975 MAKE_BLACK(RIGHT(sibling));
1977 rotate_left(sibling, rootp);
1978 sibling = LEFT(parent);
1981 COLOR(sibling) = COLOR(parent);
1983 MAKE_BLACK(LEFT(sibling));
1984 rotate_right(parent, rootp);
1989 parent = PARENT(child);
1998 * This should only be used on the root of a tree, because no color fixup
2001 * NOTE: No root pointer maintenance is done, because the function is only
2002 * used for two cases:
2003 * + deleting everything DOWN from a node that is itself being deleted, and
2004 * + deleting the entire tree of trees from dns_rbt_destroy.
2005 * In each case, the root pointer is no longer relevant, so there
2006 * is no need for a root parameter to this function.
2008 * If the function is ever intended to be used to delete something where
2009 * a pointer needs to be told that this tree no longer exists,
2010 * this function would need to adjusted accordingly.
2013 dns_rbt_deletetree(dns_rbt_t *rbt, dns_rbtnode_t *node) {
2014 isc_result_t result = ISC_R_SUCCESS;
2015 REQUIRE(VALID_RBT(rbt));
2020 if (LEFT(node) != NULL) {
2021 result = dns_rbt_deletetree(rbt, LEFT(node));
2022 if (result != ISC_R_SUCCESS)
2026 if (RIGHT(node) != NULL) {
2027 result = dns_rbt_deletetree(rbt, RIGHT(node));
2028 if (result != ISC_R_SUCCESS)
2032 if (DOWN(node) != NULL) {
2033 result = dns_rbt_deletetree(rbt, DOWN(node));
2034 if (result != ISC_R_SUCCESS)
2039 if (result != ISC_R_SUCCESS)
2042 if (DATA(node) != NULL && rbt->data_deleter != NULL)
2043 rbt->data_deleter(DATA(node), rbt->deleter_arg);
2045 unhash_node(rbt, node);
2046 #if DNS_RBT_USEMAGIC
2050 isc_mem_put(rbt->mctx, node, NODE_SIZE(node));
2056 dns_rbt_deletetreeflat(dns_rbt_t *rbt, unsigned int quantum,
2057 dns_rbtnode_t **nodep)
2059 dns_rbtnode_t *parent;
2060 dns_rbtnode_t *node = *nodep;
2061 REQUIRE(VALID_RBT(rbt));
2070 if (LEFT(node) != NULL) {
2074 if (DOWN(node) != NULL) {
2079 if (DATA(node) != NULL && rbt->data_deleter != NULL)
2080 rbt->data_deleter(DATA(node), rbt->deleter_arg);
2083 * Note: we don't call unhash_node() here as we are destroying
2084 * the complete rbt tree.
2086 #if DNS_RBT_USEMAGIC
2089 parent = PARENT(node);
2090 if (RIGHT(node) != NULL)
2091 PARENT(RIGHT(node)) = parent;
2092 if (parent != NULL) {
2093 if (LEFT(parent) == node)
2094 LEFT(parent) = RIGHT(node);
2095 else if (DOWN(parent) == node)
2096 DOWN(parent) = RIGHT(node);
2098 parent = RIGHT(node);
2100 isc_mem_put(rbt->mctx, node, NODE_SIZE(node));
2103 if (quantum != 0 && --quantum == 0) {
2111 dns_rbt_indent(int depth) {
2114 for (i = 0; i < depth; i++)
2119 dns_rbt_printnodename(dns_rbtnode_t *node) {
2122 char buffer[DNS_NAME_FORMATSIZE];
2123 dns_offsets_t offsets;
2125 r.length = NAMELEN(node);
2126 r.base = NAME(node);
2128 dns_name_init(&name, offsets);
2129 dns_name_fromregion(&name, &r);
2131 dns_name_format(&name, buffer, sizeof(buffer));
2133 printf("%s", buffer);
2137 dns_rbt_printtree(dns_rbtnode_t *root, dns_rbtnode_t *parent, int depth) {
2138 dns_rbt_indent(depth);
2141 dns_rbt_printnodename(root);
2142 printf(" (%s", IS_RED(root) ? "RED" : "black");
2145 dns_rbt_printnodename(parent);
