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      1 /*
      2  * Based on strlist.c by:
      3  * (c) 2009 Arnaldo Carvalho de Melo <acme (at) redhat.com>
      4  *
      5  * Licensed under the GPLv2.
      6  */
      7 
      8 #include <errno.h>
      9 #include <stdio.h>
     10 #include <stdlib.h>
     11 
     12 #include "rblist.h"
     13 
     14 int rblist__add_node(struct rblist *rblist, const void *new_entry)
     15 {
     16 	struct rb_node **p = &rblist->entries.rb_node;
     17 	struct rb_node *parent = NULL, *new_node;
     18 
     19 	while (*p != NULL) {
     20 		int rc;
     21 
     22 		parent = *p;
     23 
     24 		rc = rblist->node_cmp(parent, new_entry);
     25 		if (rc > 0)
     26 			p = &(*p)->rb_left;
     27 		else if (rc < 0)
     28 			p = &(*p)->rb_right;
     29 		else
     30 			return -EEXIST;
     31 	}
     32 
     33 	new_node = rblist->node_new(rblist, new_entry);
     34 	if (new_node == NULL)
     35 		return -ENOMEM;
     36 
     37 	rb_link_node(new_node, parent, p);
     38 	rb_insert_color(new_node, &rblist->entries);
     39 	++rblist->nr_entries;
     40 
     41 	return 0;
     42 }
     43 
     44 void rblist__remove_node(struct rblist *rblist, struct rb_node *rb_node)
     45 {
     46 	rb_erase(rb_node, &rblist->entries);
     47 	--rblist->nr_entries;
     48 	rblist->node_delete(rblist, rb_node);
     49 }
     50 
     51 struct rb_node *rblist__find(struct rblist *rblist, const void *entry)
     52 {
     53 	struct rb_node **p = &rblist->entries.rb_node;
     54 	struct rb_node *parent = NULL;
     55 
     56 	while (*p != NULL) {
     57 		int rc;
     58 
     59 		parent = *p;
     60 
     61 		rc = rblist->node_cmp(parent, entry);
     62 		if (rc > 0)
     63 			p = &(*p)->rb_left;
     64 		else if (rc < 0)
     65 			p = &(*p)->rb_right;
     66 		else
     67 			return parent;
     68 	}
     69 
     70 	return NULL;
     71 }
     72 
     73 void rblist__init(struct rblist *rblist)
     74 {
     75 	if (rblist != NULL) {
     76 		rblist->entries	 = RB_ROOT;
     77 		rblist->nr_entries = 0;
     78 	}
     79 
     80 	return;
     81 }
     82 
     83 void rblist__delete(struct rblist *rblist)
     84 {
     85 	if (rblist != NULL) {
     86 		struct rb_node *pos, *next = rb_first(&rblist->entries);
     87 
     88 		while (next) {
     89 			pos = next;
     90 			next = rb_next(pos);
     91 			rblist__remove_node(rblist, pos);
     92 		}
     93 		free(rblist);
     94 	}
     95 }
     96 
     97 struct rb_node *rblist__entry(const struct rblist *rblist, unsigned int idx)
     98 {
     99 	struct rb_node *node;
    100 
    101 	for (node = rb_first(&rblist->entries); node; node = rb_next(node)) {
    102 		if (!idx--)
    103 			return node;
    104 	}
    105 
    106 	return NULL;
    107 }
    108