2148 if ((! IS_ROOT(root) && PARENT(root) != parent) ||
2149 ( IS_ROOT(root) && depth > 0 &&
2150 DOWN(PARENT(root)) != root)) {
2152 printf(" (BAD parent pointer! -> ");
2153 if (PARENT(root) != NULL)
2154 dns_rbt_printnodename(PARENT(root));
2166 dns_rbt_indent(depth);
2167 printf("++ BEG down from ");
2168 dns_rbt_printnodename(root);
2170 dns_rbt_printtree(DOWN(root), NULL, depth);
2171 dns_rbt_indent(depth);
2172 printf("-- END down from ");
2173 dns_rbt_printnodename(root);
2177 if (IS_RED(root) && IS_RED(LEFT(root)))
2178 printf("** Red/Red color violation on left\n");
2179 dns_rbt_printtree(LEFT(root), root, depth);
2181 if (IS_RED(root) && IS_RED(RIGHT(root)))
2182 printf("** Red/Red color violation on right\n");
2183 dns_rbt_printtree(RIGHT(root), root, depth);
2190 dns_rbt_printall(dns_rbt_t *rbt) {
2191 REQUIRE(VALID_RBT(rbt));
2193 dns_rbt_printtree(rbt->root, NULL, 0);
2201 dns_rbtnodechain_init(dns_rbtnodechain_t *chain, isc_mem_t *mctx) {
2203 * Initialize 'chain'.
2206 REQUIRE(chain != NULL);
2210 chain->level_count = 0;
2211 chain->level_matches = 0;
2212 memset(chain->levels, 0, sizeof(chain->levels));
2214 chain->magic = CHAIN_MAGIC;
2218 dns_rbtnodechain_current(dns_rbtnodechain_t *chain, dns_name_t *name,
2219 dns_name_t *origin, dns_rbtnode_t **node)
2221 isc_result_t result = ISC_R_SUCCESS;
2223 REQUIRE(VALID_CHAIN(chain));
2228 if (chain->end == NULL)
2229 return (ISC_R_NOTFOUND);
2232 NODENAME(chain->end, name);
2234 if (chain->level_count == 0) {
2236 * Names in the top level tree are all absolute.
2237 * Always make 'name' relative.
2239 INSIST(dns_name_isabsolute(name));
2242 * This is cheaper than dns_name_getlabelsequence().
2246 name->attributes &= ~DNS_NAMEATTR_ABSOLUTE;
2250 if (origin != NULL) {
2251 if (chain->level_count > 0)
2252 result = chain_name(chain, origin, ISC_FALSE);
2254 result = dns_name_copy(dns_rootname, origin, NULL);
2261 dns_rbtnodechain_prev(dns_rbtnodechain_t *chain, dns_name_t *name,
2264 dns_rbtnode_t *current, *previous, *predecessor;
2265 isc_result_t result = ISC_R_SUCCESS;
2266 isc_boolean_t new_origin = ISC_FALSE;
2268 REQUIRE(VALID_CHAIN(chain) && chain->end != NULL);
2272 current = chain->end;
2274 if (LEFT(current) != NULL) {
2276 * Moving left one then right as far as possible is the
2277 * previous node, at least for this level.
2279 current = LEFT(current);
2281 while (RIGHT(current) != NULL)
2282 current = RIGHT(current);
2284 predecessor = current;
2288 * No left links, so move toward the root. If at any point on
2289 * the way there the link from parent to child is a right
2290 * link, then the parent is the previous node, at least
2293 while (! IS_ROOT(current)) {
2295 current = PARENT(current);
2297 if (RIGHT(current) == previous) {
2298 predecessor = current;
2304 if (predecessor != NULL) {
2306 * Found a predecessor node in this level. It might not
2307 * really be the predecessor, however.
2309 if (DOWN(predecessor) != NULL) {
2311 * The predecessor is really down at least one level.
2312 * Go down and as far right as possible, and repeat
2313 * as long as the rightmost node has a down pointer.
2317 * XXX DCL Need to do something about origins
2318 * here. See whether to go down, and if so
2319 * whether it is truly what Bob calls a
2322 ADD_LEVEL(chain, predecessor);
2323 predecessor = DOWN(predecessor);
2325 /* XXX DCL duplicated from above; clever
2326 * way to unduplicate? */
2328 while (RIGHT(predecessor) != NULL)
2329 predecessor = RIGHT(predecessor);
2330 } while (DOWN(predecessor) != NULL);
2332 /* XXX DCL probably needs work on the concept */
2334 new_origin = ISC_TRUE;
2337 } else if (chain->level_count > 0) {
2339 * Dang, didn't find a predecessor in this level.
2340 * Got to the root of this level without having traversed
2341 * any right links. Ascend the tree one level; the
2342 * node that points to this tree is the predecessor.
2344 INSIST(chain->level_count > 0 && IS_ROOT(current));
2345 predecessor = chain->levels[--chain->level_count];
2347 /* XXX DCL probably needs work on the concept */
2349 * Don't declare an origin change when the new origin is "."
2350 * at the top level tree, because "." is declared as the origin
2351 * for the second level tree.
2353 if (origin != NULL &&
2354 (chain->level_count > 0 || OFFSETLEN(predecessor) > 1))
2355 new_origin = ISC_TRUE;
2358 if (predecessor != NULL) {
2359 chain->end = predecessor;
2362 result = dns_rbtnodechain_current(chain, name, origin,
2364 if (result == ISC_R_SUCCESS)
2365 result = DNS_R_NEWORIGIN;
2368 result = dns_rbtnodechain_current(chain, name, NULL,
2372 result = ISC_R_NOMORE;
2378 dns_rbtnodechain_down(dns_rbtnodechain_t *chain, dns_name_t *name,
2381 dns_rbtnode_t *current, *successor;
2382 isc_result_t result = ISC_R_SUCCESS;
2383 isc_boolean_t new_origin = ISC_FALSE;
2385 REQUIRE(VALID_CHAIN(chain) && chain->end != NULL);
2389 current = chain->end;
2391 if (DOWN(current) != NULL) {
2393 * Don't declare an origin change when the new origin is "."
2394 * at the second level tree, because "." is already declared
2395 * as the origin for the top level tree.
2397 if (chain->level_count > 0 ||
2398 OFFSETLEN(current) > 1)
2399 new_origin = ISC_TRUE;
2401 ADD_LEVEL(chain, current);
2402 current = DOWN(current);
2404 while (LEFT(current) != NULL)
2405 current = LEFT(current);
2407 successor = current;
2410 if (successor != NULL) {
2411 chain->end = successor;
2414 * It is not necessary to use dns_rbtnodechain_current like
2415 * the other functions because this function will never
2416 * find a node in the topmost level. This is because the
2417 * root level will never be more than one name, and everything
2418 * in the megatree is a successor to that node, down at
2419 * the second level or below.
2423 NODENAME(chain->end, name);
2427 result = chain_name(chain, origin, ISC_FALSE);
2429 if (result == ISC_R_SUCCESS)
2430 result = DNS_R_NEWORIGIN;
2433 result = ISC_R_SUCCESS;
2436 result = ISC_R_NOMORE;
2442 dns_rbtnodechain_nextflat(dns_rbtnodechain_t *chain, dns_name_t *name) {
2443 dns_rbtnode_t *current, *previous, *successor;
2444 isc_result_t result = ISC_R_SUCCESS;
2446 REQUIRE(VALID_CHAIN(chain) && chain->end != NULL);
2450 current = chain->end;
2452 if (RIGHT(current) == NULL) {
2453 while (! IS_ROOT(current)) {
2455 current = PARENT(current);
2457 if (LEFT(current) == previous) {
2458 successor = current;
2463 current = RIGHT(current);
2465 while (LEFT(current) != NULL)
2466 current = LEFT(current);
2468 successor = current;
2471 if (successor != NULL) {
2472 chain->end = successor;
2475 NODENAME(chain->end, name);
2477 result = ISC_R_SUCCESS;
2479 result = ISC_R_NOMORE;
2485 dns_rbtnodechain_next(dns_rbtnodechain_t *chain, dns_name_t *name,
2488 dns_rbtnode_t *current, *previous, *successor;
2489 isc_result_t result = ISC_R_SUCCESS;
2490 isc_boolean_t new_origin = ISC_FALSE;
2492 REQUIRE(VALID_CHAIN(chain) && chain->end != NULL);
2496 current = chain->end;
2499 * If there is a level below this node, the next node is the leftmost
2500 * node of the next level.
2502 if (DOWN(current) != NULL) {
2504 * Don't declare an origin change when the new origin is "."
2505 * at the second level tree, because "." is already declared
2506 * as the origin for the top level tree.
2508 if (chain->level_count > 0 ||
2509 OFFSETLEN(current) > 1)
2510 new_origin = ISC_TRUE;
2512 ADD_LEVEL(chain, current);
2513 current = DOWN(current);
2515 while (LEFT(current) != NULL)
2516 current = LEFT(current);
2518 successor = current;
2520 } else if (RIGHT(current) == NULL) {
2522 * The successor is up, either in this level or a previous one.
2523 * Head back toward the root of the tree, looking for any path
2524 * that was via a left link; the successor is the node that has
2525 * that left link. In the event the root of the level is
2526 * reached without having traversed any left links, ascend one
2527 * level and look for either a right link off the point of
2528 * ascent, or search for a left link upward again, repeating
2529 * ascends until either case is true.
2532 while (! IS_ROOT(current)) {
2534 current = PARENT(current);
2536 if (LEFT(current) == previous) {
2537 successor = current;
2542 if (successor == NULL) {
2544 * Reached the root without having traversed
2545 * any left pointers, so this level is done.
2547 if (chain->level_count == 0)
2550 current = chain->levels[--chain->level_count];
2551 new_origin = ISC_TRUE;
2553 if (RIGHT(current) != NULL)
2556 } while (successor == NULL);
2559 if (successor == NULL && RIGHT(current) != NULL) {
2560 current = RIGHT(current);
2562 while (LEFT(current) != NULL)
2563 current = LEFT(current);
2565 successor = current;
2568 if (successor != NULL) {
2569 chain->end = successor;
2572 * It is not necessary to use dns_rbtnodechain_current like
2573 * the other functions because this function will never
2574 * find a node in the topmost level. This is because the
2575 * root level will never be more than one name, and everything
2576 * in the megatree is a successor to that node, down at
2577 * the second level or below.
2581 NODENAME(chain->end, name);
2585 result = chain_name(chain, origin, ISC_FALSE);
2587 if (result == ISC_R_SUCCESS)
2588 result = DNS_R_NEWORIGIN;
2591 result = ISC_R_SUCCESS;
2594 result = ISC_R_NOMORE;
2600 dns_rbtnodechain_first(dns_rbtnodechain_t *chain, dns_rbt_t *rbt,
2601 dns_name_t *name, dns_name_t *origin)
2604 isc_result_t result;
2606 REQUIRE(VALID_RBT(rbt));
2607 REQUIRE(VALID_CHAIN(chain));
2609 dns_rbtnodechain_reset(chain);
2611 chain->end = rbt->root;
2613 result = dns_rbtnodechain_current(chain, name, origin, NULL);
2615 if (result == ISC_R_SUCCESS)
2616 result = DNS_R_NEWORIGIN;
2622 dns_rbtnodechain_last(dns_rbtnodechain_t *chain, dns_rbt_t *rbt,
2623 dns_name_t *name, dns_name_t *origin)
2626 isc_result_t result;
2628 REQUIRE(VALID_RBT(rbt));
2629 REQUIRE(VALID_CHAIN(chain));
2631 dns_rbtnodechain_reset(chain);
2633 result = move_chain_to_last(chain, rbt->root);
2634 if (result != ISC_R_SUCCESS)
2637 result = dns_rbtnodechain_current(chain, name, origin, NULL);
2639 if (result == ISC_R_SUCCESS)
2640 result = DNS_R_NEWORIGIN;
2647 dns_rbtnodechain_reset(dns_rbtnodechain_t *chain) {
2649 * Free any dynamic storage associated with 'chain', and then
2650 * reinitialize 'chain'.
2653 REQUIRE(VALID_CHAIN(chain));
2656 chain->level_count = 0;
2657 chain->level_matches = 0;
2661 dns_rbtnodechain_invalidate(dns_rbtnodechain_t *chain) {
2663 * Free any dynamic storage associated with 'chain', and then
2664 * invalidate 'chain'.
2667 dns_rbtnodechain_reset(chain);